EEC O EDS 
 
 STEAM BOILER EXPLOSIONS, 
 
 EDWARD BINDON MARTEN, - 
 
 INST. OF MECHANICAL EXGIXEEES; ASSOCIATE OF INSTITUTION OP 
 
 CIVIL ENGINEERS, AND CHIEF EXGINEEB TO THE 
 MIDLAND STBAM BOILER INSPECTION AND ASSUBANCB Co. 
 
 LONDON ; 
 E. & F. N. SPON, 48, GEARING CROSS. 
 
 STOURBRIDGE : 
 
 R. BROOMHALL, 148, HIGH STREET. 
 1872.
 
 
 
 '&/J.
 
 PREFACE. 
 
 ACCURATE information as to Boiler Explosions must always 
 be useful to those who are 'interested in the safe working 
 of Steam Boilers. 
 
 The following pages contain very brief abstracts of records 
 obtained for the Midland Steam Boiler Inspection and 
 Assurance Company, by whose permission they are now 
 republished in a compact and convenient form. 
 
 By permission of the Council of the Institution of 
 Mechanical Engineers, the records are prefaced by a Paper 
 on Steam Boiler Explosions and their records, and on 
 Inspection as a means of prevention, read before that 
 Institution at Manchester, August 1st, 1866, and a further 
 Paper on the "Conclusions derived from the experience of 
 recent Steam Boiler Explosions," read before the same 
 Institution at Nottingham, August 3rd, 1870. 
 
 All names of Works or Firms are omitted from the 
 records as unnecessary. 
 
 1351721
 
 ON STEAM BOILER EXPLOSIONS AND THEIR RECORDS, AND ON 
 INSPECTION AS A MEANS OF PREVENTION, BY EDWARD B. MARTEN, 
 MEM. INST. M.E. A.I.C.E., EXCERPT MlNUTES OF PROCEEDINGS OF THE 
 MEETING OF THE INSTITUTION OF MECHANICAL ENGINEERS, AT 
 MANCHESTER, IST AUGUST, 1866, JOSEPH WHITWORTH, ESQ., 
 PRESIDENT, IN THE CHAIR. BY PERMISSION OF THE COUNCIL. 
 
 THE subject of Steam Boiler Explosions, which was brought before 
 this Institution in June, 1848, in a paper by the late Mr. William 
 Smith of Dudley in reference to an explosion near that place, and 
 again in 1859 in a paper by Mr. Longridge on the economy and 
 durability of stationary boilers, is one of great importance and is 
 now attracting increased attention. The first public notice of the 
 subject was by a parliamentary committee in 1817, which was 
 appointed in consequence of a very fatal boiler explosion in London 
 in 1815 ; evidence was then collected as to steamboats, and many 
 boiler explosions were referred to. That committee recommended 
 among other things that boilers should be made of wrought iron, 
 instead of cast iron or copper, which had been the materials mainly 
 used previously ; that they should be inspected and tested ; and 
 that there should be two safety valves, each loaded to one third of 
 the test pressure, under penalties for any excess. A great part of 
 the information now existing upon the subject, especially in regard to 
 the earlier explosions, is to be found in the records of inquests after 
 fatal cases ; and some of the careful reports of eminent engineers 
 on those occasions have materially assisted in the formation of 
 correct views as to the causes of explosion. Latterly also the 
 printed reports of the inspectors of mines, and more especially the 
 reports of the explosions of locomotives, illustrated by diagrams by 
 the inspectors of railways, have furnished very valuable information. 
 Since the subject has been taken up by private associations for the
 
 6 BOILER EXPLOSIONS. 
 
 prevention of explosions, many more records have been published, 
 although their usefulness is much impaired by their not containing 
 the names of the places whereby the explosions could be identified. 
 
 When the writer's attention was first directed to this subject, 
 he met with great difficulty in obtaining correct records of boiler 
 explosions, from which to arrive at the results of past experience ; 
 and wishing to base his own opinion on facts, rather than on the 
 inferences of others however reliable, he followed the example of 
 the Franklin Institute in their elaborate investigation of the subject, 
 and collected all the records he could find ; and by way of 
 facilitating reference, arranged an index, a manuscript copy of 
 which is presented with the present paper to the Library of this 
 Institution. All must be agreed as to the importance of reliable 
 information on such accidents as boiler explosions ; and the 
 writer would suggest that this Institution may materially aid in 
 obtaining the desired records and placing them within easy 
 access, by becoming the depository of reports on explosions, and by 
 inducing those who have the opportunity to forward copies of 
 reports, that these may be arranged so as to be easily found and 
 consulted. It is very desirable that these reports should as 
 far as possible be illustrated by sketches, as aids to the description ; 
 and also by slight models like those now shown to the meeting, 
 by which the whole matter may be seen at a glance. So few 
 persons comparatively have the opportunity of examining boilers 
 after explosion, that the most erroneous ideas have prevailed, 
 and theories have been advanced which would soon be dissipated 
 by practical experience or by reading accurate reports. It would 
 also very much aid in the understanding of published matter on the 
 subject, if full descriptions of each case alluded to in illustration 
 could be ootained. These records are as useful to the engineer as 
 the " precedents " or "cases " to the lawyer or the surgeon. After 
 any serious explosion, the newspapers of the neighbourhood in 
 which it has occurred contain voluminous articles describing the 
 disastrous result and the damage done, which, although useful as 
 far as they go, do not in the least assist in arriving at the cause of 
 explosion. The really important particulars, such as the description
 
 EXPLOSIONS. 7 
 
 and construction of the boiler, its dimensions, and the pressure at 
 which it worked, are in most cases omitted altogether. 
 
 The record of explosions presented to the Institution contains 
 a list of the boiler explosions in each year of the present century, 
 as far as known to the writer, with the names of the places, and 
 the description and sizes of the boilers, and the supposed cause 
 of explosion, together with references to the books or papers from 
 which further information may be obtained. Of course many 
 of the explosions have to be put down as uncertain in some of the 
 particulars ; but every year improves the record, as fresh information 
 is obtained, and with the assistance of the members of this 
 Institution it might be made far more perfect and extensive. 
 
 The total number of explosions here recorded is 1046, and they 
 caused the death of 4076 persons and the injury of 2903. The 
 causes assigned for the several explosions are very numerous, and 
 are no doubt incorrect in many cases ; but they may be generally 
 stated as follows : 
 
 397 are too uncertain to place under any heading ; but of the rest 
 145 were from the boilers being worn out, or from corrosion, or 
 
 from deteriorated plates or rivets. 
 
 137 from over pressure, from safety valves being wedged or 
 overweighted, in some cases intentionally, or from other 
 acts of carelessness. 
 125 from faulty construction of boiler or fittings, want of stays, or 
 
 neglect of timely repair. 
 119 from collapse of internal tubes, generally from insufficient 
 
 strength. 
 
 114 from shortness of water, or from scurf preventing the proper 
 contact of the water with the plates ; or from improper 
 setting so as to expose the sides of the boiler to the flame 
 above the water line. 
 
 9 from extraneous causes, such as effect of lightning striking 
 down the stacks upon the boilers, or from fire in the building 
 or explosion of gas in the flues. 
 1046 total number of explosions.
 
 8 BOILER EXPLOSIONS. 
 
 The exploded boilers were of the following descriptions : 
 232 are not sufficiently described to place under any head ; but of 
 
 the rest 
 
 320 were Marine boilers of various forms. 
 141 were Cornish, Lancashire, or other boilers internally fired. 
 120 were Locomotive, or other multitubular boilers. 
 116 were plain Cylindrical boilers, externally fired. 
 64 were Balloon or haystack, wagon, Butterley, British-tube, 
 
 elephant, or Trevithick boilers. 
 
 29 were Portable, agricultural, upright, or crane boilers. 
 14 were Heating apparatus or kitchen boilers. 
 10 were Upright boilers attached to puddling or mill furnaces at 
 ironworks. 
 
 1046 total number of explosions. 
 
 The theories as to the causes of explosion have been numerous. 
 In the early days of the steam engine, when the steam was used 
 only as a condensing medium and the pressure in the boiler was 
 frequently allowed to get below atmospheric pressure, many boilers 
 were destroyed by the excess of the external atmospheric pressure 
 becoming too great, causing them to be collapsed or crumpled up ; 
 and this led to the use of the atmospheric valve still found on old 
 boilers. Even so lately as last year, 1865, a boiler in the neighbour- 
 hood of Bury, Lancashire, has suffered in this way by collapse from 
 external pressure ; its appearance after the accident is shown in Fig. 1. 
 
 Fig. 1. 
 
 which is copied from a photograph. The early explosions were so 
 palpably due to the weakness of the boilers, which compared with 
 those of the present day were most ill constructed, that no one
 
 BOILER EXPLOSIONS. 9 
 
 thought of any other cause than the insufficient strength of the 
 vessel to hear the expansive force of the steara contained in it. 
 "When the advantages of high-pressure steam hecame recognized, 
 and the boilers were improved so as to hear the increased strain, 
 the tremendous havoc caused hy an explosion led many to think 
 that something more must he required than the expansive force of 
 the steam to produce such an effect; and they appear to have 
 attributed to steam under certain conditions a detonating force, or a 
 sudden access of expansive power that overcame all resistance. To 
 support this somewhat natural supposition, it was asserted that the 
 steam became partially decomposed into its constituent gases, 
 forming an explosive mixture within the boiler. That this belief 
 is still sometimes entertained is seen from the verdict of a jury even 
 in the present year, 1866, in the case of the explosion of a plain 
 cylindrical boiler at Leicester, shown in Fig. 2., the real 
 
 Fig. 2. 
 
 cause of which appears to have been that the shell of the 
 boiler was weakened by the manhole. It seems hardly necessary 
 to point out the fallacy of imagining decomposition and recomposition 
 of the steam to take place in succession in the same vessel without 
 the introduction of any new element for causing a change of 
 chemical combination ; but it is necessary to refer to this supposition, 
 as the idea is shown to be not yet extinct. 
 
 Again it has been asserted that the steam when remaining quite 
 still in the boiler becomes heated much beyond the temperature due 
 to the pressure ; and that therefore when it is stirred or mixed or 
 brought more in contact with the water by the opening of a valve 
 or other cause, the water evaporates so rapidly as to produce an 
 excessive pressure by accumulation of steam. In support of this view 
 the frequency of explosions upon the starting of the engine after a 
 short stand is adduced ; but it is very doubtful whether by this means 
 a sufficient extra pressure could be produced to cause an explosion,
 
 10 BOILER EXPLOSIONS. 
 
 unless the boiler had been previously working up to within a very 
 small margin of its strength. Explosions are seldom caused by a 
 sudden increase of pressure, but rather by the pressure gradually 
 mounting to the bursting point, when of course the effect is sudden 
 enough. Nor is it necessary in many cases to look for much increase 
 of pressure as the cause of explosion ; for it is far more often the 
 case that the strength of the boiler has gradually degenerated by 
 wear or corrosion, until unable to bear even the ordinary working 
 pressure. It is so very easy, when examining the scene of an 
 explosion, for the first cause of rupture to be confounded with the 
 causes of the subsequent mischief, that in many cases erroneous 
 conclusions have been arrived at in this way. 
 
 The most important points to find out in connection with any 
 explosion are the condition of the boiler and all belonging to it 
 immediately before the explosion, together with the locality of the 
 first rent, the direction of the line of rupture, and the nature of the 
 fracture ; as everything occurring after the instant of the first rent is 
 an effect and not a cause of explosion. As soon as the first rent has 
 taken place, the balance of strain in the fabric is disturbed, and 
 therefore the internal pressure has greatly increased power in 
 continuing the rupture ; and also the pressure being then removed 
 from the surface of the water, which is already heated to the 
 temperature of the steam, the whole body of the water gives out its 
 heat in the form of steam at a considerable pressure, and thus 
 supplies the volume of steam for carrying on the work of 
 destruction. When thus quickly generated, the steam perhaps 
 carries part of the water with it in the same way that it does in 
 ordinary priming ; and it has been thought by some that the 
 impact of the water is thus added to that of the steam, to aid in 
 the shock given to all surrounding obstacles. 
 
 It is seldom that one out of a bed of boilers explodes without 
 more or less injury to the others on either side of it ; but sometimes 
 two boilers in one bed, or three, or even five, have exploded 
 simultaneously. 
 
 The causes of boiler explosions may be considered under the two 
 general heads of
 
 BOILER EXPLOSIONS. 11 
 
 Firstly, faults in the fabric of the hoiler itself as originally 
 constructed, such as had shape, want of stays, had material, 
 defective workmanship, or injudicious setting: and 
 
 Secondly, mischief arising during working, either from wear and 
 tear, or from overheating through shortness of water or accumulation 
 of scurf ; or from corrosion, in its several forms of general thinning, 
 pitting, furrowing, or channelling of the plates ; or from flaws or 
 fractures in the material, or injury by the effect of repeated strain ; 
 or from undue pressure through want of adequate arrangements 
 for escape of surplus steam. 
 
 There is no doubt that many of the early explosions were from 
 faults of construction. The stronger materials now used were then 
 found so difficult to manipulate that others easier to work were 
 chosen, and often the shape of the boiler was only selected as the one 
 easiest to make. The early boilers were made of copper or cast 
 iron, with leaden or even wooden tops, and of the weakest possible 
 shape. Such was the boiler used by Savery, shown in Fig. 3. 
 
 Fig. 3. 
 and the Tun Boiler and Flange boiler, Figs. 4 and 5. The 
 
 Fig. 4. Fig. 5. 
 
 very fatal explosion in London in 1815, referred to by the 
 parliamentary commission previously named, was of a cast-iron 
 boiler, which failed because one side was too thin to bear the 
 pressure, as the casting was of irregular thickness. The steam being
 
 12 
 
 BOIIEK EXPLOSIONS. 
 
 at that time used only at or below atmospheric pressure as a means 
 of obtaining a vacuum by condensation for working by the external 
 pressure of the atmosphere, so little was pressure of the steam 
 thought of, that boilers were proposed and it is believed were 
 actually constructed with hooped wooden shells, like barrels, and 
 internal fireplaces and flues of copper ; and even a stone chamber 
 was named as being a suitable shell for a boiler, with internal 
 fireplace and copper flue passing three times the length of the inside 
 and out at the top, like an ordinary stove and piping. These boilers 
 must have been something like the sketches given in Figs. 6 and 7, 
 
 Fig. 6. 
 
 Fig. 7. 
 
 and were intended to be exposed only to the external pressure of the 
 atmosphere.
 
 BOILER EXPLOSIONS. 
 
 13 
 
 Cast iron was frequently used for the shell of boilers, with an 
 internal fireplace and tubes of wrought iron, as shown in Fig. 8, 
 
 Fig. S. Fig. 9. 
 
 and boilers of this construction are still to be found in use at some 
 of the older works at the present day. As the outside shell and 
 front plate are l inch thick and are not exposed to any wear at all, 
 these boilers are sufficiently strong. A duplicate front plate with 
 set of tubes attached is always kept on hand in case of need. 
 Another form of cast-iron boiler is shown in Fig. 9., made 
 in several parts put together with flange joints, with an internal 
 fireplace and flue also made of cast iron. When cast iron 
 was used for the parts exposed to the fire in boilers intended for high 
 pressure, it was sometimes employed in the form of tubes of small 
 diameter and proportionately thinner ; as in Woolf's boiler, so much 
 spoken of in the evidence before the parliamentary committee 
 of 1817. This boiler, shown in Fig. 10., consisted of nine cast- 
 
 Fig. 10. 
 iron pipes, about 1 foot diameter and 9 feet long, set in brickwork
 
 14 
 
 BOILER EXPLOSIONS. 
 
 so that the flame played all round them. These small tubes were 
 connected with another of larger size placed transversely above 
 them, forming a steam receiver, and this again with a still larger 
 one, which formed a steam chamber. No details of any explosions 
 of the three last mentioned boilers have been obtained ; but it is 
 known that the cast iron was found a most treacherous material, 
 especially when exposed to the action of the fire ; and that the effect 
 of explosion was very disastrous, because the boiler burst at once 
 into many pieces, each of which was driven out with great velocity, 
 and the danger was not mitigated by the circumstance of large 
 masses holding together, as is found to be the case with wrought-iron 
 boilers when exploded. 
 
 When wrought-iron boilers came into use the shapes were most 
 varied, and the dimensions much larger than before. One of the 
 earliest was the Wagon boiler, shown in Fig. 11, with round top 
 
 Fig. 11. 
 
 Fig. 12. 
 
 and plain flat sides, which could only be made to bear even the 
 smallest pressure by being strengthened with numerous stays. In 
 most cases of explosion of this class of boiler the bottom was 
 torn off, owing to the angle iron round it being weakened by the 
 alternate bending backwards and forwards under each variation of 
 pressure, as all the sides and the bottom must be constantly 
 springing when at work. Such was the explosion at Chester in 
 1822, and many others. This shape was soon improved in its steam 
 generating powers by making the sides concave instead of flat, as 
 shown in Fig. 12, so that the heating surface was greater and also
 
 BOILER EXPLOSIONS. 
 
 15 
 
 in a better position to receive the heat from the flame in the flues. 
 This shape was further elaborated by rounding the ends as in Fig 13, 
 
 Fig. 13. 
 
 and in some cases making the bottom convex to correspond with the 
 top, as in Fig. 1 4. All these forms however still required numerous 
 
 Fig. 14. 
 
 stays to retain them in shape, the safety of the boiler being 
 dependent upon the stays ; and numerous explosions show the 
 weakness of these boilers. They generally gave way at the bottom, 
 as in an explosion that occurred at Manchester in 1842, where the 
 boiler had been weakened by frequent patching ; they also sometimes 
 exploded through the failure of the stays. 
 
 A very early improvement in the right direction consisted in 
 making the shell circular ; and some few large boilers still exist that
 
 16 BOILER EXPLOSIONS. 
 
 were made completely spherical, as show in Fig. 15, so that the whole 
 
 Fig. 15. 
 
 Fig. 16. 
 
 of the iron was exposed to tension only, and required no assistance 
 from stays, and the boiler had no tendency to alter its shape under 
 varying pressure. This shape however had the great disadvantage 
 of possessing the least amount of heating surface for its size or cubic 
 contents ; and also it was very liable to injury from sediment on the 
 bottom, which accumulated on the most central spot. The spherical 
 form was therefore soon modified into the shape shown in Fig. 16, by 
 making the bottom more shallow, although still convex ; and afterwards 
 by putting flat or concave sides and a flat or concave bottom, with the 
 
 Fig. 17. 
 angle constructed either of bent plates or angle iron, as in Figs. 17
 
 BOILER EXPLOSIONS. 17 
 
 and 18, which represent the forms known so well in the 
 
 Fig. 18. 
 
 Staffordshire district as the common Balloon or Haystack boiler. 
 Many of these have been made of very great size, measuring 
 as much as 20 feet diameter, and containing so much water and steam 
 as to be most formidable magazines for explosion. Perhaps no form 
 of boiler has exploded more than this, partly because of the great 
 number that have been used, but chiefly because of the inherent 
 weakness of the shape. The records however have not been obtained 
 of the great majority of these explosions, because they seldom 
 caused sufficient damage or loss of life to attract much attention, 
 as these boilers generally worked in isolated positions at collieries. 
 The bottom is only prevented from blowing down into the fireplace 
 by numerous stays from the top, and the angle iron round the 
 bottom of the sides is much tried by the constant springing of 
 the plates under every alternation of pressure ; and the weakness 
 thus occasioned is increased by the angle resting on the brickwork 
 and being exposed to corrosion. The effect of this continued 
 alternation of strain is well shown by the elastic model exhibited. 
 
 Notwithstanding the dependence of these boilers upon stays for 
 their strength, many have been made as large as 12 and 15 feet 
 diameter without stays ; and explosion sooner or later has been the 
 consequence. Such was an explosion that took place at Smethwick
 
 18 BOILER EXPLOSIONS. 
 
 in 1862, which is shown in Fig. 19. As the force of the 
 
 Fig. 19. 
 
 explosion was only slight, the effect of the bottom giving way, and 
 the consequent rolling over caused by the reaction of the issuing 
 steam and water, is clearly seen. Another example that occurred 
 at Wednesbury in 1862 is shown in Fig. 20, where the explosion was 
 
 Fig. 20. 
 
 rather more violent, the bottom of the boiler being torn off all round 
 and left upon the firegrate, and rent nearly into two pieces ; while 
 the top and sides were thrown some height in one mass, and were 
 only put out of shape by the fall. The weakness of this boiler had 
 been further increased by making the bottom angle of angle iron, as
 
 BOILEB EXPLOSIONS. 
 
 19 
 
 shown enlarged in Fig. 21, with a ring of flat plate A interposed 
 
 Fig. 21. 
 
 Fig. 22. 
 
 between the angle-iron ring and the concave bottom of the boiler ; 
 so that all the effect of the springing of the bottom, as shown by the 
 dotted lines, was thrown upon the angle iron, which was accordingly 
 found cut off all round. Had the concave bottom been made to rise 
 direct from the angle iron, as in Fig. 22, the springing could not 
 have been so great, and the angle iron would only have had to stand 
 the shearing strain of retaining in its place the rigid bottom ; but as 
 about one foot all round the bottom was flat, and the concavity was 
 only in the central part, the angle-iron ring had to bear an up and 
 down strain, as shown by the dotted lines in Fig. 21, and the 
 bending action was more severe than it would have been if the 
 bottom had even been made quite flat all over. 
 
 Fig. 23. 
 A further form of the Balloon boiler is shown in Fig. 23,
 
 20 BOrLEB EXPLOSIONS. 
 
 where the heating surface of the bottom is increased by an internal 
 central dome-shaped fireplace, with an arched and curved flue 
 conducting the flame through one revolution within the boiler before 
 passing again round the outside. This construction however must 
 necessarily have diminished the strength of the boiler greatly. In 
 the drawing the top of the boiler, as indicated by the dotted lines, 
 is removed to show the interior. 
 
 The desire to add to the strength of boilers by lessening the 
 diameter of the shell led to the construction of the Plain Cylindrical 
 boilers. They were made first with flat ends of cast iron, which 
 frequently cracked and gave way when exposed to the fire, as 
 described in many of the early American explosions. The flat ends 
 when made of wrought iron, as shown in Fig. 24, are exposed to the 
 
 Fig. 24. 
 
 same strain as the bottom of the balloon and wagon boilers, and are 
 constantly springing with variation of pressure like drum heads, 
 causing injury to the angle-iron joint. They also require long stays 
 through them to hold in the ends, and these are subject to so much 
 vibration that they seldom continue sound for long together, 
 especially when joined with forked ends and cotters. 
 
 As the flat ends of such boilers are always being sprung by 
 each alternation of pressure into a more or less spherical shape, 
 as shown by the elastic model exhibited, this consideration no 
 doubt led to the ends being made hemispherical, as shown in
 
 BOILER EXPLOSIONS. 21 
 
 Fig. 25 ; and plain cylindrical boilers with these hemispherical ends 
 
 Fig. 25. 
 
 are now so commonly used that they far outnumber any other form 
 of boiler. Their shape renders them very strong, as the whole of 
 the iron is in simple tension, and internal pressure has no tendency 
 to alter the shape, as is shown by the elastic model exhibited. 
 There is one circumstance very much in favour of the plain 
 cylindrical boilers, and that is that they can be so easily cleaned 
 and repaired, as a man can stand properly at his work at every part 
 and the whole of the interior surface is exposed equally to view. 
 They are of course exposed to all the evils of boilers externally 
 fired, the part under greatest strain being weakened by the action 
 of the fire ; and the bottom is also exposed to injury from accumula- 
 tion of mud and chips of scurf, which cannot be prevented from 
 falling there, and lying upon the part exposed to the direct action 
 of the fire. When made of great length, such as 70 or 80 feet, as 
 is the practice for applying the waste gas from blast furnaces, these 
 boilers are also liable to seam-rips or "broken backs," owing to the 
 greater expansion of the bottom exposed to the fierce flame for its 
 whole length, than of the top which is kept cooler by exposure to 
 the air ; and it would therefore be better to have a succession of 
 short boilers, rather than only a single one, where great length is 
 required. 
 
 One boiler has been seen by the writer where extreme length 
 was avoided by curling the boiler round until the ends met
 
 22 BOILER EXPLOSIONS. 
 
 forming a Ring or Annular boiler. This boiler is shown in Fig. 26, 
 
 Fig. 26. 
 
 and is 5 feet diameter with 25 feet external diameter of the ring, 
 or a mean length of about 63 feet ; it has been found to work well 
 for some years, although exposed to the heat of six puddling 
 furnaces. 
 
 Explosions of plain cylindrical boilers have been very frequent 
 indeed, although they have not caused a proportionate number of 
 deaths, because they work usually in isolated positions at colliery and 
 mine engines. The sketch shown in Fig. 27, represents an 
 
 Fig. 27. 
 
 explosion that occurred at Darlaston in 1863, and illustrates the 
 way in which these boilers usually explode. They generally open 
 first at a longitudinal seam over the fire, which has become dete- 
 riorated by accumulations of scurf preventing proper contact of the
 
 BOILER EXPLOSIONS. 23 
 
 water, so that the plates become overheated, their quality injured, 
 their edges cracked or burnt, and the rivets drawn or loosened. The 
 rent generally continues in the longitudinal direction to the sound 
 seam beyond the bridge at the one end, and at the other end 
 to the seam joining the front end to the shell ; and then runs up each 
 of the transverse seams, allowing the rent part of the shell to open 
 out flat on both sides, and liberating both ends of the boiler, which 
 fly off in opposite directions. Of course it is seldom that an explosion 
 is quite so simple as this, as the direction of the flight of the various 
 pieces is so much influenced by the last part that held in contact 
 with the main body of the boiler. The want of due observation of 
 this point has often led to erroneous conclusions 
 
 In the explosion shown in Tig. 28, and in the model exhibited, 
 
 Fig. 28. 
 
 which occurred at Westbromwich in 1864, the lower part of the 
 side of an upright boiler was blown out ; and the liberated part 
 was also divided into two pieces, each of which fell some distance 
 behind the boiler, in an opposite direction to the side from which 
 they came. The explanation of this became obvious on examination, 
 as the cause of the rupture had been the corrosion of the bottom, 
 and the rent had run up the seams until it met the angle iron of the 
 side tubes, round which it ran to the first seam above. This seam 
 acted as a hinge on which the ruptured pieces turned, and they 
 swung round so violently that they were wrenched off, but not 
 before they had pulled the boiler over and received the diverting 
 force which gave them their direction, for they flew off at a tangent, 
 to the circle in which they had swung round on the sound upper 
 seam as upon a hinge.
 
 24 BOILER EXPLOSIONS. 
 
 In order to avoid having a large diameter for plain cylindrical 
 boilers, especially -where exposed to the fire, hoilers have heen used 
 that have supplied the required steam power by a combination of 
 several cylinders of small diameter. One of these known as the 
 Elephant boiler, has been so much used in France that it is 
 sometimes called the French boiler ; it is shown in Fig. 29, 
 
 Fig. 29. 
 
 and consists of two cylinders of small diameter connected by upright 
 conical tubes to a large cylinder above. Another form called the 
 Betort Boiler, shown in Fig. 30, has been described at a previous 
 
 Fig. SO. 
 
 meeting of this Institution (see Proceedings Inst. M. E. 1855 
 page 191). The disadvantages of these two combinations of plain 
 cylinders are that they are not easy to clean or examine internally, 
 and also there is not free exit for the steam, which has to find its 
 way along small channels, and carries the water away with it, 
 causing priming, and also retarding the generation of steam and
 
 BOILER EXPLOSIONS. 
 
 25 
 
 endangering the boiler plates. With a view to strengthen the plain 
 cylinder made of wrought-iron plates, the seams are sometimes 
 made to run diagonally, as shown in Fig. 31, on the principle that, 
 
 Fig. 31. 
 
 as the longitudinal is the weakest seam and the transverse the 
 strongest, a diagonal between them gives the greatest amount of 
 strength to the boiler as a whole. 
 
 Plain cylindrical and wagon boilers have for many years been 
 made with internal tubes of various shapes and arrangement, through 
 which the flame passes to add to the heating surface. These are 
 shown in dotted lines on the previous drawings of wagon boilers, 
 Figs. 11 and 12. They are also shown in Fig. 32, where a tube 
 
 Fig. 32. 
 
 passes from over the fire to the front of a plain cylindrical
 
 26 BOILEB EXPLOSIONS. 
 
 boiler ; in Fig. 33 two tubes pass from the sides to the front : in 
 
 Fig. 33. 
 Fig. 34 the tube passes from the back, but returns over the fire and 
 
 Fig. 34. 
 passes again to the back : and in Fig. 35 a tube from the back 
 
 Fig. 35. 
 
 passes out through a cross tube in each side. The boilers in all 
 these cases are fired externally. This addition of tubes has tended 
 very much to increase the size of these boilers in order to make
 
 BOILER EXPLOSIONS. 
 
 27 
 
 room for the tubes. These boilers are now found of 9, 10, and even 
 11 feet diameter; and this large shell being fired externally is 
 exposed to the same dangers as those described in the plain 
 cylindrical boiler, while it is not so easy to keep clean on account 
 of the obstruction offered by the internal flues. When the flame 
 has passed under the whole length of the bottom of these large 
 boilers before going through any tube, it is doubtful whether the 
 heating surface of the tube helps much in the generation of steam ; 
 but the tube is of use in reducing the quantity of water in the 
 boiler, as it occupies a considerable space. 
 
 Explosions of these boilers have sometimes taken place by 
 collapse of the tubes, but much more generally by the failure 
 of the shell over the fire, as shown in the sketch Fig. 36, 
 
 Fig. 36. 
 
 representing an explosion that occurred at Wolverhampton in 1865, 
 in which the first rent took place in a seam over the fire where 
 frequent repair had led to a considerable length of longitudinal 
 seam being in one continuous line. The four plates over the fire 
 parted and opened out until they had ripped two seams completely
 
 28 
 
 BOILEK EXPLOSIONS. 
 
 round the boiler ; and the plates were thrown in one flat piece, as 
 shown, upon a bank behind. The main body of the boiler with the 
 tubes was turned over, and the front end blown away. 
 
 A modification or amalgamation of several of the forms of 
 boilers already mentioned led to the construction known as the 
 Butterley boiler, shown in Fig. 37, with a wagon-shaped end over 
 
 Fig, 37. 
 
 the fire, continued in a single tube within a plain cylindrical shell 
 beyond. This boiler has been found to generate steam very rapidly ; 
 but the extreme weakness of the construction over the fire and along 
 the tube, especially at the part where the front end of the tube widens 
 out in a bell mouth to meet the wagon-topped fireplace, has led to 
 so many explosions that few boilers are now made of this form. 
 A very early explosion that occurred at Edinburgh in 1821 was of a 
 boiler somewhat of this shape, only that the wagon-topped fireplace 
 was much longer. Other explosions of this form of boiler occurred 
 at Ashton-under-Lyne in 1845, at "Wolverhampton in 1854, and at 
 Tiptonin 1856. 
 
 The desire to economise fuel led to placing the fire inside the 
 
 Fig. 38. 
 boiler, in a tube running from end to end, as shown in Fig. 38,
 
 BOILER EXPLOSIONS. 
 
 29 
 
 and the great number of boilers of this form used in Cornwall gave 
 it the name of the Cornish boiler. The exceedingly good duty 
 performed by these boilers led many to believe them the most 
 perfect for economy and durability; but the great number of 
 explosions, or more properly of collapsed flues, that have happened, 
 have altered this opinion, and led to the double -flue boiler shown in 
 Fig. 39, in which not only is the heating surface increased but the 
 
 Fig. 39. 
 
 strength also, by having two tubes of smaller diameter in the same 
 shell. There are a great many varieties of the two-tube boiler, 
 which have been made for the purpose of obtaining various particular 
 results. In some cases the two tubes have been made to unite into 
 a single tube immediately behind the fires, forming what is known 
 as the Breeches-tube boiler, as shown in Fig. 40, and in other 
 
 t'ig. 40. 
 instances the outside shell of the boiler has been made oval, us
 
 30 BOILKE EXPLOSIONS. 
 
 shown in Fig. 41, with the two tuhes continued through from end 
 
 Fig. 41. 
 
 to end. The heating surface has also been increased, and the 
 strength of the main tubes, by placing smaller transverse tubes 
 across them at right angles ; but these advantages are gained by 
 increased complication, leading of course to greater difficulty in 
 examination and repair. 
 
 The frequent failure of tubes by collapse when used for high 
 pressures, and also the results of careful experiments, led to 
 the simple addition of strengthening rings of different makes 
 around the exterior of these tubes, by which the shell and the 
 tubes are rendered of equal strength. It has taken considerable 
 time for the belief in the weakness of large tubes when exposed to 
 external pressure to become general, and a great many boilers 
 are still made and used having even large tubes without the 
 strengthening rings ; and in some districts such boilers are used in 
 great numbers and at far higher pressures than can be considered 
 judicious. In more than one bed of boilers, one boiler after 
 another has exploded by the collapse of the tube from the want 
 of strengthening rings, and yet these have still been believed 
 unnecessary ; and the cases of isolated boilers of this construction 
 where the large tubes have collapsed are extremely numerous, yet 
 any other reason than the weakness of the tube has been considered 
 more probable as the cause of explosion A sketch of a boiler
 
 BOILEB EXPLOSIONS. 31 
 
 with collapsed flue is given in Fig. 42, which exploded at 
 
 Fig. 42. 
 
 Burton-OD -Trent in 1865 ; and it is selected from many others 
 because it was a new boiler, well made and mounted, and was a good 
 example of the weakness of a large tube to resist high external 
 pressure when made of great length without the support of 
 strengthening rings. 
 
 There are a great many advantages in the tubular boiler internally 
 fired. The shell which is exposed to the greatest tension is not also 
 exposed to the first action of the fire. The fire is in the midst of 
 the water, so that the greatest effect is obtained from it ; and the 
 heating surface immediately over the fire, from which most steam 
 is generated, has not so great a depth of water above it for the 
 steam to pass through as in the externally fired boilers heated from 
 the bottom. The tubes also act as stays to the ends ; and the mud 
 in the water falls off the tubes, where it would do mischief, and 
 settles on the bottom, where it is comparatively harmless. 
 
 These tubular boilers are however subject to disadvantages 
 peculiarly their own. It is not so easy to move about within them 
 for cleaning and examination as in the plain cylindrical boiler, as 
 the tubes fill up the space so much. The difference of expansion 
 between the highly heated tube and the comparatively cool shell 
 produces a strain, which causes the ends to bulge out ; or if the ends 
 are made rigid, the strain sets up a contortion in the tube, which 
 causes furrowing of the plates by making the iron softer or more 
 susceptible of corrosion in certain lines of strain. Notwithstanding 
 these drawbacks however this form of boiler is an excellent one. 
 
 Many modifications in the forms of boilers have been made to 
 enable the manufacturers to use the waste heat from various 
 processes, especially from the making of iron. The plain cylindrical
 
 32 
 
 BOILER EXPLOSIONS. 
 
 boiler has been used in this way, with sometimes as many as eight 
 puddling furnaces made to work upon one boiler. One of the 
 earliest special arrangements for this purpose was the Upright 
 boiler with central tube, shown in Pig. 43, which was originally 
 
 iff. 43. 
 
 Fig. 44. 
 
 made for two furnaces ; and about 7 feet diameter and 1 6 feet high. 
 The size has since been increased to 10 feet diameter and 28 feet 
 high, as shown in JFig. 44. These boilers are made for one, two, 
 three, or four puddling furnaces; and consist of a cylinder with 
 spherical ends, standing upright, with a central tube from the 
 bottom to about half the height, into which the side tubes join. 
 The heat from each furnace plays over a portion of the shell, and 
 then passes through the side tubes and down the centre tube into 
 the underground flue to the chimney. 
 
 These boilers have many good points : there is great heating 
 surface ; and the shell being heated all round does not strain the
 
 BOILER EXPLOSIONS. 
 
 33 
 
 plates and seams by unequal expansion so much as in the horizontal 
 plain cylindrical boiler heated only at the bottom ; and as both ends 
 are spherical there is no alteration of shape under internal pressure. 
 Moreover in consequence of the upright position of the boiler 
 a safe depth of water can easily be maintained, and yet the steam is 
 taken off so high above its surface that there is little priming ; and 
 every part can most easily be cleaned and examined, as a man can 
 stand upright both in the boiler and in the flues. But the great 
 drawback to this class of boilers is that they must stand in the midst 
 of the workmen ; so that, although they are not more liable to 
 explode than any other form of boiler, yet when they do burst they 
 necessarily endanger more lives than is usually the case with other 
 boilers that can be placed more away from the men employed at the 
 works. Should anything arise with the boiler to make it desirable 
 to withdraw the fire, this cannot be done without much delay, as the 
 furnaces have to be stopped and the iron run out. Also an explosion 
 can hardly happen without some of the melted iron being scattered 
 among the men at work. 
 
 Some of the most fatal explosions of these boilers have arisen from 
 careless construction. Such was the case in an explosion at Dudley 
 in 1862, shown in Fig. 45, where the crown plate forming 
 
 . 45. 
 
 Fig. 46.
 
 34 BOILEE EXPLOSIONS. 
 
 the top of the centre tube was attached to the sides of the tube by 
 so slight an angle iron, as shown enlarged in Fig. 46, that the 
 pressure of steam on the flat crown plate fairly sheared the angle 
 iron through, and allowed the plate to be blown down the centre 
 tube into the chimney flue, whereupon the boiler was violently 
 thrown off its seating by the reaction of the issuing steam and water 
 thus liberated. 
 
 The double-tube horizontal boiler is also used in connection with 
 iron-making furnaces in many places, one furnace working into each 
 tube. Although by this arrangement the boiler can be placed a 
 little further from the workmen, some very fatal explosions have 
 happened to such boilers, as at Masborough in 1862. 
 
 Single-furnace boilers have been much used in 
 the form of a single-tube boiler standing on end, 
 as shown in Fig. 47, with the flame passing up the 
 tube, which is continued in the form of a chimney 
 on the top of the boiler. The tube passes through 
 the steam at the top, so that the plate is not 
 protected from overheating by contact with water ; 
 and this has caused explosion in some instances, 
 although the tube has been lined on the inside 
 with firebrick to shield the [ plate from the flame. 
 Another great disadvantage of this Chimney boiler 
 is that the space between the tube and the shell 
 is so narrow that it is almost impossible to examine 
 or clean it internally. 
 
 A further arrangement for a single-furnace boiler 
 is the Elbow boiler, shown in Fig. 48, where the 
 two difficulties mentioned in the previous boiler 
 are avoided. 
 Fig. 47. 
 
 Many internally fired upright boilers of various shapes have been
 
 BOILEE EXPLOSIONS. 35 
 
 constructed to suit various purposes. One of a large size that has 
 
 Fig. 48. 
 
 been at work many years is shown in Fig. 49, with an internal 
 fireplace and a suspended cone and cross tube for increasing the 
 
 Fig. 49. 
 
 heating surface. This boiler is set in brickwork in such a way that 
 the heat passes through the side tubes and round the exterior shell 
 before going off to the chimney. 
 
 A very fatal explosion at Stoke-upon-Trent, in 1863, resulted from 
 an attempt to work a boiler of somewhat the same general form, but 
 without the same careful attention to the details of construction.
 
 36 BOILEE EXPLOSIONS. 
 
 This boiler is shown in Fig. 50 ; the internal fireplace is of conical 
 
 Fig. 50. 
 
 Fig. 51. 
 
 shape, 4 ft. 6 ins. diameter on the top and 6 ft. 10 ins. at bottom, 
 and was joined to the external shell by a flat annular bottom. 
 Almost the first time it was worked at high pressure the conical 
 fireplace collapsed, breaking off at the seam at the top of the cone, 
 and blowing down upon the grate, as shown in Fig. 51. The flat 
 bottom was then left without the support of the cone and side tubes, 
 and gave way all round the outside angle iron ; and the top flew up 
 a great height into the air, and fell a crumpled heap, as shown in 
 the sketch In this case the only wonder is that a boiler of such 
 weak construction worked at all without explosion. 
 
 There yet remains to be noticed a very large and varied class of 
 boilers that have been designed with the express object of avoiding 
 explosion. Some of these, made of cast-iron pipes of small diameter, 
 have already been referred to. When steam carriages were first 
 constructed, boilers were tried made of a cluster of small pipes, set 
 both upright and horizontally, connected with a general receiver 
 and with each other by still smaller pipes. These were found to
 
 BOILER EXPLOSIONS. 37 
 
 have such small circulation of water that they very soon burnt out, 
 and also led to much priming. Afterwards, narrow chambers made 
 of corrugated plates set like the cells of a battery were tried, but 
 without much success. The multitubular boilers of the locomotive 
 type soon superseded all others as quick steam generators, and 
 until lately they have been considered as almost absolutely safe from 
 explosion. It is found however that the barrel of these boilers is 
 peculiarly liable to furrowing, owing to the strain weakening the 
 iron in certain lines. Perhaps no boiler shows more clearly than 
 the locomotive how necessary it is that every part should be open 
 to examination; and also how unwise it would be to use for 
 stationary purposes small cramped up boilers, only intended to 
 meet the necessities of locomotion. Many explosions of locomotive 
 boilers have taken place ; but it is not necessary to give details in 
 this paper, as they are fully given in the published official reports 
 of the government inspectors. 
 
 Among the form of boilers designed to obtain very rapid 
 generation of steam, combined with increased safety from explosion, 
 may be specially named that consisting of a system of small pipes 
 within a shell with an artificial circulation of water, and also the 
 boiler consisting of a cluster of cast-iron spheres, both of which 
 have been described at previous meetings of the Institution (see 
 Proceedings Inst. M. E. 1861 page 30, and 1864 page 61) ; but 
 neither has been much used in this country at present. The boilers 
 also which consist chiefly of small tubes hanging down into the fire, 
 with smaller tubes or other arrangements within them for securing 
 a natural circulation, deserve mention, as they appear successfully 
 to accomplish that end. 
 
 The principle of all these small boilers appears to be that only 
 a small quantity of water should be contained in them, so that there 
 should not be a reservoir of danger in the shape of a mass of highly 
 heated water ready to be converted into steam if a rupture takes 
 place : and it cannot be denied that this is an advantage. But on the 
 other hand these boilers of small capacity, which evaporate their 
 whole contents in a few minutes, are subject to new dangers from
 
 38 BOILEK EXPLOSIONS. 
 
 that very cause ; and although admirably adapted for purposes 
 where steam is wanted quickly on a sudden emergency, as in the 
 case of fire engines, or where the generating power required varies 
 each moment, as in the locomotive, they are for the most part ill 
 adapted for ordinary stationary purposes, such as the mill or the 
 colliery. They require constant firing and vigilant attention to the 
 feed, and cannot he left for a time with safety like the ordinary 
 stationary boilers. It has to be borne in mind also that the very 
 reservoir of danger so much dreaded is also a reservoir of power, 
 which assists in the steady maintenance of the machinery in motion. 
 The large mass of water heated to the evaporating point, the heated 
 brickwork of the flues, and the large fireplace, are so many assistances 
 to regularity, and enable the man in charge to attend to his other 
 duties without the risk of spoiling the boiler or letting down the 
 steam by a few minutes' absence from the stoke hole. Steam 
 employers are found at present to prefer the known dangers of the 
 large boilers to the supposed safety of small boilers, which they 
 fear are troublesome in practice. 
 
 Many of the early boilers were rendered weak by the injudicious 
 manner of arranging the seams. The longitudinal seams were made 
 in a continuous line from end to end, as shown in Fig. 24, page 20, 
 with the transverse seams also continued completely round the boiler, 
 so that at the corner of each plate there were four thicknesses of iron. 
 The crossing of the seams, as in Fig. 25, page 21, adds much to the 
 strength, and also often prevents a rent from continuing forward to a 
 dangerous extent. 
 
 It is scarcely requisite to mention the necessity of good material 
 and workmanship to secure strength in a boiler, however perfect 
 the design. If the plates are of weak and brittle iron, or imperfectly 
 manufactured, they will never make a good boiler. Apart from the 
 strain upon the boiler when at work, the iron has to undergo the 
 strain of the necessary manipulation, shaping, and punching, 
 during the construction of the boiler. If the plates forming the 
 boiler are not well fitted to their places before the rivet holes are
 
 BOILER EXPLOSIONS. 
 
 39 
 
 made, the errors have to be partially rectified by using the drift in 
 the holes to an unwarrantable extent, and then using imperfect 
 rivets to fill up the holes that do not correspond with each other ; 
 and the mischief is too frequently increased afterwards by excessive 
 caulking, in the endeavour to stop the leaking which is sure to show 
 itself. In this way a boiler is often exposed to most unequal internal 
 strain between its several parts before it is set to work at all ; and 
 when the heat is applied to it, the mere expansion causes undue 
 contortion, and leads to seam rips, and ultimately to disaster. 
 Several specimens of faulty rivetting and caulking were exhibited to 
 the meeting, and a sketch of one of them is shown in Fig. 52. 
 
 Fig. 52. 
 
 The strength of a boiler is often very much lessened by the 
 injudicious manner in which the mountings are fixed upon the 
 boiler, and many explosions are the consequence of this defect. Not 
 only are a great many holes for fittings cut out of the boiler in one 
 Hoe, but these holes are made needlessly large. Steam domes are 
 often so placed as greatly to weaken the shell of the boiler, the hole 
 cut out of the plate being made the full diameter of the dome ; and 
 in some cases the domes or steam chests have been made square or 
 rectangular, so as to weaken the shell still more, as shown in Fig. 53. 
 
 Manholes are often a source of danger, if not properly arranged 
 and duly strengthened. Even in very small boilers they are often 
 placed with the longest diameter in the longitudinal direction of the 
 boiler, so that the shell is greatly weakened, as in the sketch,
 
 40 BOILER EXPLOSIONS. 
 
 Fig. 54, of an exploded, boiler at Walsall in 1865. This boiler 
 
 Tig. 54. 
 
 Fig. 53. 
 
 was 5 ft. 3 ins. long and 2 ft. 6 ins. diameter, and yet the manhole 
 was 18 inches by 13 inches, and placed within a few inches of one 
 end. The end was fastened in by angle iron, which was not 
 welded, and consequently there was so little strength at the small 
 portion of the shell between the end and the manhole that it gave 
 way and liberated the end and the manhole lid, after which the 
 main body of the boiler was thrown by the reaction across several 
 streets to a great distance. 
 
 A somewhat similar injudicious arrangement of the manhole is 
 shown in Fig. 55, where a manhole 17 inches by 14 inches was 
 
 Fig. 55. 
 
 cut out of the flat top of a steam dome only 2 ft. 6ins. diameter, 
 without any strengthening ring to compensate for it. The repeated 
 strain of screwing up the manhole lid, combined with the pressure 
 of the steam, caused the lid to force its way out through the 
 plate and blow away. This explosion occurred at Birmingham 
 in 1865.
 
 BOILEB EXPLOSIONS. 41 
 
 The preceding examples have shown how explosions often result 
 from faults in the construction of boilers ; and the following instances 
 illustrate the explosions caused by mischief arising during working. 
 A boiler perhaps more than any other structure is subject to wear 
 and tear ; and let it be worked ever so carefully, it will seriously 
 deteriorate. The wonder is, considering the work they have to 
 perform, that so many boilers are found which have worked twenty, 
 thirty, or even fifty years without explosion. The terms wear and 
 tear however are too vague for this subject, and the mischief met 
 with must be considered under distinct heads. 
 
 There is no doubt that the thing most to be dreaded for boilers 
 is corrosion ; because when the plate is once thinned, it cannot be 
 strengthened again, but must remain permanently weakened. 
 Corrosion the more deserves attention because it is easily detected by 
 moderate vigilance, and can generally be prevented by moderate care, 
 or by the boilers being so arranged that they can be readily examined 
 in every part. Corrosion has been the direct and unmistakeable cause 
 of a very large proportion of the explosions that have happened : 
 it occurs both inside and outside the boiler, according to circum- 
 stances, and attacks the iron in various ways and in different places. 
 
 Internal corrosion sometimes takes place from bad feed water, 
 and its effects are different in extent in the different parts of the 
 same boiler. It very seldom thins the plate over a large surface 
 regularly, but attacks the iron in spots, pitting it in a number of 
 holes. These are sometimes large, as if gradually increasing from a 
 centre of action ; and sometimes small, but so close together as to 
 leave very little more space whole than that which is attacked. A 
 very curious example of the latter was exhibited to the meeting, and 
 shown in Figs. 56 and 57, cut from the lower part of the shell 
 of a large tubular boiler externally fired. The corrosion was 
 greatest along that part of the shell most exposed to heat, and was 
 so extensive that two boilers exploded simultaneously. The boilers 
 had been at work sixteen years, but the corrosion commenced 
 about eight years before the explosion, when the feed water was 
 rendered corrosive by being obtained from some iron mines.
 
 42 BOILEE EXPLOSIONS. 
 
 This explosion occurred at Aberaman in 1864. The corrosion 
 
 Fig. 56. 
 
 Fig. 57. 
 
 had been seen going on for years, and was not considered 
 sufficient to cause danger; but the depth to which it extended 
 through the thickness of the metal is seen in the half size section, 
 Fig. 57. Another sample equally curious was exhibited to the 
 meeting, and shown in Figs. 58 and 59, taken from the sweep plate 
 over the fire in a plain cylindrical boiler which had worked about ten 
 years. The feed water was occasionally bad, and attacked the iron 
 over the area DDD, where unprotected by scale. The protection 
 afforded by scale against occasional corrosive feed water is worthy 
 of notice. In the two specimens exhibited it is seen that the 
 protection has been perfect where the scale has not been chipped 
 off ; and the edge of the sound part projects over the hollow, as
 
 BOILER EXPLOSIONS. 43 
 
 seen in the half size sections, Figs. 57 and 59, the corrosive water 
 
 
 Fig. 58. 
 
 Fig. 59. 
 
 having eaten away a larger area beneath than that through which 
 it first entered the surface of the iron. 
 
 Internal corrosion is frequently observed where boilers are fed 
 from canals or streams in the neighbourhood of chemical works 
 from which corrosive matter is discharged at intervals into the 
 water. The corrosion takes place in isolated spots, but causes deep 
 holes ; which seems to be accounted for on the supposition that the 
 scale previously upon the plate cracks during the cooling of the 
 boiler for cleaning, and forms a blister, so that a piece of about 
 2 inches area is raised slightly from the iron. When the boiler is 
 again put to work, this blister becomes filled with the corrosive 
 water, which is held there without circulation and causes corrosion. 
 When the boiler is again emptied these blisters may be seen, and if 
 broken show the blackened water and the injured surface. In
 
 44 BOILEK EXPLOSIONS. 
 
 future working each of these blisters forms a constant unprotected 
 point for attack. It is frequently seen further that such corrosion 
 is arrested if water be used which deposits scurf ; but fresh blisters 
 and renewed corrosion will result from a return to the use of the 
 bad water. 
 
 The internal corrosion called furrowing has proved a frequent 
 cause of explosion, especially in locomotive boilers. It differs from 
 other corrosion by being in deep narrow continuous lines with abrupt 
 edges. It will sometimes go completely through a plate ; and is 
 found where a sudden change of thickness occurs, either along the 
 lines of the seams, or opposite the edge of angle-iron attachments. 
 This effect is supposed to be due to the alternate springing of 
 the plates under each variation of the pressure or temperature, 
 causing the line of least resistance to receive a strain somewhat 
 similar to that produced by bending a piece of iron backwards 
 and forwards for the purpose of breaking it. This line of injury 
 is exposed to constant attack from corrosion, because the scurf is 
 always thrown off from it. 
 
 External corrosion is a far more frequent cause of explosion in 
 stationary boilers; and it arises from many causes. The most 
 frequent cause, although the most easily detected, is leakage from 
 the joints of the fittings on the top of the boiler, which are too 
 frequently attached by bolts instead of rivets. This evil is much 
 increased when the boilers are covered with brickwork, which holds 
 the water against the plates, and hides the mischief from observation. 
 It is astonishing to find how much damage is allowed in this 
 way to go on without attention, until the tops of boilers are 
 corroded so thin that little holes burst through. These are 
 sometimes found stopped with wooden pegs or covered by screwed 
 patches of plate, either of which cause leakage that hastens the 
 mischief, as shown by the sample exhibited. Boilers exposed to the 
 weather will of course become corroded like anything else made of 
 iron and not painted ; and yet so much mischief is sometimes caused 
 by leakage beneath improper covering that exposure may almost
 
 BOILEB EXPLOSIONS. 
 
 45 
 
 be said to be the smaller evil of the two, as it is better to see what 
 is going on than to rest in false security. No covering will be 
 found cheaper, or better, in the long run, than a roof, which prevents 
 the loss of heat by exposure, and yet allows free access to all the 
 fittings and joints on the top of the boiler. 
 
 Some examples of the evils of covering can be given that have 
 come under the writer's observation. A set of boilers had been well 
 covered by arches of brickwork, so built as to keep out all water, 
 and also set so as to touch the boilers only at intervals, leaving a 
 space generally of a few inches. After about seven years' working, 
 the whole of the tops of the boilers were discovered to be dangerously 
 thin, and had to be renewed. The cause was leakage from the 
 joints of fittings and seams of the boilers, and the issuing steam had 
 been drawn along the space between the boilers and the arches, and 
 had escaped at a place where it had not attracted notice. In another 
 case, a somewhat similar set of boilers were covered with ashes, to 
 prevent the loss of heat by radiation ; and the rain and the leakage 
 beneath the ashes, in conjunction with the corrosive matter from the 
 ashes themselves, thinned the tops of the boilers to a dangerous 
 extent in less than two years. A sketch of the corrosion caused in 
 this instance by covering with ashes is shown in Figs. 60 and 61. 
 
 lig. GO.
 
 46 BOIX.ER EXPLOSIONS. 
 
 Similar mischief has been noticed in boilers covered with sand, 
 
 Fig. 61. 
 
 as shown in the sketches Figs. 62 and 63, which represent an 
 instance of corrosion after eight years' working ; although nothing 
 
 Fig. 62. 
 
 Fig. 63. 
 
 forms a better covering than sand for preventing loss of heat by 
 radiation. In both these examples it will be seen that the corrosion 
 has continued until the thickness of the plate has been so eaten 
 away that a hole has been burst out at SS. A very good covering is 
 formed by brickwork .in cement ; or various cements made for the 
 purpose, which adhere to the surface of the plate and yet show 
 leakage ; or such materials as sacking or felt ; or sheet-iron 
 casing, leaving about 6 inches of air space all round the boiler.
 
 BOILER EXPLOSIONS. 
 
 47 
 
 But all these have the great objection that they hide the boiler 
 from inspection, except by the expensive process of removing the 
 covering ; and in this way dangers that have caused explosion 
 have remained hidden from observation. 
 
 Explosions have also taken place from general corrosion of the 
 surface of the boilers in the flues. A new boiler which was set on 
 sidewalls built upon a foundation of porous rock was found to have 
 become corroded all along the bottom in less than two years, owing 
 to the dampness which rose from the foundations causing a constant 
 presence of vapour. The corrosion was peculiar, and more like that 
 found on old iron left for a long time in a damp place ; for the iron 
 plate fell to pieces when touched, and large flakes could be raised 
 from the surface, and the greater part of the thickness of the plate 
 could be removed with the fingers. Somewhat similar corrosion 
 had taken place in a boiler which exploded at Loughborough in 
 1863 ; the bottom of the shell became rent at the corroded part, and 
 as the fracture continued spirally round the boiler several times, 
 nearly all the shell was peeled off in the curious manner shown in 
 Fig. 64. The explosion shown in Fig. 65, which occurred at Leeds in 
 
 Fig. 64. 
 
 1866, also arose from corrosion of the bottom of the boiler. 
 
 The greater part of the corrosion found in the side flues of 
 boilers is caused by the leakage of seams. Many boilers are emptied 
 for cleaning as soon as work is over on Saturday night, and long 
 before the brickwork of the fireplaces and flues has cooled ; and
 
 BOILER EXPLOSIONS. 
 
 consequently, the boiler, having no water in it, is made much hotter 
 than it ever is in working, and the seams are injured and sprung 
 
 Fig. 65. 
 
 and the rivets loosened by the extra expansion so caused. This is 
 sometimes done intentionally, in order to loosen the scale by the 
 greater expansion of the iron than of the scurf. When the boiler is 
 again set to work, the seams and rivets leak and cause that corrosion 
 which is called channelling. This has been observed to occur to 
 such an extent that all the seams in a boiler have been seen thus 
 corroded ; and the same has sometimes been found in all the boilers 
 in a large manufactory. Specimens of this channelling were exhibited 
 to the meeting. One in particular, shown in Figs. 66 and 67, 
 
 Fig. 66.
 
 BOILEK EXPLOSIONS. 49 
 
 deserves attention, as it shows the effect of a jet of steam and 
 
 Fig. 67. 
 
 water from the leaking rivet K, in cutting a series of channels into 
 the plate along the course of the dotted lines EEE, and producing 
 a hole in the plate at S. This corrosion had teen going on for 
 about four years, but was in a part of the boiler seldom seen in 
 ordinary examination. Many explosions have resulted from this 
 form of corrosion ; for when a rent is once made, the fracture 
 continues along the thinned channel of the plate. 
 
 The corrosion most to be dreaded, because most difficult to 
 detect, is that which takes place where the boiler is in contact with 
 brickwork ; and it is found alike in all forms of boilers set in brickwork. 
 When found at the part where the side flues are gathered in at the 
 top against the boiler, it is usually occasioned by the leaking of 
 fittings or feed pipes, or by rain being allowed to run between the 
 boiler and the brickwork. More than one explosion has been caused 
 by the droppings from a roof being allowed to fall upon the tops of 
 the flues. When the corrosion is found at the point where the 
 bottom flue walls touch the boiler, it is frequently caused by the 
 leaking of seams that have been strained by the weight of the 
 boiler ; and this often arises from want of care to replace the 
 brickwork, after repair of the boiler or flues, in such a position as 
 to take again its proper proportion of the weight of the boiler. 
 Cases have been met with where the shape of the bottom of 
 large boilers has been quite altered by such means. The 
 brackets on the sides of heavy boilers have not only been strained so 
 that the rivets or bolts have leaked and caused corrosion, but they 
 have also bent or cracked the side plates of the boiler. The 
 bracket shown at B in Fig. 53, page 40, made of only an angle iron 
 with a piece of plate attached, is especially liable to cause injury if 
 the brickwork is not rebuilt close up to the angle iron, as the
 
 50 BOILER EXPLOSIONS. 
 
 leverage is so great. This is avoided by the better form of bracket 
 shown at C, consisting of an elbow of flat bar-iron rivetted at top 
 and bottom to the boiler. 
 
 In the old balloon and wagon boilers, the angle where the bottom 
 joined the sides scarcely ever remained sound for long when in contact 
 with the brickwork, and many of those that exploded have been 
 found almost corroded through where they stood upon the brickwork. 
 The explosion before alluded to and shown in Fig. 7, was caused 
 by corrosion of the bottom of the boiler where it was set on the 
 brickwork. Many boilers are so set that the brickwork of the flues is 
 made to follow the shape of the boiler, with as little space between 
 as possible ; but the slight advantage gained in increased heating 
 effect is far outweighed by the impossibility of getting into the flues 
 for examination. It is only by having the flues sufficiently roomy 
 that proper examination can be made, and that the indications on the 
 brickwork of leaking can be seen and remedied, and corrosion 
 arrested. A remarkable case of corrosion occurred in a boiler with 
 an oval shell, set upon a middle wall. The flues were too narrow 
 for a man to enter, and a leak in the bottom was only discovered by 
 the boiler nearly running empty while the engine pumps were 
 standing for a short time. It was subsequently found that the 
 whole bottom where it rested on the wall was extensively corroded 
 in a continuous line, and that explosion was only prevented by the 
 numerous stays across the bottom to compensate for the oval shape. 
 Fig. 68, shows the position and extent of the corrosion, and 
 
 lig. 68. 
 
 the plate was completely in holes at the parts indicated by the
 
 BOILEB EXPLOSIONS. 
 
 51 
 
 black marks. This corrosion was supposed to have been going on 
 for about three years. 
 
 It is sometimes asserted that corrosion cannot be the cause of an 
 explosion, because the corroded place would simply give way and 
 let off the steam harmlessly, or at least the boiler would not be 
 displaced from its seating. When the corrosion is only local, and 
 surrounded by sound plates of sufficient strength to arrest the 
 extension of the fracture, this may be the case, as in an explosion 
 at Sheffield in 1865, shown in Fig. 69, where a piece of plate 
 
 Fig. 69. 
 
 was blown out on one side of the boiler, allowing the steam 
 and water to escape without displacing the boiler ; the thickness of 
 the plate at that part had been reduced to l-8th inch by corrosion 
 in about \\ years, which had been caused by leakage at the seams 
 from inefficient repair with bolts instead of rivets, and also from the 
 moisture having been allowed to be kept against the plate by the 
 brickwork. But even under such circumstances, if the piece blown 
 out should be from the bottom, the whole boiler may be thrown 
 a great distance by the reaction of the issuing steam, as in an 
 explosion at Leeds in 1865, shown in Fig. 70. If the corrosion 
 
 Kg. 70.
 
 52 BOILEB EXPLOSIONS. 
 
 extends for any length, the first rent is almost sure to continue until 
 a complete explosion is the result. Several of the small models 
 exhibited to the meeting showed the line of fracture in various cases of 
 explosion. One showed the appearance of a plain cylindrical boiler 
 after explosion caused by corrosion along the whole length where it 
 rested on brickwork ; this explosion occurred at Wigan in 1865, and 
 a sketch of it is given in Fig. 71. 
 
 Fig. 71. 
 
 Many explosions of boilers have been caused by accumulation of 
 scurf. The mischief is not so much from scurf being gradually 
 deposited all over the interior of the boiler to a dangerous thickness 
 as from the chips off the sides falling in heaps on the bottom. The 
 plate beneath this accumulation becomes overheated, because not in 
 contact with the water, and softens and sinks down into a " pocket," 
 which if unnoticed will soon burn quite through. If the scurf that 
 has caused the mischief is thick and hard enough to resist the 
 pressure for a little time, the hole enlarges, until the scurf suddenly 
 gives way and allows the contents to issue so violently as to disturb 
 the boiler, or at least to blow the fire out of the grate. Such was 
 an explosion at Bilston in 1863, where a large plain cylindrical 
 boiler, 9 ft. diameter, was heated by three large fires placed side by 
 side along the bottom ; and a large " pocket " burst out over the third 
 grate, and scalded the attendant to death. A similar pocket in a 
 boiler, 4ft. 6 ins. diameter, which exploded at Dudley in 1864, after 
 having been at work six weeks without cleaning, is shown in the
 
 BOILER EXPLOSIONS. 58 
 
 transverse section, Fig. 72. In this case the scurf had filled 
 
 
 Fig. 72. 
 
 up the circle of the boiler to a depth of 3 inches at the bottom, 
 as shown in the drawing, and was of a very hard description ; 
 and the boiler plate was bent out in a gradual curve, and thinned 
 to about T ' ff inch, the original thickness being inch. 
 
 The whole bottom of a boiler is sometimes injured, and the plates 
 buckled and the seams sprung, from the accumulation of mud. 
 One case may be mentioned where the water was very full of mud, 
 and the boilers were worked day and night during the week but 
 stopped for several hours on Sunday, during which time the deposit 
 of mud was so thick that it did not get thoroughly disengaged again 
 from the bottom when the boiler was set to work, but hardened into 
 a mass. Although many of these pockets and injuries to the plates 
 may occur without serious damage, they sometimes cause that first 
 rent which destroys the equilibrium of the structure and leads to 
 explosion. Some of the specimens of scurf exhibited to the Meeting 
 show that their thickness is made up of small chips, carelessly left 
 after cleaning or fallen from the sides of the boiler, as seen in 
 Fig. 73, or from cotton waste or other matter left in the boiler 
 
 Fig. 73
 
 54 BOILER EXPLOSIONS. 
 
 and forming a nucleus for the scurf to accumulate upon. Other 
 specimens show that foreign matter must have been put into the 
 boiler to stop leaking. 
 
 Accumulations of scurf in the feed pipes at the point of entrance 
 into the boiler have also caused explosion by stopping the supply of 
 water. The same result is caused by the freezing of the water in 
 the pipes which are exposed, and each winter one or two boilers are 
 injured or exploded from this cause, especially small household 
 boilers placed behind kitchen grates. Scurf cannot be considered 
 so great an evil as corrosion, since it can be removed, and if this is 
 done in time, the boiler is restored to its original condition. 
 
 The advantage of a pure water, which does not deposit scurf, is 
 so great for the supply of boilers that it is always worth while to 
 go to considerable expense for obtaining it ; or to take some steps 
 for purifying the feed water as much as possible. If it is only mud 
 mechanically suspended, which would deposit by gravity on the 
 bottom of the boiler, frequent use should be made of the blow-off 
 apparatus. If the impurity is light enough to be carried to 
 the surface in the form of scum, the blow-off apparatus should 
 discharge from the surface of the water as well as from the bottom. 
 If the impurity is chemically suspended in the water, some 
 one of the many substances which form the refuse from various 
 manufactures, and which may contain suitable ingredients, should be 
 used to counteract the effect of the impurity. Common soda will 
 answer the purpose perhaps better than anything else. It must not 
 be forgotten however that the blow-off apparatus must afterwards 
 be used more frequently, to rid the boiler of the foreign matter, 
 or the mischief will be increased. In marine boilers, constant 
 attention is necessary to get rid of the saline deposit ; and in 
 stationary boilers using impure water an equally systematic attention 
 is needed to get rid of the earthy deposit. 
 
 Perhaps no cause of explosion is oftener mentioned than shortness 
 of water, and this is not unfrequently coupled with turning on the 
 feed suddenly into an overheated boiler. Many explosions have 
 been attributed to this cause, when closer investigation would have
 
 BOILER EXPLOSIONS. 
 
 55 
 
 revealed some far more probable reason. For instance, shortness of 
 water was stated as the cause of the explosion, at Abercarn in 1865, 
 of a single-tube boiler with a very large flue tube, which collapsed 
 upwards from the bottom. The top of the tube and the sides of 
 the shell had not the slightest mark of overheating, although exposed 
 to the flame of three furnaces, one of which worked through the 
 tube, and the others on each side of the shell. In this case the 
 cause of explosion was clearly the weakness of the tube, and not 
 shortness of water. It is erroneous to suppose that if a boiler runs 
 dry, or if the feed is turned into a red-hot boiler, there must 
 necessarily be an explosion. If a boiler unconnected with any other 
 runs rapidly empty, from the breaking of the blow-off pipe or any 
 such cause, it will simply get red-hot and sink out of shape upon 
 the fire, as may often be seen, but no explosion would happen. If 
 the water only falls gradually, as it would if the feed were turned 
 off and evaporation continued, the parts exposed to the fire would 
 get overheated as the water left them. If the subsidence of the 
 water were very slow, those parts might get red-hot, and so much 
 softened and weakened as to be incapable of bearing the pressure, 
 when an explosion would take place, as at Smethwick, in the present 
 year, where the flues were set above the water line, as shown in 
 Fig. 74. 
 
 Fig. 74. 
 
 If however the water were turned on again before the over- 
 heating had gone so far, and the feed pipe were, as usual, carried 
 down to nearly the bottom of the boiler, the water would gradually 
 creep up the heated sides and cool the plates, the heat of which 
 would not be sufficient to cause greater evaporation than the
 
 5f> BOILER EXPLOSIONS. 
 
 ordinary safety valves would cany off. The danger would not 
 arise so much from the excess of steam generated by the heat 
 accumulated in the heated plates of the hoiler, as from the injury, 
 and strain that would be caused to the plates by the undue 
 expansion and sudden contraction, especially as this action would 
 take place on only a portion of the boiler. A singular case, bearing 
 on this point, may be mentioned. A four-furnace upright boiler, 
 like that shown in Fig. 44, happened to run so nearly empty, 
 through the accidental sticking of the self-acting feed apparatus, 
 that the level of the water sank to the top of the hemispherical 
 end forming the bottom of the boiler. The feed apparatus then 
 became released of itself, and, the feed being turned full on, the 
 water gradually rose until the whole occurrence was only discovered 
 by the leaking at the seams that had been sprung, which caused so 
 much steam in the flues as to stop the working of the furnaces. 
 The overheating had been sufficient to buckle the plates, and in one 
 place a rupture had almost commenced ; but there was no explosion. 
 By way of direct experiment upon this point, boilers have been 
 purposely made red-hot and then filled with cold water, without 
 causing explosion. 
 
 It has been supposed that boilers sometimes explode from 
 overheating without the water level being below the usual point, or 
 without the accumulation of scurf previously alluded to, but simply 
 by the rapidity of the evaporation from an intensely heated surface 
 causing such a continuous current of steam as to prevent the proper 
 contact of the water with the heated plate. Such has been the 
 cause assigned for the explosion of a three-furnace upright boiler at 
 Birmingham in 1865, shown in Pig. 75. A piece of plate 
 about 3 ft. by 1^ ft. was blown out of the side, at a place where an 
 enormous flame impinged continually. The plates had first 
 bulged out, and then given way in the centre of the bulge, each 
 edge being doubled back and broken off. There was no positive 
 evidence as to the water supply ; but the crown of the centre tube, 
 which was much above the bottom of the part blown out, remained 
 uninjured. 
 
 A somewhat similar rase was that of a large horizontal boiler
 
 BO1LKK EXPLOSIONS. 
 
 57 
 
 at Kidderminster, the tube of which collapsed in 1865, as shown 
 in Pig. 76. It was heated by four furnaces, one of which 
 
 Fig. 76. 
 
 Fig. 75. 
 
 worked into the tube, one under the bottom, and one on each side ; 
 and all the furnaces worked into the same end of the boiler. The 
 tube was found to have partially collapsed at that end, and the top 
 had dropped 1 1 inches. This was repaired in the first instance, but 
 was afterwards again found injured by overheating, although not so 
 seriously. It is very probable that the extremely rapid ebullition 
 from the sides and bottom, from which the steam had to pass up 
 the narrow space between the tube and the shell, produced such a 
 foaming that very little solid water could reach the top of the tube 
 where it was exposed to extreme heat. 
 
 Many explosions have been attributed to deterioration of the iron 
 through long use, as in an explosion at Durham in 1864, and another 
 at Haswell, near Sunderland, 1865, where the boilers had worked 
 constantly for 25 and 30 years respectively. When an explosion 
 arises from the failure of a plate which has not been properly welded 
 in rolling, there is no question that it was unsound when put in,
 
 58 BOILER EXPLOSIONS. 
 
 and escaped notice ; but when the plate that fails is found to be 
 brittle and of bad iron, the fault is rather attributed to the effect of 
 working than to original bad quality. Of course this is not always 
 the case, as the injury done to plates by overheating has been already 
 explained. Pieces of plate have in some cases been erroneously 
 pronounced to be deteriorated by work, which have been taken from 
 situations in the boilers where they were not exposed to any action of 
 fire that could cause overheating ; and therefore in reality the injury 
 could only have taken place when the boiler was being made, 
 by burning the iron in bending it to the required shape. A frequent 
 cause of fatal injury to boilers is injudicious repair, whereby 
 the crossing of the seams is destroyed, as in the explosion at 
 Wolverhampton in 1865, previously referred to and shown in 
 Pig. 36. Moreover the edges of the old plates, already tried by 
 the first rivetting and the subsequent cutting out of the rivets, 
 are frequently strained again by the use of the drift to draw them 
 up to the strong new plates ; and many a seam rip is thus started 
 which ultimately causes explosion. 
 
 Many explosions have been caused by the want of proper apparatus 
 for enabling the attendant to tell the height of the water and the 
 pressure of the steam, and also by the want of sufficient apparatus for 
 supply of feed water and escape of steam, or by the failure of one or 
 other of these ; but such explosions can only be referred to generally 
 in the present paper. The mountings on a boiler are usually so open 
 to observation, and the importance of having them good and efficient 
 is so universally acknowledged, that much remark is not needed. 
 Mention has already been made of the sticking of self-acting feed 
 apparatus as a cause of mischief, and similar failures of floats and 
 gauges have constantly happened ; but this should by no means be 
 considered to condemn self-acting apparatus, either for assisting in 
 the steadiness of working, or for giving warning of danger. The 
 apparatus however should be relied on for assistance only ; and an 
 attendant cannot be called careful who leaves a boiler dependent on 
 such apparatus without watching. The self-acting principle has 
 been seen by the writer applied in a novel and useful way in a 
 recording pressure gauge, which proved the more interesting as it
 
 BOILER EXPLOSIONS. 59 
 
 had shown the actual pressure of steam at the time of the explosion 
 of one of the boilers with which it was connected. 
 
 Among the numerous boiler explosions that have been attributed 
 to over-pressure through deficient arrangements for escape of steam, 
 in many cases the safety valves have been placed on the steam 
 pipes in such a manner that the communication with them was cut 
 off whenever the steam stop- valve was shut, which is just the time 
 when the safety valves are most wanted. Safety valves are too often 
 found needlessly overweighted ; and it is believed that many boilers 
 are constantly worked with safety valves so imprudently arranged 
 and weighted, that they could not carry off all the steam the boilers 
 would generate without a very great increase of pressure. 
 
 It is concluded that enough has now been said to show that 
 boiler explosions do not arise from mysterious causes, but generally 
 from some defect which could have been remedied if it had been 
 known to exist. It only remains therefore to consider what is the 
 most ready and efficient way to discover the true condition of a 
 boiler. It has been maintained that this end is best accomplished 
 by what is called the hydraulic test, in which a pressure of water is 
 maintained in the boiler for a given time at a certain excess above 
 the working pressure. This test is undoubtedly useful so far as it 
 goes, and is perhaps the only one that can be applied to boilers with 
 small internal spaces, such as locomotive boilers, not admitting of 
 personal inspection over the whole of the interior ; and it is also 
 admirable for testing the workmanship of a new boiler. But on the 
 other hand the conditions of a boiler at work are so different from 
 those which exist during the hydraulic test, that this alone cannot 
 be depended on ; for old boilers have been known to stand this test 
 to double their working pressure without apparent iujury, although 
 known to be dangerously corroded. The difficulty also of seeing or 
 measuring the effect of the hydraulic test upon large boilers set in 
 elaborate brickwork is so great that little practical benefit has 
 resulted in many cases. 
 
 It is believed by the writer that the surest way to ascertain the 
 true condition of a boiler is to examine it at frequent intervals iu
 
 60 BOILEE EXPLOSIONS. 
 
 every part, both inside and outside ; and as this can only be done 
 when both the boilers and the flues can be readily entered, it is 
 specially important that facility for examination should be made a 
 consideration in selecting a construction of boiler. Permanent safety 
 should be considered as an element of economy, in addition to its 
 still higher importance in reference to the preservation of life.
 
 61 
 
 ON THE CONCLUSIONS DERIVED FROM THE EXPERIENCE OF 
 RECENT STEAM BOILER EXPLOSIONS, BY EDWARD B. MARTEN, MEM. 
 INST. M.E., EXCERPT MINUTES OF PROCEEDINGS OF THE MEETING 
 OF THE INSTITUTION OF MECHANICAL ENGINEERS, AT NOTTINGHAM, 
 SRD AUGUST, 1870, THOMAS HAWKSLEY, ESQ., VICE-PRESIDENT, IN 
 THE CHAIR. BT PERMISSION OF THE COUNCIL. 
 
 THE records of Steam Boiler Explosions in recent years are very 
 numerous, as the increased attention drawn to the subject in this 
 and other countries has placed far more information at disposal ; 
 and the experience of the last four years, since a former paper was 
 read by the writer on the subject of boiler explosions, has confirmed 
 the opinion then expressed, that all boilers, however good in original 
 construction, are liable in the course of time to get into bad order 
 and explode. The particulars of the explosions during this period 
 are given in the Tables appended to the present paper, which show 
 the number of explosions due to each cause in each class of boiler, 
 distinguishing those of the United Kingdom from those in foreign 
 countries. An analysis is also given of the explosions in the last 
 four years, showing the causes of explosion of each form of boiler ; 
 and also a summary of the causes of explosion under the three 
 general heads of (1) faults in construction or repair: (2) faults in 
 working which creep on insidiously and unnoticed : (3) faults which 
 might be seen and guarded against by careful attendants. Nearly 
 all of the faults in these three classes would have been detected by 
 periodical examination. 
 
 In the case of Cornish, Lancashire, and other boilers with 
 internal flues, the faults of construction which have caused explosions 
 have been weakness in the tubes, combustion chambers, ends, domes, 
 or manholes ; and explosions in these, as in other classes of boilers,
 
 62 BOILEK EXPLOSIONS. 
 
 have also resulted from external or internal corrosion, shortness of 
 water, undue pressure of steam, and scale or mud on the boiler plates. 
 
 In plain cylindrical boilers, and others without internal flues, 
 explosions have resulted from the boiler ends being made flat, and 
 also from frequent repairs producing seam rips, especially in boilers 
 having the plates arranged lengthways instead of in rings. 
 
 In marine boilers, weak flues and weak ends have also led to 
 explosion, in addition to the other causes mentioned above. 
 
 Locomotive boilers have in two cases exploded in consequence of 
 the strains thrown upon them by their being used as a frame for 
 the engine. 
 
 Other explosions have resulted from want of stays, and from too 
 much heat impinging on some particular part ; and in domestic 
 boilers from freezing of pipes under pressure. 
 
 Altogether the total number of explosions in this country that 
 have been recorded during the past four years has amounted to 219, 
 which may be classed under the following heads : 
 
 Faults of construction or repair 95 
 
 Faults to be detected only by periodical examination 62 
 
 Faults which should be prevented by careful attendants . . . 5i 
 Extraneous or uncertain causes 8 
 
 Total 219 
 
 By these 219 explosions 315 persons were killed and 450 injured. 
 
 The following are the particulars of the construction of the 
 
 219 exploded boilers : 
 
 Cornish, Lancashire, or other boilers with internal flues . . . B4 
 
 Plain Cylindrical boilers or others without internal flues ... 54 
 
 Marine boilers r 12 
 
 Agricultural boilers 11 
 
 Locomotive boilers 10 
 
 Furnace-upright boilers , 8 
 
 Crane boilers 6 
 
 Rag steamers, &c 6 
 
 Balloon and Elephant boilers 5 
 
 Domestic boilers, &c 16 
 
 Not sufficiently described 7 
 
 Total 219
 
 BOILEK EXPLOSIONS. 
 
 03 
 
 The causes of these 219 explosions may also be classed as 
 follows : 
 
 "Worn out, corroded, or burnt plates 89 
 
 Undue pressure, overloaded valves, intentional or from carelessness 25 
 Bad construction, defective fittings or stays, or want of repair . 69 
 
 Shortness of water, formation of scale or mud, or external flues 
 
 set too high 28 
 
 Extraneous or uncertain causes 8 
 
 Total 219 
 
 Sketches are given of the most instructive examples of boiler 
 explosions during the last four years, which are sufficient to explain 
 themselves, with a brief reference to their special features. 
 
 Although the importance of periodical examination as the best 
 safeguard against explosion is generally admitted, a great number of 
 those who make or use boilers have not at present sufficient belief 
 in its importance to adopt this course. Boilers are still constructed 
 or set in such a manner as to render examination next to impossible ; 
 and are continued to be worked without making it the duty of those 
 who mind them, or of any one else, to examine every part at 
 frequent intervals ; and hence such explosions have occurred as 
 shown in Fig. 1, No. 12, 1870, iu which the original position of the 
 
 Fig. 1. 
 
 boiler before explosion is indicated by the dotted lines. It is thought
 
 64 
 
 BOILER EXPLOSIONS. 
 
 by many steam users that all has been done which is possible, if 
 their boilers are the best that can be procured, and are set in the 
 most approved way ; and it is taken for granted that such boilers 
 should last for many years, under the idea that a good boiler can 
 never explode unless the feed is neglected. Similar boilers are often 
 referred to as having worked safely for ten or twenty years, but it 
 is forgotten that they may be exposed to the insidious action of 
 
 furrowing on the inside or channelling on the outside, such as caused 
 the explosions of the originally good boilers shown in Figs. 2, 3, 4, 
 and 5, Nos. 35, 1870; 50, 1866; 46, 1869 ; and 25, 1870. 
 
 Fig. 3. 
 
 Much mischief arises from special classes of boilers, fittings, or 
 apparatus, being looked upon as promising permanent safety from
 
 BOILER EXPLOSIONS. 
 
 65 
 
 explosion ; while the inevitable circumstance is overlooked that it is 
 only BO long as everything is maintained in good condition that 
 safety is insured. An apparatus, for instance, for preventing 
 explosion from shortness of water or over-pressure, however perfect 
 
 Fig. 5. 
 
 Fig. 4. 
 
 for any such object, would be quite inefficient as a safeguard 
 against explosion from corrosion, furrowing, channelling, or weak 
 construction. It is curious to note how often it is the case that every 
 other part of an establishment is subject to severe and perpetual 
 scrutiny, the engines especially being overhauled with the most 
 scrupulous regularity ; while the boilers, the very source of the 
 power and the heart of the whole business, are left to themselves 
 for long periods, even for years, without examination ; and it is too 
 often only after bitter experience that owners have understood the 
 need of this examination. In this, as in many other matters, 
 experience has shown that there is no royal road to safety, and 
 that immunity is only secured by unremitting care and constant 
 watchfulness. It should never be forgotten that even a good boiler 
 can explode ; for however good at the outset, sooner or later the 
 time must eventually arrive, when such wear and tear will have 
 taken place as will result in dangerous weakness, unless the boiler is 
 carefully and systematically attended to. Although a boiler may 
 even last safely for ten to thirty or more years if worked slowly and 
 with care, no confidence can be placed in a boiler which has worked 
 so long, unless it is examined in every part.
 
 66 
 
 BOILER EXPLOSIONS. 
 
 The opinion is more general than many are aware of, that 
 explosions as a rule are caused by shortness of water and the sudden 
 turning on of the feed water upon red-hot plates ; and the 
 appearances of injury in the plates from fire, arising in the ordinary 
 
 Fig. 6. 
 
 course of working, have been frequently mistaken for signs of 
 overheating from shortness of water at the time of explosion, as 
 illustrated in Figs. 6 and 7, No. 24, 1867, and ]S T o. 59, 1866. 
 
 Although boilers do explode from the softening of the plates by
 
 BOILER EXPLOSIONS. 
 
 67 
 
 overheating in consequence of shortness of water, yet it is very 
 doubtful whether the turning on of the cold water at such a time is 
 ever the cause of explosion. The feed water heing always 
 introduced at the hottom of the boiler, as in Figs. 8, 9, and 10, 
 
 Fig. 8. 
 
 Fig. 10. 
 
 Fig. 9. 
 
 cannot be scattered suddenly near the overheated parts, but must 
 rise gradually up the sides ; and the boiler would have gone to pieces 
 from the giving way of the softened parts long before the water 
 reached them, as was the case in the explosions shown in Figs. 1 1 
 and 12, end of 1868. The experiment of injecting cold water into 
 red-hot boilers has been carefully tried more than once, without 
 producing any explosion. 
 
 Although it may be too much to suppose that boiler explosions 
 will ever be entirely prevented, it is important that those who have
 
 68 
 
 BOILER EXPLOSIONS. 
 
 the care of boilers should understand better what are the true 
 causes of explosion, in order that they may know what to guard 
 against in addition to shortness of water. This better understanding 
 
 Fig. 
 
 Figs. 11. 
 
 of the subject has been much retarded by the supposition that the 
 causes of boiler explosions are beyond the comprehension of the boiler 
 minders ; and still more by the important differences of opinion 
 among those under whom they work. Much evil has resulted from 
 the promulgation of strongly expressed views, which have been 
 founded upon facts but of too limited extent, and such as must 
 become modified by consideration of the facts of a large number and 
 variety of explosions. Mysterious theories to account for explosions 
 have been resorted to only from want of clearer explanations. 
 
 Before considering in detail the causes of explosion, it is necessary 
 to recall to mind that beyond question there is sufficient accumulated 
 force in any working boiler to cause all the violent effects of an 
 explosion, if this force be suddenly liberated. In Figs. 13 and 14, 
 No. 18, 1869, and No. 63, 1866, are shown the violent effects of the
 
 BOILER EXPLOSIONS. 
 
 69 
 
 rupture of vessels employed for steaming rags, which were filled 
 with steam only. In ordinary boilers however there is present, 
 
 Fig. 13. 
 
 besides the steam, a quantity of water heated much beyond the 
 atmospheric boiling point ; and when rupture takes place and the 
 pressure is suddenly relieved, part of this water evaporates, and keeps 
 
 Hg. 14. 
 
 up the supply of steam to continue the rupture and destruction. 
 The explosion of a boiler differs from the discharge of electricity or 
 lightning, which cleaves the air and instantly leaves a vacuum ; it 
 also differs from the discharge of detonating compounds which act 
 suddenly and leave a vacuum ; but it more nearly resembles the 
 discharge of gunpowder, which burns sufficiently slowly to keep up 
 a continuous pressure behind a projectile until it leaves a gun ; and 
 each cubic foot of water in a boiler working at 60 Ibs. pressure has 
 been shown to produce in. steam an explosive effect equal to one 
 pound of gunpowder. None of the elaborate but unlikely theories 
 of decomposed steam, or of electric accumulations, suppose a force
 
 70 
 
 BOILER EXPLOSIONS. 
 
 BO fitted to cause destruction as that contained in the highly heated 
 water existing in all working boilers. 
 
 The following appear to be the general results to be derived 
 from the experience of the explosions in this country during the 
 last four years. 
 
 First as to faults of construction which fall under the department 
 of the boiler maker or repairer. One of the most apparent causes 
 of explosion in stationery boilers is the loss of strength occasioned 
 by frequent repair, not only from the injury done to the old plates 
 by removing rivets, but from the want of bond in the new work. 
 
 Fig. 15. 
 
 This has lead to many of the explosions of the Plain Cylindrical 
 boilers, such as are shown in Figs. 15, 16, and 17, No. 45, 1869, 
 No. 32, 1870, and No. 20, 1870. Where the plates are arranged 
 
 Jig. 16.
 
 BOILER EXPLOSIONS. 
 
 71 
 
 longitudinally instead of in rings, the danger is increased, as there 
 is less chance of a dangerous rip being arrested by a crossed joint. 
 
 Fig. 17. 
 
 So great a number of boilers with continuous longitudinal Beams, 
 especially in the North, have worked for twenty or thirty years, 
 that it can hardly be supposed they are any weaker than the boilers 
 made in rings ; but they are more liable to explode, for if a seam 
 rip occurs, it more easily extends along the seam, and leads to the 
 general break up of the boiler, shown in Fig. 18, No. 59, 1869. 
 
 Fig. 18. 
 
 Perhaps no boilers have worked for a greater number of years 
 than the Plain Cylindrical boilers, many specimens being in existence 
 and apparently in good order which were put to work fifty or sixty 
 years ago. When such boilers have been too much or injudiciously
 
 72 BOILEK EXPLOSIONS. 
 
 repaired, they are treacherous and uncertain ; but their rupture and 
 explosion occur not so much on account of fault of shape, as 
 from the simple reason that like willing horses they are easily 
 overworked. The grates are usually twice as large as the fair 
 proportion to the heating surface, producing the double evil of 
 forcing more heat through the iron plates over the fire than they can 
 transmit without injury, and allowing a great amount of heat to pass 
 away to the chimney without useful effect. Careful experiment 
 shows that nearly as good duty can be obtained with the plain 
 cylindrical boiler as with any other form, provided the rate of 
 combustion is in fair proportion to the extent of heating surface in 
 the boiler. The circumstance that many plain cylindrical boilers have 
 exploded is not sufficient to condemn this make of boiler, which is 
 the cheapest, simplest, and most easily set. If the number of 
 explosions alone were to be taken as the guide, it would lead to the 
 condemnation of the Cornish and Lancashire boilers, from the 
 experience of the past four years. But in case of both plain 
 cylindrical and other forms of boilers, most of the dangers admit of 
 remedy, and can be guarded against by frequent examination. 
 
 Five very fatal explosions have occurred of boilers heated by 
 Puddling and Mill Furnaces, leading in some cases to the supposition 
 that this form of boiler is more liable to explosion than others. 
 They were not adopted however in the iron-making districts without 
 great care and consideration, and theje does not seem ground for 
 attributing special danger to them. The causes of the five explosions 
 referred to of these boilers were manifest, and would have led to 
 the explosion of any form of boiler ; the loss of life however was 
 great, because the situation of the boilers was among a large number 
 of workmen. The steam power required in ironworks so far exceeds 
 that in any other trade, that an ironwork is half composed of boilers ; 
 the workmen are necessarily within the range of explosion of many 
 boilers, and hence the great loss of life when such an accident 
 occurs. The explosions of such boilers shown in Figs. 19 and 20, 
 !No. 24, 1868, and No. 31, 1868, were from external and internal 
 corrosion respectively of the bottoms, rendering them too weak to 
 bear the ordinary pressure.
 
 BOILEK EXPLOSIONS. 
 
 73 
 
 Those shown in Figs. 21 and 22, No. 23, 1870, 
 and No. 53j 1869, were from the collapse of 
 
 Fig. 19. 
 
 the central tubes, which were weakened by 
 external and internal corrosion respectively. 
 In Fig. 24, No. 35, 1868, the shell was in bad 
 
 Fig. 20. 
 
 Fig. 21.
 
 74 BOILEE EXPLOSIONS. 
 
 order from over work and receiving too much heat from four large 
 
 Fig. 22. 
 furnaces, one of these especially causing a constant mass of flame 
 
 Fig. 24.
 
 BOILER EXPLOSIONS. 
 
 75 
 
 to impinge upon a single plate, which resulted in a seam rip. 
 The greatest number of explosions and the greatest loss of life 
 and personal injury have been in the case of Cornish and Lancashire 
 boilers, or others with internal flues. In the county of Cornwall 
 itself there have been many explosions, as often from the rupture of 
 the shell, Fig. 23, No. 58, 1869, as from the collapse of the tube, 
 
 Fig. 23. 
 
 Fig. 25, No. 35, 1869. The temporary patching on some of these 
 old boilers was most extensive, Fig. 26, No. 52, 1869, and the only 
 wonder really was that they held together as long as they did. 
 The belief that shortness of water is the only cause which can 
 
 Fig. 25. 
 
 lead to the collapse of tubes is so strong, that the boiler minders 
 have often been condemned almost unheard in cases of explosion, 
 as if there were no room for doubt that their neglect was the 
 cause. Explosions from weakness of tubes are not however
 
 76 
 
 BOILER EXPLOSIONS. 
 
 confined to Cornwall, as for example in Fig. 27, No. 42, 1868, 
 where the flue was oval and very weak : although it was supposed 
 that shortness of water caused the accident, from the idea that 
 nothing else could account for it. The strain caused by the varying 
 
 Fig. 26. 
 
 temperature of the internal tubes in Cornish or Lancashire boilers, 
 and the difficulty of staying their flat ends so as to make them 
 sufficiently secure without being too rigid to allow for the expansion 
 of the tubes, render them liable to corrosion or "furrowing" in 
 particular lines of strain, the destructive action of which is very 
 
 Fig. 27. 
 
 rapid ; while the large quantity of brickwork around the outside, 
 necessary to form the external flues, also renders them liable to 
 corrosion in the parts most difficult of access. In this favourite
 
 BOILER EXPLOSIONS. 
 
 77 
 
 Form of boiler therefore careful and frequent examination in every 
 part is more needed than in boilers of simpler form and setting ; and 
 the increasing number of explosions among these boilers seems to 
 establish that they are only trustworthy if frequently examined 
 and kept in perfect order. 
 
 Several instances have occurred of explosion of Portable Crane 
 Boilers. Their small size has led to their condition being disregarded, 
 under the idea that scarcely any pressure could burst them. In 
 practice it is found however that they are often exposed to greater 
 pressure than other boilers, because the fire is large and quick in 
 proportion to their size ; and they often have to stand for a 
 considerable time with the steam up, and their exposed position and 
 long intervals of rest add to the chances of corrosion, as shown by 
 
 Fig. 28. 
 
 the example in Fig. 28, No. 14, 1869. The large manholes without 
 strengthening rings, that are so often put in these boilers, have been 
 the cause of explosions such as that shown in Fig 29, No. 57, 1866, 
 
 Fig. 29. Fig. 30. 
 
 The same remark applies to some of the portable or agricultural
 
 78 
 
 BOILER EXPLOSIONS. 
 
 boilers which have exploded, such as those shown in Figs. 30 and 
 31, No. 43, 1868, and No. 12, 1869. 
 
 Much mischief is often caused by bad imitation of well planned 
 boilers. Thus in boilers of the Cornish form, the ends are made 
 
 Fig. 31. 
 
 sometimes so rigid as to give no allowance for the expansion of the 
 tube, and the result is such continued strain as to cause constant 
 leaking and the consequent risk of fracture. In furnace boilers the 
 tops of the crowns of the inside tubes are often made flat, as in 
 Fig. 37, instead of being domed ; or the inside tube is of undue 
 size, as in Fig. 21, No. 23, 1870, see page 73. Furnace boilers 
 
 
 Fig. 37. 
 
 have been made with the omission of the stays that are so 
 peculiarly necessary in that form, whereby both ends have been 
 left free to bulge outwards with the pressure, as in Fig. 32.
 
 BOILER EXPLOSIONS. 
 
 79 
 
 Cornish boilers are often altered to the plain cylindrical form, 
 without compensation being made for the loss of strength caused by 
 the removal of the tube ; this has led to such explosions as shown in 
 
 Fig. 32. 
 
 Fig. 33, No. 47, 1869, where two tubes where taken out, and 
 Fig. 34, No. 42, .1867, where one tube was taken out. One of the 
 most frequent and serious causes of loss of strength is the repairing 
 of externally fired boilers. Not only are the patches sometimes 
 
 Fig. 33. Fig. 34. 
 
 only bolted on in a temporary manner, as in Fig. 35, No. 29, 1869, 
 but even where they are rivetted on there is an entire want of bond 
 or crossed joint, as in the case of the exploded boilers shown in 
 
 Fig. 35.
 
 80 
 
 BOILEE EXPLOSIONS. 
 
 Figs. 15, 16, and 17, see page 70 and 71, No. 10, 1869, and 
 Fig. 36. 
 
 Fig, 36. 
 
 An attempt is made in Fig. 38 to show the effect of wear and 
 tear of boiler plate in an ordinary upright furnace boiler, such as is 
 shown in Fig. 37. The external surface is exposed to intense heat 
 and consequently expands, while the internal surface is kept cool by 
 contact with the water and expands to a much less degree. The 
 continued repetition of this process produces the same effect of 
 
 Fig. 38. 
 
 cracking the surface as that seen in the anvil blocks of steam 
 hammers ; and the strength of the plate is reduced in proportion to 
 the destruction of the continuity of its surface. The deleterious effect 
 of this process is much increased if the boiler is subject to alternate
 
 BOILER EXPLOSIONS. 
 
 81 
 
 heating and streams of cold air on opening the fire-doors. To avoid 
 it the flame should have room to spread over as large a surface as 
 possible, without impinging on one particular point, and the firing 
 should be as regular as possible ; and hence the greater freedom from 
 injury in boilers mechanically fired or heated by gas. The above 
 action is quite distinct from the overheating of the plates that 
 occurs when no water is in contact with them, which simply softens 
 them and reduces their strength, as in Fig. 39. It is believed that 
 many boilers suffer from overheating without being short of water : 
 
 Fig. 39. Fig. 40. 
 
 and an attempt is made to show this action in such an upright boiler as 
 is represented in Pig. 37, page 78, by the enlarged section of the side 
 shown in Fig. 40. The flame is shown impinging on a limited surface, 
 as before, and the steam rises so rapidly from the inner surface as to 
 maintain a continuous stratum of steam between the iron and the 
 water, and the plate consequently becomes overheated at that part. 
 When the intense flame subsides by an alteration of the working of 
 the furnace, the stream of steam diminishes, and the water returns 
 and suddenly cools and contracts the plate, but often not before it 
 has commenced to get out of shape. This has perhaps led to the 
 explosion shown in Fig. 59, No. 37, 1868, page 82. The same 
 thing may happen to the crowns of tubes of internally fired boilers 
 when over fired, as in Fig. 41. Success has attended the use of 
 internal linings to boilers, arranged so as to ensure a rapid circulation 
 over the most heated parts, and also to catch all the mud and 
 loose scale.
 
 82 
 
 BOILER EXPLOSIONS. 
 
 In order to enable boiler minders to make proper periodical 
 examinations, it is necessary that care should be taken to arrange 
 both the boilers and the flues with that view ; and this can be done 
 
 Fig. o ( J. 
 
 without materially injuring the efficiency of the boiler. Ordinary 
 plain cylindrical boilers can be entered easily, as in Fig. 42 ; 
 and although the small spaces between the tubes and the shells of 
 
 Fig. 41. Fig. 42. 
 
 Cornish and Lancashire Boilers, as shown in Fig. 43, render the 
 complete examination troublesome, there is no difficulty in seeing 
 those parts most likely to need examination, such as the^crowns of 
 
 Fig. 43. 
 
 Fig. 44.
 
 BOILER EXPLOSIONS. 
 
 83 
 
 the tubes and the end plates and angle iron. It is in the external 
 flues that greater accommodation is needed, as in many cases these 
 are so narrow that the boiler is quite inaccessible without pulling 
 down the brickwork, as in Figs. 44 and 45. The loss of heating effect 
 
 Fig. 45. Fig. 46. 
 
 caused by the use of wider flues is so little, that it is far outweighed 
 by the greater security obtained from the more efficient examination 
 that is thereby rendered practicable. The flues of the plain cylindrical 
 boiler are easily made wide enough for a man to pass through them. 
 The flues of Cornish and Lancashire boilers should be made as shown 
 in Figs. 46 and 47, so that a man can enter them without such 
 inconvenience as in Fig. 48. One point of danger being the use of 
 
 i^illHBHHHBMBMHil^^ 
 Fig. 47. Fig. 48. 
 
 wide mid-feather walls, on which corrosion is apt to take place, 
 these should be narrowed and the weight of the boiler supported on 
 side brackets ; the top of the mid-feather and side walls can then 
 be constructed with sight holes as at A A in Figs. 49 and 50, so as 
 to give the means of examining the plates near each seam by simply 
 removing loose bricks. 
 
 The explosions of fourteen Domestic or Heating-Apparatus 
 Boilers are included in the list of explosions, Table III ; and some
 
 84 
 
 BOILEB EXPLOSIONS. 
 
 notice is required to be taken of these, because they have led to the 
 loss of the lives of those who could not be expected to know their 
 construction or how to guard against accident ; and as these boilers 
 are seldom seen or examined after they are once set, they should be 
 
 Fig. 49. 
 
 Fig. 50. 
 
 the more carefully constructed. In one or two cases these boilers 
 were of a rectangular shape, as in Fig. 51, No. 41, 1868, ill 
 adapted to bear internal pressure, and yet placed in connection with 
 cisterns in the roofs of lofty houses, so as to expose them to a 
 hydrostatic pressure almost up to their bursting strength without any 
 addition of steam pressure. The most usual cause of explosion is 
 
 Fig. 51. Fig. 52. 
 
 the lighting of the fire during frosty weather in a house that has 
 been left vacant, so that steam pressure accumulates in the boiler 
 whilst the exit is frozen up, as was the case in Fig. 52, No. 6, 1870. 
 The cast-iron boilers commonly used, Fig. 53, end of 1869, are 
 
 Fig. 53. 
 
 Fig. 54. 
 
 capable of bearing but little pressure ; and the wrought iron boilers,
 
 BOILEIi EXPLOSIONS. 
 
 85 
 
 as in Fig. 54, No. 7, 1870, are found often so badly welded as to be 
 but little stronger ; but even if they were as strong as they could be 
 made, the stoppage of the pipes by ice would lead to explosion. 
 Steam pressure may be guarded against by a safety valve ; but as 
 this may become set fast in a little time, it would be far better to 
 avoid all chance of steam accumulation by such an arrangement as 
 that shown in Fig. 55, where the circulating boiler is placed within 
 
 Fig, 56. 
 
 Fig. 55. 
 
 an open-topped boiler behind the kitchen fire, and only receives its 
 heat through the hot water surrounding it, and therefpre cannot 
 itself become sufficiently hot to generate steam. 
 
 A few remarks may be useful as to those faults arising in 
 working which fall under the department of the boiler minders. 
 Not a few of the explosions during the last four years have occurred 
 from acts of simple carelessness, such as where a blow-off pipe was 
 left open, so that the boiler was nearly emptied of water while at 
 work ; or in another case where two boilers were fed at the same 
 time through a common pipe without a back valve, and the water 
 from one "kicked " over into the other. "Undue pressure has been 
 allowed to accumulate by safety valves being tied down, as in the 
 agricultural boiler, Fig. 56, No. 16, 1867 ; or by an extra weight 
 being put upon the safety valve, as in an instance where three bricks 
 were fastened to the lever and the fires were lighted earlier than 
 usual, under the idea that an accumulation of steam could be raised 
 during the night to make a good start in the morning. Another 
 explosion was caused by working a boiler at more than three times 
 its proper pressure to meet a temporary emergency. In not a few
 
 86 
 
 BOILER EXPLOSIONS. 
 
 cases of explosion there was no pressure gauge on the boiler, or the 
 gauge was out of repair in consequence of being placed on the steam 
 pipe, so that it vibrated with every stroke of the engine ; as in the 
 examples shown in Figs. 24 and 16, No. 35, 1868, No. 32, 1870, 
 pages 70 and 74. 
 
 Corrosion has been the direct cause of many of the explosions. 
 In one or two cases the corrosion was known to exist, but the 
 renewal of the boiler was too long delayed, as in Fig. 57, No. 8, 1869, 
 
 fig. 57. 
 
 in others it took both owners and minders by surprise, as in Fig. 1 , 
 No. 12, 1870, page 63. It is said that to produce rapid rusting of 
 iron there must be present oxygen, water, and carbonic acid ; and 
 as all these are present in a boiler flue when there are leaks, it is not 
 surprising that so many cases occur of explosions from corrosion. 
 
 Much mischief is often done by the injudicious use of compositions 
 in the boiler that are designed to prevent incrustation, especially 
 where there is no blow-off cock or where its use is neglected. A 
 hard deposit on the boiler plates is, in the writer's opinion, not so 
 injurious as the soft and muddy deposit produced by the use of such 
 compositions. A hard scale is equivalent to thickening the plate ; 
 and although this is sufficiently mischievous, the injury to the plates 
 is much more rapid when a thicker but spongy deposit entirely 
 prevents contact of the water and impedes the transmission of the 
 heat. An attempt to illustrate this is given in Fig. 58, which is an 
 enlarged view of a portion of such a boiler as is shown in Fig. 37.
 
 BOILER EXPLOSIONS. 
 
 87 
 
 The money spent in boiler compositions would be better applied in 
 securing a supply of proper water, or in filtering and purifying the 
 water before it enters the boiler. 
 
 Fig. 58. 
 
 The writer has had to mention only faults in boilers ; but it is 
 not to be inferred that all boilers are working in actual danger. 
 A very small percentage perhaps are so ; but without periodical 
 examination no one can feel sure of the condition of any boiler. It 
 is not likely that explosions in future will be from exactly the same 
 causes as those now described, because the known faults will be 
 avoided. For instance no new Balloon, Wagon, or Butterley boilers 
 are now made ; and the peculiar faults and the weakness of the 
 tubes in Cornish and others of the better classes of boilers are now 
 so well known as to be generally avoided ; and as information 
 spreads, many evils will become things of the past. 
 
 As periodical examination has been so strongly advocated, it 
 might seem natural to desire that it should be enforced by 
 government authority ; but this is by no means recommended. A 
 select parliamentary committee has been recently investigating the 
 subject, with a view to ascertain whether that would be desirable, but 
 has adjourned for the session without coming to any decision on this 
 point. Even if a perfect system of government inspection could be 
 contrived and perfectly administered, it would have the effect of 
 taking the responsibility from the owners, who are the natural 
 guardians of the safety of their boilers. Although the loss of 70 lives 
 per annum by boiler explosions is sufficiently deplorable, the deaths 
 by railway accidents are more than three times that number ; yet
 
 88 BOILER EXPLOSIONS. 
 
 very little inspection of railways is held to be necessary, and that 
 inspection takes place chiefly before the commencement of working or 
 after accidents, A coercive system may introduce more evils than it 
 cures, especially as at present so much difference of opinion exists 
 respecting the causes of boiler explosions. In the opinion of the 
 writer, far more real good arises from the calm discussion of the 
 facts and from the spread of correct information by such societies as 
 this Institution, than from enforcing by law any action which is not 
 perhaps believed by the majority of steam users to be at all necessary 
 or useful. It has been at times suggested to increase the power and 
 responsibility of coroners in holding inquests upon those killed by 
 boiler explosions, by requiring them to obtain scientific evidence 
 and to insist that the causes of the explosions shall be added to the 
 verdicts of juries. But it is believed that this would only encumber 
 an important institution, because a jury who might well decide 
 whether a person had been killed by any criminal carelessness would 
 not be a suitable tribunal to decide between possibly conflicting 
 scientific evidence ; and also, as an inquest may result in a verdict of 
 manslaughter, the eliciting of information on such an occasion is 
 checked by the natural fear of inadvertently involving some one in 
 BO serious a charge. The public at large, and steam users generally, 
 would gain more information and guidance from the scientific evidence 
 itself than from the verdict of a coroner's jury ; and it is believed 
 much good has resulted in preventing locomotive boiler explosions by 
 publishing the reports of the government inspecting engineers, who 
 have gained their knowledge of the facts in conversation with all 
 those concerned, and have added recommendations which have been 
 promptly acted upon. 
 
 The writer's object has been that the boilers found most 
 convenient and best suited for the different purposes for which they 
 are used should be made to work with safety, rather than that 
 reliance should be placed upon the qualities of any particular kind of 
 boiler or fittings. No form of boiler at present admits of absolute 
 reliance upon its freedom from risk. 
 
 The following general conclusions appear to arise from the 
 consideration of the records of boiler explosions.
 
 BOILEE EXPLOSIONS. 89 
 
 1 . That the force accumulated in an ordinary boiler is enough to 
 account for the violence of an explosion. 
 
 2. That no form of boiler, however -well constructed and fitted, 
 is free from the liability to explosion, if allowed to get out of order ; 
 and that boilers which bear the hydraulic test may still be dangerous. 
 
 3. That the condition of a boiler can be satisfactorily ascertained 
 only by periodical examinations, and that no boiler should work 
 without being thoroughly examined at short intervals. 
 
 4. That the cost of periodical examination is so little as to be far 
 outweighed by the greater security obtained ; and that the settings 
 of all boilers should be constructed with, a view to facilitate 
 examination. 
 
 5. That the surest way to make systematic examination general 
 is to spread as widely as possible correct information as to the facts 
 and ascertained causes of boiler explosions, and to inform boiler 
 owners and minders what dangers to guard against ; and that this 
 is preferable, and more likely to lessen explosions than enforcing 
 any system of inspection by legal enactment.
 
 90 
 
 BOILEE EXPLOSIONS. 
 
 
 Si 
 
 l-q 
 
 PH 
 
 .a. 
 
 
 3 
 
 ooooocor-icooao^ 
 
 ,_ 
 
 II 
 
 1 
 
 I CO C* rH rH * 
 
 o 
 
 
 1 
 
 
 co 
 
 H ~ 
 
 
 0? CS rH rH ! 
 
 t- 
 
 W ^D 
 
 co cy o 
 
 3 5 
 
 fa 
 
 
 
 H P 
 
 i 
 
 1 
 
 rH r-( CJ 
 
 00 
 CO 
 CJ 
 
 e ' 
 
 i 
 
 t- OO t^ O CO CO CZ) 
 
 I O 
 CO 
 
 5 1 
 
 H 
 
 I-l 
 
 
 
 1 s 
 
 > 
 
 "5 00 CO C* t- -d 10 
 
 
 .5 CO 
 
 ' 
 
 CO CO ^^ ^H J'* 
 
 Ml 
 
 00 
 
 i 
 
 ^ 
 
 CO 
 
 fl 1 ~ l 
 
 O ID 
 
 fa 
 
 
 
 S g 
 
 3 
 
 .- 
 
 
 
 "s* a 
 
 'S 
 
 rH CO TH O i-H O* 
 
 a> 
 
 rH 
 
 " 
 
 a 
 
 
 
 
 to 
 
 CD 
 00 
 
 1 
 
 030030303 
 
 
 
 rH 
 
 O 
 
 EH 
 
 CO rH i-l rH CM 
 
 
 
 a 
 
 
 
 
 1-3 
 
 
 
 
 s 
 
 & 
 
 CO i-H C< 0* rH C5 
 
 ^ 
 
 
 "3 
 
 O Of 
 
 c 
 
 
 
 S 
 
 CJ 
 
 CO 
 
 _o 
 
 rf3 
 
 
 
 J 
 
 t 
 
 
 
 O5 
 
 & 
 
 p 
 
 rH rH c* 
 
 t- 
 
 H 
 
 fa 
 
 
 
 
 . i i . 
 ^O *^ 
 
 
 
 80 . . fcH . . 
 
 
 
 ^ >. 
 
 
 
 *J3 > i 
 
 
 
 -a - -e t E 
 
 
 
 O O 
 
 
 
 _2 *. c^ 
 
 
 jj 
 
 g 
 
 M 
 
 o 
 
 % s w 
 
 ^ -e j . J Jf . 1 
 
 * 8 3 ^ QJ o 
 
 OQ S ^1 - 
 
 
 
 
 
 1 
 
 "o "g 3^ t> ^ 
 
 
 
 
 
 
 * * -*j [^ * c3 ^2 * C 
 
 . 
 
 
 * M E fit H 
 
 
 
 F^4 1 HVJ * 
 
 
 
 '1 ''iJg'ijsT. 
 
 5 IJ '& I -Ef s 
 
 O j3 ^JJ .^ ^^ ^ o 
 
 ' 
 
 
 
 
 
 -s 1 & -} | S i 1 
 
 liliriiii 
 
 O 
 
 H
 
 BOILER EXPLOSIONS. 
 
 91 
 
 a> 'a 
 
 S 3 
 
 2 & 
 
 o 
 co 
 
 
 
 n 
 
 - 
 
 w 
 
 I 
 
 i 1 cs 
 
 .^, 
 
 il -P 
 
 I* 
 
 la
 
 92 BOILER EXPLOSIONS. 
 
 TABLE III. 
 
 Analysis of Steam Boiler Explosions in the United Kingdom 
 
 during the Four years ending 30th June, 1870, 
 showing the Causes of Explosion of Boilers of different descriptions. 
 
 A = Faults in construction or repair. 
 
 Q = Faults which should be detected by periodical examination. 
 C = Faults which should be prevented by careful attendants. 
 Q = Causes extraneous or uncertain. 
 E=number of Explosions. K= number of persons Killed. 1= number of persona injured. 
 
 CORNISH, LANCASHIRE, or other Boilers with internal flues. 
 
 E K I 
 (-Weak Tubes .. 26 17 41 
 
 I Weak combustion chambers 587 
 
 j "Weak ends . . 3 10 10 
 
 A 1 Weak dome . . 100 
 
 Weak manhole . . Ill 
 
 LEad repair .. 3 5 2 E K I 
 
 39 41 61 
 
 | External Corrosion . . 18 42 101 
 
 * Internal Corrosion . . 645 
 
 24 46 106 
 
 / Shortness of Water . . 14 11 23 
 
 C 1 Scale or mud . . 310 
 
 ( Undue Pressure . . 4 14 4 
 
 21 26 27 E K I 
 
 . 84 113 194 
 
 PLAIN CYLINDRICAL, or other Boilers without internal flues. 
 
 f Weak flat ends .. 8 9 12 
 
 Weak manhole .. 102 
 
 Frequent repair producing \ 
 A- "S seam rip in boilers with J 15 18 28 
 plates arranged lengthways ) 
 
 32 38 67 
 
 T. ( External Corrosion . . 
 ( Internal Corrosion . . 
 
 16 10 25 
 
 / Shortness of Water . . 210 
 
 C j Scale .. 110 
 
 ' Undue pressure . . 34 
 
 663 
 
 54 54 95 
 
 Carried forwards 138 167 289
 
 BOILER EXPLOSIONS. 
 
 93 
 
 MARINE BOILERS. 
 
 / Weak flues 
 A < Weak ends 
 ' Bad material 
 
 E K 
 3 6 
 
 2 6 
 1 3 
 
 Brought forwards 
 I 
 3 
 
 5 
 1 E K I 
 
 61 ^ Q 
 
 138 167 289 
 12 37 23 
 
 10 ft 14 
 11 20 29 
 
 8 40 27 
 226 
 
 T> f External Corrosion . . 
 ' Internal Corrosion 
 
 2 10 
 3 1 
 
 3 
 
 4 
 
 511 7 
 
 C Shortness of water 
 
 1 11 
 
 7 
 1 11 7 
 
 LOCOMOTIVE BOILERS. 
 A Boiler used as frame for engine 
 
 2 1 
 
 
 2 
 1 3 
 
 j, ( External Corrosion . . 
 ' Internal Corrosion 
 
 2 1 
 2 
 
 4 
 
 3 
 417 
 
 , Broken connecting-rod 1 i o 
 | pierced boiler . . j 
 
 | Dome caiight by rail way bridge 1 1 
 Uncertain causes . . 20 
 
 1 
 
 
 
 4 
 
 43 5 
 
 AGRICULTURAL BOILERS. 
 A Weak manhole 
 
 1 1 
 
 
 4 
 111 
 
 T> f External Corrosion 
 
 1 
 
 1 Internal Corrosion 
 
 Q f Shortness of water 
 ' Undue pressure 
 
 2 3 
 1 1 
 
 1 
 6 15 
 
 3 
 
 7 
 3 4 10 
 
 
 15 
 - - 7 15 15 
 
 FURNACE UPRIGHT BOILERS. 
 (Too much flame on one part 
 Frequent repair producing 1 
 seam rip J 
 
 1 2 
 
 1 13 
 
 
 
 
 2 
 2 15 
 
 -, , ( External Corrosion 
 i 
 1 Internal Corrosion 
 
 2 13 
 2 15 
 
 11 
 
 C 
 
 j OQ If 
 
 C Shortness of Water . . 
 
 2 3 
 
 8 
 3 8 
 
 ELEPHANT BOILERS. 
 A Weak ends or want of stays 
 
 l a 
 
 
 2 
 12.9 
 
 B External Corrosion . . 
 
 1 
 
 4 
 
 101 
 
 
 
 
 
 Carried forwards 181 277
 
 94 
 
 BOILER EXPLOSIONS. 
 
 CRANE BOILERS. 
 A Weak manhole 
 B External Corrosion . . 
 C Shortness of water 
 
 RAG STEAMERS, &c. 
 iWeak manhole 
 Bad material . . 
 Want of stays 
 
 C Undue Pressure 
 
 FEED-WATER HEATERS. 
 D Uncertain causes 
 
 DOMESTIC BOILERS. 
 A Weak shape 
 
 B Corrosion 
 
 C Undue Pressure from } 
 freezing of Pipes j 
 
 BALLOON BOILERS. 
 B External Corrosion 
 
 C Uudue Pressure 
 
 E 
 
 3 
 1 
 
 K 
 
 7 
 
 4 
 
 7 
 3 
 
 2 
 
 Brought forwards 
 
 E K I 
 373 
 
 143 
 
 220 
 
 6 4 10 
 126 
 
 206 
 
 181 277 386 
 6 13 5 
 
 6 10 
 2 
 
 14 U 21 
 322 
 
 7 6 12 
 
 2 
 
 3 
 1 
 1 
 
 2 
 
 2 
 1 
 
 1 
 
 
 
 5 
 5 
 
 
 1 
 
 2 
 
 6 
 
 2 
 
 
 
 6 
 
 3 
 2 
 
 9 
 
 4 
 
 
 7 
 
 7 
 
 
 
 9 
 
 3 
 2 
 
 9 
 
 2 
 1 
 
 4 
 
 
 7 
 
 1 
 1 
 
 7 
 5 
 
 9 
 
 2 
 
 
 2 
 
 1 
 
 2 
 
 1 
 
 1 
 
 
 
 BOILERS OF UNCERTAIN DESCRIPTION, 
 A Weak manhole . . 10 
 
 
 
 1 
 
 4 
 2 
 
 
 
 6 
 
 
 
 
 9 
 3 
 
 C Steam entered through blow- ) 
 | off pipe from another boiler > 
 p j while cleaning . . ) 
 
 j Steam pipes broken . . 
 ^Shortness of Water . . 
 
 P Uncertain causes 
 
 1 
 
 2 
 1 
 
 1 
 
 4 
 1 
 
 2 
 
 3 
 4 
 
 2 
 
 
 
 3 
 
 
 TOTALS 
 
 219 315 450
 
 BOILER EXPLOSIONS. 
 
 95 
 
 TABLE IY. 
 
 Summary of causes 
 of the Steam Boiler Explosions comprised in Table III. 
 
 
 E 
 
 K 
 
 I 
 
 Causes of Explosion. 
 
 Number 
 of 
 Explosions. 
 
 Number of 
 persons 
 Killed. 
 
 Number of 
 persons 
 Injured. 
 
 A Faults in construction or repair . 
 
 95 
 
 128 
 
 167 
 
 B Faults which should be detected by } 
 periodical examination . j 
 
 62 
 
 105 
 
 185 
 
 C Faults which should be prevented by 
 careful attendants . . } 
 
 54 
 
 79 
 
 84 
 
 Q Extraneous or uncertain causes . 
 
 8 
 
 3 
 
 14 
 
 Totals 
 
 219 
 
 315 
 
 450 
 
 
 

 
 BRIEF ABSTRACTS 
 
 FROM REPORTS ON 
 
 STEAM BOILER EXPLOSIONS, 
 
 PRESENTED TO THE 
 
 MIDLAND STEAM BOILER INSPECTION & ASSURANCE Co,, 
 
 EDWARD BINDON MARTEN, 
 
 CHIEF ENGINEER TO THB COMPANY. 
 
 Description is shortened as much as possible, and facilitated by 
 slight sketches, showing the position of the fragments or line of fracture, 
 and the general construction of the Boilers. 
 
 REPUBLISHED BY THE PERMISSION OF THE COMPANY. 
 
 STOtTRBRIDOE : B. BBOOMHALL, PRINTER, HIGH STREET. 
 1869.
 
 BOILER EXPLOSIONS IN 1866. 
 
 No. 1. Nottingham. January 1st. none injured. 
 
 Locomotive, 110 Ibs., standing with steam up near a platform. 
 All but the fire box was blown away, the main portion being thrown 
 a distance of 400 yards. The first rent took place at a longitudinal 
 seam of the barrel where grooving had gone on very rapidly, which 
 was not discovered when examined and tested a short time before. 
 
 No. 2. Walsall. (Fig. I.) January 2nd. 
 
 2 injured. 
 
 Fig. 1. 
 Butterley, 26ft. Gin. long, and 9ft. diameter. The waggon-shaped
 
 BOILER EXPLOSIONS IN 1866. 
 
 top to the fire place was 8ft. Gin. long, and was attached to the 
 bell-mouth of the internal tube, which then continued circular to the 
 back of the boiler. The tube was 3ft. Gin. diameter. All the 
 plates were about 7-16ths inch thick, and although the boiler was 
 an old one, they were nowhere reduced in thickness by wear. The 
 usual pressure of steam was 18 Ibs., and a self-registering guage 
 showed that at the time of explosion it did not exceed 20 Ibs. 
 
 The top of the fire grate on the right side rent longitudinally, and 
 the upper part of the shell consisting of four rings of plates, and 
 also the top of the fire place opened out and blew away to a 
 considerable distance. 
 
 The front end also blew away. The bell-mouth of the tube was 
 blown to the front, and the tube which remained in the back part of 
 the shell collapsed upwards. 
 
 The cause of the explosion was most likely the intrinsic weakness 
 of boilers of this shape, especially over the fire, where the top is 
 only retained in its shape by numerous stays. The boiler had been 
 very frequently repaired, at this the weakest place, and its strength 
 had been thus so reduced as to make it unable to bear even a few 
 pounds more than the ordinary working pressure. 
 
 The whistle was found to have been gagged by hemp, carefully 
 inserted, so that there is ground for supposing there had been 
 intentional unfair usage. 
 
 No. 3. Blyth. (Fig. 1.) January 8th. 1 killed 1 injured. 
 
 Fig. 2. 
 Marine, 20ft. long, and 5ft. diameter, with internal fire place and
 
 BOILER EXPLOSIONS IN 1866. 
 
 return flue, 14 Ibs. There were altogether three rents in the tube 
 over the fire, as a small band was held in its place by a stay from 
 the tube to the shell. The escaping contents scalded those near, but 
 no damage was done to anything but the boiler. 
 
 The cause was stated to be shortness of water. There was 
 no water guage. 
 
 No. 4. London. January 9th. 1 killed. 
 
 One tube Cornish, 28ft. long, 6ft. Gin. diameter, with one tube 
 3-6 diameter, f inch plates, 45 Ibs. 
 
 The tube collapsed in an incline direction from weakness without 
 strengthening rings. 
 
 The appearance after explosion was nearly the same as that shown 
 in sketch given at No. 12 explosion. 
 
 No. 5. Glasgow. (Fig. 3.) January 13th. 
 
 4 killed, 4 injured. 
 
 Pig. 3. 
 
 Two tube Cornish, 22ft. Sin. long, and 7ft. Tin. diameter, f inch 
 plates, tubes 2ft. Tin. diameter, 40 Ibs. 
 
 About 8ft of the back portion of the shell was torn off, leaving 
 the tubes and ends intact. 
 
 The cause of the explosion was considered to be excessive pressure, 
 but how accumulated did not transpire. 
 
 It is most natural to expect that there must have been corrosion 
 under the bottom to cause the first rent.
 
 BOILER EXPLOSIONS IN 1866. 
 
 No. 6. Coatbridge. January llth. 
 
 Cornish. No details have been obtained. 
 
 1 injured. 
 
 No. 7. York. (Fig. 4.) January 18th. 
 
 1 killed, 2 injured. 
 
 ... J 
 
 Fig. 4. 
 
 Agricultural, 8ft. 2in. long, 3ft. Gin. diameter in the barrel, 
 5-16ths inch plates, internal fire box, 2ft. 4in. wide, 2ft. 4in. high, 
 and 2ft. lOin. deep. From the back of this fire box, two 12-inch 
 tubes passed to an internal chamber at the back of the barrel. 
 From this again passed nine 3f inch tubes to an exterior smoke-box 
 fixed over the fire door. The boiler was fitted with one spring safety 
 valve, which was screwed down tight, but there was no pressure 
 guage. The front plate was intended to be bolted on so that the 
 fire-box and tubes could be taken out for cleaning, but it had been 
 rivetted, leaving no means of cleaning, and it was nearly full 
 of scurf. 
 
 The crown plate of fire-box which was too flat and unstrengthened, 
 rent at the front and along both top edges, and was driven into the 
 fire. The boiler was thrown backwards and reared against a wall, 
 resting on the front right hand corner. 
 
 The cause of the explosion was that the very dirty state, caused 
 overheating where the water was not in proper contact with the 
 plates, and the defective construction did not admit of proper 
 cleaning. The mountings were insufficient for the proper protection 
 of the boiler.
 
 BOILER EXPLOSIONS IN 1866. 
 No. 8. Durham. (Fig. o.) January 29th. 1 killed, 3 injured. 
 
 Plain Cylinder Boiler with hemispherical ends, 30ft. long and 6ft. 
 diameter, f inch plates, 30 Ibs. It was the second from the engine 
 in a bed of five, and had been at work three years, then remained 
 idle for eight years, working again fourteen years. The boiler was 
 mounted with two safety valves 3f and 4 inches diameter, a float 
 and alarm whistle. The boiler had been more than once repaired 
 over the fire with several new plates. One seam over the fire had 
 been observed to leak about a week before the explosion, but not 
 seriously, and had been caulked. The boiler had just been started 
 after cleaning. Six months before explosion, the boiler had been 
 tested to 69 Ibs. 
 
 About 5 feet of the front end of the boiler opened out flat, and 
 was thrown to the rear about 60 yards ; the front hemispherical end 
 was liberated and thrown 20 yards also to the rear and right hand. 
 The back part of the boiler was thrown in a mass, and after 
 bounding twice, lodged at a distance of 230 yards. 
 
 The cause of the explosion appeared to be from the failure of a 
 seam over the fire place in a plate deteriorated by age, and over- 
 heated through a deposit of scurf and mud.
 
 BOILER EXPLOSIONS IN I860. 
 No. 9. Birmingham. (Fig. 5.) February 7th. 1 killed, 4 injured. 
 
 Fig. 5. 
 
 Plain Cylindrical Boiler, with hemispherical ends, 23ft. long, and 
 5ft. diameter, f inch plates, 50 Ibs. It was set so as to be fired 
 under the bottom if required, but the grate was seldom used. The 
 principal heat was supplied from a mill furnace, the neck of which 
 was at the left hand of the bacfc, and the flame was carried by a 
 wheel flue round the front of the boiler to the stack on the right 
 hand side of the back. The boiler was fitted with a 4|-inch safety 
 valve, and also a float, but it was suspected that the latter had 
 broken from the rod. 
 
 A horizontal seam about the middle of the left hand side had 
 given way, and the upper portion of the 3rd and 4th rings of plates 
 had spread out like a lid without being detached from the boiler. 
 The front end became detached and was thrown some distance to 
 the front. 
 
 The cause of explosion was, that the left side of the boiler became 
 overheated, and so much softened, that it first bulged outwards with 
 the ordinary working pressure, and then rent open. The over-heating 
 was most likely the result of shortness of water, but it might possibly 
 have been in consequence of the intense heat of a mill furnace 
 impinging on a small area so near the water line, leading to such 
 rapid ebullition as to prevent sufficient contact of the water to keep 
 the plates cool.
 
 BOILER EXPLOSIONS IN 1866. 
 
 No. 10. Dunse. February 14th. 1 injured. 
 
 Locomotive. It exploded while standing in a shed, but no 
 particulars have been obtained. 
 
 No. 11. Middlesbro'. February 26th. 1 injured. 
 Marine, in a small tug boat, but no details have been obtained. 
 
 No. 12. Gainsbro' (Fig. 7) February 26th. 1 injured. 
 
 Fig. 7. 
 
 One Tube Cornish, 21ft. long, 5ft. diameter, with one tube 
 2ft. llin. diameter, plates f inch, 64 Ibs. There were no strength- 
 ening rings on the tube. The boiler was second-hand, and had only 
 worked a part of a day at its new position when it exploded. 
 
 The tube collapsed from weakness without strengthening rings. 
 
 No. 13. Redruth. (Fig. 8.) March 3rd. 1 killed. 
 
 Fig. 8. 
 
 One Tube Cornish, 31ft. 9in. long, and 5ft. 9in. diameter, tube 
 3ft. Sin. diameter, inch plates, 40 Ibs. 
 
 The tube had been repaired with a bolted patch on the left side 
 the day before the explosion, and it is presumed it was slightly out 
 of the circular shape, as it collapsed sideways, the top being thrown
 
 BOILER EXPLOSIONS IN 1866. 
 
 up above its proper height. There was no evidence of shortness 
 of water. 
 
 The tube without strengthening rings was too weak to sustain 
 the ordinary working pressure. 
 
 No. 14. London. March 5th. 7 injured. 
 
 Cornish, at 27 Ibs., but as the boiler was not injured, it is only 
 noticed as an explosion, because of the imprudence of placing 
 fittings in such dangerous positions. The boiler was beneath a work 
 room, and the lever of the safety valve became displaced, allowing 
 the valve to blow out, and the escaping steam rushed into the room 
 above and scalded seven men very badly. 
 
 No. 15. Manchester. March 6th. 1 kitted. 
 
 This was a Boiler with two internal fireplaces, connected into one 
 flue at the back. 
 
 The crowns of both furnaces were collapsed, and slightly rent, 
 and the escaping steam and water scalded the attendant. 
 
 The water was 8 or 9 inches below its proper level, allowing the 
 furnace crowns to become overheated and unable to bear the 
 working pressure. 
 
 Each furnace had been fitted with a fusible plug, but they 
 proved inefficient. 
 
 No. 16. Norwich. (Fig. 9.) March 13th. 1 killed, 1 injured. 
 
 Fig. 9. 
 
 This was a very small boiler, 8ft. long, and 3ft. 2in. diameter, 
 with two small tubes. It was fired externally.
 
 BOILER EXPLOSIONS EN 1866. 
 
 The dome was blown off and the rents continuing, the top opened 
 out on each side, and the upper portion of both back and front 
 was bent back. 
 
 The dome cut away the whole of the top plate, and so much 
 reduced the strength that it would not bear the ordinary working 
 pressure. 
 
 No. 17. Dudley. (Fit/. 10.) March IQth. none injured. 
 
 Fig. 10. 
 
 Plain Cylinder Boiler, 36ft. long, 5ft. Gin. diameter, 60 Ibs. 
 It had frequently been repaired over the fire, so that the longitudinal 
 seams ran for several plates without break of joint. A patch 
 had been put on a few days before explosion, and as the rivet holes 
 had badly fitted, there had been much strain caused by drifting, 
 and the rivets were much distorted. 
 
 A longitudinal searn gave way over the fire, when two rings of 
 plates opened out, rending the transverse seams at each side until 
 completely separated, and fell in two parts at a distance of about 
 100 yards in front of the boiler The front end was liberated and 
 fell in one piece about 100 yards beyond the two pieces of the shell. 
 The main body of the boiler was driven back a few yards and 
 rolled over so as to be up-side down, but was little injured. 
 
 The frequent and badly executed repair over the fireplace, had 
 so weakened the structure as to make it unable to bear the very 
 high ordinary pressure. This frequent repair over the fireplace 
 had been made necessary by very hard firing and deposits of scurf 
 from muddy water, preventing the proper contact of the water with 
 the plates.
 
 BOILEE EXPLOSIONS IN 1866. 
 
 No. 18. Liverpool. March 22nd. 1 killed. 
 
 This was a small Boiler to supply steam for some steam winches 
 on board a steam boat, and exploded from the overheating of the 
 upper tubes through shortness of water, or from over pressure in 
 consequence of having only one safety valve. 
 
 No. 19. Leeds. (Fig. 11.) March 21th. 2 killed, 18 injured. 
 
 Fig. 11. 
 
 Two Tube Cornish, 24ft. 6in. long, 6ft. 6in. diameter, tubes 
 2ft. 6in. diameter, f inch plates, 54 Ibs., fitted with steam guage, 
 blow-off cock, 1 inch dead weight safety valve, loaded to 54 Ibs., 
 and 4f inch lever safety valve, loaded to 62 Ibs., and had been at 
 work about five years. 
 
 Nearly the whole of the two back rings of the shell were torn off 
 and opened out, and the boiler was turned partly round, and moved 
 upon its seat sideways and forwards. 
 
 There was extensive corrosion at the under side of the back of 
 shell, where the first rent took place, caused by the leaking of the 
 joints and seams. 
 
 No. 20. Swansea. (Fig. 12.) April 4M. 5 killed, 4 injured. 
 
 One Tube Cornish Boiler, 30ft. long, and 7ft. diameter, tube 
 slightly oval about 4ft. diameter, -j 7 g- inch plates, 43 Ibs., fitted with 
 3 inch safety valve, which is much too small for such a boiler, 
 glass water guage, two guage cocks, and pressure guage.
 
 BOILER EXPLOSIONS IN 1866. 
 
 The tube collapsed from end to end. The front end was blown 
 out with a short length of the tube attached, and was driven against 
 
 Fig. 12. 
 
 a wall about 30 yards to the front. The main body of the shell, 
 and the back end, with the collapsed tube within it, were driven 
 back against another wall, about the same distance away. Very 
 great damage was done to the surrounding property. 
 
 The cause of the explosion was the weakness of the tube of so 
 large a diameter, without strengthening rings, which made it unable 
 to bear the ordinary working pressure. It is very probable, 
 however, that at the time of the explosion, the pressure was con- 
 siderably more than usual during the stoppage of the engine, and 
 the confusion caused by a man becoming entangled in the machinery. 
 
 No. 21. Morpeth. April Wth. 1 killed. 
 
 Plain Cylinder Boiler, 34ft. long, and 5ft. diameter, f inch plates 
 placed lengthways, 33 Ibs. 
 
 The explosion took place at a seam in the front part of the bottom 
 of the boiler just over the fire. This rupture allowed the sides to 
 to expand, until the boiler was completely destroyed and torn into 
 seven pieces. 
 
 The cause of the explosion was supposed to be the defective state 
 of the seams over the fire, which, being place longitudinally, were 
 in the weakest position.
 
 BOILER EXPLOSIONS IN 1866. 
 No, 22. Shiffnal. (Fig. 13.) April 2\st. none injured. 
 
 Fig. 13. 
 
 Two Tube Cornish, 15ft. long, 6ft. diameter, tubes 1ft. Sin. 
 diameter, f inch plates, 40 Ibs. The heat was supplied by two 
 furnaces, one of which played into each tube. 
 
 The left hand tube collapsed from shortness of water, and tore 
 away from the angle iron iu. the front plate, and allowed the 
 contents to issue violently and scatter the brickwork, but the boiler 
 was not disturbed. 
 
 No. 23. Burnley. April 26th. 2 killed, 2 injured. 
 
 Small internally fired Boiler, 5ft. high, 2ft. 4in. diameter, and 
 was intended to work at 70 Ibs. The fittings were defective, the 
 spiral spring of the safety valve being most easily altered, so as to 
 cause over pressure. The manhole was not strengthened by any 
 ring, and the first rents commenced at that point. 
 
 The cause of the explosion was over pressure and defective 
 construction. 
 
 The sketch at No. 57 explosion in this year, is of a similar boiler 
 which exploded from nearly similar causes. 
 
 No. 24. Bilston. (Fiy. 14.) May 13th. none injured. 
 
 Balloon or Haystack Boiler, about 16ft. diameter, T 5 ff inch plates, 
 and worked at very little above atmospheric pressure. 
 
 The boiler was chiefly used to store water during the time another 
 boiler by the side of it was emptied. When the water was required 
 to refill the other boiler, a fire was lighted under the balloon, and 
 sufficient steam generated to drive the water from it into the other 
 boiler. The safety valve never being used, it had become fast, and
 
 BOILER EXPLOSIONS IN 1866. 
 as a little more steam than usual had accumulated, the bottom gave 
 
 Fig. 14. 
 
 way, and the reaction of the issuing contents made the boiler rise 
 from its seat, and it fell on its side at some distance away flattened 
 by the fall. 
 
 No. 25. Westbrotntcich. (lig. 15.) May 25th. none injured. 
 
 Fig. 15. 
 
 One Tube Cornish Boiler, 15ft. long, and 4ft. Gin. diameter, taper 
 tube, 2ft. 9in. diameter in front, and 2ft. diameter at back, f inch 
 plates, 40 Ibs. The boiler rested on two walls forming the bottom 
 flue. There was a safety valve, a glass water guage, a pressure 
 guage, and two fusible plugs upon the tube. 
 
 Two longitudinal rents took place on the under side of the shell, 
 allowing two strips, forming the central part, to open out by the 
 continuation of the fracture, until they were blown to a considerable
 
 BOILER EXPLOSIONS IN 1866. 
 
 distance. The tube with the front end, and one ring of the shell 
 were thrown to the front, while the back end was thrown to the 
 rear, the smallest end of the tube having torn away from the back. 
 The shell was deeply corroded where it rested on the side walls 
 of the bottom flue, and the strength of the boiler was thereby so 
 much reduced, that it was unable to bear the ordinary working 
 pressure. 
 
 No. 26. Halifax. (Fig. 16.) May 26th. 1 Mkd. 
 
 Fig. 16. 
 
 One Tube Cornish, 24ft. 6in. long, and 5ft. diameter, taper tube, 
 slightly oval in the front, 2ft. Sin. diameter, and 2ft. diameter at 
 the back, f inch plates. The boiler was fitted with glass water 
 guage, float, self-acting feed apparatus, and safety valve loaded to 
 52 Ibs., and also a mercury guage. 
 
 The tube collapsed over the fire, a rent taking place in the second 
 ring of plates. The issuing steam and water caused the death of a 
 man in front, but the shell of the boiler was not injured or moved. 
 
 The cause of the explosion was shortness of water, and as the 
 glass guage was set unusually low, the man in charge may have 
 been deceived. The oval shape of the fireplace, and the laminated 
 iron, as shown in the fracture, rendered the tube peculiarly liable 
 to collapse. 
 
 No. 27. Durham. May 26t?i. 1 killed. 
 
 Plain Cylinder Boiler, 34ft. long, 5ft. diameter, f inch plates, 
 45 Ibs., fitted with two 5-inch safety valves, and 2 floats. 
 
 The boiler was torn in two pieces, that were thrown to a con- 
 siderable distance. The first rent had taken place immediately 
 over the fire.
 
 BOILER EXPLOSIONS IN 1866. 
 
 The cause of the explosion was the weakening of the shell by 
 frequent repair over the fire, rendered necessary by the deposit from 
 the muddy water preventing proper contact of the water with 
 the plates. 
 
 No. 28. Durham. May 21th. I killed. 
 
 Plain Cylinder Boiler, 32ft. long, 6ft. diameter, -f inch plates, 
 35 Ibs., fitted with two safety valves, two floats, and two alarm 
 whistles. 
 
 The boiler was lifted from its seat, and one end was separated 
 and thrown to a considerable distance. 
 
 The cause of the explosion was weakening of the shell from 
 repair a few days before, and perhaps over pressure, as the guage 
 was found some time after, and indicated that the pressure had at 
 some time exceeded 80 Ibs. 
 
 No. 29. Redruth. May 28th. 1 killed, 4 injured. 
 
 One Tube Cornish, 30ft. Sin. long, 6ft. Sin. diameter, tube, 4ft. 
 diameter, T 7 ff inch plates, 40 Ibs. 
 
 The tube collapsed, and rent, and the issuing steam and water 
 scalded those near, as it was too weak to bear the ordinary 
 working pressure. 
 
 No. 30. Leicester, (fig. 17.) May 3lst. 1 killed, 1 injured. 
 
 Fig. 17. 
 
 Plain Cylinder Boiler, with dished ends, and only 4ft. 2in. long, 
 and 2ft. 6in. diameter, inch plates. It was most inefficiently 
 mounted, the safety valve was only l-inch diameter, and of such
 
 BOILER EXPLOSIONS IN 1866. 
 
 faulty construction, that it would not open under a pressure of 
 162 Ibs. There was no steam guage or float, and the guage cocks 
 were defective. There was no means of putting water in the boiler 
 when there was a pressure of steam. The manhole was very large 
 for so small a boiler. 
 
 Four rents started from the manhole and continued along the top 
 of the boiler and round the end seams. A tongue-shaped strip of 
 the top plate was attached to the back end plate ; two strips about 
 a foot wide on either side were blown away. The boiler had been 
 turned nearly round in its flight, and fell with the back about 
 12 feet from the original position of the front. 
 
 The boiler was worked until it was nearly dry, and, during a 
 temporary stoppage of the engine, an accumulation of steam caused 
 a greater pressure than the boiler could bear. 
 
 No, 31. Newcastle. June 1th. none injured. 
 
 Marine Boiler in a Tug Boat. 
 
 The boiler was blown completely out of the vessel, and the 
 greater part of it fell into the water, and a large piece alighted on 
 a crowded quay, but without doing any damage. 
 
 The cause of the explosion was supposed to be over-pressure 
 during a temporary stoppage of the engine. 
 
 No. 32. Barnard Castle. (Fig. 18.) June llth. 
 
 2 injured. 
 
 Fig. 18. 
 Agricultural, of about 7 horse power. The barrel of the boiler
 
 BOILER EXPLOSIONS IN 1866. 
 
 was 6ft. lin. long, 2ft. Sin. diameter the fire-box end was 3ft. 
 wide, and 2ft. 4in. deep ; the fire-box was 2ft. 5 Jin. wide, and 
 2ft. Tin. high, and 1ft. 9Jin. deep, with 23 tubes passing from it 
 through the barrel to the smoke box and chimney. The boiler was 
 fitted with a 2in. safety valve, which was intended to blow at 45 Ibs., 
 but as there was no ferrule, it is supposed to have been screwed 
 down to a much greater pressure. 
 
 The upper portion of the shell over the fire-box rent through the 
 manhole, and allowed the shell to open out and fall on each side. 
 A large portion of the front plate was also torn off. 
 
 The cause of the explosion was the weakness of the manhole, 
 which was not strengthened by any ring, and also excessive pressure 
 from want of proper safety valve. 
 
 No. 33. Breage. June llth. 1 killed. 
 
 Cornish Boiler, 36ft. 6in. long, and 6ft. diameter, inch 
 plates, 45 Ibs. 
 
 The tube collapsed and rent, and the issuing contents caused the 
 death of the attendant. 
 
 The weak tube of such large diameter, \vas unable to bear the 
 ordinary working pressure, having no strengthening rings. 
 
 No. 34. Nottingham. June 19th. 2 killed, 4 injured. 
 
 Locomotive, inch plates, 140 Ibs. 
 
 The explosion occurred at the left hand side of the ring of plates 
 in the barrel next the fire-box, and below the foot-plate. The rent 
 tore along the edge of the lap and into the next ring of plates. 
 The reaction of the issuing contents threw the engine off the rails. 
 
 The cause of the explosion was partial corrosion at the point of 
 rupture and strain of the plates, as the boiler itself formed part of 
 the frame of the engine. 
 
 No. 35. Richmond. June 26th. 2 injured. 
 
 Locomotive, being tried for the first time. The funnel came in 
 contact with a bridge, and the dome was also torn off.
 
 BOILER EXPLOSIONS IN 1866. 
 
 No. 36. Gainsbro' June 29th. none injured. 
 
 No details have been obtained. 
 
 No. 37. Durham. July 2nd. 4 killed. 
 
 Plain Cylindrical Boiler, 30ft. long, and 6ft. diameter, f inch 
 plates, 28 Ibs. It had been repaired a short time before the 
 explosion, with 5 new plates. 
 
 The boiler was torn up into several pieces, but the main portion 
 remained flattened out on the seating, while some smaller pieces 
 were sent 250 yards away. 
 
 The cause of the explosion was the deterioration of the boiler, 
 and its frequent repair over the fireplace. 
 
 No. 38. Liverpool. June 12th. 4 injured. 
 
 Elephant Boiler, 20ft. long, and 4ft. diameter, g inch plates, and 
 worked at low pressure. The bottom shell had a tube through its 
 whole length. 
 
 A rent took place in the lower part of the fireplace, and extended 
 along the bottom, and the reaction of the issuing contents caused 
 the top to rear up. 
 
 The cause of the explosion was supposed to be that the bottom 
 plates were worn too thin to bear the ordinary pressure. 
 
 No. 39. Sheffield. July 4th. none injured. 
 
 Two Tube Cornish Boiler, externally fired, 30ft. long, and 6ft. 
 diameter, inch plates, 40 Ibs. 
 
 The second seam over the fire gave way, and the plate sank down 
 upon the fire, 
 
 The cause of the explosion was the deterioration of the seams 
 over the fire, in consequence of the deposit of scurf which could 
 not be properly cleared off owing to the internal tubes. 
 
 No. 40. Oldham. July 14th. none injured. 
 
 Boiler, with two internal furnaces, 9ft. Gin. long, and 2ft. llin. 
 diameter, g inch plates, uniting into one tube beyond.
 
 BOILER EXPLOSIONS IN 1866. 
 
 The furnace crown collapsed near the front of the boiler. 
 
 There was an extra weight upon the safety valve, and the steam 
 valve was left closed, so that more pressure accumulated than the 
 boiler could bear. 
 
 No. 41. Oxford. July 23rd. 3 injured. 
 
 Rag Boiler, not used for the generation of steam. It was a plain 
 cylinder, with hemispherical ends, about 16ft. long, and 7ft. diameter. 
 There was a neck at each end upon which the boiler revolved, and 
 through one of these the steam was admitted to a pressure of 30 Ibs., 
 in order to assist in cleaning the rags. There was a large manhole 
 for filling and emptying. 
 
 The boiler rent in the middle, and each half was blown to 
 some distance. 
 
 The manhole was so large, that the strength of the boiler was too 
 much reduced, and the constant strain of revolving caused a central 
 seam to give way at the ordinary pressure. 
 
 The sketch to No. 63 is of a similar boiler. 
 
 No. 42. Tumtall. (Fig. 19.) July 28tJi. 
 
 2 killed, 7 injured. 
 
 Tig. 19. 
 
 Boiler, 3Gft. Gin. long, and 8ft. 9in. diameter, J s inch plates, with 
 flat back and hemispherical front end, 36 Ibs. A tube 3ft. 3in. 
 diameter, passed from the back end nearly to the front, and returned
 
 BOILER EXPLOSIONS IN 1866. 
 
 to the back end, but of 6 inches less diameter and then passed to an 
 iron chimney. The fire grate was beneath the hemispherical end. 
 
 The angle iron of the flat back end gave way, and separated from 
 the shell and with the tubes attached was blown to a good distance, 
 and the reaction drove the shell far in the opposite direction. 
 
 The cause of the explosion was the bad construction of the boiler, 
 as the back end was quite unsupported, as there were no stays, and 
 the bend of the tubes was not attached to the shell. 
 
 An adjoining boiler which was being cleaned inside by two men, 
 was rolled off its seat by the force of the explosion. 
 
 No. 43. Widnes. August 2nd. 2 killed, 6 injured. 
 
 Plain Cylindrical Boiler, with flat ends, 23ft. long, 5ft. Sin. 
 diameter, inch plates, 40 Ibs. 
 
 Both the flat ends were blown out, and the first ring of plates at 
 the front end torn off. 
 
 The cause of the explosion was the weakness of the flat ends 
 without stays. 
 
 No. 44. Sunderland. August 1th. 1 killed, 3 injured. 
 
 Locomotive, 13ft. 4in. long, 3ft. llin. diameter, with 140 2-in. 
 tubes. The fire-box was 4ft. 5in. long, 3ft. Gin. broad, and 5ft. deep, 
 and made of copper, inch thick, 100 Ibs. It was fitted with two 
 4-in. safety valves, and a steam guage. 
 
 The fire-box gave way about the middle of the left side, 2ft. Gin. 
 below the water line, where corroded to J inch, and the issuing water 
 and steam scalded those near. 
 
 No. 45. Runcorn. (Fig. 20.) August 22nd. 3 killed, 5 injured. 
 
 Fig. 20.
 
 BOILER EXPLOSIONS IN 1866. 
 
 Marine Multitubular, 5ft. Sin. long, and 6ft. 6in. diameter, with 
 two internal tubular furnaces, which joined to an internal chamber 
 of large size, and small tubes passed to a smoke box and chimney in 
 the front over the fire doors. Both ends were flat. 
 
 The flat back end was insufficiently stayed, and was blown 
 completely out and torn into two pieces, the lower portion remaining 
 in the vessel, and the upper part falling in the water, and the 
 reaction of the issuing contents caused the boiler to be thrown on to 
 the side of the quay. 
 
 No. 46. Hull. (Fig. 21.) August 25th. 1 injured. 
 
 Fig. 21. 
 
 One Tube Cornish, 24ft. Sin. long, and 6ft. diameter, taper tube 
 3ft. 5in. diameter, for about 7ft. Gin. in length, and 2ft. Gin. diameter 
 for the rest of the length, 33 Ibs. 
 
 The tube was much corroded, and the fireplace gave way on left 
 side, and was so much torn, that the plates were forced out of 
 the front. 
 
 No. 47. Morecomle. August 21th. 3 killed, 1 injured. 
 
 Marine, of the usual construction, and had been tested to 60 Ibs. 
 
 It gave way at the lower portion of the back, and the issuing 
 steam and water scalded those near. 
 
 A seam rent, 6ft. Gin. long, had not been detected by testing. 
 
 No. 48. Tuddenham. August 29th. 2 killed, 2 injured. 
 
 Agricultural. It burst during a temporary stoppage from accumu- 
 lation of steam, causing undue pressure.
 
 BOILER EXPLOSIONS IN 1866. 
 
 JVb. 49. Glasgow. August 31st. 3 killed, 6 injured. 
 
 Upright Boiler, 36ft. high, 5ft. Gin. diameter, T 7 5 inch plates, 
 45 Ibs. 
 
 The bottom gave way from shortness of water, and the main bulk 
 of the boiler was thrown straight up into the air to a great height, 
 but descended again on its seating. 
 
 No. 50. Chatham. (Fig. 22.) September 1th. 2 killed, 30 injured. 
 
 Two Tube Cornish, 22ft. long, 7ft. Gin. diameter, with tubes, 
 3ft. diameter, J s inch plate, 60 Ibs.
 
 BOILER EXPLOSIONS IN 1866. 
 
 Some rents took place at the under side of the shell, allowing the 
 central portion to open out and blow away. The portion containing 
 the dome was thrown to the left, and the other to the right. The 
 front end, with 3 rings of the shell, with the tubes and back end, 
 were but little moved from their original position. The tubes were 
 dented in on the top and bottom, by the fall of some large coping 
 stones upon them, but the crowns of the furnaces were uninjured, 
 and there was no sign of shortness of water or overheating. 
 
 Extensive corrosion on the under side of the shell, where it rested 
 on the brickwork, had so reduced the strength, that it was unable 
 to bear the working pressure. 
 
 In the sketch the fragments are drawn so as to show their position 
 when in the boiler. 
 
 No. 51. Newark. September 21st. none injured. 
 
 One tube Cornish. The tube collapsed from shortness of water, 
 and the escape of the steam and water blew off the door frame. 
 
 No. 52. Ashton. September 23rd. 1 injured. 
 
 Plain Cylindrical Boiler, 7ft. long, and 2ft. diameter, f inch plates, 
 30 Ibs. 
 
 The upper part of the boiler at the first ring of plates was torn 
 off, and the front end was blown out. 
 
 Extensive external corrosion, where the plates rested against the 
 brickwork, rendered the boiler too weak to bear the ordinary 
 pressure. 
 
 No. 53. Norwich. (Fig. 23.) September 25th. 1 kitted. 
 
 Fig. 23. 
 One Tube Cornish, 20ft. long, 4ft. Gin. diameter, tube 2ft. 6in.
 
 BOILER EXPLOSIONS IN 1866. 
 
 diameter, inch plates, 100 Ibs. It was double-rivetted, and the 
 crown of tube was strengthened with angle iron. The shell was 
 formed of six rings, each of two plates alternately jointed top and 
 sides. The third ring from the front had stripped off, and was 
 thrown to the right and forwards against a wall. The line of rent 
 was confined to the plates forming the ring, which was an outer 
 one, and covered the two adjoining rings in the laps, the rent being 
 from the edge of the inner lap to the nearest rivets. The first rent 
 had taken place in the solid iron, about 1 inch from the rivets of a 
 seam on one side, and from this the rent had extended along the 
 seams on either side, and of course the whole ring soon tore off when 
 the equilibrium was destroyed by the first rent. 
 
 The fittings of the boiler were sufficient, except that there was 
 only one safety valve, and that was so constructed that it could 
 only open a very little way. 
 
 The cause was a defect in the iron at the point of the first rent, 
 and accumulated pressure during the time of standing. 
 
 No. 54. Macclesfield. September 25th. none injured. 
 
 Multitubular Boiler, with large internal fireplace, 60 Ibs. 
 
 The furnace crown became overheated from shortness of water, 
 and was crushed down and torn across two seams. The boiler was 
 lifted from its seat and thrown back against a stone wall. 
 
 No. 55. Chelmsford. October 5th. 1 killed, 7 injured. 
 
 Agricultural, 45 Ibs., and had only just been set to work. 
 The crown plate to the fire-box was so deeply corroded from long 
 wear that it gave way, and the issuing contents scalded those near. 
 
 No. 56. Greenwich. (Fig. 24.) October 8th. 2 killed, 2 injured, 
 
 Marine, 16ft. long, slightly oval, front end flat, 8ft. 6in. wide, 
 7ft. lOin. high, and the dimensions of the back hemispherical end 
 were 2ft. less each way, inch plates, 26 Ibs. There were two 
 internal fireplaces, of irregular shape, uniting at the back into one 
 flue of similar shape, which did not come to the front, but passed 
 through the steam space, and exit at the top of the boiler.
 
 BOILER EXPLOSIONS IN 1866. 
 
 While the vessel was waiting to start, with steam up, the wing 
 furnace of the starboard boiler collapsed on the wing side, as shown 
 
 Fig. 24. 
 
 by the dotted lines, and allowed the steam and water to escape into 
 the stoke hole. 
 
 The side of the furnace next the shell was rent along the edge of 
 a longitudinal seam in a line, which was slightly nicked in the 
 caulking. This rent extended about 5ft. 6in. from the front, and 
 then at a cross seam it went along the line of rivets from the crown 
 to the bottom of the furnace. Beyond this cross seam the furnace 
 was collapsed, until it nearly touched the other side of the furnace, 
 and the bulge died away towards the back end. There was also a 
 rent in the lower part of the front of the shell, as shown in 
 dotted line. 
 
 The cause of the explosion was the weakness of the shape of the 
 flue, which was not stayed to the shell. It had evidently gradually 
 been giving way some time before the explosion, and eventually 
 collapsed at nearly the ordinary pressure. Symptoms of the same 
 alteration of shape were noticed in the corresponding flue of the 
 other boiler. 
 
 No. 57. Liverpool. (Fig. 25.) October 9th. 7 killed, 1 injured. 
 
 Crane Boiler, 5ft. 6in. high, and 2ft fiin. diameter, with internal 
 conical fire-box, with two cross tubes and a chimney at the top, 
 inch plates, 75 Ibs. 
 
 The outer shell of the boiler was rent into many pieces, leaving 
 the central conical fireplace intact. The nature of the rents showed 
 that the plate round the manhole, which was unstrengthened by a
 
 BOILER EXPLOSIONS IN 1866. 
 
 ring, had first given way, and all the other fractures had led away 
 from that point. This is confirmed by the fact, that the manlid 
 
 Fig. 25. 
 
 was thrown a good distance, with force enough to make its way 
 through the timber walls of a cabin. The front plate divided into 
 many pieces, and scattered right and left, while the back plate was 
 thrown through a cabin in the opposite direction to the manhole. 
 
 The central flue showed a slight indication of overheating, but 
 the construction was such that the upper portion passed through the 
 steam space, and was always exposed to the action of the fire, 
 without the protection of the contact of water. The manhole 
 without a ring on its edge to strengthen the plate, and held in by 
 two clamps, which caused additional strain when carelessly screwed 
 up, was by far the weakest place. The engine was standing after 
 a short time of working, and as the safety valve was very defective, 
 and could be screwed down until tight, against almost any pressure, 
 it is most probable that the pressure mounted much higher than 
 usual, when the weakest part gave way, and led to the sudden 
 tearing up and scattering of the whole fabric. 
 
 Faulty construction of both boiler and fittings, rendered it unable 
 to bear that accumulated pressure, which the safety valve ought to 
 have made impossible. 
 
 No. 58. Durham. October 13th. 1 killed. 
 
 One Tube Cornish, 14ft. long, 6ft. diameter, internal flue 3ft. 3in., 
 by 2ft. lOin., f inch plates, 27 Ibs., standing on three saddles, with 
 a bearing surface of 3ft. by 4 inches.
 
 BOILER EXPLOSIONS IN 1866. 
 
 A portion of plate 20in. by 18in., at the bottom of the boiler, 
 was so corroded that it was blown out, and the issuing contents 
 scalded a man to death. 
 
 No. 59. Bristol. (Fig. 26.) November 1st. 
 
 7 killed. 
 
 Fig. 26. 
 
 Two Marine Boilers exploded simultaneously. They were 1 6ft. 
 long, 6ft. 6in. diameter at the flat front ends, and somewhat less at 
 the hemispherical back ends. Each had two internal fireplaces, 
 united in one flue, which returned nearly to the front and passed up 
 through the steam space, and out at the top of shell into the funnel. 
 The central fireplaces were not circular, and the outside fireplaces 
 and the return flues were still more distorted, but the weakness of 
 the shape was somewhat compensated for by stays between the 
 tubes, and from the tubes to the shell. The mountings to the boiler 
 were of the ordinary kind and efficient. 
 
 The under sides of the shells were so deeply corroded that they 
 were rent longitudinally for their whole length, allowing the sides 
 to open out and tear away from the front ends. Each shell fell at 
 a considerable distance. The furnaces, with parts of the front ends 
 attached, fell into the water, but except one of the side flues that 
 was a little collapsed, they were uninjured. Small pieces of the 
 front ends were thrown to a great distance. The sides of the vessel 
 were so completely blown out that she sank.
 
 BOILER EXPLOSIONS IN 1866. 
 
 The corrosion was no doubt caused by the leakage of the vessel, 
 keeping the shells of the boilers constantly wet. 
 
 No. 60. London. (Fig. 27.) November 3rd. none injured. 
 
 n 
 
 Fig. 27. 
 
 Agricultural, barrel was 3ft. 9in. long, and 2ft. Gin. diameter, 
 70 Ibs. From the internal fire-box the heat passed through a 
 number of 1-inch tubes to the front smoke box and chimney. 
 
 During a stoppage for breakfast, the fire-box end was torn from 
 the barrel, and from the position of those fragments that could be 
 found, the boiler appeared to have turned over. Part of the fire-box 
 was sent through the stage upon which the boiler was travelling, 
 and the barrel with the tubes remaining in it, first struck a rail 
 which caused it to be dented in, and then rebounded to a point 
 about 100 yards from its original position. 
 
 Enough of the fragments were not recovered from the river to 
 trace the cause of the explosion, but it is presumed that, although 
 when the boiler was left, only 20 Ibs. pressure was shown by the 
 guage ; the fire door being left closed, the pressure must have risen 
 to a point much above the working pressure, and to more than the 
 boiler could bear. 
 
 No. 61. Bilston. (I iff. 28.) October 1st. none injured. 
 
 One Tube Cornish, 22ft. long, 6ft. diameter, tube 4ft. 6in. 
 diameter, f inch plates, 12 Ibs. There was an unusually large dome 
 at the back end, 5ft. diameter, and the whole of the shell was cut 
 out from under it, so that the construction was peculiarly weak.
 
 BOILEK EXPLOSIONS IN 1866. 
 
 The boiler had been off for cleaning, and steam was being got up 
 in the night, aud it was said that an extra pressure was caused by 
 
 Fig. 28. 
 
 the stop valve being left closed, but it could not have been very 
 great, or the large tube would have collapsed. 
 
 The dome was split in two, in the line marked in the sketch, 
 owing to the extreme weakness of the shell at the juncture of the 
 dome, and the shell was a little ruptured on each side of it, and so 
 large a rent was suddenly made, that the contents of the boiler 
 passed harmlessly into the air, without moving the boiler on its seat. 
 
 No. 62. Preston. (Fig. 29.) November llth. 
 
 1 killed, 1 injured. 
 
 FRONT VIEW. 
 
 BACK VIEW. 
 
 Fig. 29. 
 
 One Tube Cornish, 16ft. Sin. long, and 5ft. Sin. diameter, tube 
 3ft. lin. diameter, T 7 8 inch plates, 60 Ibs. 
 
 The tube collapsed from end to end, from over-pressure, as the 
 man in charge had fastened 3 bricks to the lever of the safety valve 
 causing 27 Ibs. extra pressure, under the impression that he could 
 thus accumulate a quantity of steam during the night, to be available 
 on commencing work on the morrow.
 
 BOILEE EXPLOSIONS IN 1866. 
 No. 63. Tamworth. (Fig. 30.) November 20th, none injured. 
 
 Fig. 30. 
 
 Eevolving Steam Chamber, 12ft. 6in. long, and 5ft. diameter, 
 12 Ibs. 
 
 The manhole was large, to facilitate filling and emptying, and 
 was rectangular and unstrengthened on the edges, and measured 
 3ft. 6in. in length, and 1ft. Gin. in width, and the lid fitted on the 
 inside and was held by clamps. 
 
 The boiler was much out of repair, and a crack shown in sketch, 
 from one corner of the manhole, to the commencement of the 
 hemispherical end was only temporarily prevented from leaking by 
 a screw-patch, which did not restore the strength. 
 
 The explosion happened when in revolving, the manlid was 
 downwards, and the lid was driven nearly through the floor, and 
 the shell was rent from opposite corners of the manhole, and blown 
 through the roof. 
 
 The large manhole cut away nearly all the strength on one side, 
 and the fastenings of the lid were not contrived to compensate at 
 all for the loss of strength. The constant strain when revolving, 
 also tended to weaken it. These two causes together were sufficient 
 to account for the explosion, at the usual working pressure of 12 Ibs., 
 although it is possible that it might have been increased to 35 Ibs., 
 as that was the pressure in the boiler supplying the steam, although 
 the pressure was regulated by a check valve. 
 
 This explosion (and also No. 41 in this year) clearly show that 
 a mere vessel of steam not exposed to the fire, or any chance of 
 overheating of the plates, can burst and cause very great destruction, 
 although there could be no sudden increase of pressure which is so 
 often supposed necessary to account for the havoc caused by 
 explosions.
 
 BOILER EXPLOSIONS IN 1866. 
 No. 64. Manchester. November '26th. none injured. 
 
 This Boiler was 28ft. long, 7ft. diameter, made of -j^ inch plates, 
 and worked at 50 Ibs. pressure, with two internal fireplaces united 
 into one tube beyond. 
 
 The sides of the oval chamber forming the junction of furnaces 
 and tube, crushed inwards, being of such a weak shape as to be 
 unable to resist the ordinary working pressure. 
 
 No. 65. Hull. (Fig. 31.) December 1st. 3 killed, 2 injured. 
 
 Fig. 31. 
 
 Agricultural, 7ft. Gin. long, and 3ft. Sin. diameter, J inch plates, 
 35 Ibs., fire-box 2ft. long, and 2ft. lOin. broad. Two 11^-inch 
 tubes led to an internal chamber at the other end of the boiler, and 
 three 8J-inch tubes led back again to an external smoke box and 
 chimney fixed over the fire door. 
 
 The bottom of the right hand side lower tube was forced upwards, 
 and rent along to within 12 inches of the fire-box. 
 
 The tubes were so corroded from leakage of patches, that they 
 were unable to bear the slight increase of pressure during a short 
 stoppage. 
 
 No. 66. Glasgow. December 4<A. 2 killed, 6 injured* 
 
 Two Tube Cornish, 22ft. long, and 7ft. 6in. diameter, tubes 
 3ft. diameter, and strengthened with rings in the approved manner. 
 
 The second from the back of the seven rings, was ruptured at the 
 bottom and torn off by a rent through the line of rivets on each
 
 BOILER EXPLOSIONS IN 1866. 
 
 side, and the boiler was thrown from its seat, and turned completely 
 over, so as to lie in a contrary direction to what it was before. 
 
 Extensive corrosion, from leaking of the seams beneath the 
 brickwork, where hidden from view, was the cause of explosion. 
 
 No. 67. Willenhall. December 1th. none injured. 
 
 Plain Cylinder, with hemispherical ends, 9ft. long, 3ft. Sin. 
 diameter, 20 Ibs. 
 
 The boiler was rent all along one side, and the reaction of the 
 issuing contents caused it to be thrown some yards away, and one of 
 the ends became altogether detached, and flew to a considerable 
 distance. 
 
 The plates were so thinned by corrosion, that they gave way on 
 a very slight increase of pressure during a temporary stoppage of 
 the engine. 
 
 No. 68. Glasgow. December 12th. 1 killed, 1 injured. 
 
 This Boiler was 14ft. long, with hemispherical ends, and 7ft. 
 diameter, 30 Ibs. 
 
 The cause of the explosion was over-pressure and thinness of 
 plates, wasted by corrosion. 
 
 No. 69. Manchester. (Fig. 32.) December loth. 5 injured. 
 
 Fig. 32. 
 
 Two Tube Cornish, 24ft. long, 6ft. Gin. diameter, tubes 2ft. Sin. 
 diameter, -f s inch plates, 50 Ibs. The boiler was fired in each of 
 the tubes in the ordinary way, and also the heat from two furnaces- 
 passed from the back, one on each side of the outside shell.
 
 BOILER EXPLOSIONS IN 1866. 
 
 Both the internal furnaces collapsed, until the crowns almost 
 touched the fire bars, as shown in dotted lines, but without fracture. 
 The back of the shell, on the right side, had evidently been over- 
 heated, and had rent along the centre of a bulge, and this rent had 
 extended along the line of rivets of the 'transverse seam on each 
 side, allowing two rings of the plates of the shell to open out flat 
 as shown. There was a bulge on the plate, on the right side of 
 shell, corresponding with the one which parted on the opposite side. 
 
 The cause of the explosion was overheating of the plates from 
 shortness of water. 
 
 Ko. 70. Aberdeen. December 2ith. 1 injured- 
 
 No particulars have been obtained.
 
 BOILER EXPLOSIONS IN 1867. 
 
 No. 1. Hull. 
 
 January 2nd. 
 
 , 1 injured. 
 
 A small Boiler to heat a bath. It exploded, causing great damage, 
 because the connecting pipes were frozen. All such boilers should 
 have a proper safety valve. 
 
 No. 2. Durham. (Fig. 1.) January 2nd. 
 
 3 kilkd, 3 injured. 
 
 Fig. 1. 
 
 Plain Cylinder, 33ft. long, 6ft. diameter, 33 Ibs. pressure. Only 
 set two days, but was old and deteriorated, and had worked before at 
 another place. It had been turned | round, and old fitting-holes 
 stopped. First rent was supposed to be in a seam at front end, over 
 the fire. Main portion of shell was driven back, and front end 
 forward, and torn in its flight. The cause of explosion was, that 
 the seam in front was overheated and injured, and also incautious 
 working without a steam guage.
 
 BOILER EXPLOSIONS IN 1867. 
 No. 3. Sheffield, (fig. 2.) January 2nd. 1 killed, 4 injured. 
 
 Fig. 2. 
 
 One Tube externally fired, 30ft. long, 6ft. 6in. diameter, with 
 dished ends. Tube 2ft. 9in. diameter, slightly oval. Pressure 
 60 Ibs. Tube collapsed sideways from end to end, because it was 
 not strengthened by hoops or other means, which were the more 
 needed, because it was slightly oval, and the longitudinal seams were 
 nearly in one line. 
 
 No. 4. Preston. January 3rd. 1 killed. 
 
 Boiler for heating apparatus. Fire was lighted without noticing 
 that as there was no safety valve, and that all escape of steam was 
 prevented by the connecting pipes being frozen. 
 
 No. 5. Westerham. January 5th. 1 killed. 
 
 Cast-iron Boiler for heating water for a horse shower bath, fixed 
 behind an ordinary fireplace. Burst and caused great damage, owing 
 to the pipes being frozen. There was no safety valve. 
 
 No. 6. Barr. January 9th. 1 killed, 3 injured. 
 
 Kitchen Boiler, which burst because the supply pipes were stopped 
 by frost, and there was no safety valve. 
 
 No. 7. London. January llth. 1 killed. 
 
 Cornish, 12ft. long, 4ft. 6in. diameter, tube 2ft. 4in. diameter, 
 
 pressure 40 Ibs. Small piece of plate was blown out near the 
 
 bottom, and the boiler was displaced by the reaction of issuing
 
 BOILER EXPLOSIONS IN 1867. 
 
 Contents. The cause of explosion was extensive external corrosion 
 on the lower part. 
 
 No. 8. Preston. January 16th. none injured. 
 
 Kitchen Boiler. Burst and did great damage, because pipes were 
 frozen preventing escape of steam. There was no safety valve. 
 
 No. 9. Brechin. January 23rd. 1 killed. 
 
 Kitchen Boiler. Fire had been out some days, and the boiler 
 burst soon after re-kindling it and did much damage, because the 
 supply pipes were stopped by frost, and there was no safety valve 
 for escape of steam. 
 
 No. 10. Sunderland. (Fig. 3.) January 26tk. 
 
 3 injured. 
 
 Tig. 3. 
 
 Plain Cylinder, 30ft. long, 6ft. 2in. diameter. Pressure 30 to 
 35 Ibs. Rent into four pieces, which were flattened out and scattered 
 on to other boilers, but are arranged in sketch so as to show their 
 original position in the boiler. It had worked a very long time, and 
 was overheated and injured along the fractured line. 
 
 No. 11. Exeter. (Fig. 4.) January 30th. 2 killed, 2 injured. 
 
 Elephant Boiler, 16ft. long, 5ft. diameter, tubes 1ft. lOin. diameter, 
 
 45 Ibs. pressure. Flat end blew out, throwing boiler upwards by
 
 BOILER EXPLOSIONS IN 1867- 
 reaction, but shell and tubes were not injured. The flat end wag 
 
 Fig. 4. 
 
 -not sufficiently stayed, having only one stay-rod to the centre, the 
 bolt of which was broken. 
 
 No. 12. Glasgow. February 8ih. 1 killed, 4 injured. 
 
 Small Boiler to 6-horse power engine. Gave way at centre of 
 furnace, and water forced out at both ends, and it was suspected 
 that the water was low. 
 
 No. 13. Sheffield. (Fig. 5.) February llth. 
 
 4 injured. 
 
 Fig. 5. 
 
 Cornish, about 30ft. long. Tubes 3ft. unstayed. Tube collapsed 
 sideways, and was rent from grate bars to end, without injuring front 
 plates or shell. It was said to be short of water, but most likely 
 the true cause was the weakness of the tube. 
 
 No. 14. Manchester. February loth. none injured. 
 
 Two flued, 28ft. long, 6ft. 9in diameter, slightly oval ; plates 
 f inch ; tube 2ft. Sin. diameter, pressure 45 Ibs Shell had once 
 been externally fired. Rent along the seams which were in one
 
 BOILER EXPLOSIONS IN 1867. 
 
 line, and a large piece of the plate blew away, leaving tubes 
 uninjured. The cause of explosion was defective form and worn out 
 state of shell. 
 
 No. 15. Weymouth. (Fig. 6.) March 12th. 1 killed, 3 injured. 
 
 Fig. 6. 
 
 Agricultural, 45 Ibs. pressure. Fire-box blew off, and the outer 
 hell separated from it. The cause of explosion was over-pressure 
 from the safety valve being screwed down. 
 
 No. 16. Lynn. (Fig. 7.) March 19th. 
 
 8 killed, 4 injured. 
 
 Agricultural, 45 Ibs. pressure. Fire-box and tubes blew out. 
 The cause of explosion was over- pressure, as the safety valve was 
 ' tied down with string. 
 
 No. 17. Blacklraes. 
 
 3 killed, 1 injured 
 
 Colliery Boiler, 30 Ibs. pressure. Rent in two while the engine 
 was standing, but no details obtained.
 
 BOILEK EXPLOSIONS IN 1867. 
 . 18. JBarnsley. (Fig. 8.) March 29th. 2 killed, 2 injured. 
 
 Small plain Cylinder, with ends nearly flat, 4ft. Tin. long, 2ft. 
 4in. diameter, plates T 3 5 inch. No emptying plug or feed-pipe, and 
 only a very small hand-hole. Front end attached by slight angle 
 iron, which gave way, leaving the shell unmoved. The cause of 
 explosion was the internal corrosion of front end owing to very bad 
 water being used. The plates were reduced to a knife edge in line 
 of fracture. 
 
 Wo. 19. Cornwall. (Fig. 9.) April Wth. 
 
 1 killed, 1 injured. 
 
 Fig. 9. 
 
 Cornish, one tube 32ft. long, 6ft. diameter, tube 3ft. lOin. diameter, 
 plates f inch, pressure 25 to 40 Ibs. It was 20 years old, but just 
 repaired and reset. Furnace tube failed and collapsed from one end 
 to the other, except about 4 feet of front, owing to its weakness, 
 being unstrengthened by hoops or cross tubea. 
 
 20. Belfast. (Fig. 10.) April ZMh. 
 
 1 killed, 2 injured. 
 
 Fig. 10. 
 Plain Cylinder, 6ft. long, 2ft. 5in. diameter, plates inch, pressure
 
 BOILER EXPLOSIONS IN 1867. 
 
 90 Ibs. The end blew out from excessive pressure, as the escape 
 from the safety valve was prevented by a plug in the exit pipe. 
 
 No. 21. Birmingham. (Fig. 11.) May 9th 
 
 2 injured. 
 
 Fig. 11. 
 
 Plain Cylinder, 3ft. 2in. long, 1ft. Sin. diameter, plates ^ inch, 
 pressure 30 Ibs. Workmanship and material very inferior. Piece 
 of top ripped out from manhole and allowed manlid to blow out 
 through manhole. The cause of the explosion was, the large 
 manhole and over-pressure. The safety valve was too small, and 
 very roughly made. 
 
 No. 22. Hartlepool. (Fig. 12.) May 10th. 
 
 1 killed, 1 injured. 
 
 Fig. 12. 
 
 Locomotive, 130 Ibs. pressure. Barrel blown away and broken to 
 pieces, leaving fire and smoke boxes. The cause of explosion was 
 supposed to be the strain on the boiler caused by its being made a 
 stay to the frame without allowance for expansion, and thereby 
 weakening a horizontal seam. 
 
 No. 23. Newark. (Fig. 13.) May 18th. 
 
 4 injured. 
 
 Fig. 13.
 
 BOILER EXPLOSIONS IN 1867. 
 
 Cornish, one tube 20ft. Gin. long, 5ft. 4^in. diameter, tube 3ft. 
 diameter, plates inch, pressure 64 Ibs. The ends came out and 
 tube collapsed for its full length, every joint being broken. The 
 cause of explosion was bad construction and workmanship, and tube 
 too weak for pressure. 
 
 No. 24. Tamworth. (Fig. 14.) June th. 
 
 2 hilled. 
 
 Two tnbe, externally fired, 30ft. long, 7ft. diameter, tubes 2ft. 4in. 
 diameter, pressure 50 Ibs. Two plates lately put in bottom gave 
 way, and shell rent along bottom and opened out, dividing into
 
 BOILER EXPLOSIONS IN 1867. 
 
 several pieces, which were scattered to great distances, but are 
 arranged in sketch so as to show their original position. The cause 
 of explosion was too frequent repair over the fireplace, and external 
 firing. 
 
 No. 25. Dudley. (Fig. 15.) July 10th. 
 
 1 killed, 2 injured. 
 
 Fig. 15. 
 
 Balloon, 22ft. diameter, pressure 5 Ibs. Bottom blew out and 
 was torn in pieces. Main portion of shell fell over on to another 
 boiler. The cause of explosion was deep corrosion along the bottom 
 where it rested on the brickwork. 
 
 No. 26. Batley. (Fig. 16.) July llth. 
 
 3 killed, 3 injured. 
 
 Fig. 16.
 
 BOILER EXPLOSIONS IN 1867. 
 
 One tube Cornish, 26ft. long, 8ft. 10in. diameter, tube 5ft. 
 diameter, for 8ft. Gin. of front end, tapering to 4ft. diameter at back, 
 pressure 30 Ibs. Rent along bottom, allowing central ring of plates 
 to open out. The whole boiler was thrown some distance by the 
 reaction of issuing contents. The cause of explosion was corrosion 
 at mid-feather wall, the plates being little thicker than paper. 
 
 No. 27. Rotherham. (Fig. 17.) July 13th. none injured. 
 
 Fig. 17. 
 
 Two tube Cornish, 31ft. long, 7ft. diameter, tube 2ft. Tin., tapering 
 to 2ft., pressure 55 Ibs. Left band tube collapsed, and about the 
 centre of collapse, plate was torn in two pieces from seam to seam. 
 The cause of explosion was overheating, because the water was 
 being let low before all the fire was out. 
 
 No. 28. Bilton. (fig. 18.) July 24th, 1 injured. 
 
 Fig. 18. 
 
 Locomotive. Side-plate in the upper part of high top fire-box 
 blew away. The cause of explosion was most likely the boiler being 
 made the frame of the engine without allowance for expansion. 
 
 No. 29. Ecclesfield. August 5th. 1 killed, 2 injured. 
 
 Full particulars were not obtained, but the steam and hot water 
 were allowed to come in from a neighbouring boiler through the 
 blow-off pipe while the men were cleaning.
 
 BOILER EXPLOSIONS IN 1867. 
 No. 30. Belfast. (Fiy. 19.) August 21th. 7 killed, 3 injured. 
 
 lig. 19. 
 
 Cornish, 18ft. long r 4ft. 9in. diameter, tube 1ft. Gin. diameter, 
 plates | inch, pressure 50 Ibs. There were no stays. End plate 
 blew out while being caulked at a jump joint in back angle iron. 
 The cause of explosion was bad construction and want of stays, and 
 also want of proper care in working. 
 
 No. 31. Plashetts. September 2nd 
 
 Locomotive, but no details obtained. 
 
 2 injured. 
 
 No. 32. Ashton. September 9th. none injured. 
 
 Two flued, 40 Ibs. pressure. The cast-iron mouth-piece of man- 
 hole fractured from insufficient strength, and allowed lid and upper 
 flange to blow off. 
 
 No. 33. Blackburn. October 4th. 4 injured. 
 
 Water Heater, made of large bottle- shaped pipes placed in the flue, 
 he force of explosion caused the neighbouring boilers to be unseated. 
 No details have been obtained as to the cause of the explosion. 
 
 No. 34. London. (Fig. 20.) October 1th.. 1 killed.. 
 
 fig. 20.
 
 BOILER EXPLOSIONS IN 1867. 
 
 One tube Cornish, lift, long, 4ft. diameter, plates inch, tube 
 2ft. lin. diameter, pressure 50 Ibs. Gave way underneath. Top 
 thrown upwards. Front part and tube thrown to the front. The 
 cause of the explosion was extensive corrosion at the bottom where 
 it touched the walls. 
 
 No. 35. Preston. October 31st. none injured. 
 
 Cornish, 26ft. long, 5ft. 6in. diameter, tube 2ft. llin. diameter, 
 plates f inch. Pressure 30 Ibs. Tube collapsed for want of proper 
 strengthening hoops, blowing out back end, and throwing boiler 
 forward. 
 
 No. 36. Durham. (Fig. 21.) November 3rd. 1 killed, 1 injured. 
 
 Fig. 21. 
 
 Plain Cylinder, 19ft. long, 6ft. diameter, pressure 40 Ibs. It was 
 36 years old, and iron deteriorated and also much patched. The 
 cause of explosion was over-pressure for so old a boiler. 
 
 No. 37. Bradford. (Fig. 22.) November 6th. 2 killed, 3 injured. 
 
 Fig. 22. 
 Agricultural, wagon-shaped, 6ft. Sin. long, 3ft. high, 2ft. 4in. wide,
 
 BOILER EXPLOSIONS IN 1867. 
 
 plates inch, pressure 50 Ibs. Upper portion of barrel blew off. 
 The cause of the explosion was over-pressure from locked safety 
 valve and defective construe tioD. 
 
 No. 38. Sheffield, (fig. 23.) Wwemlvr 1th, 1 injured. 
 
 Fig. 23. 
 
 Plain Cylinder, 12ft. Sin. long, 3ft. llin. diameter, pressure 
 20 Ibs, flat front, and round back end. Main portion thrown back 
 and front forward. Front torn all round the root of angle iron, and 
 stay rivets drawn through flat end. The cause of explosion was 
 weakness of construction of flat end, and bad safety valve, which 
 could have been loaded to 60 Ibs. 
 
 No. 39. Langley Mill. (Fit). 24.) November \\th. 3 killed, 10 injured. 
 
 Fig. 24. 
 
 Plain Cylinder, 40ft. long, 5ft. diameter, plates ^ inch, pressure 
 45 to 50 Ibs. Parted at third seam, and front thrown forward and 
 main portion backwards. The cause of explosion was a seam-rip of 
 old standing near patch at place of first rupture. 
 
 No. 40. Bradford. (Fig. 25.) November 14th. 4 Mled, 3 injured. 
 
 Breeches tube 25ft. Gin. long, 7ft. Gin. diameter, plates T 7 g- inch, 
 pressure 30 Ibs. Front end and fire-grate tubes and taper junction
 
 BOILEE EXPLOSIONS IN 1867. 
 
 were thrown to the front in one piece. Main shell not injured. 
 Back part of tube remained in boiler. Bottom part of taper 
 
 Fig. 25, 
 
 junction where flattened to receive the two fire tubes, collapsed 
 upwards. The cause of explosion was the want of proper stays or 
 strengthening tubes, and consequent weakness. There was only one 
 safety valve of small size. 
 
 No. 41. Chippenham. (Fig. 26.) November 2lst. 3 killed, 2 injured. 
 
 r 
 
 Fig. 26. 
 
 One tube Cornish, lift, long, 5ft. diameter, pressure 44 Ibs. Tube 
 gave way at an old crack at back of strap-plate and partially 
 collapsed. 
 
 No. 42. Dudley. (Fig. 27.) November 21th. 
 
 1 killed. 
 
 Fig. 27.
 
 BOILER EXPLOSIONS IN 1867. 
 
 Plain Cylinder, 25ft. long, 6ft. diameter, plates T 7 5 inch, pressure 
 50 Ibs. Had been a one tube Cornish, but tube had been taken out, 
 leaving flat ends. Back end was blown out. Main shell thrown 
 forwards. The cause of explosion was weakness of construction in 
 not sufliciently strengthening the flat end to compensate for loss 
 of tube. 
 
 No. 43. Shields. (Fig. 28.) December 1th. 
 
 none injured. 
 
 Fig. 28. 
 
 One tube Cornish, 28ft. long, 6ft. diameter, tube 4ft. diameter, 
 plates f inch. Pressure 28 Ibs. Tube collapsed for the whole 
 length, but no particulars of the cause obtained. 
 
 No. 44. Belfast. December 14th. 2 killed. 
 
 Some repair had been done to a Boiler, and a blank flange used to 
 stop oft' the steam was being removed without shutting the stop- 
 valves to the other boilers, and the joint blew out when the bolts 
 were loosened. 
 
 No. 45. Manchester. (Fig. 29.) December 23rd. 6 killed, 4 injured. 
 
 Fig. 29. 
 
 One tube Cornish, 18ft. long, 6ft. diameter, tube 3ft. 2in. diameter, 
 plates f inch. Pressure 25 Ibs. Kent along bottom, and two rings
 
 BOILEK EXPLOSIONS IN 1867. 
 
 of plates blown away, but tube and ends not much injured. The 
 cause of explosion was extensive corrosion on the part resting on 
 the midfeather wall. 
 
 No. 46. Barnsky. (Fig. 30.) December 28th. 1 killed. 
 
 Fig. 30. 
 
 Balloon, lift. Gin. diameter, and lift. 6in. high, plates f inch. 
 Bottom domed up 3ft. Gin. over fire; ordinary pressure 8 Ibs. Boiler 
 had worked two days at 25 Ibs. pressure, but safety valve loaded 
 to 16 Ibs. The cause of explosion was undue pressure for an old 
 boiler of such weak shape. 
 
 Ne. 47. Leeds. (Fig. 31.) December 3Qtb. 2 injured* 
 
 Fig. 31. 
 
 Two tube Cornish, 22ft. long, 7ft. 2in. diameter, tubes 2ft. 7io. 
 diameter, pressure 15 Ibs. Rent along bottom, and shell blown 
 away, leaving tubes and ends nearly uninjured. The cause of
 
 BOILEK EXPLOSIONS IN 1867. 
 
 explosion was, that the bottom was corroded to a knife edge all along 
 the midfeather wall. 
 
 No. 48. Shields. (Fig. 32.) December 31st. 
 
 2 killed, 1 injured. 
 
 Fig. 32. 
 
 Plain Cylinder, 30ft. long, 4ft. Gin. diameter, plates f inch, 
 pressure 29 ]bs. Rent over fire near where a new plate had lately 
 been put in. Front part of shell opened out and rent, and back end 
 blew away in one piece. The cause of explosion was deterioration 
 from 20 years' wear, and bad management.
 
 BOILER EXPLOSIONS IN 1868. 
 
 No. 1. Newcastle. (Fig. 1.) January 13th. 
 
 none injured. 
 
 Fig. 1. 
 
 One of three. Plain Cylinder, 27ft. long, 5ft. diameter, inch 
 plates, 35 Ibs pressure. The boiler was much torn up, and all the 
 fragments thrown to the front of their original position. The cause 
 of the explosion was that the boiler was very old and much 
 deteriorated, so that it was unable to bear the ordinary pressure. 
 The longitudinal arrangement of the plates, and the entrance of the 
 feed directly on the bottom, no doubt contributed to the weakness. 
 
 No. 2. Glasgow. January 21th. 1 killed, 5 injured. 
 
 One of four. Kier or steam chamber, and not used for generating 
 steam. It was 8ft. Gin. high, 6ft. 6in. diameter, ^ inch plates, 
 40 Ibs. pressure. It was rent from top to bottom, owing to inferior 
 iron and workmanship.
 
 BOILEK EXPLOSIONS IN 1868. 
 No. 3. Sheffield. (Fig. 2.) January 28th. 
 
 1 Tolled. 
 
 Fig. 2. 
 
 One of four. One tube Cornish, 26ft. 4in. long, 6ft. 6in. diameter. 
 Tube 3ft. 9in. diameter, f inch plates, 15 Ibs. pressure. The dotted 
 line shows outside shell of boiler. The tube collapsed from end to 
 end while the steam was being raised, owing to the weakness of so 
 large a tube without strengthening rings. 
 
 No. 4. London. (Fig. 3.) January 29th. 
 
 1 killed. 
 
 Fig. 3. 
 
 One tube Cornish, 18ft. Sin. long, 4ft. lOin. diameter, inch 
 plates. Tube 3ft. diameter, T 5 ff inch plates. In sketch the external 
 shell is shown in outline to allow the tube to be seen. The tube 
 collapsed owing to shortness of water, and rent open at one seam, 
 allowing the contents to issue violently, although the boiler itself 
 was not disturbed. 
 
 No. o. Bolton. (Fig. 4.) January 31st. 
 
 1 injured. 
 
 Fig. 4. 
 
 Locomotive, 90 Ibs. Sketch shows interior view of fire-box with
 
 BOILER EXPLOSIONS IN 1868. 
 
 front removed. The left side of the copper fire-box burst inwards 
 owing to the plate in line of fracture being corroded to less 
 than inch. 
 
 No. 6. Stoke. (Fig. 5.) February 6th. 
 
 none injured. 
 
 Fig. 5. 
 
 One of three. One tube Cornish, with two external fire grates 
 with a water tube over each fire. It was 30ft. 2in. long, 6ft. 
 diameter. Tube 3ft. diameter, inch plates, 40 Ibs. pressure. 
 External shell is shown in dotted lines to allow of the tubes being 
 seen. The tube had formerly been placed rather higher in the 
 boiler. The tube collapsed sideways, having become overheated from 
 shortness of water. The boiler itself was but little disturbed. 
 
 No. 7, Keko. (Fig. 6.) February llth. 
 
 none injured. 
 
 One tube Cornish, 9ft. 9in. long, 4ft. 6in. diameter. Tube 2ft. 3in. 
 diameter, -j 5 ff inch plates, 30 Ibs. pressure. The boiler rent open at 
 the bottom, and was thrown a considerable distance by the reaction 
 of the issuing contents. The plates along the bottom were reduced 
 by corrosion to ^ ff inch where in contact with the brickwork, so that 
 the boiler was unable to bear the usual working pressure.
 
 BOILER EXPLOSIONS IN 1868. 
 No. 8. Durham. (Fig. 7.) February 12th. 2 killed, 1 injured. 
 
 Fig. 7. 
 
 One of four. External shell is shown in dotted lines in sketch, 
 to allow the tubes to be seen. It was 20ft. long, 7ft. diameter, 
 40 Ibs. pressure. The two internal fire grates in the flues were 
 2ft. Sin. diameter, which joined at the back with a central return 
 flue to a chimney passing out of the top of the boiler. The sides 
 of flues were flattened to allow them to be packed closer together, 
 and especially the central return flue, which was flattened on both 
 sides, and thus rendered so weak that the left side collapsed and 
 allowed the contents of the boiler to issue, blowing out the grate 
 on the left side. 
 
 No. 9. Halifax. (Fig. 8.) March 3rd. 
 
 none injured. 
 
 Plain Cylinder, with flat ends, 18ft. Gin. long, Sft. 11 in. diameter, 
 ^ inch plates, 50 Ibs, pressure. The back end gave way at the root 
 of the angle iron all round, and was thrown 60 yards to the rear. 
 The boiler was forced forward, and tilted up by the reaction of the 
 issuing contents, and forced through a wall. The cause of explosion 
 was the want of sufficient stays to the flat end.
 
 BOILER EXPLOSIONS IN 1868. 
 2fb. 10. Newcastle. (Fig. 9.) April 4th. 1 killed, 4 injured. 
 
 Fig. 9. 
 
 One of four. Plain Cylinder, 28ft. long, 6ft. diameter, f inch 
 plates, 30 Ibs. pressure. The boiler was much torn and scattered, 
 and much damage was done. The plates were improperly arranged 
 longitudinally. The boiler gave way at a patch lately put on, and 
 had become so deteriorated by nearly 30 years' wear, that it was 
 unable to bear the usual pressure. 
 
 2fo. 11. Aberdeen. April 1th. 1 killed. 
 
 Two tube Cornish, 6ft. diameter. Pew particulars have been 
 obtained. The upper part of front end was blown out and did 
 considerable damage. Most likely this was for want of proper stays. 
 
 Jfo. 12. April loth. 1 injured. 
 
 One of four. One tube Cornish, 15ft. long, 4ft. 7in. diameter. 
 Tube 2ft. Sin. diameter, inch plates, 60 Ibs. pressure. The tube 
 collapsed and rent open near the bridge, owing to its weakness with 
 such thin plates and no strengthening rings. 
 
 No. 13. Cornwall. May 1st. 1 killed. 
 
 No details obtained. One tube Cornish. Tube collapsed, owing 
 to its weakness without strengthening rings. 
 
 No. 14. Cornwall. May 9th none injured. 
 
 Few particulars obtained. One tube Cornish, 34ft. long. Tube 
 4ft. diameter, inch plates, 40 Ibs. pressure. Tube collapsed owing 
 to its weakness without strengthening rings.
 
 BOILER EXPLOSIONS IN 1868. 
 
 No. 15. Oldham. May llth. 1 killed, 1 injured. 
 
 A very small plain cylinder, 3ft. Sin. long, 1ft. Sin. diameter, 
 inch, plates, 45 Ibs. pressure. It burst at a faulty place at the 
 lower part of the back, on the left hand side, allowing the hot water 
 to issue, but the boiler was not much disturbed. 
 
 No. 16. Bristol. May llth. 1 killed. 
 
 Marine. Single internal fire grate, with small return tube, 7ft. 
 9in. long, 5ft. 4in. diameter, f inch plates, tube 2ft. Tin. diameter, 
 inch plates, 62 Ibs. pressure. Tube collapsed and rent open owing 
 to its weak, corroded, and deteriorated condition, and the contents 
 issued so violently, as to cause much damage to the boat. 
 
 No. 17. Hull. (Fig. 10.) May 12th. 2 killed, 2 injured. 
 
 Fig. 10. 
 
 One of two. Plain Cylinder, 4ft. 9in. long, 3ft. diameter, inch 
 plates, 25 Ibs. pressure. This was a second-hand boiler, and rent 
 into several pieces just after being put to work, owing to its having 
 become thinned to inch by corrosion. 
 
 No. 18. Coatbridge. May 15th. 1 injured. 
 
 Plain Cylinder, flat ends, 15ft. long, 5ft. diameter, g inch plates, 
 30 Ibs. pressure. The back end blew out and caused considerable 
 damage, and the boiler was thrown some distance. The end was 
 very insufficiently stayed. 
 
 No. 19. Gravesend. (lig. 11.) May 28th, 2 killed. 
 
 Fig. 11. 
 
 One of two. Marine, 13ft. 5in. long, 7ft. 2in. diameter, -fe inch 
 plates, 25 Ibs. pressure. The fire was in two internal furnace tubes
 
 BOILER EXPLOSIONS IN 1868. 
 
 united at the back, and the flame was returned to the front by four 
 smaller tubes. The furnace tubes were of exceedingly weak shape 
 as the sides followed the curve of the shell, but were not attached 
 to it by proper stays, so that the left hand tube collapsed upwards, 
 and one seam rent open and allowed the contents to violently escape. 
 It is probable there may have been greater pressure than usual at 
 the time, but the furnaces without stays were unsafe, even at the 
 ordinary pressure. 
 
 No. 20. Durham. (Fitj. 12.) June 8th. 
 
 2 killed. 
 
 Fig. 12. 
 
 One of eight. Plain Cylinder, 30ft. long, 6ft. diameter, f inch 
 plates, 35 Ibs. pressure. The plates were arranged longitudinally. 
 Boiler had worked 27 years, and was much deteriorated, and gave 
 way at an old fracture over the grate, and was torn into 4 pieces, 
 which were thrown a great distance. 
 
 No. 21. Huddersfield. (Fig. 13.) June 20th. 
 
 1 killed, 6 injured. 
 
 Fig. 13.
 
 BOILER EXPLOSIONS IN 1868. 
 
 One tube Cornish, 24ft. long, 6ft. diameter. Tube 3ft. Sin. 
 liameter, f inch plates, 40 Ibs. pressure. The seams were arranged 
 diagonally, but the rents had not followed the seams, but had torn 
 the plates. The shell gave way where extensive corrosion had 
 reduced the plates to inch in thickness, and all the shell was blown 
 off, and the tube thrown over and turned end for end. 
 
 No. 22. June 22nd. none injured. 
 
 Two tube Cornish, 27ft. long, 7ft. 6in. diameter. Tube 3ft. 
 diameter, -f s inch plates, 70 Ibs. pressure. Left hand tube collapsed 
 from end to end owing to its weakness without strengthening rings. 
 
 No. 23. Halifax. July 9th. 6 injured. 
 
 Two tube Cornish, 20ft. long, 6ft. 3in. diameter. Tube 2ft. 3in. 
 diameter, f inch plates, 55 Ibs. pressure. The shell was blown 
 completely off, leaving the tubes and ends intact. The bottom was 
 extensively corroded, so that the strength of the boiler was so 
 reduced as not to be able to bear the usual pressure. 
 
 No. 24. Wrexham. (Fig. 14.) July 9th. 
 
 2 injured.
 
 BOILER EXPLOSIONS IN 1868. 
 
 Two Furnace Upright, 22ft. high, 8ft. lOin. diameter, inch 
 plates, 14 Ibs. pressure. Small piece was blown out of the bottom, 
 and the issuing contents disturbed the brickwork surrounding the 
 boiler. The plate was corroded to a knife edge in the line of 
 fracture, from the leaking of the adjacent blow-pipe joint. 
 
 No. 25. Dundee. July 13th. 1 killed, 1 injured. 
 
 Two tube Cornish, 28ft. Gin. long, 7ft. diameter, inch plates. 
 Tube 2ft. 2in. diameter, T 7 g inch plates, 40 Ibs. pressure. Both 
 furnaces collapsed, and ruptured from overheating through shortness 
 of water. 
 
 No. 26. Halifax. July 14th. 3 injured. 
 
 Locomotive, 10ft. 9in. long, 4ft. diameter, inch plates, 130 Ibs. 
 pressure. Nearly all the barrel was blown away. The inside was 
 very much corroded, and there was a deep furrow at the line of 
 first rupture, caused by the alteration in form of the boiler in the 
 strain of working. This is usually obviated by substituting butt 
 for lap joints, so that the pressure does not tend to alter the circular 
 shape of barrel. 
 
 No. 27. Limerick. July 21st. 2 killed, 1 injured. 
 
 Locomotive. Few particulars are obtained. The connecting rod 
 broke, and the loose end attached to the crank pierced the boiler, 
 and allowed the contents to issue and scald those near. 
 
 No. 28. Hanky. (Fig. 15.) July 31st. 1 killed. 
 
 fig. 16.
 
 BOILEE EXPLOSIONS IN 1868. 
 
 One of three. Plain Cylinder, 36ft. 9in. long, 5ft. diameter, 
 f inch, plates, 50 Ibs. pressure. The boiler parted at a seam over 
 the fire bridge. The front end was thrown upwards and to a 
 considerable distance to the front. The back part of the boiler was 
 forced backwards. The first rent took place at a seam-rip at the 
 ruptured seam, and the boiler exploded while the fire was being 
 drawn in order to repair the faulty place. 
 
 No. 29. Easter .Ross. August 8th. 2 killed, 3 injured. 
 
 Agricultural. It exploded while travelling, by its own steam 
 power. The engine had stuck fast, and extra pressure of steam was 
 raised to try and extricate it. The boiler was torn in pieces, and 
 scattered to a great distance. 
 
 No. 30. Bikton. (Fig. 16.) August llth. 1 Mled. 
 
 Fig. 16. 
 
 One of two. Plain Cylinder, 30ft. long, 5ft. diameter, |- inch 
 plates, 46 Ibs. pressure. The boiler gave way on the side where 
 the plates were overheated by the water being too low, and the 
 front part of the shell was* flattened out and thrown some distance 
 to the rear, as its course was influenced by its remaining attached 
 to the rest of the boiler as by a hinge ; while the front end was 
 rent into several pieces, and the back end was thrown also to the 
 rear and rolled down a declivity into a stream.
 
 BOILER EXPLOSIONS IN 1868. 
 
 No. 31. Liverpool. 
 
 (Fig. 17.) August 20th. 
 7 killed, 5 injured. 
 
 Two Furnace Chimney Boiler, 42ft. 4in. 
 high, 6ft. 9in. diameter, inch plates, 50 Ibs. 
 pressure. Nearly half the bottom plate was 
 blown out, and the issuing contents found then- 
 way into the furnace and increased the damage. 
 The line of rupture near where it joined the 
 shell was corroded almost to a knife edge, which 
 so reduced its strength as to make it unable to 
 bear the usual working pressure of steam, 
 in addition to that of the column of water 
 in the boiler. 
 
 No. 32. Accrington. August 31st. 1 killed. 
 
 A Kier or Steam Bleaching Chamber, some- 
 what like No. 2, and not used for generating 
 steam, 9ft. high, 8ft. diameter, % inch plates, 
 50 Ibs. pressure. The bottom blew out, and 
 the shell was torn to pieces. The cause of 
 explosion was weakness of the ruptured end, 
 and want of care in working. 
 
 No. 33. Birmingham. September llth. 1 killed, 
 
 1 injured. 
 
 Two tube Cornish. The manlid was wrongly 
 fixed outside with internal clamps. It was 
 being screwed up tighter to stop leaking when 
 the bolt broke, and the lid came off and allowed 
 the contents of the boiler to escape. 
 
 Fig. 17.
 
 BOILEE EXPLOSIONS IN 1868. 
 No, 34. Greatbndffe. (Fig. 18.) September 2lst. 
 
 /E7777 777 
 
 i E ^-^ 
 
 5 
 
 none injured. 
 
 Fig. 18. 
 
 One of four. One tube, externally fired, 18ft. 6in. long, 6ft. 6in. 
 diameter. Tube 3ft. diameter, - inch plates, 40 Ibs. pressure. In 
 sketch the shell is shown in dotted lines to allow the tube to be 
 seen. The tube collapsed from end to end and ruptured at two 
 seams, and the contents issued so- violently as to knock down the 
 brick-work and displace the . boiler. The tube was in a very weak 
 and corroded condition, and unable to bear the usual working 
 pressure. 
 
 No. 35. Moxley. (Fig. 19.) September 28th. 13 killed, 2 injured. 
 
 Fig. 19. 
 One of four. Four Furnace Upright, 22ft. high, 10ft. 6in.
 
 BOILER EXPLOSIONS IN 1868. 
 
 diameter, T 7 ff inch plates, 40 Ibs. pressure. The boiler was rent into 
 nine pieces, one of which was not found. The dotted line in sketch 
 shows the outline of the boiler before explosion, and the fragments 
 are arranged as nearly as possible in their original position. The 
 first rent was at a seam-rip opposite the largest furnace, from whence 
 the rupture opened in every direction. This seam-rip must have 
 existed some time before explosion, and must have extended from 
 rivet to rivet, until the boiler was so much weakened as to be unable 
 to bear the usual pressure. 
 
 No. 36. Wimford. September 30th. 1 killed. 
 
 Plain Cylinder. Few particulars obtained. The end over the 
 fire burst open and allowed the contents to escape. A thick accumu- 
 lation of scale on the bottom had caused the plate to become 
 overheated by preventing proper contact of the water. 
 
 No. 37. Elsecar. (Fig. 20.) October 2nd. 2 killed. 
 
 Fig. 20. 
 
 One of four. Two Furnace Upright, 21ft. high, 7ft. diameter, 
 -j^ inch plates, 58 Ibs. pressure. A large piece of plate was blown 
 out of the side of the boiler, and the reaction of the issuing contents 
 threw the boiler over on to its side. The plate was said to be over- 
 heated from shortness of water, but as the centre tubes were 
 uninjured, the ruptured plate may have become overheated from the 
 intense heat impinging on one place, causing so rapid a generation 
 of steam as to prevent proper contact of water.
 
 BOILER EXPLOSIONS IN 1868. 
 
 No. 38. Glasgow. October 12th. 1 killed, 1 injured. 
 
 Plain Cylinder, 39ft. long, 5ft. diameter, inch plates. A small 
 piece of plate about one-and-half-feet area blew out of the bottom, 
 and the contents issued so violently as to do much damage, although 
 the boiler itself was not otherwise injured. The ruptured plate was 
 corroded to r ' 5 inch thickness by the leaking of seams, caused by 
 the feed water entering close to the bottom of the boiler. 
 
 No. 39. Swansea. October 13th. 2 killed, 1 injured. 
 
 One of twenty-four. One tube Cornish, worked by two furnaces, 
 23ft. long, 6ft. (tin. diameter. Tube 3ft 9in. diameter, inch 
 plates, 40 Ibs. pressure. The tube was divided by a wall down the 
 middle. The tube collapsed sideways. It was said that one side 
 was overheated through shortness of water, but it is more than 
 probable the explosion was owing to the weakness of so large a tube 
 without strengthening rings. 
 
 No. 40. Preston. October 16th. 2 injured. 
 
 This was an arrangement of pipes, called an " Economiser," placed 
 in the flues of a set of boilers for heating the feed water. It was- 
 shattered into fragments, causing considerable damage. As the 
 whole apparatus was said to be in proper order, the explosion had 
 been attributed to coal gas in the flues, and some peculiarities in the 
 ruptured pipes bear out the supposition. 
 
 No. 41. London, (fig. 21.) October 19th. 6 injured. 
 
 Fig. 21. 
 
 Kitchen Boiler, for supplying hot water to the top of a lofty 
 house. It was rectangular, 3ft. Gin. wide, 2ft. Gin. high, and 1ft. 
 deep. The front was blown out and caused considerable damage.
 
 BOILER EXPLOSIONS IN 1868. 
 
 The boiler was of most -weak shape, and although no pressure of 
 steam was intended, it appeared to have been overlooked that the 
 column of water to the top of the house would give sufficient 
 pressure to make such a boiler unsafe. 
 
 No. 42. London. (Fig. 22.) October 30th. 2 killed, 10 injured. 
 
 Fig. 22. 
 
 One tube Cornish, 15ft. long, 5ft. diameter, f inch plates, 50 Ibs. 
 pressure. Tube oval at fire end, 2ft. llin. wide, 2ft. Gin. high. 
 Circular beyond bridge, tapering to 2ft. diameter at back end. In 
 sketch outside shell is shown in dotted lines to allow tube to be 
 seen. The front of the tube burst beneath the fire bars, and rent 
 upwards. Tube collapsed beyond bridge and rent open at each side, 
 but remained intact over the fire. The oval part of the tube was of 
 so very weak a shape, that it burst open, and the collapse of the 
 back part followed as a consequence. 
 
 No, 43. Birmingham. (Fig. 23.) December 2nd. 1 injured. 
 
 Fig. 23. 
 
 Small Portable Boiler, 4ft. 9in. high, 2ft. Sin. diameter, J inch 
 plates, 40 Ibs. pressure. The shell was rent completely off. The 
 explosion arose from the large size of the manhole, which had no 
 guard ring on the edge, and the lid had strained it and caused several 
 cracks, and at last forced itself through the boiler, and the rents 
 spread in every direction, and caused the break up of the boiler.
 
 BOILER EXPLOSIONS IN 1868. 
 No. 44. Newcastle. (Fig. 24.) December \\th. 3 killed, 3 injured. 
 
 /ffft\ 
 
 WJ-JrM 
 
 Marine Upright, 13ft. Sin. high, 6ft. Gin. diameter, inch plates. 
 Internal fire-box 8ft. Gin. high, 6ft. diameter at bottom, 5ft. Sin. 
 diameter at the top, f inch plates, 50 Ibs. pressure. In the sketch 
 the shell is shown in dotted lines to allow the internal fire-box to be 
 seen. The boiler was rent into many pieces, many of which were 
 lost in a river, so that a satisfactory conclusion as to the cause of the 
 explosion was impossible. The boiler was not very firmly stayed, 
 and it is supposed that it was weakened by corrosion round the 
 fire doors. 
 
 No. 45. Hartlepool. 
 
 December 2Qth. 
 
 1 injured. 
 
 Marine, with 3 internal fireplaces joined at the back. The back 
 of the junction tube gave way at a place deeply corroded, and allowed 
 the contents of the boiler to escape. 
 
 NOTE. Two more illustrations may be given which are not 
 sufficiently important to include in the above list. 
 
 Wttlenhall. (Fig. 25.) December 24th. none injured. 
 
 One of two. Plain Cylinder, 25ft., Gin. long, 5ft. Gin. diameter,
 
 BOILER EXPLOSIONS IN 1868. 
 g inch plates, 30 Ibs. pressure. The water was allowed to get low, 
 
 Fig. 25. 
 
 and the overheated plates opened and allowed the steam to escape 
 harmlessly. 
 
 Stoke. (Fig. 26.) 
 
 December 9th. 
 
 none injured. 
 
 Fig. 26. 
 
 One of eight. Four Furnace Upright, 22ft. high, 9ft. diameter, 
 , 7 5 inch plates, 45 Ibs. pressure. The water was allowed to get so 
 low that the shell was overheated and rent, and the side tube slightly 
 collapsed, and the injury was not discovered until the feed water had 
 risen up to the rupture, when it ran into the furnaces without causing 
 any violent explosion, although cold water had been put into a 
 red hot boiler.
 
 STOURBRIDGE : 
 PRINTED BY R. BROOMHALL, HIGH STREET.
 
 BOILER EXPLOSIONS IN 1869. 
 
 No. 1. Chesterfield. (Fig. 1.) January 14th. 4 killed, 2 injured. 
 
 One of two. One tube Cornish, 26ft. Gin. long, 6ft. diameter, 
 tube 3ft. Sin. diameter, inch plates, 46 Ibs. pressure. The guage 
 glass was broken and the float was either out of order or unobserved, 
 as the water was allowed to get 9 inches below the usual level, so 
 that the crown of the furnace became overheated and collapsed, and 
 rent open where a patch had been put on some little time before. 
 
 No. 2. Manchester. (Fig. 2.) January 22nd. none injured. 
 
 lig. 2. 
 
 Locomotive. The barrel was 10ft. 6in. long, 4ft. diameter, 
 -j 7 5 inch plates, 130 Ibs. pressure. The engine was 14 years old,
 
 BOILEE EXPLOSIONS IN 1869. 
 
 and had lately been tested to 180 Ibs. hydraulic pressure. The 
 seams near the bottom were so deeply " furrowed " or corroded just 
 above the lap joint in a continuous line that they rent open. 
 
 No. 3. Greatlridge. (Fig. 3.)' January 26th. 1 kitted, 1 injured. 
 
 Fig. 3. 
 
 One of two. Plain Cylinder, with flat ends, 22ft. long, 4ft. Sin. 
 diameter, inch plates, 60 Ibs. pressure. There had formerly been 
 a tube -with internal furnace, and this had been removed without 
 sufficient stays to compensate for the loss of strength. The 
 plates were arranged in the weakest way with seams in one line 
 from end to end, and the strength of the boiler had been further 
 reduced by very frequent patching. Fracture commenced about the 
 centre of the long seam under the dome, which had gradually ripped 
 from rivet to rivet, until unable to bear the ordinary pressure. The 
 boiler exploded because it was completely worn out, and shows how 
 treacherous and uncertain a boiler becomes by constant patching 
 and alteration. See also No- 45. 
 
 No. 4. Rotherham. (Fig. 4.) January 27th. 
 
 1 injured. 
 
 One of five. Plain cylinder, with dished ends, 36ft. long, 
 4ft. 6in. diameter, j| inch plates, 55 Ibs. pressure. It had worked 
 about 8 years, and was much patched over the fire end, and had 
 lately been put into what was supposed to be thorough repair. As 
 there was no need of an inquest the wreck was quickly cleared and
 
 BOILER EXPLOSIONS IN 1869. 
 
 some of the fragments cut up, but enough particulars were obtained 
 to give some idea of the nature of the explosion. 
 
 Fig. 4. 
 
 The first rent must have taken place in the bottom seams over the 
 fire, where weakened by frequent reqair. 
 
 No. 5. Durham. (Fig 5.) February 2nd. 1 killed, 4 injured. 
 
 Fig. 5. 
 
 One of twelve. Plain cylinder, 13 years old, 30ft. long, 6ft. 
 diameter, f inch plates, 35 Ibs. pressure. The plates were arranged 
 lengthways, so that the seams were in continuous lines from end to 
 end. This has often been mentioned as giving far less strength 
 than where the plates are placed in rings. There had been consider- 
 able repair at various times, and just previous to explosion the boiler 
 had been placed as was supposed in thorough repair, and some new
 
 BOILER EXPLOSIONS IN 1869. 
 
 plates had been put over the fireplace. The first rent appears to 
 have taken place where one of these plates joined the old work. 
 The rent quickly extended along a straight seam, and the boiler was 
 blown into three pieces. The explosion was simply caused by the 
 boiler having been weakened by frequent repair until unable to bear 
 the ordinary working pressure. Externally fired boilers, when so 
 frequently patched become treacherous and uncertain, and more 
 especially so when the seams run from end to end. See No. 59. 
 
 No. 6. South Wales. February 12th. : 2 injured. 
 
 This was a colliery boiler. Yery few particulars were obtained. 
 The roof of the engine house was blown off, the boiler was torn 
 from its fittings and turned right round, and knocked down three 
 walls and fell in an upright position. 
 
 No. 7. Cornwall' (Fig. 6.) February 15th. none injured. 
 
 Fig, 6. 
 
 One of four. One tube Cornish, 37ft. Gin. long, 7ft. diameter. 
 Tube 4ft. 4in. diameter, T 7 ff inch plates, 40 Ibs. pressure. 
 
 The tube collapsed for the whole length beyond the bridge, and 
 the back end of boiler was blown out. The portion of tube over 
 the fire was left intact, and the fusible plug was uninjured. The 
 cause of the explosion was the weakness of the tube of such large 
 diameter and so great length. See No. 57. 
 
 No. 8. Yarmouth. (Fig. 7.) February 23rd. 3 injured. 
 
 Marine, 17ft. long, and 15ft. high, f inch plates, 15 Ibs. pressure. 
 The top was blown off, the plates having been extensively corroded.
 
 BOILER EXPLOSIONS IN 1869. 
 
 The boiler had also been much weakened by altering it from a round 
 to a flat top without sufficient stays. 
 
 Fig. 7. 
 No. 9. Drogheda- March 3rd. 2 injured. 
 
 The roof of a shed was blown off, but no particulars have been 
 obtained. 
 
 No. 10. West Bromwich. (Fig. 8.) March 9th. 
 
 3 injured. 
 
 Fig. 8. 
 
 One of two. Plain cylinder, 25ft. long, 4ft. 6in. diameter, inch 
 plates, 42 Ibs. pressure. The boiler had been very frequently 
 repaired, and a seam gave way where a large patch had just 
 previously been put on over the fire, in doing which the rivet holes 
 of the old work had evidently been cracked, rendering the boiler 
 unable to bear the usual working pressure. See No. 45.
 
 BOILER EXPLOSIONS IN 1869. 
 
 No. 11. Cornwall. March ISth. none injured. 
 
 One tube Cornish. The tube collapsed from want of water. 
 
 No. 12. Broscley- (Fig. 9.) April 1st. 1 killed, 4 injured. 
 
 Fig. 9. 
 
 Multitubular, 9 years old, 8ft. Gin. long, barrel 6ft. long, and 
 2ft. 4in. diameter, ^ inch plates, 50 Ibs. pressure. The cylinder 
 was attached to right side of the top of the boiler over the fire box, 
 and on the other side there was a very large manhole, the edges of 
 which were corroded, and so strained and cracked by the screwing up 
 of the manlid, as to be unable to bear the working pressure. The 
 rent started in all directions from the manhole allowing the boiler 
 to split up into three pieces. See Nos. 18 and 36. 
 
 No. 13. Cornwall. April llth. none injured. 
 
 One tube Cornish but no particulars. 
 
 No. 14. Barking- (Fig. 10.) April 19th. 4 killed, 2 injured. 
 
 Fig. 10.
 
 BOILER EXPLOSIONS IN 1869. 
 
 Portable Crane, 8 years old, 8ft. Sin. high, 4ft. 4in. diameter, 
 with internal fire box, 6ft. high and 3ft. Gin. diameter, and chimney 
 passing out at the top, -j 5 ff inch plates, 40 Ibs. pressure. The 
 internal fire box crushed in sideways, and the shell was rent into 
 several pieces. The attachment of the fire box to the shell was 
 made by bending the plates, as shown in enlarged sketch, and this 
 is not so rigid as double angle iron and had evidently strained the 
 chimney tube. This weakness had been so increased by deep cor- 
 rosion just at the bend of the plates that it had given way. The havoc 
 and loss of life was far greater than would have been supposed 
 possible from so small a boiler, but similar cases are mentioned in 
 No. 43, 1868, and No. 57, 1866. 
 
 No. 15. Durham- (Fig. 11.) April 2Srd. 
 
 none injured. 
 
 Fig. 11. 
 
 One of two. Plain cylinder, with plates arranged lengthways, 
 30ft. long, 6ft. diameter, $ inch plates, 9 Ibs. pressure. A seam 
 gave war on the right side over the fire and immediately rent along 
 the straight seam from end to end, and the boiler was thrown in 
 one mass a great distance to the left. The boiler was very old and 
 much weakened by frequent repair, and at the time of explosion 
 was being imprudently worked at twice its usual pressure for a 
 temporary purpose. See No. 59.
 
 BOILER EXPLOSIONS LN 1869. 
 No. 16. Bury. (Fig. 12.) April 29th. now* injured. 
 
 Fig. 12. 
 
 Double Furnace, internally fired, 28ft. long, 7ft. diameter, T 7 ff inch 
 plates, 55 Ibs. pressure. Furnace tubes 7ft. long, 3ft. diameter, 
 inch plates. The crown of the left hand furnace collapsed and 
 the right hand furnace was slightly altered in shape, as if from 
 overheating by shortness of water, although the true cause was 
 supposed to be the thickening of the water by use of anti-incrustation 
 composition, preventing proper contact of the water with the plates. 
 
 No. 17. Liverpool. (Fig. 13.) May 12th. 1 killed, 1 injured. 
 
 Fig. 13. 
 
 Plain cylinder, 10ft. long, 3ft. diameter, inch plates, 50 Ibs. 
 pressure. The ends were flat made of plates, with turned edges, 
 and there was such extensive corrosion on the inside of the bend 
 that the back end came out and was blown 30 yards to the right 
 and : \ rear, the rest of the boiler being thrown to the front. The 
 front plate had been repaired with angle iron where similarly 
 corroded, and the shell was also much patched. The fractured 
 edges were not T 1 g- inch thick, so that the boiler was not fit to carry 
 any pressure with safety.
 
 BOILER EXPLOSIONS IN 1869. 
 No. 18. Abingdon. (Fig. 14.) May 13th. 2 killed, 2 injured. 
 
 .%. 14. 
 
 Revolving Rag boiler, 16ft. long, 6ft. diameter, ^ in plates. 
 There was no fire applied to the hoiler itself, but it received steam 
 through one end from other ordinary boilers at 50 Ibs. pressure. 
 There were two large rectangular manholes for putting in and 
 taking out the rags, with cast iron frames and lids, attached by bolts 
 with large nuts or clamps. 
 
 The explosion appeared to have taken place when, in revolving, 
 the manlids were approaching the bottom, and the first part to give 
 way was at one of the manholes where the frame was previously 
 broken. The cause of the explosion was the weakness of the man- 
 holes, which were very large, and both in the same line, and the 
 attachment of the lids was insecure, as the bolts did not go through 
 the lids, or in any way help to compensate for the large portion of 
 the plate cut away. The boiler was only supported at each end, 
 and had to act as a hollow girder to bear not only its own weight but 
 the repeated shocks of the heavy material inside falling over and 
 over in addition to the pressure. See Nos. 41 and 63, 1866. 
 
 No. 19. Glasgow. May 19th. 1 killed, 1 injured. 
 
 Two tube Cornish. One of the tubes collapsed for a length of 
 8 feet having become overheated through shortness of water. 
 
 No. 20. Durham. (Fig. 15.) May 29th. 3 injured. 
 
 One of ten, 16 years old, Plain Cylinder with plates arranged 
 lengthways, 34ft. long, 5ft. 6in. diameter, j 7 a inch plates, 50 Ibs.
 
 BOILER EXPLOSIONS IN 1869. 
 
 pressure. The boiler gave way at one of the long straight seams 
 near the bottom, and rent into five pieces, which were scattered to 
 
 Fig. 15. 
 
 wide distances, but are so drawn in sketch as to show whereabouts 
 in the boiler they came from. The boiler had been weakened by 
 frequent repair until unable to bear the ordinary pressure. See 
 No. 59. 
 
 No. 21. South Wales. (Fig. 16.) May 31st. 5 killed, 4 injured. 
 
 lig. 16. 
 
 One of three, very old, plain Cylinder, with flat ends, 34ft. long, 
 6ft. diameter, g inch plates, 40 Ibs. pressure. There had formerly 
 been a tube through the boiler, and when this was taken away new 
 flat ends had been put in without sufficient stays to compensate for 
 the loss of the tube. The front end was blown out, and the 
 reaction sent the boiler upwards and broke it into three pieces. 
 See No. 47.
 
 BOILER EXPLOSIONS IN 1869 
 No. 22. Bingley. (Fig. 17.) June 9th. 15 killed, 33 injured. 
 
 Fig. 17. 
 
 Two tube Cornish, 16ft. long, 6ft. 9in. diameter, T 7 ff inch plates, 
 50 Ibs. pressure. Tubes 2ft. 6in. diameter. The bottom was so 
 much corroded that it rent open, and the boiler was torn to pieces 
 which were scattered to wide distances. The boiler had been much 
 neglected and badly used, and the safety valve was insufficient, of 
 bad construction, and overloaded, and the alarm whistle was gagged. 
 
 No. 23. Cornwall. June 14th. 
 
 Cornish, but no particulars have been obtained. 
 
 1 injured. 
 No. 24. Durham. (Fig. 18.) June 16th. 3 killed, 1 injured. 
 
 Fig. 18. 
 One of three. Plain Cylinder, with plates arranged lengthways,
 
 BOILER EXPLOSIONS IN 1869. 
 
 30ft. long, 6ft. Gin. diameter, f inch plates, 28 Ibs. pressure, 
 25 years old. 
 
 A seam gave way over the fire where there had been frequent 
 repair, and the boiler was rent into two pieces, which were thrown 
 to some distance. See No. 59. 
 
 No. 25. Airdrie. 
 
 June 23rd. 
 
 2 killed, 3 injured. 
 
 Two tube Cornish, 35ft. long, 6ft. diameter. Tube 3ft. 2in. 
 diameter over fire, and 2ft. diameter beyond, 60 Ibs. pressure. 
 The tube collapsed over the fire, having been very much weak- 
 ened by frequent repair. 
 
 No. 26. Nuneaton. (Fig. 19.) July 5th. 
 
 3 injured. 
 
 Fig. 19. 
 
 Plain Cylinder, 25ft. long, 4ft. 6in. diameter, fa inch plates, 
 25 Ibs. pressure. The plates along the line of rupture were corroded 
 to -j 1 ^ inch, and in some places much less, so that the boiler was 
 quite unfit for the ordinary working pressure.
 
 BOILER EXPLOSIONS IN 1869. 
 No. 27. Birmingham. (Fig. 20.) July 6th. 
 
 1 injured. 
 
 Fig 20. 
 
 Small Plain Cylinder, 5ft. long, 2ft. 2in. diameter, \ inch plates, 
 25 Ibs. pressure. Both sides of the boiler were corroded nearly 
 through so that the strength was entirely gone, and it rent in two 
 at the ordinary pressure. 
 
 No. 28. Wishaw. July 9th. 2 killed, 2 injured. 
 
 One of six. Breeches Tube. The tube or combustion chamber 
 collapsed, having become overheated through shortness of water. 
 
 No. 29. Kidderminster. (Ffy. 21.) July 16th. 1 killed, 4 injured. 
 
 Fig. 21. 
 
 Plain Cylinder, 21ft. long, 4ft. Gin. diameter, f inch plates, 
 50 Ibs. pressure. The boiler was very old and very much corroded. 
 It had slightly rent open at some former time, and a most wretchedly 
 made patch, shown in enlarged sketch, had been put on to stop 
 leaking, made of thin sheets of iron inside and out and pasteboard 
 between, held together by 36 slight bolts. Of course this patch did 
 not restore the strength of the boiler, and it soon leaked badly, and
 
 BOILER EXPLOSIONS IN 1869. 
 
 the leaking hastened the corrosion of the plate below, until it was 
 nearly eaten away, and quite unfit to bear the working pressure. 
 
 No. 30. Leeds. July IQth. 4 injured. 
 
 One of three, 12 years old. Two tube Cornish, 32ft. long, 
 7ft. 6in. diameter. Tube 2ft. lOin. diameter, g inch plates, 45 Ibs. 
 pressure. The right hand tube collapsed from end to end sideways, 
 and ruptured in the furnace, and part of the tube was blown out. 
 The cause of the explosion was simply the weakness of the tube 
 without strengthening rings 
 
 No. 31. South Wales. (Fig. 22.) July 19th. 1 killed. 
 
 Fig. 22. 
 
 One of two. Plain Cylinder, 32ft. long, 5ft. diameter, $ inch 
 plates, 40 Ibs. pressure. It gave way where deeply corroded on 
 the inside. 
 
 No. 32. Burslem. (Fig. 23.) July 22nd. 1 killed, 3 injured. 
 
 One of six. Plain Cylinder, 36ft. long, 6ft. diameter, inch 
 plates, 50 Ibs. pressure. Although the boiler was not an old one, 
 it had been much repaired at the seams with strap plates. It was 
 said that the water was very bad, and deposited much mud, which 
 allowed the seams to get overheated and injured. The seam which
 
 BOILEE EXPLOSIONS IN 1869. 
 rent was an original one, and no doubt was ripped as the others had 
 
 Fig. 23. 
 
 been before repair, and that this rip extended from hole to hole 
 until a rupture at the ordinary pressure was the result. 
 
 No. 33. Preston. 
 
 August 4th. 
 
 1 killed. 
 
 Locomotive. In shunting the engine was dragged under a bridge 
 that was not intended for locomotives to pass, and the dome was 
 knocked off. 
 
 No. 34. London. (Fig. 24.) August llth. 
 
 3 killed. 
 
 Fig. 24. 
 
 Marine, 8ft. long, 5ft. Gin. diameter, inch plates, 80 Ibs. pressure- 
 The flat front end gave way at the angle iron all round, allowing 
 the front with tubes attached, and the shell to be thrown in opposite 
 directions. 
 
 The front being flat was very weak, and depended for its strength 
 on gusset stays and small bolts connecting the back of the combus- 
 tion chamber and the round end of the shell. These stays were
 
 BOILER EXPLOSIONS IN 1869. 
 
 very defective and insufficient, and the angle iron was bad and not 
 welded into one ring, and the boiler was therefore unfit to bear the 
 ordinary pressure, and gave way at the weakest place. 
 
 No. 35. Cornwall. (Fig. 25.) August 16tk. 
 
 none injured. 
 
 Fig. 25. 
 
 One tube Cornish, 32ft. long, 6ft. 6in. diameter. Tube 4ft. 
 diameter, ^ inch plates, 40 to 50 Ibs- pressure. There was no 
 steam guage. 
 
 The tube collapsed from end to end, both ends being torn, but the 
 boiler was not moved from its seat. The fusible plug was uninjured. 
 The cause of the explosion was the weakness of the large tube. 
 See No. 57. 
 
 No. 36. Leicester. (Fig. 26.) September 1st. 
 
 1 injured. 
 
 Fig. 26. 
 
 Upright, 5ft- Gin. high, 4ft. diameter, ^ inch plates, 40 Ibs. 
 pressure. The top of the boiler was blown out- The rent com- 
 menced in the manhole, which was unguarded by a ring, and cracks 
 two inches long had existed before explosion. See Nos. 12 and 18.
 
 BOILES EXPLOSIONS IN 1869 
 No. 37. Preston. (Kg. 27.) September 3rd. 1 killed, 1 injured. 
 
 Fig. 27. 
 
 One of two. Two tube Cornish, 30ft. long, 7ft. 2in. diameter. 
 Tube 2ft. Sin. in furnaces, and 2ft. 4in. beyond, f inch plates, 50 Ibs. 
 pressure. 
 
 The left furnace crown collapsed and ruptured, and the right 
 furnace crown was slightly altered in shape. The two boilers were 
 connected by one feed pipe without back valves, so that the water 
 from this boiler was forced into the other and allowed the tubes to 
 be overheated. 
 
 No. 38. Liverpool. (Fig. 28.) September Bth. 1 killed, 1 injured. 
 
 Kg. 28. 
 
 One tube Cornish, 22ft. Gin. long, 6ft. diameter, 3ft. tube, T r y inch 
 plates, 55 Ibs. pressure. 
 
 The tube collapsed over the fire. It was so much thinned by 
 corrosion, and so many of the rivet heads were eaten off, that there 
 was not strength left to bear the ordinary pressure.
 
 BOILER EXPLOSIONS IN 1869. 
 No. 39. Boxmoor. (Fig. 29.) September 10th. 1 killed, 4 injured. 
 
 Fig. 29. 
 
 One of three. One tube Cornish, 27ft. 3in. long, 5ft. diameter. 
 Tube 2ft. lOin. over furnace, and 2ft. Sin. beyond, f inch plates, 
 40 Ibs. pressure. One ring of plates was blown out of the back 
 end of shell. 
 
 There was such extensive external corrosion on the seating at the 
 bottom that the boiler was unable to bear the working pressure. 
 
 No. 40. Hull. (Fig. 30.) September 16th. 1 killed, 1 injured. 
 
 Fig. 30. 
 
 Breeches Tube, 13 years old, 30ft. long, 7ft. diameter. Furnace 
 tube 2ft. lOin. diameter. Main tube 3ft. 5 Jin. diameter, and 
 originally made to work at 20 Ibs. pressure, but working lately at 
 45 Ibs. The main tube collapsed. The boiler was not adapted for 
 the pressure at which it was worked, and the tube was much 
 weakened by the overheating caused by a thick incrustation of scale, 
 and was not strengthened by any rings or stays, and was of very 
 weak construction as the plates were arranged lengthways.
 
 BOILER EXPLOSIONS IN 1869. 
 No. 41. South Wales. (Fig. 31.) September 26th. 1 killed, 1 injwred. 
 
 Fig. 31. 
 
 One of two, 20 years old. Plain Cylinder, 36ft. long, 6ft. 6in. 
 diameter, -^ inch plates, 35 Ibs. pressure. 
 
 The plates and rivet heads were very much reduced in thickness 
 by internal corrosion, and in many places were only inch or less. 
 
 October 6th. 2 killed, 6 injured. 
 
 Two tube Cornish, 22ft. long, 7ft. 6in. 
 
 No. 42. Warrington. 
 
 One of seventeen, 
 diameter. Tube 2ft. 6in. diameter, T 7 g- inch plates, 45 Ibs. pressure. 
 
 The left hand tube collapsed. The blow-off cock was left open 
 until the water was so low as to allow the tube to be overheated. 
 
 No. 43. Rowley. (Fig. 32.) October 13th. 
 
 none injured. 
 
 Fig. 32. 
 
 Plain Cylinder, with flat ends, 15ft. long, 3ft. lOin. diameter, 
 g inch plates, 25 Ibs. pressure. 
 
 The back end ripped all round the angle iron, and was blown out, 
 and the rest of the boiler was thrown forward a considerable 
 distance.
 
 BOILEK EXPLOSIONS IN 1869. 
 
 There had once been an internal tube, and when this was taken 
 out the flat end had no stay, and was unfit to bear the usual 
 pressure. See No. 47. 
 
 JVo. 44. Newcastle. (Fig. 33.) October \Wh. 2 killed, 5 injured. 
 
 Fig. 33. 
 
 Plain Cylinder, with plates arranged lengthways, 29ft. long, 6ft. 
 diameter, f inch plates, 25 Ibs. pressure. 
 
 Although only 3 years old the boiler had always given trouble, 
 and had been very frequently repaired. Some new plates had just 
 been put in the bottom, and as the primary rent was in the old 
 plates adjoining them, it is most likely they had caused seam rips 
 in the old metal. 
 
 The frequent repair had reduced the strength until unequal to 
 bear the ordinary pressure. See No. 59. 
 
 No. 45. Greatbridge. (Fig. 34.) October 18th. 2 killed, 2 injured. 
 
 Fig. 34. 
 One of eight, 15 years old. Plain Cylinder, 40ft. long, 6ft.
 
 BOILER EXPLOSIONS IN 1869. 
 
 diameter, inch plates. The boiler had originally carried 60 Ibs., 
 but lately only 40 Ibs. The boiler had been worked very hard, and 
 had been so often repaired, that many of the seams were continuous 
 for a long distance without break of joint, so that its strength was 
 reduced until unable to bear the ordinary pressure. 
 
 The treacherousness and uncertainty of boilers with one patch 
 over another has often been pointed out, as in Nos. 3, 4, 10, and 32. 
 
 No. 46. Accrington. (Fig. 35.) October 19th. 2 killed, 3 injured. 
 
 Fig. 35. 
 
 One tube Cornish, 14ft. 6in. long, 5ft. diameter. Tube 2ft. lOin. 
 diameter, T 7 5 inch plates, 40 Ibs. pressure usually, and sometimes 
 60 Ibs. One ring of plates was blown out of shell. 
 
 The boiler was so very badly corroded at the bottom, that the edges 
 of the rent were quite sharp like a knife, and the boiler was there- 
 fore unable to bear the usual working pressure. The flues were too 
 narrow to enter for proper inspection, and the bearing surfaces were 
 too wide and retained moisture against the plates. 
 
 No. 47. Lydney. (Fig. 36.) October 
 
 1 tilled. 
 
 Fig. 36.
 
 BOILER EXPLOSIONS IN 1869. 
 
 One of four. Plain Cylinder with round front and flat back end, 
 36ft. long, 6ft. diameter, -j 7 5 inch plates, 20 Ibs. pressure. 
 
 The flat end \vas blown out, the rent extending all round the 
 angle iron. 
 
 There had originally been a breeches tube in the boiler with a 
 strong stay to the front end, but when this was taken out no stays 
 were put to the flat end to compensate for the loss of their support. 
 The angle iron attaching the flat end was made in four pieces instead 
 of being welded, and it was reduced to ^ inch thick by external 
 corrosion, so that it was not strong enough to bear the ordinary 
 working pressure. 
 
 The extreme imprudence of altering boilers without due care to 
 preserve their strength has been often pointed out. See Nos. 21 
 and 43. 
 
 No. 48. Newcastle. (Fig. 37.) October 29th. none injured. 
 
 Fig. 37. 
 
 One of six. Plain Cylinder, with plates arranged lengthways, 
 40ft. long, 5ft. Sin. diameter, 40 Ibs. pressure. 
 
 The boiler gave way at the fire end, and divided in two, and both 
 pieces were blown to a great distance. The boiler was old and had 
 been much repaired, and the seams running from end to end made 
 it very weak, but the immediate cause of the rupture was supposed 
 to be shortness of water and consequent overheating of the plates. 
 See No. 59.
 
 BOILER EXPLOSIONS IN 1869. 
 No. 49. StocTcport. October 80th. 
 
 1 killed. 
 
 Fig. 38. 
 
 One of eight. Two tube Cornish, 30ft. long, 7ft. 4in. diameter. 
 Tube 2ft. 1 lin. diameter, f inch plates, 50 Ibs. pressure. 
 
 The crown of the right hand tube became overheated from short- 
 ness of water, and bulged down and rent half round at the second 
 seam of rivets. 
 
 No. 50. Durlwm. (Fig. 38.) November 2nd. 
 
 1 injured. 
 
 Fig. 39. 
 
 One of four. Plain Cylinder, with the plates arranged length- 
 ways, 33ft. long, 6ft. Gin. diameter, | inch plates, 35 Ibs. pressure. 
 A seam over the fire slightly to the right side gave way where there 
 had been frequent repair to stop leaking. At the part which gave 
 way there had formerly been a side fire, which had perhaps damaged 
 the seams. This boiler was known to have been in bad condition 
 and needing repairs. See No. 59.
 
 BOILER EXPLOSIONS IN 1869. 
 
 No, 51. Sheerness. (Fig. 39.) November 3rd. 11 killed, 7 injured. 
 
 Fig. 40. 
 
 One of three. Marine, 15ft. 6in. long, 6ft. diameter. Furnace 
 Tube 2ft. 4in. diameter, f inch plates, 80 Ibs. pressure. 
 
 The left hand tube collapsed and ruptured, and the contents issued 
 at the front and scalded all near. The right hand tube was also 
 slightly out of shape on the top. 
 
 The cause of the collapse was, that the water had been allowed 
 to get below the crowns of the furnaces. There was no means of 
 ascertaining how the shortness of water occurred, as all were killed 
 who had the opportunity of knowing. 
 
 No. 52. Cornwall. (Fig. 40.) November 25th. 1 injured. 
 
 Fig. 41.
 
 BOILER EXPLOSIONS IN 1869. 
 
 One of five, 30 years old. One tube Cornish, 36ft. long, 7ft. 
 diameter. Tube 3ft. 1 Oin. diameter, T 7 5 inch plates, 40 Ibs. pressure. 
 
 The shell was rent into several large pieces and thrown to some 
 distance. The tube was also thrown out and broken, chiefly by its 
 fall and striking against walls. 
 
 The boiler was corroded very badly on the seating, which must 
 have been known, as there were numerous small screw patches to 
 prevent leaking at the corroded places. The shell was in such bad 
 condition, that it was quite unfit to bear the ordinary working 
 pressure. See No. 58. 
 
 No. 53. Bilston. (Fig. 42.) December 3rd. 8 killed, 1 injured. 
 
 Eig. 42. 
 
 One of three. Four Furnace Upright, 20ft. high, 10ft. diameter. 
 Centre tube 10ft. high, 4ft. Gin. diameter, side tubes 2ft. diameter, 
 inch plates, 35 Ibs. pressure. 
 
 The central tube collapsed, and the bottom part was blown out,
 
 BOILER EXPLOSIONS IN 1869. 
 
 and allowed the contents of the boiler to issue from the bottom into 
 the culvert leading to the stack, and into the necks of the furnaces 
 from which it was heated. The reaction sent the boiler up to a 
 great height, and it divided into eleven fragments, which were very 
 widely scattered. Comparatively little damage was done to the 
 furnaces and premises, only the brickwork surrounding the boiler 
 being thrown down. 
 
 Although it had only worked a short time at this place, it was 
 very old, and the central tube was corroded until only inch thick 
 in many places, and many of the rivet heads were quite eaten away. 
 It was altogether so worn out that it was quite unfit to work at 
 any pressure. 
 
 No. 54. Cornwall. (Fig. 43.) December 6th. none injured. 
 
 Kg. 43. 
 
 One tube Cornish, 32ft. long, 6ft. diameter. Tube 4ft. diameter, 
 1 ^ inch plates, 40 to 50 Ibs. pressure. The tube collapsed from 
 end to end, and the front portion was blown out with the front end, 
 and the back end was left attached to the shell, and but little moved 
 from its seat. 
 
 The cause was doubtless the weakness of such a large tube. 
 
 This is the third explosion at this engine. One of the previous 
 explosions is discribed at No. 35. 
 
 No. 55. Stonehaven. December 9th. 
 
 Locomotive, but no particulars have been obtained. 
 
 2 injured. 
 
 No. 56. Cornwall. (Fig. 44.) December 10th. none injured. 
 One tube Cornish, 26ft. long, 6ft, 6in. diameter, tube 3ft. lOin.
 
 BOILER EXPLOSIONS IN 1869. 
 
 diameter, -jj inch plates, 40 Ibs. pressure. The tube collapsed and 
 ruptured in the central part from weakness. 
 
 // 
 
 Fig. 44. 
 No. 57. Cornwall. (Fig. 45.) December l\th. none injured. 
 
 Pig. 45. 
 
 One tube Cornish, 32ft. long, 6ft 6in. diameter. Tube 4ft. 
 diameter, f inch plates, 60 Ibs. pressure. 
 
 It was an old boiler, and some of the plates of the tube were 
 thinned by corrosion, but it had only just been put to work at this 
 place, and burst the first day of working. 
 
 The tube collapsed beyond the bridge, and the back part with the 
 back end plate was blown out to a great distance The front end 
 was also ruptured, and the whole boiler was sent forwards The 
 tube over the fire had not collapsed. The cause of explosion was 
 the weakness of such a large tube without strengthening rings. 
 
 Many similar boilers have exploded in the same way from the 
 same cause, as described in Nos. 28, 30, 35, 40, 54, and 56. 
 
 No. 58. Cornwall. (Fig 46.) December 14th. 2 killed. 
 
 One tube Cornish, 26ft. Sin. long, 6ft. diameter. Tube 3ft. lOin.
 
 BOILER EXPLOSIONS IN 1869. 
 
 at front end, and 3ft. beyond, ^ s inch plates, 40 Ibs. pressure. 
 The shell was rent into several pieces, which were scattered to 
 wide distances. The tube was also thrown to a great distance, but 
 was uninjured. The boiler was 36 years old. The shell was very 
 badly corroded, and temporarily repaired with screw patches to stop 
 
 Fig. 46. 
 
 leaking, so that the boiler was unfit to bear the usual pressure. 
 See No. 52. 
 
 No. 59. Durham. (Fig. 47.) December 29th. 2 killed, 1 injured 
 
 Fig. 47. 
 
 One of three Plain Cylinder, with plates arranged lengthways, 
 47ft. long, 6ft. diameter, inch plates, 30 Ibe pressure. It gave
 
 BOILEB EXPLOSIONS IN 1869. 
 
 way at the seams over the fire, where the edges of the plates had 
 been injured by injudicious and excessive repairing and caulking. 
 The pieces were sent to great distances. The weakness of boilers 
 with seams from end to end in continuous lines has often been 
 pointed out. Eight of the exploded boilers this year, Nos 5, 15, 
 20, 24, 44, 48, 50, and 59, and many others in former years were 
 of the same objectionable construction. 
 
 The following, not being steam boilers, are not included in the 
 list, but the details may be useful. 
 
 Oldbury. March 10th. 4 killed. 
 
 Tar Still, 10ft. high, 7ft. diameter, with round top and domed 
 bottom, g inch plates, and not intended to work at any pressure. 
 The vapour passing away became congealed, and stopped up tho 
 small exit pipe, and pressure accumulated sufficiently to burst the 
 weak shaped vessel. 
 
 The bottom came completely out and was left upon the fire, while 
 the top ascended to a great height and fell a long distance away. 
 The loss of life was owing to the material igniting and suffocating 
 those who were thrown down by the explosion. 
 
 Greatbridge. December 29th. 2 killed. 
 
 Tar still, 12ft. high, 12ft. diameter, inch plates, and not used 
 at any pressure usually. 
 
 The upper part separated from the bottom, rending in the angle iron 
 all round. The angle iron near the outlet pipe was corroded nearly 
 away, as shown in enlarged sketch, and the rivet heads were eaten 
 completely off.
 
 BOILER EXPLOSIONS IN 1869. 
 
 It was supposed that the intense frost, during a long stoppage for 
 holidays, had caused the worm to be stopped up and pressure to 
 
 accumulate, as in the one previously described. But it is perhaps 
 more probable that the vessel gave way because it was corroded so 
 thin in so important a part as the angle iron. The explosion was 
 very slight, the damage and loss of life being from the fierce fire 
 which immediately succeeded it. 
 
 Darlington. August 26th 2 injured. 
 
 Domestic. Eectangular, and made of wrought iron. The front 
 blew out. It was said that all the communication pipes were shut, 
 and therefore steam accumulated until the weakest part gave way. 
 
 Manchester. 
 
 December 29th. 
 
 1 killed, 1 injured. 
 
 The sketch is to a much larger scale than the others-
 
 BOILEK EXPLOSIONS IN 1869. 
 
 Domestic, 14in. wide, llin. high, and about lOin. deep, made of 
 cast iron J inch thick- It had close top and two circulating pipes to 
 warm a bath about 10ft. above it. The supply cistern was about 
 17ft. above the boiler. The front was blown out into the kitchen. 
 It was said that the pipes were frozen, and that steam pressure had 
 thus accumulated. 
 
 The boiler was of a treacherous material and weak shape, and 
 unfit to bear safely the 7 Ibs. pressure the column of water from the 
 cistern would give. The fire also acted on the sides of the boiler 
 without any intervening brickwork. If a closed top boiler is used, 
 there should be a dead weight safety valve to prevent pressure. 
 A far safer plan is to have the kitchen boiler with open top and 
 the circulating heater within it, so that it can never get overheated, 
 as it only obtains its heat from the water in the open boiler. 
 
 R. Eroomhall, Printer, Stourlridge.
 
 BOILER EXPLOSIONS IN 1870. 
 
 No. 1. Newcastle. (Fig. \.) January 1th. 3 killed, 1 injured. 
 
 One of five. Cornish, 13 years old, 30ffc. long, 6ft. 6in. diameter. 
 Tube 3ft. Sin. diameter, f inch plates, 30 Ibs. pressure. Tube 
 collapsed sideways from weakness, and the front part and the front 
 plate were blown out, carrying the attendants into a deep and 
 swollen river which ran close in front of boilers. 
 
 No. 2. South Wales. (Fig. 2.) January 15th. 1 killed, 4 injured. 
 
 Plain cylinder, very old, 32ft. long, 5ft. diameter, T 7 ff inch plates, 
 30 Ibs. pressure. Externally corroded to -fa inch, and gave way 
 near a seam, the front being thrown forward into a house, and the
 
 BOILEB EXPLOSIONS IN 1870. 
 
 back end 150 yards to the rear, carrying away the stack. It had 
 been badly repaired with bolted patches which had hastened cor- 
 
 Fig. 2. 
 
 rosion, and as it was known to be nearly worn out, it was to have 
 been replaced in a few days. 
 
 No. 3. WorTcsop. (Fig. 3.) January 28th. 
 
 2 killed. 
 
 Fig. 3. 
 
 Domestic, 2ft wide, 1ft. lOin. high, and 7in. deep, f inch plates, 
 with badly welded joints. The circulating pipes to cistern, 15ffc. 
 above, were frozen, and steam pressure accumulated and blew out 
 the front. 
 
 No. 4. Ipswich. (Fig. 4.) February 4th. 
 
 Fig, 4. 
 
 1 killed.
 
 BOILER EXPLOSIONS IN 1870. 
 
 One of three. Cornish, 7 years old, 24ft. long, 5ft. diameter. 
 Tube 3ft. diameter, T 7 5 inch plates, 65 Ibs. pressure. The boiler 
 was good and well fitted, but an accumulation of salt on tube caused 
 overheating and rupture of 3rd seam. 
 
 No. 5. Sheffield. (Fig. 5.) February 8tt. 2 killed, 6 injured. 
 
 One of three. Eag Boiler, 2 years old, lift, diameter, 9ft. 
 deep, -j 7 5 inch plates. Steam was supplied from the engine exhaust, 
 and was usually about 10 Ibs. pressure, but as the boilers from 
 which the steam was originally supplied worked at 60 Ibs., it is 
 possible this was sometimes exceeded. The vessel was of very weak 
 shape for even 10 Ibs. pressure. 
 
 No 6. Derby. (Fig. 6.) February 14th. 1 killed, 2 injured. 
 
 Fig. 6. 
 
 Domestic, 1ft. high, 1ft. wide, Sin. across top, and I2in. across 
 bottom, made of cast-iron, T 7 ff inch thick. The fire had been let out 
 sometime, and the circulating pipes to cistern 16ft. above were 
 frozen, and on lighting fire steam was formed for which there was 
 no escape, and the boiler was shattered.
 
 BOILER EXPLOSIONS IN 1870. 
 No. 7. Sheffield. (Fig. 7.) February 14th. 2 killed, 1 injured. 
 
 \ ' . " 
 
 f.' it -* 
 *. i 
 
 !a. I 
 
 Domestic, used for warming rooms above, 2ft. 6in. wide, 2ft. 
 high, 9in. across top, and 13in. across bottom, f inch plates. The 
 circulating pipes to cistern, 12ft. above, were frozen, and steam was 
 formed for which there was no vent, and boiler was rent open. The 
 joints were so badly welded that they soon gave way, and little 
 damage was done to property. 
 
 No. 8. Walsall. (Fig. 8.) February 19th. 
 
 none injured. 
 
 Fig. 8. 
 
 One of two. Plain cylinder," 12 years old, 30ft. long, 7ft. 
 diameter, inch plates, 50 Ibs. pressure. The seams and plates
 
 BOILEB EXPLOSIONS IN 1870. 
 
 were overheated by shortness of water, and gave way at ordinary 
 pressure. It is supposed the water " kicked " into the other boiler, 
 as there was no back valve to prevent this whenever one boiler 
 happened to be fired a little harder, and consequently at slightly 
 higher pressure than the other. There was no damage except to 
 the boiler. 
 
 No. 9. Birmingham. (Fig. 9.) February 25th. none injured. 
 
 Fig. 9. 
 
 Cornish, 5 years old, 32ft. long, 7ft. diameter. Tube 2ft. 4in. 
 diameter, -fa inch plates, 30 Ibs. pressure. Cracked along the 
 bottom of front end where internally " furrowed." The boiler was 
 not disturbed, but as the water escaped into an iron furnace the 
 bricks were scattered, but little damage done. The boiler was 
 intended for two tubes, and therefore there was a large part supported 
 only by stays, allowing of a slight movement with varying pressure 
 which facilitates the corrosion in certain lines of strain called 
 " furrowing." In this case they were so close to the angle iron 
 and filled with scale that they were difficult to detect. 
 
 .ZVo. 10. Cornwall. (Fig. 10.) March I7tk. 5 injured. 
 
 Fig. 10. 
 
 Upright Boiler, 2 ft. high, 1ft. 9in. diameter, i inch plates. It
 
 BOILER EXPLOSIONS IN 1870. 
 
 gave way where deeply corroded externally round the bottom angle 
 iron. The top was blown through the roof and did considerable 
 damage, the bottom being left in the grate. 
 
 No. II. Sheffield. (Fig.ll.} March 27th. 
 
 I injured. 
 
 Fig. 11. 
 
 Agricultural or Contractor's Engire, 9ft. 2in. long, 2ft. 6in. 
 diameter, inch plates, 30 Ibs. pressure. The heads of stays on 
 each side were corroded outside and drew through the holes, 
 allowing the angles of fire box to open. Boiler was not disturbed 
 and no damage was done. 
 
 No. 12. Portsmouth. (Fig. 12. ) March 29th. 3 killed, 1 injured. 
 
 Fig. 12. 
 One of two. Cornish, 9 years old, 22ft. long, 6ft. diameter.
 
 BOILER EXPLOSIONS IN 1870. 
 
 Tube 3ft. diameter, f inch plates, 40 Ibs. pressure. Gave way at 
 midfeather wall where corroded to ^ inch, at a place where flues 
 were too narrow to enter. Two rings of plates were torn out and 
 blown into an adjoining street, while the reaction of the escaping 
 contents forced the boiler into a building in a very singular manner, 
 doing very great damage. This case is of peculiar interest, because 
 although the cause of explosion was so plain to see, all the old 
 theories of decomposition of steam, and ignition of hydrogen, were 
 revived, and it was even stated that " a bad boiler could not 
 explode, as the corroded part would give way, and allow the 
 steam to escape harmlessly," and any cause seemed to be con- 
 sidered more probable than the plain and simple one, that it was 
 corroded to the thickness of card board. Like many other examples 
 this explosion shows that however well a boiler is tended, it should 
 be examined in the flues to make sure that it is safe. 
 
 No. 13. Manchester. March 30th. 
 
 2 killed, 3 injured. 
 
 Underground. Some alterations were being done to some brick 
 arching, which fell upon and broke steam pipes, and the escape of 
 steam suffocated those near. 
 
 No. 14 Warrington. (Fig. 13. J April 15th. 6 killed, 3 injured. 
 
 Fig. 13.
 
 BOILER EXPLOSIONS IN 1870, 
 
 Lancashire, used for evaporation only, 24ft. 6in. long, 8ft. 
 diameter, f inch plates, and usually worked with .little or no 
 pressure. 
 
 The boiler was very old and much patched, and incapable of 
 bearing the 15 Ibs. pressure which was temporarily put upon it. 
 
 No. 15. Scotland. April 18th. none injured. 
 
 Plain cylinder, said to have exploded from shortness of water, 
 but no particulars have been obtained. 
 
 No. 16. Cornwall. (Fig. 14.) April l&th. 1 killed, 1 injured. 
 
 One of two. Cornish, very old, 34ft. long, 6ft. diameter. Tube 
 3ft. lOin. diameter, inch plates, 50 Ibs. pressure. The tube 
 collapsed and the front part was blown out, and the boiler was 
 forced back a little. It was said to have been short of water, but 
 the weakness of a tube of such large diameter was most likely the 
 true cause. 
 
 No. 17. Wellington. (Fig. 15.) April 22nd. none injured. 
 
 One of two. Balloon, very old, lift, high, 9ft. 6in. diameter, 
 | inch plates, 5 Ibs. pressure. The bottom was corroded externally
 
 BOILER EXPLOSIONS IN 1870. 
 
 to inch, and temporarily repaired with screw patches, and was 
 so reduced in strength that it gave way at the ordinary pressure. 
 
 Fig. 15. 
 
 The top was blown about 20 yards away, but little damage 
 was done. 
 
 No. 18. Cornwall. 
 
 May. 
 
 none injured. 
 
 Cornish, 30ft. long, 6ft. diameter. Tube 3ffc. Gin. diameter, 
 40 Ibs. pressure- Boiler gave way under bottom where corroded 
 very thin, but little damage was done. 
 
 No. 19. Darlaston. (Fig. 16.^ May. 
 
 none injured. 
 
 Fig. 16. 
 
 Cornish, 15ft. long, 4ft. Sin. diameter. Tube 1ft. 6in. diameter, 
 T 7 ff inch plates, 40 Ibs. pressure. Tube collapsed and ruptured, 
 having been softened by overheating through shortness of water. 
 Yery little damage was done. 
 
 No. 20. Westlromwich. (Fig. 17.) May 12th. 2 killed. 
 
 One of three- Plain cylinder, 5 years old, 34ft. long, 6ft-
 
 BOILER EXPLOSIONS IN 1870. 
 
 diameter, T 7 g- inch plates, 45 Ibs. pressure. Gave way by the rent 
 of a ripped seam over the fire, which had been repeatedly tempo- 
 rarily patched without restoring the strength or stopping the rip. 
 
 Fig. 17. 
 
 Three rings were torn out of the middle, while the front end was 
 blown into the bed room of a house, and the back part of the boiler 
 was thrown across a canal through two walls into a distant street. 
 Great damage was done. 
 
 No. 21. Dublin- (Fig. 18 J May 18th. 3 killed, 6 injured. 
 
 H@ffir^\ 
 
 Fig. 18. 
 
 Cornish. Second-hand, but just started at this place, 26ft- long, 
 6ft. diameter. Tube 3ft. diameter, f inch plates, 40 Ibs- usual 
 pressure. Tube collapsed from end to end. The pressure at time 
 was supposed to be 70 Ibs., and as there was no evidence of shortness 
 of water, it is presumed the tube gave way from weakness. The 
 boiler was moved forward about 20 feet, but much damage was 
 done to premises.
 
 BOILEK EXPLOSIONS IN 1870. 
 No. 22. Bury. (Fig. 19.) May 25th. 
 
 none injured' 
 
 Fig. 19. 
 
 Domestic Saddle, 5ft. long, 3ft- high, 2ft- 6in. wide, $ inch 
 plates, 15 Ibs. pressure, the cistern being 30ft- above. There were 
 no stays between the inner and outer shell, and the space between 
 them was too small to allow proper circulation of water to keep the 
 plates from overheating, so that it was hardly fit for its ordinary 
 pressure, and the top was blown off. 
 
 No. 23. Kidsgrove. (Fig. 20.) May 26th. 13 lotted, 9 injured- 
 
 Fig. 20. 
 
 One of three. Four Furnace Upright, 12 years old, 17ft. 6in. 
 high, 9ft. diameter. Centre tube 5ft. 9in. diameter, f inch plates, 
 40 Ibs. pressure. The centre tube was much corroded on the inside 
 and collapsed inwards from consequent weakness, allowing the 
 contents to issue at the bottom of the boiler, and the reaction 
 sent the whole boiler high up into the air, and on to a roof causing 
 great damage.
 
 BOILEE EXPLOSIONS IN 1870. 
 24. Lowestoft. (Fig- 21. ) May 27th. 
 
 2 killed. 
 
 W 
 
 Fig. 21. 
 
 Crane or Donkey boiler on board a vessel. About 6ft. high, and 
 3ft. diameter, 25 Ibs. pressure. The internal fire box collapsed from 
 the softening of the plates through shortness of water, the blow off 
 pipe having been left open too long. Little or no injury was done 
 to the ship. 
 
 No. 25. Birmingham. (Fig. 22 J June 2nd- 2 killed, 1 injured. 
 
 Fig. 22. 
 
 Cornish, 6 years old, 2 1ft. long, 6ft. diameter. Tube 3ft. diameter, 
 f inch plates, 40 Ibs. pressure. The tube was so much weakened 
 by cracks and by being out of true circle, that it collapsed from end 
 to end at the ordinary working pressure. 
 
 No. 26. Wigan. (Fig. 23.) June 6th. 
 
 none injured. 
 
 tig, 23.
 
 BOILEK EXPLOSIONS IN 1870. 
 
 One of two. Cornish, 28ft. 7in. long, 5ft. 4in. diameter. Tube 
 
 3ft. diameter, slightly oval, f inch plates, 50 Ibs. pressure. Tube 
 
 collapsed over the fire and .ruptured from -weakness. The boiler 
 was not moved and the damage was not great- 
 
 No. 27. Bury. 
 
 June 9th. 
 
 1 injured. 
 
 Lancashire. The plates were reduced to T ^ inch by external 
 corrosion, so that the boiler was not able to bear the ordinary 
 pressure, but no details have been obtained. 
 
 No. 28. WorUngton. (Fig. 24.) June 9th. 
 
 'C\ i 
 
 7 injured- 
 
 Fig. 24. 
 
 One of two. Cornish, nearly new, 16ft. long, 5ft. diameter, 
 $ inch plates, 45 Ibs. pressure. Three plates over fire collapsed 
 from overheating through shortness of water. 
 
 No. 29. Nottingham. (Fig. 25.) June 13th. 
 
 3 injured- 
 
 Fig. 25. 
 
 Ten years old. Plain cylinder, with flat ends, 10ft. long, 2ft- 
 diameter, diagonal seams, inch plates, 25 Ibs. pressure- The
 
 BOILER EXPLOSIONS IN 1870. 
 
 whole shell was blown 80 yards to the front, and the chimney and 
 engine house much damaged. It was much corroded and badly 
 patched, so as to be unfit to carry pressure. 
 
 No. 30. Blackburn. (Fig. 26.) June 17 th. 2 killed, 1 injured. 
 
 trim 
 
 Fig. 26. 
 
 Sixteen years old. Galloway, 26ft. long, 7ft. diameter, g inch 
 plates, 56 Ibs. pressure. There was a combustion chamber between 
 the furnace tubes and the main tube, and this had been lately 
 repaired insecurely, and gave way and burst upwards. The boiler 
 was not moved, but the contents issued so violently that a good deal 
 of damage was done to surrounding premises. 
 
 No. 31. Glasgow- (Fig. 27.) June 17th. 
 
 none injured. 
 
 Fig. 27. 
 Crane Boiler, about 2 years old, 7ft- high, 4ft. diameter, inch
 
 BOILER EXPLOSIONS IN 1870. 
 
 plates, 50 Ibs. pressure. The internal fire box collapsed and the 
 external shell was blown to pieces. There was no sign of shortness 
 of water, but it is supposed that the fire box was not circular, and 
 therefore too weak to bear the ordinary pressure. 
 
 No. 32. Eilston. (Fig. 28.) June 2lst. 
 
 2 killed, 6 injured. 
 
 Fig. 28. 
 
 One of seven. Plain cylinder, 30 years old, 30ft- long, 8fc. 3in 
 diameter, inch plates, 35 Ibs. pressure. It gave way over fire 
 place, where it had been weakened by frequent repair, which had 
 caused a seam rip near a patch. The fragments were widely 
 scattered, and much damage was done to the premises. The 
 insecurity of boilers so frequently repaired with patch upon patch 
 has been often pointed out. 
 
 No. 33. Darlington. (Fig. 29.) June 24th. 2 injured. 
 
 One of twelve. Two Furnace Upright, about 2 years old, 20ft.
 
 BOILER EXPLOSIONS IN 1870. 
 
 high, 8ft. diameter, r 7 ff inch plates, 30 Ibs. pressure. The water 
 was allowed to run so low that the plates softened by the overheat- 
 
 ing, and a small piece was blown open and threw down the 
 brickwork. 
 
 No. 34. Dudley. (Fig. 30.) June 25th. 
 
 2 injured. 
 
 JFi-ff. 30. 
 One of two. Balloon, 34 years old, 12ft. diameter, 10ft. high,
 
 BOILER EXPLOSIONS IN 1870. 
 
 f inch plates, 7 Ibs. pressure. There were no stays, and the boiler 
 was of very weak shape, and as the boiler it worked with was 
 loaded to 15 Ibs., it is presumed this also was exposed to that 
 pressure, and burst in consequence. It gave way at the angle at 
 front over the fire, and was thrown over the engine house. 
 
 No. 35. Manchester- \(Fig. 31.) June Nth. 2 h'tttd, 1 injured- 
 
 Jig. 31. 
 
 One of four. Galloway, 4 years old, 32ft. long, 8ft. diameter, 
 -j 7 5 inch plates. Tube 2ft. lOin. diameter, originally intended for 
 40 Ibs., but worked at 65 Ibs. pressure. The left hand tube 
 collapsed sideways, having been very much weakened by internal 
 corrosion. 
 
 No. 36. July 2nd. 1 injured, 
 
 "Marine. One of the oval tubes collapsed. The boiler was 
 worked at a higher pressure than it was capable of bearing safely, 
 but no particulars have been obtained. 
 
 No. 37. Scotland. July 3rd. 2 fatted, 3 injured. 
 
 Plain Cylinder, 3 years old, 20ft. long, 4ft. diameter, 25lbs. 
 pressure. It was so corroded inside about the water line from bad 
 water, that it gave way at the ordinary pressure. The boiler was 
 thrown 160 yards from its seat.
 
 BOILER EXPLOSIONS IN 1870. 
 
 No. 38 July 29th. none injured. 
 
 Cornish, 26ft. long, 5ft. 9in. diameter, tube 3ft. Gin. diameter, 
 /j inch plates, 35 Ibs. pressure. The boiler rent open where exter- 
 nally corroded to -^ inch, and 3 widths of plates were torn away. 
 
 No. 39. Nottingham. August 12th. none injured. 
 
 Tubulous Boiler, quite new, made entirely of tubes. One tube 
 gave way at defective weld, but no other damage was done. 
 
 2fo. 40. Leicester. (Fig. 32 .) August \StJi. 4 killed, 5 injured. 
 
 Fig. 32. 
 
 Upright Boiler, nearly new, 10ft. high, 5ft. diameter, with inter- 
 nal fire box, % inch plates, 45 Ibs. pressure. The shell was rent 
 into many pieces, which were widely scattered, doing much damage. 
 The safety valve was defective and incapable of relieving the pres- 
 sure, and the spring indicated wrongly, so that a much higher 
 pressure was used than the boiler could bear safely. 
 
 No. 41. Newcastle-on-Tyne. (Fig. 33.) Sep. 14th. 5 killed, 20 injured 
 
 One of two. Plain Cylinder, with plates arranged lengthways, 
 
 17 years old, 27ft. long, 6ft. diameter, f inch plates, 30lbs. pressure,
 
 BOILER EXPLOSIONS IN 1870. 
 
 
 
 mechanically fired. It had just been extensively repaired over the 
 fire, but it gave way at the back end, where a plate had been put 
 in some time before, and it is supposed that a seam rip or injury to 
 
 Fig. 33. 
 
 the old plate, not visible outside or in, was then set up, which was 
 perhaps increased by the strain of late repairs and gave way as soon 
 as steam was again raised to working pressure. See !N"o. 55 this 
 year and many others in past years of similar construction. 
 
 No. 42. Nottingham. (Fig. 34 .) September 15th. 
 
 I kilkd. 
 
 Fig. 34. 
 
 Tubulous, or all tubes, li- years old, 100 Ibs. pressure. Steam 
 was being raised with too little water in the boiler, so that the tube 
 became overheated and incapable of bearing pressure, and rent open, 
 and as the boiler was in a small space the steam suffocated the 
 attendant, but the boiler was not disturbed or the premises injured. 
 
 No. 43. Tunstall. (Fig. 35.) September 17th. 3 killed, 1 injured. 
 
 One of four. Plain Cylinder, 8 years old, 36ft. long, 5ft. diameter, 
 f inch plates, 50 Ibs. pressure. It gave way at fifth seam, where a
 
 BOILEE EXPLOSIONS IN 1870. 
 seam rip, caused by bad repair, had so far weakened it that it was 
 
 Fig. 35. 
 
 unable to bear the usual pressure, and the ends were blown in 
 opposite directions. 
 
 No. 44. Exeter. (Fig. 36.) September 
 
 1 killed. 
 
 fig. 36. 
 
 Lancashire, 2 years old, 3lft. long, 7ft. diameter, tube 2ft. lOin. 
 diameter, with 56 Field tubes in each, f inch plates, 45 Ibs. pressure. 
 The right hand tube collapsed and ruptured from softening of plates 
 through shortness of water. The fire was blown out and set the 
 premises on fire and much damage was done. 
 
 No. 45. Cardiff. October 1st. 1 killed, 2 injured. 
 
 Locomotive, 4 years old, 14ft. long, 4ft. diamer, ^ inch plates, 
 120 Ibs. pressure. The fire box was reduced to ^ inch by corro- 
 sion, and unable to bear the usual pressure and rent open, and the 
 escaping contents rushed out at the fire doors and injured those near.
 
 BOILEE EXPLOSIONS IN 1870. 
 Wo. 46. Liverpool. (Fig. 37.) October 4th. 4 kitted, 4 injured. 
 
 Fig. 37. 
 
 Plain Cylinder, 6ft. 6in. long, 3ft. 6in. diameter, f inch plates, 
 80 Ibs. pressure. The plates were corroded both inside and out, 
 and in some places reduced to less than -fa inch in thickness, and it 
 was quite unfit to bear the ordinary pressure. The damage to the 
 surrounding property was very great although the boiler was so 
 small. The shell of the boiler was thrown across a street into an 
 upper room of the house opposite. 
 
 No. 47. Bathgate. October 14th. 
 
 Bag Boiler. The boiler became exposed to higher pressure than 
 it was intended to bear. The boiler house was destroyed, but no 
 particulars have been obtained. 
 
 No. 48. Walsall. (Fig. 38.) October 19th. 1 killed, 2 injured- 
 
 Fig. 38. 
 
 Cornish, 7 years old, 13ft. 3in. long, 5ft. 6in. diameter, tube 3ft. 
 6in. diameter, | inch plates, and supposed to work at 30 Ibs. pres- 
 sure. The guage was so out of order that it only indicated half the 
 real pressure. The tube was not in good condition and had leaked 
 very much and was quite unfit for the pressure of 60 Ibs. to which
 
 BOILER EXPLOSIONS IN 1870. 
 
 the valve was loaded. The tube collapsed beyond the bridge, and 
 the contents issued at the back and drove the boiler forward 30 feet 
 and into a workshop. 
 
 No. 49. Soho. (Fig. 39.) October 19th. 
 
 I killed, 1 injured. 
 
 \ 
 
 Fig. 39. 
 
 One of four. Lancashire, 23ft. long, 7ft. diameter, tube 2ft. 6in. 
 diameter, 30 Ibs. pressure, usually, but 15 Ibs. at time of explosion. 
 The left side of left tube collapsed and rent owing to shortness of 
 water. 
 
 No. 50. North Wales. (Fig. 40. ) October 19th- 1 killed, 8 injured. 
 
 Fig. 40. 
 
 One of two. Cornish, 26ft. long, 5ft. 6in. diameter, tube 3ft. 
 diameter, ^ inch plates, 23 Ibs. pressure. The bottom was so 
 thinned by external corrosion that it was not able to bear the usual 
 pressure and rent open. The boiler was turned upside down, and 
 the house much injured.
 
 BOILER EXPLOSIONS IN 1870. 
 No. 51. Berwick. (Fig. 41.) October 2lst. 
 
 I killed. 
 
 Fig. 41. 
 
 Cornish, 12ft. long, 4ft. Sin. diameter, tube 2ft. 4in. diameter, 
 f inch plates, 32 Ibs. pressure. The tube collapsed, having become 
 overheated through shortness of water. 
 
 No. 52. Sheffield. (Fig. 42.) October 26ft. 1 killed, 1 injured- 
 
 Fig. 42. 
 
 Locomotive, 11 years old, 9ft. 6in. long, 4ft. diameter, inch 
 plates, 80 Ibs. pressure. The top plate over fire box was blown off, 
 having given way along a "furrow" caused by corrosion in a line 
 of strain owing to position of stays. It was in a part of the boiler 
 where it is not usual to find it, and as it could not be seen, it 
 increased until unable to bear the usual pressure. 
 
 No. 53. Darlaston. (Fig. 43.) October 27ft. 
 
 3 injured. 
 
 Fig. 43. 
 Plain Cylinder, 22ft. long, 4ft- diameter, T T d inch plates, 25 Ibs.
 
 BOILER EXPLOSIONS IN 1870. 
 
 pressure. The water was allowed to get so low that the sides were 
 softened by overheating, and rent open. The boiler was not moved 
 and only a few bricks were disturbed. 
 
 No. 54. Cornwall. (Fig. 44.) October 2Tth. 
 
 1 killed. 
 
 Fig. 44. 
 
 One of three. Cornish, 12 years old, 36ft. long, 6ft. diameter, 
 tube 3ft. 9in. diameter, inch plates, 38 Ibs. pressure. The tube 
 collapsed from end to end, the front and central parts being blown 
 out. The shell and back of tube were thrown in one piece to the 
 rear, and much damage was done. It was supposed to have been 
 short of water, because the tube had collapsed, but it is more likely 
 it collapsed because of its weakness without strengthening rings. 
 A tube in this boiler collapsed in a similar way about 5 years 
 previously. 
 
 No. 55. Newcastle. (Fig- 45. ) November 17th. 1 killed, 2 injured. 
 
 One of seven. Plain Cylinder, with plates arranged lengthways, 
 30 years old, 26ft. long, 6ft. diameter, f inch plates, 35 Ibs. pressure, 
 mechanically fired. Gave way at a seam on the right hand side of 
 the fire place, where the insertion of a new plate had caused injury 
 to the old plate, and it divided into two parts which were sent in 
 different directions. The uncertainty and treacherousness of these
 
 BOILER EXPLOSIONS IN 1870. 
 
 straight seamed boilers has often been pointed out. See No. 41, 
 and many examples in former years. 
 
 Fig. 45. 
 
 No- 56. South Wales. November 19th. 
 
 none injured. 
 
 Cornish, 7ft. diameter, tube 4ft. diameter, 40 Ibs. pressure. Tube 
 collapsed from weakness. 
 
 No. 57. Shields. (Fig. 46.) November 24th. 1 killed, 2 injured. 
 
 Fig. 46. 
 
 One of two. Marine, second hand when put in 3 years since. 
 Return tube 12ft. 4in. long, slightly oval, 6ft. diameter at front, 
 and 5ft. 6in. at back; tube, oval, 3ft. lOin. wide, and 3ft. deep, -f s 
 inch plates, 25 Ibs. pressure. The tube collapsed. It was in such 
 a corroded and cracked condition, and so badly repaired, with screw 
 patches, that it was unable to bear the ordinary pressure,
 
 BOILER EXPLOSIONS IN 1870. 
 No- 58. Manchester. (Fig. 47.) December 2nd. 
 
 3 injured. 
 
 Fig. 47. 
 
 One of two. Balloon, used for evaporating only, nearly new, 9ft. 
 high, and 9ft. diameter, % inch plates, not usually worked at any 
 pressure. The top was thrown 60 yards away, and the bottom left 
 on furnace. The boiler was temporarily exposed to pressure which 
 it was too weak a shape to bear. 
 
 No- 59. Bilslon. (Fig. 48.y December 2nd. 1 killed, 2 injured. 
 
 Fig. 48. 
 
 Plain Cylinder, 5 years old, 14ft. 9in. long, 4ft. 9in. diameter, 
 inch plates, 30 Ibs. pressure. The water was allowed to get so low 
 that the sides became softened by overheating and rent open, and 
 blew the fire upon those near, but without disturbing the boiler or 
 brickwork.
 
 BOILER EXPLOSIONS IN 1870. 
 
 No- 60. Hanley. (Fig- 49.) December 16th. 1 kitted, 5 injured. 
 
 yfftnrr- 
 
 ?v/// c 
 
 ! I N44- 
 
 1 
 
 L. 
 
 I If// 
 
 49. 
 
 One of two. Balloon, 30 years old, 15ft. diameter, inch plates, 
 worked at 20 Ibs. pressure. It rent in two and threw down the 
 engine house and chimney. The boiler was not intended to work 
 at more than 5 Ibs. pressure, and was quite unable to bear the extra 
 pressure to which it was exposed. 
 
 No. 61. Leeds, (Fig. 50 J December 24th. 
 
 1 injured- 
 
 Fig. 50. 
 
 Domestic, wrought iron, welded, 13 inches wide, 12 inches high. 
 The house had been empty, and the pipes to cistern, 26 feet above,
 
 BOILER EXPLOSIONS IN 1870. 
 
 had frozen, and when a fire was lighted the accumulated pressure, 
 having no escape, forced out the front. 
 
 No- 62. Leamington. (Fig. 51.) December 25th. none injured- 
 
 Fig. 51. 
 
 Domestic Saddle, wrought iron welded, 1ft. 9in. long, and the 
 same width and height- The circulating pipes were stopped by ice, 
 and the accumulated pressure forced down the underside and rent 
 open the joint- The building was injured. 
 
 No. 63. Morley. (Fig. 52.) December 25th. none injured. 
 
 Fig. 52. 
 
 Domestic Saddle, wrought iron welded, 2ft. 6in. long, 1ft. 6in. 
 wide and high. The circulating pipes being stopped by ice the 
 accumulated pressure forced out the plate on the under side. The 
 building was injured. 
 
 No. 64. Liverpool. (Fig. 53.) December 25th. 2 injured. 
 
 Fig. 53. 
 
 Domestic, 1ft. Sin. wide and high, 1ft. deep, % inch cast iron. 
 The circulating pipes were stopped with ice, and the accumulated 
 pressure forced out the front, and did great damage to the house-
 
 BOILER EXPLOSIONS IN 1870. 
 No. 65. London. (Fig. 54.) December 25th. 
 
 1 killed. 
 
 Fig. 54. 
 
 Domestic, wrought iron, 1ft- 3in. wide, 1ft. 4in. high, 6in. deep, 
 f inch thick. The circulating pipes to the cistern ahout 30ft. above 
 were stopped with ice, and the accumulated pressure rent the boiler 
 in the welded joints, and did great damage to the house. 
 
 No. 66. DuTcinfield. (Fig. 55.) December 26th. none injured. 
 
 Fig. 55. 
 
 Domestic, cast iron, g inch thick, 1ft. 3in. wide, 1ft. deep. The 
 circulating pipes were frozen, and the pressure accumulated and 
 rent the boiler to fragments and did great damage to the room. 
 
 No. 67. NorthaHerton. (Fig. 56.) December 29th. 1 injured. 
 
 Fig. 56.
 
 BOILEK EXPLOSIONS IN 1870. 
 
 Locomotive, 20 years old, 12ft- 9in. long, with plates arranged 
 lengthways, 3ft. Sin. diameter, inch plates, 80 Ibs. pressure. The 
 barrel appears to have given way on the under side near fire box, 
 and opened out and rent into fragments. As the pieces containing 
 the probable first rent were missing, nothing positive could be ascer- 
 tained. It may have contributed to the rupture that the engine 
 drew from the fire box instead of from the frame. 
 
 No. 68. London. (Fig. 57.) December 29th. none injured. 
 
 Fig. 57. 
 
 Domestic, Saddle, wrought iron, welded, 1ft. Gin. long, 1ft. 2in. 
 wide, and 1ft. high, ^ inch thick. The circulating pipes to cistern 
 25ft. above were frozen, and the accumulated pressure forced the 
 crown out of under side of boiler, and caused great damage to 
 
 premises. 
 
 
 
 No- 69. London. December 3Qth- none injured. 
 
 Domestic, the circulating pipes were frozen, and the accumulated 
 pressure caused the boiler to rent open, but little damage was done. 
 
 No- 70. Burton. Date not ascertained. 1 killed. 
 
 Plain Cylinder, underground, internally corroded until too weak 
 to bear ordinary pressure. 
 
 JR. Broomhalf, Printer, Stourbridge.
 
 BOILER EXPLOSIONS IN 1871. 
 
 No. 1. Tranmere. (Fig. 1.) January 1st. 
 
 1 injured. 
 
 Fig. 1. 
 
 Domestic. Cast-iron, 1ft. 4iu. wide, 1ft. high, and llin. deep. 
 The circulating pipes being frozen the pressure accumulated, and 
 rent the boiler into pieces, doing great damage. 
 
 No. 2. Rochdale. (Fig. 2.) January 2nd. 
 
 1 injured. 
 
 Fig. 2. 
 
 Plain cylinder, lift, long, 3ft. lin. diameter, inch plates, 25 Ibs. 
 pressure. Ruptured at a bad patch over grate, around which were
 
 BOILER EXPLOSIONS IN 1871. 
 
 many old cracks, and the rent passed along the bottom, and through 
 the unguarded manhole, and round several of the transverse seams, 
 dividing the boiler into 4 or 5 pieces, which were widely scattered, 
 but are arranged in sketch near their original position. 
 
 No. 3. January 2nd. none injured. 
 
 Cornish, 32ft. long, 6ft. 6in. diameter, f inch plates, 30 Ibs. 
 pressure. Tube ruptured at first seam over the fire from weakness 
 caused by internal corrosion. 
 
 No. 4. Middlesbro. (Fig. 3.) January 4th. 
 
 1 killed. 
 
 Fig. 3. 
 
 Domestic, 1ft. 3in. wide, 1ft. high, 11 in. deep, -^ ff inch thick. 
 The circulating pipes being frozen, the pressure accumulated and 
 rent the boiler open, doing considerable damage. 
 
 No. 5. Stirchley. (Fig. 4.) January 9tL 1 killed, 4 injured. 
 
 Fig. 4. 
 
 One of five, about 30 years old. Lancashire, 18ft. 2in. long,
 
 BOILER EXPLOSIONS IN 1871. 
 
 7ft Gin. diameter. Tubes 2ft. diameter, inch plates, 12 Ibs. 
 pressure. Kuptured at corroded steam pipe joint at top of front 
 end, and the rent followed along the angle ring of shell which was 
 also corroded, and then along the seams of some plates in the 
 bottom, placed longitudinally, allowing the top of the boiler to open 
 up like a lid, without moving it much out of its original position. 
 
 No. 6. Cornwall. January 12th. 1 killed. 
 
 Cornish, 30ft. long, 6ft. diameter, 7 7 ff inch plates, 35 Ibs. pressure. 
 The ball weight of the safety valve was unusually near the steam 
 pipe, and it is supposed that the boy who was scalded having put 
 his dinner on the pipe to warm, it slipped between the ball and 
 pipe ; and that in trying to extricate it he lifted the valve which 
 was held open by the " pasty " wedged under the ball. 
 
 No. 7. Dairy. January 13th. 3 injured. 
 
 One of two, 25 years old. Plain cylinder, 24ft. long, 4ft. diameter, 
 -j 5 ff inch plates, 30 Ibs. pressure. Gave way at a ring seam where 
 much corroded near the back end, which was blown to the rear, 
 the front end being thrown considerably forwards, and the shell 
 was torn into many fragments which damaged the engine house, 
 and so injured the other boiler that it also was rent into pieces and 
 thrown some distance away. One safety valve was made to serve 
 for the two boilers, and the connecting valve being shut there was 
 no escape from this boiler, so that the bursting pressure soon 
 accumulated. A similar boiler attached to the same engine exploded 
 ,in April, 1870, and is mentioned as No. 15 in the "records" of 
 that year. 
 
 No. 8. S. Wales. January 15th. none injured. 
 
 Plain cylinder, 5 years old, 35ft. 6in. long, 4ft. lOin. diameter, 
 inch plates, 55 Ibs. pressure. Some plates over the fire became 
 red hot from the accumulation of scale some inches thick upon them 
 and gave way, and the reaction of the issuing contents sent the 
 boiler some distance and did much damage.
 
 BOILER EXPLOSIONS IN 1871. 
 
 No. 9. Manchester. January 16th. 1 injured. 
 
 Plain cylinder, flat ends, very old, 8ft. 4in. long, 3ft. diameter, 
 f inch plates, 50 Ibs. pressure. The front plate was blown out, and 
 the boiler was thrown backwards for some distance. The boiler was 
 corroded until too weak to bear the ordinary pressure. 
 
 l^o. 10. Sunderland. January 17th. 1 killed, 1 injured. 
 
 Marine. The steam expansion joint was placed between two 
 opposite curves in the pipe, and one end drew out when first under 
 pressure. 
 
 No. 1 1 . Leslie. January 26th. 2 
 
 Cornish, 10ft. long, 4ft. diameter. Tube 2ft. 4in. diameter, plates 
 7 5 S inch, 40 Ibs. pressure. Gave way at bottom where it rested on 
 the brickwork, the plates being completely eaten away by external 
 
 corrosion. 
 
 No. 12. Gateshead. (Fig- 5.) January 27th. 
 
 none injured. 
 
 lig. 5. 
 
 Domestic, 3ft. high, 2ft. wide, and 1ft. lin. deep, f inch plates. 
 The circulating pipes being frozen, the pressure accumulated, and 
 rent the boiler open doing great damage. 
 
 No. 13. Bradford. (Fig. 6.) February 1st. 
 
 1 killed. 
 
 Fig. 6. 
 
 Plain cylinder, 5 years old, flat ends, 7ft. Sin. long, 3ft. 4in.
 
 BOILER EXPLOSIONS IN 1871. 
 
 diameter, f inch plates, 45 Ibs. pressure. The 
 safety valve was loaded to 70 Ibs., and this pressure 
 was too great for the insufficient stay to the flat 
 end, which was blown out, the boiler being thrown 
 backwards. 
 
 No. 14. Dover. February 5th. 
 
 1 killed. 
 
 
 Marine, 70 Ibs. pressure. The boiler was not 
 moved from its place, and the damage appeared to 
 have been slight, but no particulars have been 
 obtained. 
 
 No. 15. Newcastle. (Fig. 7.) Feb. IQth. none injured. 
 
 One of three, 3 years old. Chimney, 27ft. high, 
 5ft. diameter. Tube 2ft. 9in. diameter, inch 
 plates, 25 Ibs. pressure. Collapsed about half-way 
 1>~-1 U P the tube from overheating through shortness 
 
 Fig. 7. 
 No. 16. Birmingham. (Fig. 8.) 
 
 February 15th. 
 
 3 injured. 
 
 One of two, 1 year old. Portable upright, 6ft. high, 3ft. diameter,
 
 BOILER EXPLOSIONS IN 1871. 
 
 T 7 5 inch plates, 25 Ibs. pressure. There was but one safety valve, 
 and that was on the other boiler. The junction valve between the 
 boilers was closed, when left for the night, without the fire being 
 properly put out, and there being no outlet for the steam the 
 pressure accumulated, and the boiler ruptured at the unguarded 
 manhole and rent into fragments, much damaging the closely 
 packed houses near. 
 
 No. 17. Stockton. 
 
 March 8th. 
 
 none injured. 
 
 Locomotive. The connecting rod broke and pierced the boiler, 
 allowing contents to issue violently. A similar case was mentioned 
 as No. 27, July 21st, 1868, and others have occurred in previous 
 years. 
 
 No. 18. Bradford. (Fig. 9.) March 9th. 1 killed, 1 injured. 
 
 F,g. 9. 
 
 One of six, 3 years old. Lancashire, 27ft. long, 7ft. diameter. 
 Tubes 2ft. 8in. diameter, slightly oval, J v inch plates, 60 Ibs. 
 pressure. The left hand tube collapsed downwards from overheating 
 through shortness of water. The boiler was not moved, and little 
 damage was done to premises. 
 
 No. 19. Glasgow. 
 
 March llth. 
 
 3 killed, 3 injured. 
 
 liag Boiler. The screws of the manlid were loosened before the 
 steam was exhausted, and the issuing contents scalded those near.
 
 BOILER EXPLOSIONS IN 1871. 
 
 No. 20. Wootton Bassett. (Fig. 10.) March \\th. 2 killed, 1 injtired. 
 
 _ 
 
 ^. 10. 
 
 Cornish, 12ft. long, 4ft. Sin. diameter. Tube 2ft. Sin. diameter, 
 f inch plates, 72 Ibs. pressure. Tube collapsed downwards from 
 overheating through shortness of water. This was the second time 
 the tube had collapsed, although the boiler had only worked 
 18 months. 
 
 No. 21. Newcastle. (Fig. 11.) March 16th. 
 
 1 killed. 
 
 11. 
 
 Plain cylinder, flat ends, 16ft. long, 3ft. Gin. diameter, ^ inch 
 plates, 25 Ibs. pressure. There being no stays to support the flat 
 ends the varying pressure caused a slight movement backward and 
 forward (sometimes called " drum-head " motion), which facilitated 
 corrosion in certain lines of strain, and produced a "furrow" at 
 the front near the bottom, which rent open. The boiler was not 
 moved, and little damage was done to the premises. 
 
 No. 22. Brigg. (Fig. 12.) March 17th. 
 
 1 killed, 1 injured. 
 
 Fig. 12. 
 One of five, 5 years old. Plain cylinder, 68ft- long, 4ft- 4in.
 
 BOILER EXPLOSIONS IN 1871. 
 
 diameter, plates f s inch full, 65 Ibs. pressure. Heated by gas. 
 Rent at fourth seam, the front end being thrown a great distance 
 forward, and the back end to the rear, displacing the other 4 boilers. 
 The ruptured seam was next to a patch where the cutting out of 
 the old rivets and putting in of new had caused a seam-rip. 
 
 23- S. Wales. (Fig. 13.) March 18th- none injured. 
 
 Fig. 13. 
 
 One of two, 36 years old. Lancashire, 30ft. long, Oft. diameter. 
 Tubes 3ft- diameter, inch plates, 22 Ibs. pressure. The boiler 
 was rent into 3 pieces. Five rings of the back part were torn off 
 and thrown to the rear. Four rings in the middle were opened out 
 flat and fell across the other boiler, and the remaining part of the 
 shell with the tubes were left on the seating. The boiler was old 
 and much patched, and was corroded too thin to bear the usual 
 pressure. 
 
 No. 24. Lynn. (Fig. 14.) March 23rd. 2 killed. 
 
 Cornish, 10 years old, 7ft. Sin. long, 3ft. 2in. diameter. Tubes 
 1ft. lOin. diameter, f inch plates, 36 Ibs. pressure. The tube 
 ruptured at the last ring of plates, and was forced inwards, allowing
 
 BOILER EXPLOSIONS IN 1871. 
 the contents to issue at the back. The boiler was slightly thrown 
 
 Fig. 14. 
 
 forward. It was only used occasionally, but was so much reduced 
 by internal corrosion as to be unable to bear the usual pressure- 
 
 No. 25. Northwich. (Fig- 15.) May 3rd- I killed, 1 injured- 
 
 Fig. 15. 
 
 Marine, 7 years old, 9ft 2in. long, 6ft. lin. diameter. Furnace 
 tube 2ft. diameter, and 3 inch small tubes, $ inch plates, 81 Ibs. 
 pressure. There were two bands as clips round the outside of boiler. 
 Gave way at a seam where some new bottom plates had been, 
 inserted, and where the old plate was so thinned by internal corrosion 
 as to be unable to bear the usual pressure. A small plate was blown 
 out and shattered into three pieces, and the boiler was turned end 
 for end. 
 
 No. 26. Earnstaple. May 9lh. 1 killed. 
 
 Revolving Hag boiler of plain cylindrical shape, with three filling 
 holes. The steam was supplied from other boilers. The central lid 
 was unscrewed, without trying, by a small hole for the purpose, 
 whether there was any pressure, and the lid came off, and the 
 contents issued and scalded the attendant. 
 C
 
 BOILER EXPLOSIONS IN 1871. 
 No. 27. Leamington. (Fig. 16.) May 18^. 1 killed, 2 injured. 
 
 Fig. 16. 
 
 Portable multitubular, 9 years old, 8ft- 6in. long, 2ft. Gin. 
 diameter, -j 5 5 inch plates, 50 Ibs. pressure. The safety valve was 
 fastened down by a nail (A) between the lever and the 
 cover, and in consequence the pressure accumulated to 
 more than the boiler could bear, and it was rent into 
 many pieces, which were widely scattered. 
 
 No. 28. May 20th. none injured. 
 
 Portable vertical, of peculiar construction, with return down flue 
 tubes, 6ft. high, 4ft. 6in. diameter, inch plates, 35 Ibs. pressure. 
 The shell was torn off, the bottom having given way through 
 weakness, from want of proper stays, from the crown of the fire box 
 to top of the boiler- 
 
 No. 29. Hull. (Fig. 17.) May 22nd. 
 
 3 killed, 1 injured. 
 
 tig. 17. 
 Lancashire, 22ft- 6in. long, 7ft- 6in. diameter- Tubes 2ft. lOin-
 
 BOILER EXPLOSIONS IN 1871. 
 
 diameter, f inch plates, 70 Ibs. pressure. The tube was somewhat 
 corroded on the top, and gave way over the fire from weakness. 
 
 No. 30. Bath. May 25th- 1 killed, 1 injured. 
 
 Revolving Eag boiler of plain cylindrical shape, but revolving on 
 trunnions, in the opposite direction to No. 26, 12ft. high, 6ft. 
 diameter, ^ inch plates, 50 Ibs. pressure. The steam was supplied 
 from another boiler. The cover at one end was insecurely fastened 
 and was blown off. 
 
 No. 31. Oakengates. (Fig. 18.) June 6th. 
 
 none injured. 
 
 Fig. 18. 
 
 One of two, 20 years old. Balloon, 14ft. diameter, inch plates, 
 6 Ibs. pressure. The pressure was allowed to far exceed the proper 
 height during a temporary stoppage of the engine, and the bottom 
 was rent off, and the top thrown some distance, but very little 
 damage was done- 
 
 No- 32. Wellinglro'. (Fig. 19.) June nth. 1 killed, 2 injured. 
 
 Fig. 19. 
 
 Cornish, 28ft- long, 6ft- diameter- Tube 3ft diameter, f inch
 
 BOILER EXPLOSIONS IN 1871. 
 
 plates, 40 Ibs. pressure. Tube collapsed from weakness, and partly 
 tore away from the back end, and the reaction from the issuing 
 contents forced the boiler back a long way. 
 
 No. 33. Tunstal. (Fig. 20). June 2Sth. 8 failed, 20 injured. 
 
 Fig. 20. 
 
 Cornish, 43ft. long, 6ft- Oin. diameter, T 7 ff inch plates. Tube 3ft. 
 diameter, | inch plates, 50 Ibs. pressure. The tube collapsed 
 sideways from end to end through weakness, being without strength- 
 ening hoops, and with continuous longitudinal seams. The back 
 end and part of the tube were thrown to the rear, and the rest of 
 the boiler was thrown to the front, and separated into several 
 fragments. 
 
 No. 34. Glasgow. July 9th. 3 killed. 
 
 The lid of a steam valve was being removed while under pressure, 
 and the steam escaped and scalded those near. 
 
 No- 35. Rotherham. (Fig. 21.) July llth. 
 
 none 
 
 Fig. 21. 
 
 Cornish, 10 years old, 7ft. long, 6ft. Gin. diameter. Tube 3ft. Sin. 
 diameter, I inch plates, 45 Ibs. pressure. Gave way where much
 
 BOILEK EXPLOSIONS IN 1871. 
 
 corroded by the damp brickwork of the central wall, and the back 
 ring of plates was torn out, and the boiler turned up on end, and 
 much damage was done to the premises. 
 
 No. 36. 
 
 July 17th. 
 
 none injured. 
 
 Cornish, 16 years old, 12ft. long, 4ft. diameter, -j 7 s inch plates, 
 48 Ibs. pressure. Gave way at the bottom and rent open, a belt of 
 plates being blown away to some distance. The bottom had been 
 extensively corroded, by the boiler being left exposed to wet for 
 many years before it was set at this place, rendering it unfit to bear 
 the usual pressure. 
 
 No- 37. Cumnock. (Fig. 22.) July 28th. 
 
 m 
 
 i 
 
 1 injured. 
 
 Fig. 22. 
 
 One of five, about 20 years old. Plain cylinder, 20ft. long, 4ft. 
 diameter, fa inch plates, 45 Ibs, pressure. The boiler had been much 
 patched and altered, and was in very poor condition, and unfit to 
 bear safely the ordinary pressure. Rupture commenced near the 
 feed pipe, and ran along one side and then round each end, both of 
 which were liberated and thrown far away, the barrel of the boiler 
 spreading out on to the neighbouring boilers, one of which was 
 much injured. 
 
 No. 38. Shields. (Fig. 23.) August 1st. 1 killed, 7 injured. 
 
 Multitubular, 10 years old, 7ft. long, 3ft. Gin. diameter, , 5 6 inch 
 plates, 50 Ibs. pressure, but valve loaded to 80 Ibs. Rupture 
 commenced^at the unguarded manhole, and the shell was rent into
 
 BOILER EXPLOSIONS IN 1871. 
 
 several pieces which were much scattered. The safety valve was 
 defective, and the boiler had been much weakened by many patches, 
 
 Fig. 23. 
 
 and was in poor condition and unable to bear the pressure at which 
 it was worked at the time of explosion. 
 
 No. 39. Wakefield. August 3rd. 1 killed, 1 injured. 
 
 One of five. Rag boiler, 5 Ibs. pressure from the exhaust steam 
 of an engine. The manhole was of very large size and insecurely 
 fastened, and was blown off. 
 
 No. 40. Cornwall. (Fig- 24.) 
 
 2 killed- 
 
 Fig. 24. 
 
 Cornish, 30ft. long, 6ft. Sin. diameter. Tube 4ft. Sin. diameter, 
 18 Ibs. pressure. Kuptured near brickwork at the bottom where 
 much corroded externally, and one ring of plates was rent open. 
 The boiler was displaced, and the premises were greatly damaged. 
 
 No. 41. Shields. August 26th. none injured. 
 
 Chemical pan, 12ft. long, 5ft. Gin. diameter, f inch plates. The 
 end was blown off, the rivets not being strong enough for the 
 pressure of 35 Ibs, as supplied from the boilers.
 
 BOILER EXPLOSIONS IN 1871. 
 . 42. Blackburn. (Fig. 25.) August 29th. 1 killed, 2 injured. 
 
 Lancashire, 26ft. long, 6ft. Gin. diameter. Tubes 2ft. 9in. 
 diameter, f inch plates, 60 Ibs. pressure. The left hand tube 
 collapsed from overheating through shortness of water, and the 
 contents issued violently and scalded those near. 
 
 No. 43. Hereford. Augunt 2 injured- 
 
 Chemical boiler, Plain cylinder, 12ft. 6in. high, 4ft. 6in. diameter, 
 | inch plates, with cast-iron hemispherical ends with manhole in each. 
 The pressure of 34 Ibs. was obtained from another boiler. The 
 bottom end gave way where the casting was defective, a piece was 
 blown out, and the reaction of the issuing contents projected the 
 boiler through the roof, through which it again descended and did 
 much damage. 
 
 No. 44. Cardiff. (Fig 26.) September 1st- 2 killed, 2 injured. 
 
 Fig. 26. 
 
 Marine. Multitubular, 6ft. long, 6ft. diameter, 60 Ibs. pressure. 
 The under side of fire box gave way at the front rivets, the heads of 
 which were corroded, and a tongue of plate was torn upwards, 
 allowing the contents to issue so violently, that those near were 
 carried overboard and drowned.
 
 BOILER EXPLOSIONS IN 1871. 
 No. 4,0. Gresley. (Fig. 27.) September 2nd. 
 
 Fig. 27. 
 
 One of six, 2 years old. Plain cylinder, 40ft. long, 5ft. diameter, 
 | inch plates, 50 Ibs. pressure. This case was peculiar, as the back 
 part of the boiler was found a long way to the front, and the front 
 end in the rear. An accumulation of scale caused pocket to form, 
 and a hole to burn through the bottom over the grate, allowing the 
 contents to issue so violently that the boiler was sent over end for 
 end, when the front end was knocked off and thrown to the rear, 
 and the contents then issuing more violently, the reaction sent the 
 rest of the boiler in one piece a great distance to the front, where it 
 fell, and was crushed nearly flat and broken into several fragments. 
 
 No. 46. Cornwall (Fig. 28.) September 16th. 
 
 4 injured- 
 
 Fig. 28. 
 
 One of two, 18 years old. Cornish, 32ft. 9in. long, 6ft. Gin. 
 diameter. Tube 4ft. diameter, g inch plates, 45 Ibs. pressure. The 
 tube collapsed from end to end, dropping together like an old sack, 
 and cracking at the edges. A small piece at the front end was 
 blown out. The cause was supposed to be shortness of water as
 
 BOILER EXPLOSIONS IN 1871. 
 
 there was no guage glass, but it was far more likely the weakness 
 of so large a tube without strengthening hoops. The pressure was 
 doubtless more than usual, as the engine had made a temporary 
 stand. A similar collapse took place in the next boiler in December, 
 1869, and is described as No. 57 in the " records" of that year. 
 
 No. 47. Hull. (Fig. 29.) September 22nd. 2 injured. 
 
 Fig. 29. 
 
 Vertical, with, fire box of peculiar corrugated construction, 7ft. 
 Gin. high, 3ft. diameter, 50 Ibs. pressure. Gave way round the 
 bottom of fire box where much, corroded and rent open, and the 
 reaction of the issuing contents carried the whole boiler to a 
 consderable distance. The pressure guage had been removed, and 
 the safety valve did not act freely, and the pressure accumulated to 
 more than the boiler could bear. 
 
 No. 48. Grindleton. (Fig. 30.) September 26th. 1 killed. 
 
 Fig. 30. 
 
 Lancashire, 3 years old, 20ft. long, 7ffc. diameter. Tube 2ft. 2in. 
 diameter, 2 inch plates, 60 Ibs. pressure. The boiler gave way at 
 the second ring of plates from the back end, at the side where 
 externally corroded to a knife edge, by brickwork made damp by 
 being next the side of a hill. The rents extended round the boiler, 
 D
 
 BOILER EXPLOSIONS IN 1871. 
 
 and it was turned nearly bottom, upwards, and the shell opened out 
 in the curious way shown in the sketch. 
 
 No. 49. Bradford. October 9th. none injured. 
 
 One of three. Portable, multitubular, 8ft. long, 2ft. 6in. diameter, 
 80 Ibs. pressure. There was no safety valve, dependence being 
 placed on that of the boiler to which it was connected. Steam was 
 got up without opening the connecting steam cock, and the 
 consequent excessive pressure forced off the front end. 
 
 No. 50. Tipton. October 17 th. none injured. 
 
 One of twenty, 22 years old. One tube worked by two furnaces, 
 36ft. long, 6ft. Sin. diameter. Tube from end to left side 2ft. Sin. 
 diameter, inch plates, 30 Ibs. pressure. The tube collapsed from 
 overheating through shortness of water, and cracked at the edges 
 and allowed the contents to escape without any violence. 
 
 No. 51. Bury. October 2lst. 2 killed, 1 injured. 
 
 A wall fell upon and broke the steam pipes, and the escaping 
 eteam scalded those near. 
 
 No. 52. October 25th. 2 injured. 
 
 Chemical boiler. Plain cylinder, 9ft. 3in. long, 6ft. diameter, 
 | inch plates. The back end was blown out, and the boiler moved 
 forward a few yards, and the premises were much injured. The 
 outlet pipes were choked up, and more pressure accumulated than 
 it was capable of bearing. 
 
 No. 53. Chesterfield. (Fig. 31.) October 25th. none injured. 
 
 Plain cylinder, 6ft. 6in. long, 2ft. 2in. diameter, /^ inch plates, 
 80 to 100 Ibs. pressure. The manhole was weak and unguarded
 
 BOILER EXPLOSIONS IN 1871. 
 
 with a strengthening ring, and ruptured and allowed the lid to blow 
 out. The rents spread along a part where strength was much 
 
 Fig. 31. 
 
 reduced by the rivets being countersunk to make room for attach- 
 ments. The safety valve was defective and overloaded, and there 
 was no guage, and the boiler was unfit to bear the pressure to which 
 it was exposed. 
 
 No. 54. Northwich. October 2Sth. 
 
 1 killed, 1 injurtd. 
 
 Chemical. The cover was unscrewed before the pressure was off, 
 and the contents blew out violently and scalded those near. 
 
 No. 55. Bowling. (Fig. 32.) October SOth. 1 killed, 1 injured. 
 
 Fig. 32. 
 
 One of two, 17 years old. Marine, 12ft. 7in. long, 6ft. Sin. 
 diameter. Tube 4ft. wide, 2ft 9in. high, 16 Ibs. pressure. The 
 tube was much weakened by corrosion and screw-patching and 
 collapsed upwards, with the slightly increased pressure of a 
 temporary stoppage of the engine.
 
 No. 56. Sihton. 
 
 BOILEE EXPLOSIONS IN 1871. 
 
 October. 
 
 none injured. 
 
 Chemical, 9ft. long, slightly oval, 4ft. greatest diameter, f inch 
 plates, 2 Ibs. pressure. Although not at work, it is supposed that a 
 gas was gently passing off through a small pipe, 30ft. long, to 
 a receiver which was under repair, and that this gas being 
 accidentally lighted, communicated through the pipe with that in 
 the boiler and exploded it. One end was blown off, the rupture 
 passing completely round through the solid plate. 
 
 No. 57. Newcastle. (Fig. 33.) November 5th. 
 
 none injured. 
 
 Off. 33. 
 
 Cornish, 25ft. long, about 6ft. diameter. Tube 3ft. 6in. diameter, 
 f inch plates, 30 Ibs. pressure. Tube collapsed from overheating 
 through shortness of water. 
 
 No. 58. Gravesend. (Fig. 34.) November 8th. 
 
 2 killed. 
 
 Fig. 34. 
 
 One of two. Marine, 16ft. 6in. long, 8ft. 4in. diameter. Tube 
 of irregular shape, about 2ft. lOin. high, | inch plates, 27 Ibs.
 
 BOILER EXPLOSIONS IN 1871. 
 
 pressure. The guage was so much out of order, that it only showed 
 24 Ibs. under a real pressure of 80 Ibs. The safety valve was 
 defective and overloaded, and the pressure was sufficient to collapse 
 and rupture the side flue, and the contents rushed out at the front. 
 
 tfo. 59. Bihton. (Fig. 35.) November 12th. 
 
 none injured. 
 
 Fig. 35. 
 
 One of four. Cornish, about 20 years old, 26ft. long, 6ft. 6in. 
 diameter, fa inch plates, 40 Ibs. pressure. Tube 3ft. 9in. diameter 
 had been made in two parts, joined in the centre by a narrow plate 
 f inch thick, and it collapsed at this joint, so that the top met the 
 bottom, and thus so retarded the issue of the contents after being 
 set in motion, that a shock was produced, which blew out an end 
 and half the tube in opposite directions. The shell was left resting 
 in its seat, and little damage was done to premises. The tube had 
 much the appearance of collapse from shortness of water, but the 
 most probable cause was that it was too weak without strengthening 
 hoops to bear the ordinary pressure with safety. 
 
 No. 60. Dm. (Fig. 36.) November llth. 
 
 2 killed. 
 
 Jiig. 36. 
 Portable, multitubular, about 10 years old, 8ft. Sin. long, 2ft. Tin.
 
 BOILER EXPLOSIONS IN 1871. 
 
 diameter, f inch plates, 30 Ibs. pressure. The bottom of the smoke 
 box was reduced by external corrosion to less than ^ inch in 
 thickness, and was consequently unable to bear the ordinary pressure, 
 and a piece was blown out, and the reaction of issuing contents 
 displaced the boiler a little and much damaged the premises. 
 
 No. 61. Rotherham. November 18th. 1 killed. 
 
 The screws of a manhole were loosened while the pressure 
 remained in the boiler, and the lid was blown off. 
 
 No. 62. Newcastle. November 25th. 1 killed. 
 
 One of twelve. Chimney, 28ft. high, 6ft. diameter. Tube 2ft. 
 5in. diameter, f inch plates, 25 Ibs. pressure. The blow pipe was 
 left open while some men were inside repairing, and the steam and 
 water from the blow-off of another boiler in the same pipe was 
 forced in upon them. 
 
 No. 63. Cradley. December 8th. 1 injured. 
 
 Locomotive, lift, long, 3ft. diameter, a inch plates, 95 Ibs. 
 pressure. The pressure amounted to about 134 Ibs. during a 
 temporary effort to get up a steep curved incline, and the fire box 
 was forced inwards and the outside shell outwards, and the stays 
 drawn, but little other damage was done. 
 
 No. 64. JUiddksbro*. (Fig. 37.) December 13th. 1 injured. 
 
 Locomotive, 18ft. Gin. long, 4ft. diameter, t 7 g inch plates, 120 Ibs. 
 pressure. Gave way under bottom of barrel where " furrowed " by
 
 BOILER EXPLOSIONS IN 1871. 
 
 the combined action of corrosion and the strain upon the plates, by 
 attachment to the frame of the engine. 
 
 Fig, 37. 
 
 No. 65. We&tlromwick. (Fig. 38.) December 28th. 1 injwred. 
 
 Fig. 38. 
 
 One of five, 23 years old. Balloon, 16ft. diameter, | inch plates, 
 5 Ibs. pressure. It ruptured at the back where the plates in contact 
 with brickwork were reduced by external corrosion, and the bottom 
 was forced down upon the grate, and the top rolled over on to its 
 side. The boiler was not being used, although connected with the 
 other at work. The strain upon the bottom was increased by the 
 boiler being over full and nearly to the brim. Those near were 
 drenched with nearly cold water from it when it upset. 
 
 No. 66. Glasgow. (Fig. 39.) December 30^. 11 killed, 30 injured. 
 
 Portable upright, about 8 years old, lift. 4in. high, 4ft. diameter, 
 | inch plates, 100 Ibs. pressure. The internal portion gave way
 
 BOILER EXPLOSIONS IN 1871. 
 
 where attached to the fire holes and collapsed inwards, ar>d the 
 reaction of the issuing contents forced the boiler up some distance on 
 
 Fig. 39. 
 
 to the top of a house. The safety valve did not act properly, and 
 the pressure appears to have accumulated to more than the boiler 
 could bear, during a temporary stoppage of the engine. 
 
 R. Sroomhall, Printer, Stourbridge.