7 University of California Berkeley Gift of GEORGE K. OPPENHEIM ON ILLUSTRATIONS PROGRESS IN MATERIALS SHIPBUILDING AND ENGINEERING AT THE ROYAL NAVAL EXHIBITION. W. H. WHITE, C.B., F.K.S. Reprinted from the "Journal of the Iron and Steel Institute:' No. II., for 1891. BY AUTHORITY OF THE COUNCIL. PRINTED BY BALLANTYNE, HANSON & CO. EDINBURGH AND LONDON. as HE bion and a is ting ime was >ace e as r in tab- the j, so ling for air- itry ;ess. and ;ory blic :ive has S%L J? X ^ ^ ILS HE tion and a is ting ime was )ace e as r in the >, so snce ling imi- for air- itry -ess. and ;ory blic :ive has ON ILLUSTRATIONS OF PROGRESS IN MATERIALS FOR SHIPBUILDING AND ENGINEERING AT THE ROYAL NAVAL EXHIBITION. Br W. H. WHITE, 0,3., F.R.8. AT the request of the Council, the following brief description has been prepared of the exhibits of " Materials Used in Ship and Engine Construction" at the Royal Naval Exhibition, which is about to close after a most successful season. The Executive Committee of the Exhibition, in formulating their scheme, had two great difficulties to face a very short time for preparation, and a very limited space in relation to the range and importance of the subjects to be illustrated. All that was possible, therefore, was to endeavour to proportion fairly the space available to the various sections ; and in each section to secure as representative a collection of exhibits as could be got together in the time. From the first it was desired to make the "Materials" Sub- division one which should illustrate the progress made during the last twenty years in the various branches of steel manufacture, so that the public might better appreciate the enormous influence which that progress has had upon the development of shipbuilding and marine engineering. Further, it was desired to give promi- nence to the history and present position of armour-plating for warships. The sub-committee on " Materials," of which I acted as chair- man, found the leading steel-makers in all parts of the country most desirous to co-operate in making this subdivision a success. And the result, under the unavoidable limitations of space and time above-mentioned, has been declared to be most satisfactory by experts, while it has proved of great interest to the public generally. To members of the Iron and Steel Institute, the representative collection of specimens of rolled, cast, and forged steel which has 2 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS been got together will not present many novelties. At the same time, they will not fail, when visiting the Exhibition, as I trust all will do, to inspect the " Materials," and the following notes may be of some assistance. This class of exhibits is housed, for the most part, at the southern end of the Camperdown gallery, near to the full-sized model of H.M.S. Victory. A few specimens are to be found in the grounds adjoining, and others in the exhibits of individual firms, who combine steel-making with other industries. Without further preface I will pass to a short description of the various classes of exhibits. I. MILD STEEL, FOR SHIPBUILDING, BOILER-MAKING, &c. In this class are shown numerous examples of the remarkable ductility and excellent working qualities of the material which has practically revolutionised shipbuilding and boiler-making since 1875, when a few firms in this country undertook, at the request of the Admiralty, to produce mild steel, such as had recently been brought into use for ship- work in France. The specimens of bending, stamping, flanging, welding, &c., and others showing the relative behaviour of mild steel and iron under the shock of powerful explosives, while they are of a character perfectly well known to the makers and users of steel, are of the highest interest to the ordinary visitors. They serve also as a useful reminder of the enormous advantages and great economies which have resulted from the substitution of mild steel for iron in structures made up of plates and stiffening bars. One is so apt to accept present facilities, and to forget former practice, in the rush of improvement, that it is well at times to look back ; and the collection to which reference is now being made will suggest many memories to both users and makers of steel. For example, in the days when iron was in general use, except for the Admiralty, systematic tests of tensile strength and bend- ing quality were not common in shipbuilding practice. From the very first use of mild steel, all this has been changed, and the manufacture has been regulated by thorough and searching tests, which are no less valued and insisted on by the makers FOR SHIPBUILDING AND ENGINEERING. 3 than they are by the users of the material. To this circumstance is no doubt largely due the fact, which must be impressed on every one who inspects the collection, viz., that the manufacture has become thoroughly systematised, and that the material is of uniformly excellent quality. Another fact is prominently illustrated, and deserves mention, although it is now so commonplace. The manufacturer of steel is steadily advancing in the direction of giving to the user his material in sizes and forms which greatly facilitate and cheapen construction. Take, for instance, the sections exhibited of bar- steel, suitable for frames, deck-beams, and stiffeners of all kinds. In iron the production of such special sections as #-bars, [-bars, I-bars, T-bulb, and "]-bulb was a matter of great cost and difficulty. Where the most thorough association of strength and lightness was desired, cost was put into a secondary place, it is true ; and in Admiralty practice such special sections in iron were largely used. For frames behind armour, stiffeners to bulkheads, &c., ^-bars have long been used ; but they were costly, the specialties of a few firms, and obtainable in very moderate lengths and weights. Per- sonally, I well remember the difficulties of the manufacture, and the expenditure involved. Now all this is changed. In the Exhibition are to be seen an almost endless variety of special sections, made in steel, as a matter of course, in great lengths, and at relatively moderate cost. Instead of having recourse to com- binations of plates and angle-irons, in order to secure certain sectional forms at a cheap rate, the shipbuilder now has numerous sources of supply of these sections, and thus saves labour as well as weight. To such an audience as this, nothing need be said as to the gain on the manufacturer's side obtained by the substitution of steel for iron in bars of special section. Every one will remember the days of " neutral-axis welding," " special piling," &c. &c., which seem so far distant, and yet were practised in a not very remote past. Illustrations occur also in the Exhibition of the increased sizes of plates now supplied in steel, to the great advantage of the user. Special plant of greater size and power is, of course, needed to 4 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS utilise these larger plates ; but the leading firms are not slow to realise where the balance of advantage lies, and in the plating of ships, shells of boilers, &c., advantage is taken of the advance made in size and weight. Two specimens of boiler-plate shown, i J-inch thick, are respectively 42 feet long by 6J feet wide, and 31 feet long by 7J feet wide. It may not be out of place, as a representative of the users of mild steel, to mention the advantages which result from the excellent working qualities of the material. When we started in the use of the material in the dockyards sixteen years ago, I well remember the extraordinary precautions taken in working the care in bending, the universal annealing after any operation involving heating, and general distrust. This was partly due to following the French lead, and partly to the warnings of English steel makers. The manufacture was in its earliest stages, and care was no doubt necessary ; but looking back, both makers and users were probably over-careful It need hardly be said that all this is changed ; and, if evidence were needed, the samples shown, illustrating the wonderful working qualities of the material under exceptionally distressing conditions, would afford it. The user gains in many ways. Cases of failure in working are rare ; operations, such as flanging, which required heating with iron, are done cold in steel ; and bending, scarcely possible with the best qualities of iron, is now treated as a matter of course. Machine makers, recognising the change, are constructing special appliances for doing cheaply cold flanging and bending. Flanging is taking the place of stiffening bars in many parts of ship's structures. In boiler construction no less advantages are obtained, of which many examples are shown in the form of front plates, flues, &c., by several of the leading makers. At the outset some difficulty was experienced in welding mild steel, but this has now practically disappeared. The change may be in part due to improvements in the manufacture of the material, but my impression is that the principal cause is to be found in enlarged experience on the part of the workmen. However this may be, the thorough welding quality of the material is established by the specimens exhibited, and by none more so than by the boiler flues shown by the Leeds Forge and by Messrs. John Brown and Co. FOR SHIPBUILDING AND ENGINEERING. O A remarkable illustration of the ductility of the material, and of its good welding quality, is shown by the Steel Company of Scotland, in the collapsed boiler flue of the SS. Durham. It is a matter for some regret that there is no exhibit, pictorial or otherwise, of the many instances in which accidents that would have been most serious, if not fatal, to iron ships, due to accidental collision or grounding, have been made comparatively unimportant, by the wonderful ductility of mild steel. No one can wonder, however, after looking over the specimens shown, that iron is now superseded to such a great extent by steel, or doubt that steel is destined to take the place of iron as thoroughly as the latter material was substituted for wood. So far as my inspection has gone, there appear to be no exhibits of importance indicating possible changes or improvements in the strength of steel for shipbuilding purposes. Nor do the makers of basic steel send specimens of their manufacture. In fact, with the small space available, a restriction of the exhibits was un- avoidable. II. FORGED STEEL. The exhibits of this class are numerous and important, but in- clude no novelties. There are specimens of crank and propeller shafts, connecting rods, &c., for marine engines; hoops, cores, &c., for heavy guns ; and projectiles of various sizes and patterns. In the Ordnance Section, and in the splendid collection of Messrs. Armstrong, Mitchell, & Co., will be found examples of ancient and modern guns of all sizes ; and in the exhibits of other firms of gunmakers there are many fine specimens of forgings. With these finished guns, however, we are not here concerned. Outside the Camperdown Gallery, in the grounds, is one heavy forging by Messrs. Whitworth, which may escape notice, as it is apart from their other collection. It is a hoop for a 13J-inch B.L.B. gun, 53 inches in external diameter, with a hole through it 36 inches in diameter, 23 feet long, and weighing 34 tons. Another interesting exhibit of this firm, shown also at Man- chester, I believe, is the weldless boiler shell, 12 feet in diameter, 5 feet wide, and f inch thick a splendid specimen of the working 6 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS qualities of the material, as well as an indication of its possibilities for special purposes. Messrs. Beardraore send a connecting-rod taken from a large steamer after the breakdown of her engines. It is a notable example of toughness and strength, and will be examined with interest. This will be true also of the forged steel projectiles shown by Whitworth, Hadfield, the Projectile Co., and several other firms. Many of these have actually perforated armour-plates, in tests made on them as samples of supplies, and they seem nothing worse for their transit. It is satisfactory to find such progress made by English firms in a branch of manufacture where the French took a distinct lead for a considerable time. III. CAST STEEL. The exhibits in this class are numerous and important ; they do not, however, adequately illustrate the great influence upon ship and engine construction which the introduction of cast steel of moderate tensile strength and great ductility has exercised in recent years. Specimens are to be seen of engine-framing, pistons for marine engines, gun carriages, and various details ; but of the large castings now so generally used in ship-work stems, stern- posts, rudders, shaft-brackets, &c. not even representative pat- terns are shown. No doubt the large size of these exhibits had much to do with their absence, as some of the firms exhibiting have a high reputation in this branch of manufactura The saving in time and cost of production which have resulted from the substitution of cast steel for iron forgings, particularly in warships, it would be difficult to estimate; and the change has been accompanied by increased strength and trustworthiness. No doubt in the earlier stages of this branch of steel manufacture, considerable difficulties arose ; and as one of the first to use such castings for ships of high speed and great engine-power, I can speak from personal experience of these difficulties. On the other hand, enlarged experience has enabled makers to produce sound castings of increasingly difficult and complex forms. The require- ments of the shipbuilder have thus been met more and more in the supply of castings requiring no work to be done on them in FOR SHIPBUILDING AND ENGINEERING. 7 the shipyard ; of sectional forms securing an association of light- ness and strength practically unattainable with forgings, and yet very moderate in cost, while rapidly produced. This satisfactory result has been reached the sooner because of joint action on the part of users and makers, their frequent conferences having led to mutual concessions. Possibly shipbuilders have often been inclined to demand too much from the steel-founder; but the latter has not unfrequently gone further than he otherwise might have done but for these demands. It has happened in my own experience that a class of castings declared impracticable at first has been produced, or closely approximated to, very soon when its advantages have been explained to the steel-maker. Those who are unfamiliar with this class of work may see in the Camperdown Gallery at the Exhibition a pattern for the sternpost of a warship. This particular pattern is for a bronze casting which was fitted in a cruiser that was wood-sheathed and coppered; but it closely represents in form and general character the steel stern-posts fitted in unsheathed vessels of the class. An examination of the pattern will show that, in a forging, similar lightness and strength could not be approached. A sketch of a cast steel stern-post is given on Plate 6. Another class of castings in warships, where the use of steel has been most advantageous, are the ram-stems. When these were made in forged iron, the "rabbets" to receive armour- plating, shell-plating, &c., the special forms required for the " spur," and the arrangements for attaching decks, breast-hooks, &c., all had to be obtained by costly machine work, often involving months of almost continuous labour, after the forging had come out of the shop, completed as far as the hammer could do the work. Under these conditions, it was not unusual to see the central portions of warships far advanced, while work at the bow and stern was untouched, owing to the want of stems and stern- posts. Now, thanks to the use of steel castings, no such delay is necessary. In the latest and largest battle-ships for the Eoyal Navy the ram-bows are of unusual form and of remarkable strength. Although no specimens of the castings used are shown at the Exhibition, it may be of interest to members of the Institute to have a drawing for reference, and one is appended on Plate 6. 8 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS Steel castings are now extensively used in place of forgings, for many of the details of ships' fittings. Perhaps in some instances the substitution was at first carried too far to he really economical ; hut on the whole the change has been beneficial, and promises to be lasting. In the manufacture of anchors cast steel has in recent years been extensively employed, and examples can be seen at the Exhibition. Subject to proper tests such anchors are perfectly satisfactory. IV. ARMOUR-PLATING. This section of the exhibits is of special interest. It illustrates the progress and present position of the armour-plate manufacture in this country, by means of drawings, models, and actual plates. The most recent developments and results of experiments are exemplified. Had space and time permitted the collection would have been more complete, for the Admiralty were willing to place at the disposal of the Executive sample 10^-inch armour- plates from the great series of experiments which have been in progress on board the Nettle during the last three years. This offer, however, was necessarily declined. Messrs. Cammell, Messrs. Brown, and Messrs. Vickers, are the three chief exhibitors in this section. Messrs. Beardmore show a 4-inch steel armour-plate as a sample of the contract executed by them for H.M.S. Hood. In connection with the exhibits of armour- piercing projectiles also a few specimens of armour are shown. Messrs. Cammell and Messrs. Brown, as is natural, supply the historical series of plates. They show examples of the rolled iron in general use up to 1877, of the "compound" or "steel-faced iron " armour which has been their staple manufacture for many years, and of " all-steel " armour recently made by them, including examples of nickel steel. Messrs. Brown show a series of three plates, illustrating the changes made since 1859 in the character of armour and the tests imposed. These specimens include (a.) An iron plate tested with spherical cast iron shot. (6.) An iron plate tested with pointed chilled cast iron shot. FOR SHIPBUILDING AND ENGINEERING. 9 (c.) A compound plate tested with chrome-steel pointed projectiles. They also exhibit full-sized sections of the armoured sides of the earliest and latest sea-going ships in the Royal Navy. The model of a portion of the armoured barbette for a first-class battle- ship in this collection will also attract attention. Messrs. Cammell exhibit a model of the armoured front of a " casemate " made by them for H.M. ships. It is a particularly interesting example of what can be done, with proper appliances in the way of bending steel-faced armour. This firm also show models of armour plates made by them for the barbettes of recent battle-ships, which plates are of very large dimensions. They are 17 feet long, 6J feet wide, 17 inches thick, and have a finished weight of nearly 35 tons. These monster armour plates are re- markable contrasts to the plates fitted to the Warrior in 1859, which were about 15 feet long, 3J feet wide, and 4J inches thick, weighing about 4 tons each. Seven years later, on the Hercules, 9-inch armour plates were fitted, not differing much in length and breadth from those on the Warrior, but weighing about 10 tons. In the Inflexible of 1874, armour plates 12 feet long, 9J feet broad, and 12 inches thick, each weighing about 24 tons, were fitted. In the Trafalgar of 1885, 20-inch armour plates were carried, weigh- ing from 26 to 30 tons each. Of course, to these finished weights large additions must be made when dealing with the weights re- quiring to be manipulated in the processes of manufacture ; and from this brief summary some idea may be gathered of the magni- tude of the plant required for the production of armour at present in use. Messrs. Vickers have commenced the manufacture of armour quite recently ; their first lOJ-inch steel plates having been sup- plied to the Admiralty for experimental purposes in 188889. They have since developed this branch of their business, and are now executing orders for 12-inch armour for H.M.S. Centurion, having completed other orders for lighter plates for cruisers. In their ex- hibit are shown two models of lOJ-inch steel plates fired at on board the Nettle, which will be compared, no doubt, with the corresponding models of steel and compound plates in Messrs. CammeH's collection, included in the same series of experiments. A2 10 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS This is not the place to enter into the much-debated question of the relative merits of steel and compound armour. In my remarks on Mr. Jaques' paper, read at the last meeting of this Institute, I stated what action had been taken by the Admiralty in placing orders for armour recently.* Both steel and compound armour are being used for H.M. ships of qualities approved as the result of actual firing trials, the two modes of manufacture standing on equal terms. Since 1877 great advances have been made in the manufacture of steel armour, and further improvements will doubtless be made. The competition has resulted also in considerable improvements in compound armour, and there is no reason to believe that finality has been reached in this direction. Creusot has taken a leading position in the manufacture of steel armour, and has achieved notable successes. But the specimens of Sheffield steel armour in the Naval Exhibition can, I think, bear comparison with the best French plates, and the Russian trials at Ochta last year confirm this view. These trials, and the Annapolis trials which preceded them, have brought into prominence the use of nickel as an alloy with steel for armour plates. It is only proper to note that Mr. James Riley first drew attention to this matter in a paper read before this Institute in 1889,f when he exhibited certain nickel-steel plates which had been fired at. These plates are shown at the Exhibition by the Steel Company of Scotland, and are well worth inspection although under two inches in thickness. In the discussion which arose upon Mr. Riley's paper, I expressed a hope that the Admiralty might be able to experiment on such plates, and the matter was kept in view. In April 1890, a 4-inch nickel-steel plate made by Mr. J. F. Hall (of Messrs. Jessop & Co., Sheffield) was actually fired at on board the Nettle, with very satisfactory results. Since that date a number of other firms have supplied experimental nickel-steel plates including Messrs. Cammell, Messrs. Brown, Messrs. Vickers, Messrs. Beardmore, and the Nickel Steel Syndicate. These trials have mostly been made on 4-inch plates, material of that thickness being required for the * Journal, No. I., 1891, p. 219. t 76trf.,No. L, 1889, p. 45. FOR SHIPBUILDING AND ENGINEERING. 11 secondary defence of battle-ships now building. In their collec- tions, Messrs. Cammell and Messrs. Brown show samples of such plates that have been fired at, and have withstood successfully tests which wrecked ordinary steel plates of identical dimensions. As a result, plates of this quality are now being made by these firms for five of the first-class battle-ships. The experiments are still in progress, and have included firing trials on nickel steel plates up to 10 J inches in thickness. Time is, of course, essential to the conduct and analysis of such a series of trials ; and upon the results attained must largely depend the character of future supplies of armour to the Eoyal Navy. It may, however, be asserted that there is no lack of endeavour or enterprise on the part of English manufacturers ; and it is equally true that the Admiralty has not failed to give support and encouragement to these efforts to supply H.M. ships with the best qualities of armour-protection obtainable. It only remains to add that in the various exhibits of armour will be found interesting specimens of the various kinds of bolts, " sleeves," washers, &c., used for the attachment of armour to the sides and batteries of warships. In conclusion, I must apologise for the imperfections of this paper, which has been written very hastily, under circumstances of great pressure, at the urgent request of the Council. In the Appendix are given particulars of the present Admiralty tests for various qualities of steel. The paper was illustrated by a number of photographs and drawings, from which Plates VI. to XIII. have been prepared. 12 ON ILLUSTRATIONS OF PROGRESS IN MATERIALS APPENDIX. QUALITY OF AND TESTS FOR STEEL USED FOR SHIP- WORK IN H.M. NAVY. TESTS FOR PLATE, BEAM, ANGLE, BULB, BAR, AND RIVET STEEL. Strips cut lengthwise or crosswise are to have an ultimate tensile strength of not less than 26, and not more than 30 tons per square inch of section, with an elongation of twenty per cent, in a length of 8 inches. The steel is to stand such forge tests, both hot and cold, as may be sufficient, in the opinion of the receiving officer, to prove soundness of material and fitness for the service. Rivet steel is to have an elongation of not less than twenty- five per cent, in a length of 8 inches. Strips cut crosswise or lengthwise 1 inches wide, heated uniformly to a low cherry red, and cooled in water of about 80 Fahr., must stand bending in a press to a curve of which the inner radius is one and a half times the thickness of the steel tested. If preferred by the overseer the strips may be bent, cold and untempered, double under the hammer. The strips may be cut in a planing machine, and have the sharp edges taken off. The ductility of every plate, beam, angle, &c., is to be ascertained by the application of the above temper test to the shearings, or by cold bending under the hammer. All steel to be free from lamination and injurious surface defects. One plate, beam, or angle, &c., is to be taken for tensile testing from every invoice, provided the number of plates, beams, or angles, &c., does not exceed fifty. If above that number, one for every additional fifty or portion of fifty. Steel may be received or rejected without a trial of every thickness on the invoice. Where required by the overseer, material from every " blow " or " charge " may be so tested. The pieces of plate, beam, or angle,