- c CD '{>}{i?H«ir>mf{n.!'«>3')"":;tf.»;i ■m ;if.ttl;*t"!'':tr.i*;"';*"j '. I 1 ■^m.:^ 1 'JT^ C'- ^ ^ ^;^T^^^^- J Jf RHHHBHII^IHR .^ ■l^ •;_ V : ■ f m ^^^^r ^.^i^J^^^^^^^^^^ "•r-ar m tr in iai^^|^—i ^^M f i |Hm ,** Mil 9'' - * ^i ... A O S C (i CJ O S o Pi ^ Pi ^ w l-H U ° 8 < pq THE WATER-TUBE BOILER— STATUS AND HLSTPf^^Y HE marine engineer of to-day, conversant witli j;he,Qurrer)t;'> ,"j ;, ; > . technical literature of his calling, is no longer in doubt ''"''>'' '>''', regarding the position of the water-tube boiler for marine purposes. He is not only convinced that it has come to stay, but is equally sure that it will, at no late date, supplant the boilers of the fire-tube variety in all important steamers on lake and sea. The question of its advantages and the exploitation of its disadvantages have afforded themes, during recent years, for voluminous discussions both in the technical press and in the proceedings of the great law-making bodies of this and foreign governments. By these mediums the theoretical side of the question has become too familiar to admit of further general interest, and the practical side of the radical change involved alone remains an open and keenly live topic of the times. It will be a surprise, however, to a great number of even the most advanced followers of this subject, to find that there is nothing at present in the market in the shape of a water-tube boiler that can claim great novelty of design or principle. Indeed, it will be seen from the brief outline of the history of the water-tube boiler, as given in the next chapter, that certain types of these boilers, now being pushed into prominence, have fac similes in the archives of the patent office, or are nearly identical with types tried and abandoned as defective years ago. Persevering effort and abundant capital can secure the commercial test of any type with a theoretical claim for efficiency. The type that will endure, however, must appeal to engineers through actual practical advantages both in the operation and in the care of the plant. That such permanent advantages do exist in some types of the water-tube boiler is evidenced by the increasing rapidity with which old steam vessels, formerly using fire-tube boilers, are being re-boilered with the water-tube boiler, and, more forcibly, perhaps, by the almost exclusive adoption of this variety of steam generators for the machinery of new war ships throughout the world. In the simplest form the water-tube boiler closely approaches the ideal. It embodies the greatest strength with least steaming weight. It can be constructed in the ship. Its parts subject to wear or destruction (the tubes) can be bought in any market and do not require to be bent to special forms, and can be readily renewed without specially skilled force. There are no furnaces to threaten with dropping crowns, nor any large fiat stayed surfaces under pressure and subject to bulging, or annoying and wasteful leaky seams. The speed of steam raising is phenomenal compared with that safely possible with the Scotch boiler, yet an ample body of water for safe and easy operation .is.uot 4A"^luded. It is not injured by " forcing," nor is it difficult to preserve , '\ti a ^pactic^lly constant state of efficiency. It is not therefore wonderful that ••ftSicliims haVe demanded and received definite recognition and that it is no • • • • • • « • « • •longer* an experiment. The great point of difference in the several types of water-tube boilers now on the market, lies in the character of the tubes used. These are either simple straight tubes, simple bent tubes or compound straight tubes, the latter being constructed with a smaller tube inside of each main tube for the purpose of promoting circulation, one end of each main tube being closed. The bent-tube type comprises a great variety of designs, the tubes being either actually bent to certain sinuous forms, or by use of elbows or return bends in connection with short sections of straight tubing. The bent small tube variety has obtained great prominence in torpedo boat work, where every sacrifice must be made to ligJitness for greatest power and for speed of raising steam. The objections raised to this type are no secrets, and they lie in the practical difficulty of retubing, and in preventing loss of feed (and consequent burning out of tubes) when operated by a force not specially trained. This latter is due to the small body of water in the boiler. The inaccessibility of the tube ends for outside cleaning and preservation from corrosion by wet ashes and dirt is among the " cons " to be considered. Both for war ships and merchant marine vessels the simple straight-tube type seems to best meet the requirements, and the present tendency is to show increasing preference for this kind of boiler. The advantages are so obvious as to make the selection a most natural one. The points of merit, in detail, will be shown later on. Of late it has been the fashion of some writers antagonistic to the success of the water-tube boiler to claim, inferentially at least, that the old-style cylindrical boiler possessed all virtues and no defects, and to point with trembling pen at the frightful havoc ensuing from the introduction of even the smallest quantity of salt feed in the water-tube boiler. There is no room for expounding the dangers of salt feed or any other dangers attending the cylindrical boiler service ; they all are aged and familiar, but we can properly refer to an interesting statement made by Mr. Wingfield in a speech before the Institute of Naval Architects at Newcastle, wherein he states that not only may water-tube boilers have a certain proportion of salt water mixed with the feed, but that one vessel made a large part of the voyage to South America wholly with salt feed. This reference is not quoted for misleading purposes, as all marine engineers concede the criminality of purposely using salt feed, be the boiler of shell or water-tube type, but it is noted simply as a fact confuting the state- ments of the ultra conservative holders to the fire-tube boiler, and goes to show that with a water-tube boiler properly designed and constructed, even the bug- bear of salt feed fails to materialize as ?. forbidding reality. After the recent war with Spain, it was found necessary to renew the furnaces of the battle ship "Indiana," requiring the services of not only the New York yard with its gang of boiler makers, but the furnaces had to be corrugated in a particular shop ; all this detained the ship at the yard for four months. Had the "Indiana" been equipped with say ten water-tube boilers of the straight-tube type, the tubes being expanded into place with ends accessi- ble, the first three rows over the fire might have been removed and replaced, whether blistered, burned and bent from salt and oil in the feed or from any other cause, and repairs made, entirely by the ship's talent, in not more than three weeks' time.* One of the largest firms shipping ore from Lake Superior, equipped a few years ago a new 6000-ton freighter with water-tube boilers, and, when asked what they considered one of the greatest advantages attained by the use of these boilers, replied : " We can load our vessels at the rate of a thousand tons an hour and unload them almost as quickly. This means that our stay in port is only a little over six hours. In that time we can blow a boiler down, make a joint on boiler steam piping, grind in a leaky safety valve or renew a tube ; can refill and have full steam and be ready to sail for destination as soon as the ship is loaded, and yet have no fear of straining the boilers from unequal expansion in getting steam quickly. With our old cylindrical boilers we would just about have them cooled off ready to work upon by the time the ship was loaded, and the rest of the time occupied upon the repairs, refilling, and slowly raising steam, means detention of the ship and loss to us." On the great lakes of North America, the water-tube boiler is used to a great and constantly growing extent. Here freight is carried cheaper than on any body of water in the world, and the commercial success in the adoption of this type is an assured fact and one of the strongest " cards " in the claims for its advantages. * The " Indiana " is now equipped with eight Babcock & Wilcox Water-Tube Boilers. A BRIEF HISTORY OF THE WATER-TUBE BOILER ^N 1804, about a century ago, Col. John Stevens built and operated upon the Hudson River a little steamboat, 68 feet long by 14 feet wide. The machinery of this vessel consisted of a single upright cylinder whose piston rod moved up and down a cross head, which in turn drove two cranks by means of connecting rods. From the cranks a pair of shafts led aft, and were fitted with twin screws. MACHINERY OF STEVENS BOAT, 1804 Steam was supplied by one water-tube boiler, containing lOO tubes, 2 inches in diameter and i8 inches long. One end of each tube was fastened to a central water leg, the other end being closed. The hot gases passed around these tubes, the water being inside of them. This vessel attained a speed of seven miles an hour and was one of the earliest examples of the use of the water-tube boiler for marine purposes. stevens 1804 The first purely sectional water-tube boiler was made by Julius Griffith, in 1821, who used a number of horizontal water tubes con- nected to vertical side pipes, which were in turn connected to horizontal gathering pipes, and these to a steam drum. The first sectional water-tube boiler with a well-defined circulation, was made by Joseph Eve, in 1825. His sections were composed of small tubes slightly double curved but prac- tically vertical, fixed in horizontal headers, which were in turn connected to a steam space above and water space below formed of larger pipes, and connected by outside pipes so as to secure a circulation of the water up through the sections and down the external pipes. IfI IeI (p):::::(oX=:(Q)-;;--@ii:(o) // d .. i^ A ^) >^j ^ h ^ ^ (f, ^ <\ bs 1 D A l-j ^w r ^ h ] >: A 1^ ^ h r l' ^ y ^ ^ 1 ) ^i\ \y -J U [_ JULIUS GRIFFITH, 1821 JOSEPH EVE, 1825 In 1832, Jacob Perkins, of England, invented the inner tube, or lining, for the purpose of obtaining a rapid circulation. He applied it to a boiler constructed with a number of closed-end tubes descending from the steam and water reservoir so that each would come into contact with the fire in the furnace and thereby present a more considerable surface PERKINS, 1832 to thc heat BARTLETT « CO., t ALBAN, 1843 Dr. Ernest Alban, of Plan, Mechlenburg, in 1843, experi- mented with and built a number of water-tube boilers using the principle of the closed-end tube. Alban's boilers contained tubes of 4 inches diameter and from 4 feet to 6 feet in length. The rear end of the tube was closed by a screwed cap ; the other end being fitted to a groove in the back face of the front water leg and held in place by a T-headed bolt. Two oval openings, one above the other, were made in this back face or tube sheet within the circle of the tube end. The lower opening supplied the tube with water ; the upper being intended for the escape of the steam and water from the tube. All tubes were inclined toward the water leg from | to ^^ inch to a foot, and staggered one above the other, to allow the hot gases to better impinge upon their surfaces. A few of these boilers were built, but used for experi- mental purposes and not de- pended upon for the constant generation of steam. Collet and Field, in the fifties and early sixties, built a variety of boilers, some with dropped tubes, others with tubes inclined about 45° to the horizon- tal, and still others with tubes only slightly inclined. A number of these boilers were used in England, but inherent defects existed to such an extent as to cause their popularity to be short lived. FIELD, 1866 FIELD, 1867 Lane still later endeavored to introduce this closed-end type, using tubes 5 inches in diameter, with an internal circu- lating pipe 2% inches. All the tubes were inclined upward to- ward the front end and were fastened to an upright square chamber, or box, which was divided vertically by a partition that separated the front and rear portions. The internal circulat- ing tube was fastened to this partition, the water to be evapo- rated flowing down the front side of the partition into the small pipe and around its open end to the outside steam gener- ating tube. Mr. Lane further improved this type of boiler by causing the products of combustion to pass twice across the tubes before their exit to the stack. A few of these boilers were built, but as they contained serious drawbacks in design, such as inability to empty the tubes, priming, and enforced low rate of combustion, they soon lost favor and finally entirely dis- appeared. In 1870, J. A. Miller used cast headers to which were fixed closed-end tubes with an inner circulating pipe. These tubes were LANE MILLER, ISTU placed at an angle of about 15 degrees to the horizontal and were of such length as to allow of two passages of the gases across them. In this respect Miller followed Lane very closely in design. In 1876, Anderson, Kelly and Wiegand exhibited at the Centennial Exhibition three dif- ferent varieties of boilers, each ANDERSON, 1875 WIEGAND, 18" having tubes with one end closed. These boilers were thoroughly tested by a com- mittee of eminent engineers appointed for the purpose, and all made a good showing as far as evaporation was con- cerned, but they lacked the essential features so necessary in a steam boiler intended to meet all requirements, and a very few years later found them only mentioned in history. In 1885, Thomas Morrin redesigned for the n"' time the closed-end tube boiler. With the advent of the triple-expansion engine came the demand for higher steam pressures, to cope with which the inventor constructed the water slab of his boiler entirely of steel plate. The tubes were expanded into the inner and outer faces of the slab, and formed in themselves stays for the flat tube sheets. A vertical partition was placed between the front and rear faces, and, together with the 2-inch inner tubes, directed the cir- culation. Openings or slots were made in the outer or 4-inch gener- ating tube, on each side of the verti- cal partition, for the inlet of the water and exit of the steam. Several of these boilers were built for manu- facturing and electric light plants ; but defects that existed since the time of Stevens (1804), and met with by all Morrin's predecessors, again came to the surface and caused the inventor, after much experimenting, to entirely MORRIN, 1885 abandon the design. BARTlETT i. CO., N.Y. Charles Ward, in 1887, designed, and afterward built, a number of small boilers using, in combination, tubes with one end closed and curved tubes open at both ends. The former were screwed into the bottom head of a vertical steam and water drum, while the latter connected the drum to a manifold surrounding the grate. The circulation in the closed-end tube was promoted by means of two }^-inch pipes passing through a slightly conical iron stopper at the upper end of each tube ; one pipe extending downward, directing the water to the lower end of the tube ; the other ex- tending upward a distance of six inches, con- ducting both water and the steam generated to the steam space. For small launch duty, where space and weight are the chief factors to be considered, BARTLETT & CO., N.Y. WARD, 1887 DURR, 1893 these boilers found service ; but they were never entertained for large powers. Efforts have been made to remove the inherent de- fects that exist in boilers NICLAUSSE, 1895 containing tubes with one end closed, by the introduction of specialties of peculiar design, threaded tube ends and conical joints that are ground with tool room precision, but in practice the effect of these changes has been to add to the cost of maintenance and increase the labors of the boiler-room staff to such an extent that the remedy was found to be worse than the disease. From the foregoing, it is evident that boilers in which tjibcs have been fastened into water spaces at one end and left free at the other have been rede- signed at a rate of more than one a decade since 1 804. MONTUPET, 1898 »3 In 1805, Stevens' eldest son, John Cox Stevens, realizing the disadvantages of a boiler containing tubes with closed ends, patented another form of water-tube boiler, which he described as follows : * " Suppose a plate of brass of i foot square, in which a number of holes are perforated, into each of which holes is fixed one end of a copper tube of about an inch in diameter and 2 feet long, and the other ends of these tubes inserted in like manner into a similar piece of brass ; the tubes, to insure their tightness, to be cast in the plates. These plates are to be enclosed at each end of the pipes by a strong cap of cast- iron or brass, so as to leave a space of an inch or two between the plates, or ends of the pipes, and the cast-iron cap at each end. The caps at each end are to be fastened by screw bolts passing through them into the plates. The necessary supply of water is to be in- jected, by means of a forcing pump, into the cap at one end ;'and through a tube inserted into the cap at the other end, the steam is to be conveyed to the cylinder of the steam engine. The whole is then to be encircled in brick work or masonry in the usual manner, placed either hori- zontally or perpendicularly, at option." The circulation was therefore forced, or maintained by the feed pump, the steam that was formed in the tubes being conducted from the opposite space to the engine. Stevens was led to the belief that water-tube boilers embodied the correct principles of construction, from a series of experiments made in France in 1790 by M.Balamour, under the auspices of the Royal Academy of Sciences. Balamour states : * " It has been found that, within a certain range, the elasticity of steam is nearly doubled by every addition of temperature equal to 30 degrees Fahrenheit. These experiments were carried no higher than 280 degrees, at which temperature the elasticity of steam was found equal to about four times the pressure of the atmosphere. By experiments which have been lately made by myself, the elasticity of steam at the temperature of boiling oil, which has been estimated at about 600 degrees, was found to equal forty times the pres- sure of the atmosphere (600 pounds to the square inch). It is obvious that to derive advantages from an application of this principle, it is absolutely necessary that the vessel or vessels for generating steam should have sufficient strength to withstand the great pressure from an increase of elasticity in the *" Growth of the Steam Engine," Thurston. JOHN cox STEVENS, 1805 u steam, but this pressure is increased or diminished in proportion to the capacity of the containing vessel. " The principle, then, of this invention consists of forming a boiler by means of a system or combination of a number of small vessels, instead of using, as in the usual mode, one large one ; the relative strength of the materials of WILCOX, 1S5G which these vessels are composed in- creasing in proportion to the diminution of capacity." Appreciating the advantages to be gained from this style of construction, Stephen Wilcox in 1856 further perfected Stevens' design by giving to the bank of tubes an inclination and placing overhead a steam and water drum which connected the spaces at each end cf the tubes. The necessity for a forced circulation was at once overcome, the steam and water drum forming a reservoir of sufficient volume to maintain a steady water line and give dry steam for the engine. Late in the sixties, Babcock & Wilcox modified the Wilcox boiler of 1856 (see Babcock & Wilcox, 1868). The water legs were re- moved and brick sides substituted, the steam and water reservoir being replaced by a cylindrical drum, and, to simplify design, the tubes were made straight. babcock & wilcox, isgs Although this boiler was constructed entirely of wrought-iron, it contained a very objectionable feature — that of flat stayed surfaces opposite the tube ends. To avoid the use of such stayed surfaces, the now well-known serpentine header or corrugated manifold was substituted in 1873. These headers were first made of cast-steel, and later of cast-iron. They separated the tubes into sections, facilitated examination and repair, and gave to the boiler a flexibility to withstand expansion due to sudden fluctuation in temperature. In a boiler designed by Babcock & Wilcox in 188 1, the longitudinal steam and water drum was placed crosswise and above the lower end of the bank of tubes, the steam and water of circulation entering the drum at the water line, the height of the water in the boiler being at the center line of the drum. This boiler was not adopted for stationary BABCOCK & wiLcox, 1873 usc Until the latter part of the eighties, and 15 then only in some European countries. Later, with some modifications, it has been ex- tensively used in America, as well as in Europe, and is now in very general operation in stationary plants. The design was compact, and the reduced height added to its desirability for marine BABcocK & WILCOX, 1881 ^^rk, for which purpose it was adopted by The Babcock & Wilcox Company in 1 889. Short tubes were sub- stituted for long ones, and were expanded into forged wrought-steel corrugated headers, or serpentine manifolds, instead of headers made of cast metal. Vertical side tubes, backed with light fire tiles and sheet-iron casing, were substituted for brick setting, and the general structure of the boiler materially reduced in weight. -VrKA.M YACHT "REVERIE' In 1889, a boiler of this design, built for the steam yacht " Reverie," was made entirely of forged steel, and furnished steam at 225 pounds pressure to a quadruple-expansion engine having cylinders 8, 11, i6j4 and 26 inches in diameter by 12 inches stroke. The boiler contained 800 square feet of heating surface and 28 square feet of grate, the engine easily developing 250 indicated horse-power. The success obtained with the " Reverie " boiler warranted the construction, on the same lines, of a larger boiler having 2263 square feet of heating surface 'REVERIE" BOILEF, 1889 and 53 square feet of grate. This boiler was sold to Messrs. Thomas Wilson & Sons, Hull, England, and installed in 1891 in their S. S. "Nero" (see page 49). The engines were of the triple-expansion type, with cylinders 14, 24 and 39>^ inches in diameter by 30 inches stroke. Steam of 200 pounds pressure was furnished by the boiler, the engine developing 500 indicated horse-power. This vessel has since been in con- stant service ; the economy and reliability of the boiler proving so satisfactory to the owners that eight cargo and pas- senger ships have since been fitted for this firm. In 1892 a boiler, designed to carry 250 pounds steam pressure, was built for and installed in the steam yacht "Trophy." Both weight and space were saved by this change and the speed of the yacht materially increased. BARTLETT A CO. BABCOCK & WILCOX, 1895— PATENTED 17 ^ w S < w H Cfi H ffi O H-l w P4 ti* w w < >J e< o Q ^ W H C/J 5^, P< (i^ w H u <: o Ph m 1 >o w on M tH D ^ H tx ei H w (—1 H U < ^ X ?^ U M U N K-1 i8 In 1895 some slight changes were made in the construction of the Babcock & Wilcox boiler in order to increase accessibility. The vertical side tubes were replaced by forged steel boxes at the furnace sides, with tubes above, both boxes and tubes being inclined the same as the sections, the boiler taking the form shown in the cut. (See Babcock & Wilcox, 1895, page 18.) Two boilers of this design were constructed for the 6000-ton lake freighter " Zenith City," the vessel being the largest at that time ever built on fresh water. The engines were of the triple-expansion type, with cylinders 22, 38 and 63 inches in diameter by 40 inches stroke of piston. These sizes were proportioned to economically expand steam of 225 pounds initial pressure ; this pressure being 50 pounds in excess of the ordinary practice in connection with triple engines. This first installment of water-tube boilers in the lake trade was due to the progressiveness of Mr. A. B. Wolvin. He realized the full value of a device which would reduce the weight, space and cost of operation of the machinery plant of a freight steamer, without reduction of power. He is rightly entitled to be called the "pioneer" in the use of high-pressure steam, water-tube boilers and quadruple-expansion engines in cargo steamers on the Great Lakes, and has proved the potency of these factors by the great success with which large cargoes are handled in these waters. In 1896, in order to facilitate general operation and render the drum fittings more accessible, the boiler was reversed in its relation to the fire room, or stoked from the opposite end. The firing doors were placed under the cross box forming the mud drum, or blow-off connection, the location of the steam and water drum being at the front of the boiler, immediately overhead. At the same time the economizer previously located in the up-take was abandoned, and its equivalent heating surface added to that in the boiler ; the cost of up-keep in a marine boiler economizer, due to its inaccessible situ- ation and essential piping, valveSjCtc, amounting to more than the advantages derived from its use. In 1899 this design was , , . 1 , , BABCOCK & WILCOX, 1896 further improved by the use patented 19 of longer tubes, increasing the length of the furnace, and by a system of verti- cal baffles, in connection with a roof of light fire tile placed on the lower row of tubes. This arrangement of heating surface reduced the height of the boiler, increased the furnace capacity and permitted thorough dusting of the tubes without opening the tube doors at the front or rear. The first boilers constructed on this plan were built for the U. S. S. ♦' Alert," and installed in that ship at Mare Island Navy Yard, California. Hence the design is known as the "Alert " type. BABCOCK & WILCOX "ALERT" TYPE MARINE BOILER, 1899-PATENTED REQUIREMENTS OF A MARINE WATER-TUBE BOILER HE service of a marine water-tube boiler demands the following essential features : All materials of construction should be of the best. All tubes should be absolutely straight. All joints should be expanded. All brick work should be reduced to a minimum. All parts should be accessible for cleaning and repairs. In the Babcock & Wilcox marine boiler, all pressure parts are con- structed entirely oi forged steel ; not a pound of cast-iron, cast-steel or malleable cast-iron being subjected to pressure. In the manufacture of the forged open- hearth steel headers which connect the tube ends, The Babcock & Wilcox Company spared no expense, as they well knew that no water-tube boiler would ever be a successful competitor with the Scotch type unless built entirely of the same trustworthy vt\3X.&r\d\, forged steel. Straight tubes that can be purchased in the open market are another necessity. The water-tube boiler can then be retubed with the same facility and ease as the Scotch, as each tube can be withdrawn and replaced through its own tube hole, no row of tubes being destroyed in order to replace a new tube, or a tube bent to an exact curvature in a special tube-bending machine before it can be inserted into the boiler. By the use of the expanded joint. The Babcock & Wilcox Company place in the hands of engineers a joint with which they are perfectly familiar ; the old roller expander and taper pin being the only tools required to make tight any connection in the boiler, special threads and coned joints, so difficult to keep tight under the most favorable conditions, being entirely avoided. As the furnace sides are encased with forged-steel boxes of square section, through which the circulation passes, there is no need of brick work, which adds weight and is expensive to renew. The only brick wall in use, therefore, is that common to all boilers, whether station- ary or marine — the regulation bridge wall at the rear of the grate. Lastly, a boiler to meet the requirements of every- day service, in all kinds of vessels, must be provided with facilities for keeping the exterior of the tubes free from sooty deposits, and should have a sufficient number of doors located in the casing to enable a thorough inspec- tion of its interior. e io, 1898 Oentlemen:- 1, Please forward to the Conunandlns Officer, u^S. 3. "MARXi^TTA", Kqy West, Fla., 8 fire bricirs, 4 rip,!:ts and A lefts, #R, 3440, Dabcock & Wilcox boiler, to replace broken bricks between furnace doors, 2. Your bill for thesa articles should be sent to the same offi«*j cer and should refer to Steaa Engineering RequLsltion, dated June 1, 1898. " Respectfully, The Babcock & V/ilcox Co., 29 Cortland t St., Mew York, N.Y. JUN 21 181 39 O X w Q O Pi < h o o w o H <: H ^ U. S. GUNBOATS— "MARIETTA" AND ** ANNAPOLIS " HE following interesting account of the performance of the " Marietta " is from an official report to the Navy Depart- ment by Passed Assistant Engineer W. H. Chambers, U. S. N., the Chief Engineer : " In her recent trip from San Francisco to Acapulco, Mexico, the U. S. Gunboat ' Marietta ' showed what the new type of naval vessel can do in the matter of economy of coal. "She left San Francisco on January i6th, and arrived at Acapulco January 25th, after a trip marked only by good weather and smooth seas. During the trip runs were made for periods of 48 hours each, the engine revolutions being maintained at as near a constant rate as possible, and a careful account kept of the distance run and the amount of coal burned during these times. Three different rates of revolutions of engines were taken, giving speeds of io}4, g}^ and S}4 knots, respectively. "At the 8^ -knot speed the wonderfully small coal consumption oi 6}4 tons a day was obtained. In other words, the 'Marietta' steamed 204 miles a day on only 6}4 tons of coal, or could go more than 7500 miles on her total coal supply. "When it is remembered that this coal expenditure represents not only the steaming, but the electric lighting, ventilating, cooking and heating of the ship, it can be seen how economical this is for a vessel of 1000 tons displacement," Boilers in use Duration in hours Distance, patent log, knots Mean speed, patent log, knots Mean revolutions, main engine Indicated horse-power, main and auxiliary machinery Indicated horse-power, auxiliary machinery (estimate) Indicated horse-power, main engines only Coal for all purposes for run, tons Coal for auxiliary machinery, including evaporator, blow- ers and heating ship (estimate) Coal for main engine for run Coal for main engines for day Coal for main engines per indicated horse-power . . . A and B 47-97 5077 10.58 181. 1 549-5 18.0 531-5 26.60 3.60 23.00 11.50 2.02 5-55 21.81 8.20 2.16 2 3 A and B B 63-75 47-63 609.6 543-7 9-56 9-53 160.5 160.0 371-2 360.0 16.0 17.0 355-2 343-0 27.36 17.90 4.00 13.90 7.00 1. 91 B 35-35 364.8 8.57 140.3 273.8 17.0 256.8 9.46 3-30 6.16 4-15 1.52 Auxiliaries in use — Two mam circulating pumps ; one boiler feed pump ; one dynamo ; one F. & B. pump ; steering engine ; all constantly, i — Heating ship. 2 — Heating ship about half the time ; evaporator 0.6 time. 3 — Two ventilating blowers 0.5 time ; evaporator 0.5 time. 4 — Two ventilating blowers 0.5 time ; evaporator 0.5 time. The " Marietta " is a composite gunboat, 1 74 feet in length on the water line, 34 feet breadth of beam, 12 feet draft and of 1000 tons displacement. The machinery installation consists of twin-screw vertical triple-expansion engines^ with cylinders 12, 18 and 28 inches in diameter by 18 inches stroke. The Bab- cock & Wilcox boilers are 1 1 feet 6 inches in length and 9 feet 6 inches in width, with a height over all of 1 1 feet. The grate surface aggregates 94 square feet and the total heating surface 3620 square feet. There are 57 41 H-1 o < < Q < W Pi < 4-inch and 260 2-inch tubes in boiler and 64 2-inch tubes in heater. The boiler tubes are 7 feet 6 inches in length, while the tubes 'in the heater have a length of 6 feet 8 inches. The total weight of boilers, ash pans, and all fittings (dry) is 94,016 pounds, while the aggregate weight (with water) of boiler, ash pans and all fittings is 112,016 pounds. TRIAL OF THE "ANNAPOLIS" The trial of the "Annapolis," the first finished of the six composite gunboats ordered by the Government in the early part of 1896, took place on Long Island Sound, April 22, 1897. The "Annapolis" was constructed at Elizabethport, N.J., and was the first vessel of large type in the United States Navy to be equipped with all water-tube boilers. She is 204 feet long, 36 feet wide and 22 feet 3>^ inches deep. Her displacement is 1090 tons on a draft of 12 feet. The Bureau of Steam Engineering has heretofore preferred the use of water-tube boilers in connection with those of the Scotch type ; but, after repeated investi- gations and at the request of the constructors, Babcock & Wilcox all forged- steel boilers were adopted for both the " Annapolis " and " Marietta." The boilers in the "Annapolis" are built for a working pressure of 250 pounds to the square inch, there being two in number, supplying steam to a triple-expansion engine having cylinders 15, 24)^ and 40 inches diameter, and a stroke of 28 inches. Specifications for the boilers called for a total of 3600 square feet of heating surface and 94 square feet of grate, giving a ratio of about 38 to I, the contract speed to be 12 knots and indicated horse-power 800. From the performance of the boilers on the builder's trial it was shown that over 900 indicated horse-power could be developed under natural draft, although the funnel is very short. On the official trial, ash-pit draft was used, each boiler was supplied by air from independent Sturtevant fans, the average air pressure in the ash pit being limited to one inch of water. TIME OVER 48-KNOT COURSE Cactus Markeeta Iwana Cutter Leyden Cutter Iwana Markeeta Cactus Stake Boat Time Knots Minutes Seconds 6 26 27 12 27 I i8 27 18 24 28 10 30 28 17 36 26 00 42 25 49 48 25 2% Speed in Knots 137 133 13-2 12.8 12.7 13.8 14.0 14.20 Average speed, 13.43 knots per hour. Maximum speed, 14.18 knots per hour. Minimum speed, 12.7 knots per hour. 43 o pq H-; o X ti. o < < cia U! H u < o Cfi a Lj u The maximum indicated horse-power developed by the main engine was 1400, the average being 1320 at 147 revolutions per minute. The collective indicated horse-power will average about 1360. The maximum speed was 14.2 knots and the minimum 12.7. This low figure occurred through the pilot losing sight of the Leyden's cutter on the first 6-mile leg of the return course. When the end of the "four hours at full speed" test was reached the helm was put hard to port and to starboard without reducing the speed, and the little vessel made circles with a diameter of 400 feet. In turning she heeled only 3.5 degrees. OFFICIAL TRIAL — FIRE-ROOM DATA Time Boiler Pressure Draft Pressure in Ash Pit, Inches Remarks A. M. Pounds Port starboard 9:00 220 .78 .68 9:15 220 •85 I.IO 9:30 230 1. 10 .65 10:00 223 •92 .70 10:15 225 •55 •71 10:30 223 .82 .82 10:45 225 .98 •85 10:49 Passed 24-knot stake boat and turned for home 11:00 223 .92 .91 11:15 218 .76 115 11:30 232 •65 I.IO 11:45 222 •91 .80 12:00 224 1. 00 .80 12:15 222 1. 12 1.20 12:30 232 1. 00 1.00 Indicated horse-power, main engine, 1319 12:45 234 1.20 1.20 12:47 240 Full speed until i P. M., to complete 4-hour trial Average 226 .90 .91 Before leaving the "Annapolis," Commodore Dewey (who became the famous hero at Manila, now Admiral Dewey), said that he was going to send this telegram to the Secretary of the Navy : " 'Annapolis ' trial most satisfactory ; speed 13.43." "It is not customary and hardly proper," said the Commodore, "to use adjectives in such despatches, but really, this time it cannot be helped. She deserves them." — Marine Review. 4S WAR SERVICE OF THE "ANNAPOLIS" By Lieut. G. R. Salisbury, United States Navy, Chief Engineer United States Ship "Annapolis." The little gunboat "Annapolis" has, since the breaking out of the war with Spain, been most actively engaged. During that time the service performed consisted in convoying the " Fern " with ammunition from Tampa to Key West. Three weeks on the blockade in front of Havana, where she took part in the engagement with the cruiser "Conde Venedito " and two gunboats that attempted to run the blockade, but owing to the prompt action of the blockading fleet, did not venture beyond the range of Morro's guns. The "Annapolis" was instrumental in the capture of the French steamer "Lafayette" and barque " Santiago Apostal ; " the former being released upon arrival at Key West on application of the French Ambassador. From service on the blockade. Captain Hunker was ordered to Port Tampa, to take charge of, and arrange for, convoying the Army of General Shafter to Santiago de Cuba. The fleet thus formed sailed from Tampa on June 14th, consisting of thirty-eight steamers loaded with troops and five gunboats. The sight presented as they steamed out of Tampa Bay was truly magnifi- cent. Upon arrival at Santiago, six days later, the "Annapolis" was detailed to take part in the bombardment of Siboney ; the object being to distract the attention of the Spanish while United States troops were disembarking at Daiquiri. Siboney is four miles west of Daiquiri, and it transpired afterwards that a detachment of troops dispersed by the fire of the gunboats in front of Siboney was a portion of General Linares' army on its way to contest the landing of General Shafter. After several days in front of Siboney and Daiquiri the " Annapolis " was ordered to Guantanamo Bay, and for three weeks guarded the upper part of the bay against attack of several Spanish gunboats stationed at Caimanera. Guantanamo Bay was used as a naval base, and there were at that time several colliers, supply vessels, repair ships, torpedo boats, besides cruisers and battle ships, coming constantly for coal, provisions and repairs. Later the "Annapolis" was sent to Baracoa to intercept a vessel laden with 46 provisions for the Spanish forces stationed there ; while near the town was fired upon by the fort. A short and spirited engagement followed in which the shore battery was silenced. Returning to Guantanamo Bay the ship was ordered to proceed with the "Wasp" and "Leyden" to the capture of Nipe Bay, which was successfully accomplished, after running over mines placed in the channel, driving back troops stationed on heights above the entrance, and sinking the Spanish cruiser "Don Jorge Juan" and one gun- boat. This exploit was similar to the capture of Manila Bay ; it being necessary to pass over torpedoes that, happily, proved to be inoperative, though not known to be so at the time. From Nipe the " Annapolis " went to Puerto Rico and was the first vessel to enter the Port of Ponce, that had been selected by General Miles as landing place for his army. She was then dispatched on a cruise about the island in search of transports from the United States that had been ordered to assemble at other points, and to send them to Ponce. While on this mission she took part in the cap- ture of Cape San Juan. During the war the vessel steamed 8577 miles, and her engines have made more than six million revolutions. The machinery is in splendid condition, and there has never been a moment's delay on its account. The boilers have proved to be admira- bly adapted to war service, where it is necessary to change speed and steam pressure often and quickly. Not a leak was developed, and all machinery was kept at the highest point of efficiency by the men of the engineer's force, though called upon continually for watch and regular duties. *j^?»^^5s; A 3S00-MILE Rail Shipment For The Pacific Coast 47 O P< oa o O c en S O ^ r-i O S o .. « w o o Jf ^ S o =^ COMMENTS ON THE -BATTLE OF THE BOILERS" HERE is probably no legislative body in the world whose membership includes so many eminent shipbuilders and engineers as the British Parliament, and these experts have rendered the Empire a great service in carefully scanning the Navy estimates and studying the reports submitted by the Lords of the Admiralty. Projected naval legislation is therefore intelligently criticised before being enacted into law, for everything relating to the Navy possesses a special interest for the loyal Briton, It has been because such practical and loyal technical experts have scrutinized the Navy estimates that the material of the British Empire is so efficient, and when these men declare that the boiler question is now the para- mount one in naval construction, the subject may be considered as one of impor- tance to ev^ery nation that aspires to naval power. — N. V. Tribtme, Dec. 25, 1900. From a recent speech of Hon. C. H. Wilson (Hull, W.), delivered in the House of Commons July 17th, 1900, we quote the following: " I think I ought, having had more, perhaps, practical experience of the working of the water-tube boilers at sea than any other member of the House, to give to the House the results of that experience. . . . Take the experience of my own firm. To some extent we found the same faults with the old cylindrical boilers which the Admiralty did ; and we have in the same way asked ourselves how these things could be remedied. Water-tube boilers were brought before us eight years ago, and one was put in the ship called ' Nero,' which has been continously at work ever since. In 1891 we got to work with the 'Nero,' and since then she has made 79 voyages, and run 165,965 knots. In 1895 we built the steamer called the ' Hero.' " Commander Bethell (Yorkshire, E. R., Holderness): "Were these fitted with the Belleville boilers t " Mr. C. H. Wilson : " No ; they were fitted with Babcock «& Wilcox water-tube boilers. The 'Hero' made 257 voyages out and home, that is to and from Hull to continental ports and back again, and ran 131,045 knots. In 1896 we took the old cylindrical boilers out of another of our steamers in the same way as we had done with the 'Nero,' and put water-tube boilers in her: and she has made 104 voyages, and run 106,293 knots. In 1897 we did the same thing with the 'Orlando,' which has made 68 voyages, and run 84,306 knots. In 1898 the old cylindrical boilers were taken out of the 'RoUo,' and water-tube boilers substituted, and she has made 49 voyages, and run 53,975 knots. In 1898 the 'Otto' was built for the short weekly continental trade, and was fitted with water-tube boilers. She has made 99 voyages, and run 51,894 knots. In the same year the 'Truro,' a new vessel, was fitted with water-tube boilers. She has made 94 voyages, and run 51,291 knots. In 1899 the cylindrical boilers were taken out of the 'Tasso,' and water-tube boilers put in. She has made 27 voyages, and run 44,046 knots. This steamer makes frequent voyages from Hull to the west coast of Norway and carries a great many of our friends backwards and forwards with perfect safety. Summing up the results of all these steamers, I find that they have made 800 voyages and run 700,000 knots, and 49 practically we have not experienced all the dangers and difficulties that have been predicted. I do not say that the water-tube boilers are perfect. As we go on we get more knowledge, the same as the Admiralty are getting ; and we are now getting, I hope, nearer perfection. We have steamers running to America, and we are taking the cylindrical boilers out of one of them and putting in water-tube boilers. In a few weeks this steamer will be running a voyage out and home of 7000 miles, and that will give a very good test.* Taking the other side of the question, in 1895 we had Belleville boilers put into the ' Ohio,' but they were not satisfactory, and we took them out after runs of t 11,000 knots to America and back. , . . Personally I feel convinced that the Admiralty will never go back again to the use of cylindrical boilers. I have heard it stated from the other side of the House, by the Hon. Mr. W. Allen, member for Gateshead, that there is no saving in the weight by the use of water-tube boilers. That is a great mistake. There is an enormous saving in weight. He omits altogether the enormous weight of the water in the cylindrical boilers as compared with that in the water-tube boilers ; and it is self evident that there is a very great advantage, more especially in the Navy. But even in the case of the mercantile marine, as a practical ship owner, I think it is a great advantage. Take one of our smaller ships ; there is a saving of some fifty tons of weight in boiler and water. And if that ship makes fifty trips from Hull to the Continent and back, that is 100 in all per annum. They could, by the use of water-tube boilers, carry 5000 tons more cargo." The Tribune again states : " This battle of the boilers has also been going on at Paris, Berlin, St. Petersburg and Washington, but the period has now been reached when, so far as each individual nation is concerned, a choice will have to be decided upon. Without going into technical details, it need only be said that the cylindrical boiler has had to give way on the war ship to the water-tube type. The questions of weight, space occupied and endurance have caused the change. "The United States is therefore about to solve the boiler question, and in securing a type of American design the Navy is adopting one that can be relied upon in time of emergency, for if war should come, there would be thousands from shore who would understand its manipulation after a brief period of training." Admiral Melville refers to this matter in his last report (1900), from which we quote the following paragraph : "One point in particular will illustrate the extreme value of high professional criticism in design. Some years ago the Department was urged, with no little * Extract from the Pall Mall Gazette, extra special edition, Nov. 8, 1900 : '''Editor Pall Mall Gazette: Sit — We notice a paragraph in your issue of the 6th inst. referring to our steamship ' Martello,' in which you stated that this vessel burnt 448 tons more coal on her voyage since being fitted with water-tube boilers than she did previously with ordinary cylindrical boilers. "This is quite incorrect ; the coal consumption on her first voyage with water-tube boilers being 100 tons less than the average of three years with ordinary boilers, and the speed is 1.72 knots faster. " We think, in courtesy to us, you should have given us the opportunity of verifying your figures before publishing them, which we shall at all times be pleased to do, and we should be much obliged by your letting us know how you got this most inaccurate information. The ship is now on her second voyage, and we have every reason to believe that the performance will be improved. We may add that nine of our steamers are now fitted with Babcock & Wilcox water-tube boilers. " Yours, etc., " For Thomas Wilsom, Sons & Co., Ltd., "Charles H. Wilson, M. P., Chairman.'''' 51 w in ° r/5 =y pressure, to adopt the Belleville water-tube boiler as a standard for the new ships. This Bureau opposed the innovation wholly upon a close examination of the designs, criticising the very defective features which in later years have made conspicuous the comparative inefficiency of this type over the purely straight-tube, non-screw-joint type for which I have given continuous and urgent preference. The Department is to be congratulated upon escape from this ' pressure ' and upon the conservative approval it has given to the change in the boilers of naval ships. Instead of having been encum- bered during the last war with ships powered with a type of boiler necessitating a specially trained force even for its safe operation, the most effective vessels had either retained the Scotch boiler or possessed the simple straight-tube Babcock & Wilcox boiler, and remained free from any real danger of becoming hors die combat by reason of lack of a completely experienced fire-room management, or the sudden failure of delicate or intricate special apparatus connected with the steam generators. "In many other details, difficult to make clear without purely technical descrip- tion, has the Bureau prevented the incorporation of faulty features in design and has advanced the proportional perfection of machinery." Recently there appeared in the leading German marine periodical, Schijfbau, a semi-official article v^hich summarizes the results of tests conducted at the Imperial Experimental Station at Charlottenburg. Referring to Babcock & Wilcox Marine Boilers, this summary says : " Thij; system of boilers is, besides, free from all complicated parts such as are found, above all, in the Belleville boilers. Stay bolts and braces are not required, and the tubes are entirely untrameled in their extension longitudinally ; so that leakages are hardly to be expected with fair workmanship. The circulation is simple through- out. Nickel gaskets and similar expensive joints are here unnecessary. The steam drum gives up its whole space for the reception of steam. The entire labyrinth of baffle plates, so characteristic of the Belleville boilers, and which so obstructs the passage of steam, is entirely omitted. It is therefore much easier to examine and to control the newly-produced steam as well as the steam drum itself. The Belleville boiler without a reducing valve is not feasible ; it requires a special feed pump ; a special feed-water regulation ; the burdensome water tending must be of the very best imaginable, and the fuel must be excellent. In actual practice, when the safety of the ship and the machinery are depending on such points, the many features that are required to make up such a system are well calculated to give rise to serious cares. The Babcock & Wilcox boiler, on the other hand, may be tended like any good cylindrical boiler ; their instalment requires no special arrangement, and even with a smoky coal fair results of efficiency have been obtained. These advantages develop themselves when the boilers are regarded from a mere technical standpoint. In quite a natural manner, therefore, one arrives at the conclusion that a trial with these boilers in our own Navy would be advisable, especially since the Babcock & Wilcox Company has works in Germany at Oberhausen. " Furthermore, it may be reasonably supposed that this system will adapt itself readily to the constantly varying and progressing requirement of the naval service, because it is composed of simple parts. The number of advantages which this boiler has over others in many points, will be increased by progressive studies, so that it should receive greater consideration in our Navy as well as in our merchant marine." 53 S cy H, M. S. "SHELDRAKE"— TESTS AND SEA TRIALS [HE "Sheldrake" is a torpedo gunboat of the "Salamander" class, with twin-screw triple-expansion engines of 3500 horse-power, collectively. Each engine has cylinders 22, 33 and 49 inches in diameter with a stroke of 21 inches. There are two boiler compartments — divided by a water-tight bulkhead— two boilers in the forward com- partment, and two in the after compartment. Each pair of boilers is placed back to back ; each boiler having its own stoke hold. The boilers are fired fore and aft. The total heating surface in each boiler is 2356 square feet, and the grate surface 63 square feet. The boilers are composed of 19 sections of tubes, including side sections. The tubes throughout are of solid drawn steel, galvanized on the outside by the electro-deposition process in accordance with the usual Admiralty require- ments. The tubes connecting the headers and cross boxes together are i|g inches in diameter — those between the headers are 7 feet 6 inches long, and those in the cross boxes 7 feet 4% inches. The up-take headers are connected to the steam and water drum by 4-inch tubes ; 4-inch down-comer tubes are taken from each end of the steam and water drum, and connected to a wrought mud box, this box being provided with blow-off and drain valves. The stoke holds are arranged so that the air supply may be increased by means of fans, though the up-cast from the stoke hold remain open, and for this, four 6-foot double inlet fans were supplied, driven by engines 6}4 by 5 inches, and capable of running up to 600 revolutions per minute. There are two up-takes and two funnels — one common to two boilers — the inside diameter of each funnel being 5 feet, and the height above the grate bars 45 feet. The new boilers were made under a rigorous survey by the Admiralty surveyors ; and, in accordance with the terms of the contract, one of the four boilers was erected at the constructors' works, and there subjected to tests by the Admiralty authorities, to determine its capacity and efficiency. The guarantee to the Admiralty was that one of these boilers, steamed on shore, with natural draft, would evaporate 11,000 to 12,000 pounds of water per hour, with Welsh coal, and with the feed water at hot well temper- ature, 1 10 degrees Fahrenheit. With forced draft — not exceeding 3 inches of water, it was guaranteed to evaporate 18,000 to 19,000 pounds of water per hour from 1 10 degrees Fahrenheit for two hours continuously. On the test boiler the ordinary draft was that due to a funnel fixed on the top of the boiler, 3 feet 6 inches diameter, and 45 feet high above the fire bars, corresponding to what the natural draft would be in one of these boilers in ordinary conditions of working on board ship. The assisted draft was 55 obtained by a steam jet placed in the funnel, the steam being taken from a ^-inch pipe, with the outlet reduced to about >^ an inch in diameter. No baffles were used to deflect the flame, or to reduce the area between the tubes. In the table of tests, those having the Admiralty number were carried out by the Admiralty authorities, the others were made by permission of the Admiralty for the builders' observations. H. M. S. "Sheldrake" Boiler, Pressure Parts, Casing Removed Permission was obtained from the Admiralty to place a feed heater in the up-take of the tested boiler for experimental purposes, but no heater is placed in the up-takes on board the " Sheldrake." It will be seen from the table of tests that this heater was removed after the fifth test. S6 In the first five trials it will be observed that the efficiency of 74.3 per cent. (E), with an evaporation at the rate of 4.87 pounds per square foot of heating surface, only falls to 72 per cent. (A), with an evaporation of 8.3 pounds per square foot of heating surface, and noting the intermediate trials (B, C and D), it shows that the efficiency, when evaporating up to 7 pounds of water per square foot of heating surface, is practically constant, and only above 7 pounds does the efficiency begin to fall. This proves the great elasticity in the working of the Babcock & Wilcox boiler — a result that could not possibly be obtained with the ordinary shell boiler — in other words, the amount of steam formed can vary between considerable limits without any fall in efficiency. Tests G and D — the one with an evaporation of 5.18 and the other 5.13 pounds per square foot of heating surface — give efficiencies of 81 per cent, and 74.8 per cent., the higher efficiency of the former being due to the smaller air space between the bars. With this boiler the highest efficiency with natural draft was obtained burning about 22 pounds of coal per square foot of grate surface, and }i of an inch air space between the bars. BASIN TRIALS The basin trials of this vessel took place at Devonport on the 14th, 15th,. 1 6th and 17th of November, The vessel was moored to the wharf in the usual manner in such trials, and the engines were allowed to run at such power as would take away all the steam formed by two of the boilers at a fixed rate of working. Two boilers only — alternatively those in the forward and aft compartments — were taken for each trial, so as to admit of more accurate observations. The feed water was taken from the shore, and was carefully measured on its way to the boilers ; the water from the hot well was allowed to run into the bilges. On the 14th of November the two forward boilers were tried, burning 15 pounds of coal per square foot of grate, and on the 15th the two after boilers were tried at the same rate of combustion. These two trials were to determine the economic efficiency under a moderate rate of working. On the 1 6th of November the two forward boilers were tried, burning 25 pounds of coal per square foot of grate, and on the 17th, the two after boilers were tried at the same rate of combustion ; these latter trials were for the purpose of determining the economy at the maximum rate of working. Each trial was of eight hours' duration, and was carried out with that scrupulous accuracy which is characteristic of Admiralty trials. SEA-GOING FULL POWER TRIALS The first sea trial, which took place on the 28th of November, was of eight hours' duration, and with all four boilers in use. This was an economy trial,. 1 5 pounds of coal being burnt per square foot of grate per hour. 57 TABLE OF TESTS OF "SHELDRAKE" BOILER Trials Admiralty number Date, 1897 Heating surface of boiler, square feet Heating surfa:e of heater, square feet . Grate surface, square feet Fire bars used — A for Admiralty pattern, C for corrugated pattern Air space between fire bars, inches . . Kind of fuel used Duration of trial, hours Kind of draft. — N for natural ; I for induced Amount of blast in inches of water in ash pit Average observed gauge pressure — lbs. per square inch Average observed temperature of water fed to heater, Fahrenheit Average observed temperature of water fed to boiler, Fahrenheit Pounds of coal fired, per hour .... Pounds of refuse, per hour Pounds of combustible, per hour . . . Pounds of coal consumed, per square foot of grate, per hour Pounds of water evaporated per hour under actual conditions. Feed at 70° F. Equivalent weight of water evaporated per hour with feed at 110° . . . . Pounds of water evaporated per square foot of heating surface Pounds of water evaporated per square foot of grate surface Pounds of water evaporated per sq. ft. of heating surface from and at 2 1 2° per hr. Pounds of water evaporated per sq. ft. of grate surface from and at 212° per hr. Pounds of water evaporated per pound of coal per hour (water 70°, steam pressure 200 pounds, actual observed conditions) Pounds of water evaporated per pound of coal per hour ; from and at 2 1 2° Pounds of water evaporated per pound of combustible per hour (water 70°, steam pressure 200 pounds, actual conditions) Pounds of water evaporated per pound of combustible per hour ; from and at 2 1 2° Mean temperature of gases in funnel, F. Mean temperature of gases above the heater, Fahrenheit Mean temperature in up-take below the heater, Fahrenheit Efiiciency " A " Efficiency " B " May 14 2356 63 II. 19 2356 175 63 A I full Nixon's Nav'n 3 I 0.25 185 70 2564 487 2077 40.7 19577 20250 8.3 310 9.96 372 7-63 9-15 9.4 11.28 650° 61.5% 72% 2 N 0.2 190 70 117. 5 2000 260 1740 31-74 16650 17222 7.06 264 8.48 316 c D « G III. IV. 22 24 25 28 2356 2356 2356 2356 I7.S 175 175 — t>3 63 63 54 A A C C i 1 i i V. VI. June 8 8 2356 2356 54 A scant Powell Duffryn's remaining 6 tests 9.56 11.47 600° 2 N 200 70 114 1650 91 1559 26.19 15000 15516 6.36 238 7-65 286 8.32 9.09 9.96 10.91 9.6 11.52 6:0° 650° ! 650° 67% i 73-2% 73-2% 73-5% 3 3 5 2 N . N N N 0.1 0.1 0.2 0.1 200 200 200 200 70 70 — — III 1320 67 1253 1260 75 1 185 70 1216 64 1152 70 1290 194 1096 20. g 20 22.5 24 12200 1x483 12210 I IIOO 12619 11878 12630 11481 513 4.87 5.18 4-7 193-5 182 226 205-5 6.17 5.85 6.23 565 232 219 271 248 9.24 9.11 10.04 8.6 11.09 10.94 12.05 10.32 9 77 9.69 10.6 10. 1 11.72 11.6 12.72 550° 12.12 600° 550° 550° — — 650° 74-5% 74-8% 650° 73-4% 74-3% 809% 81.2% 69-3% 77-4% 54 A scant 3 N 0.3-0.4 200 70 2280 25' 2029 42.2 18216 7-7 337 9.26 404 7-99 9-59 8.97 10.7 20'.° 644% 68.5% N. B. — Efficiency " A " is the percentage of the total heat of coal that was actually transferred to the water, that is, to/Mot^^ allowing for loss by unconsumed coal dropping through the bars, or ash. Efficiency " B " is the actual efficiency, allowing 5% for ash, and making allowance for the coal that fell through the bars unconsumed. that is to say, these figures are establisheid to show the result that would have been obtained on the assumption that the grate bars had been so arranged that no loss of unconsumed fuel took place, but only the loss by the usual percentage of ash or residue in the fuel. The total heat of combustion of the coal has been taken at 14,400 British Thermal Units per pound The temperatures of the gases were taken by noting the melting of pieces of metal, of a known melting point, placed in the funnel and up-take, and not by a pyrometer. 58 RESULTS OF SEA TRIALS Date of Trial Total grate surface in four boilers Total heating surface in four boilers Average Pressures : In boilers (gauge pressure)' .... In high-pressure casing (above atmosphere) In intermediate-pressure casing (above atmosphere) In low-pressure casing (above atmosphere) Vacuum ........ Pressure of air supply to furnace, inches of water Draft at base of chimney, inches of water Average Temperatures: External air ...... . Boiler room ....... Escaping gases at root of funnel Feed water ....... Discharge ........ Steam in boilers Fuel : Coal consumed per hour Total dry refuse Quality of coal . Power, Speed, Etc. : Average indicated horse-power Average revolutions per minute .... Average speed of vessel per hour .... Coal consumed per indicated horse-power per hour . Heating surface in square feet per indicated horse-power Indicated horse-power per square foot of grate November 28th, 1898 252 square feet 9424 square feet 152.5 pounds 122 pounds 34 pounds 1 5 absolute 25 8 inches 0.2 inch 0.2 inch 53° Fahrenheit 57° Fahrenheit 550° Fahrenheit 103° Fahrenheit 76° Fahrenheit 366° Fahrenheit 3776 pounds 5 per cent. Powell Duffryn 2642 242 17.9 knots 1.429 pounds 3-5 10.5 December ist, 18 252 square feet 9424 square feet 151 U7 39 6 26 pounds pounds pounds pounds inches 0.5 inch 0.3 inch 57° Fahrenheit 70° Fahrenheit 550° Fahrenheit I ro° Fahrenheit 82° Fahrenheit 365° Fahrenheit 6462 pounds 6 per cent. Powell Duffryn 4050 280 20.6 knots 1.57 pounds 2-3 16. On December ist a full power sea trial was made on the four boilers. During these trials the temperature of the gases at the base of the funnel was taken every half hour, by noting the melting of chemically pure metals in a similar manner as for the trials on shore. At the expiration of the full power trials, the Admiralty decided to further test the new boilers in actual sea service Accordingly, an exhaustive series of nine tests was arranged, each test to cover a distance of looo niiles. During each of these trials the engines were run at a constant rate, and an accurate record kept of the coal burned. The three after boilers only were used, the fourth being held in reserve (cold). The programme was as follows : Four 1000-mile runs with engines developing 1500 indicated horse-power at the rate of 500 indicated horse-power per boiler. Two 1000-mile runs with engines developing 1800 indicated horse-power at the rate of 600 indicated horse-power per boiler. Two 1000-mile runs with engines developing 2000 indicated horse-power at the rate of 666 indicated horse-power per boiler. One 1000-mile run with engines developing 2250 indicated horse-power at the rate of 750 indicated horse-power per boiler. 59 LATEST TYPE SEMI-MARINE BABCOCK & WILCOX BOILER-PATEN 1" ED The results obtained on these and the preceding basin and commissioning trials are as follows : SUMMARY— BASIN AND SEA-GOING TRIALS Date 1 4- 1 1-98 15-11 -98 1 6-1 1-98 17-II-98 28-1 1 -98 I -I 2-98 22- 2-99 -28- 2-99 9- 3-99 .28- 3-99 20- 4-99 5- 5-99 19- 5-99 15- 6-99 3- 7-99 20- 7-99 Nature of Trial Evaporative Evaporative Evaporative Evaporative . . . . 8 hours at 2500 I. H.-P. . 3 hours at 3000 I. H.-P. . 3 hours commissioning . 1000 miles at 1500 I. H.-P. 1000 miles at 1500 I. H.-P. 1000 miles at 1500 I. H.-P. 1000 miles at 1500 I. H.-P. loco miles at 1800 I. H.-P. 1000 miles at 1800 I. H.-P. 1000 miles at 2000 I. H.-P. 1000 miles at 2000 I. H.-P. 1000 miles at 2250 I. H.-P. o S W^ Total Mean 146 1974 .2 3 3 3 69 68 70 68i 67 66i 59 6ii 63 2f c 3 ^7 168 II16 179 1292 169' I761 165 1873 152 2642 151! 4050 119: 2735 120 1303 I20| 1506 I35I 1534 '30: 1539 I35I 1829 140' iS •45 2033 1401 204 150: 2245 Kg .0 ■43 .14 .0 .0 .0 .0 .0 .0 .0 .0 .0 1.69 1.46 1.78 1.67 1-43 1.64 i.6t 1.6 1-75 1-59 1.6 1.68 1-57 1.56 1.63 1.63 ■2 = « 3 ^ ° 15.0 15.0 25.0 25.0 15.0 25.6 17.8 12.8 12.67 14.2 I3-I 154 16.4 17.0 16.8 194 152 150 200 150 216 220 220 230 250 9.85 .198 126 126 126 126 252 252 252 189 189 i8q At the finish of the looo-mile trials, several experiments were made. The first one was on the forward boiler, when the time required to raise steam to 140 pounds pressure from cold water was taken; the temperature of the water at the start was 70 degrees, and steam was raised to 140 pounds pressure in 23 minutes. After that a stopping and starting test was made; the engines were going full speed and suddenly stopped. The front tube doors and up-take doors were immediately opened and the ash-pit doors closed ; the .steam gauge was then watched and the pressure did not rise more than 5 pounds, neither did the safety valves lift. The next test was made to ascertain how soon the operation of drawing a tube could be commenced after the fires were pulled out of the furnace. No. 4 boiler was used for this purpose. This boiler was worked at full power ; suddenly the fires were drawn and the water blown out ; in 24 minutes after hauling the fires several caps were taken off ready for drawing tubes. Then a test was made to show how quickly a tube could be taken out of a boiler. Three tubes were drawn one after the other ; the first took 1 1 minutes, the second 10 minutes, and the third 9 minutes. At the conclusion of these experiments, the "Sheldrake" had completed the whole of the Admiralty programme and returned to Devonport, where a •careful examination was made of the boilers, which were found to be in as good a condition everywhere as when they left the works. 61 <=« O w W < § i DREDGERS FITTED WITH WATER-TUBE BOILERS RUSSIAN GOVERNMENT DREDGERS FIRED WITH NAPHTHA NOVEL feature in the dredgers shown in the accom- panying photograph, which have been built by Messrs. La Societe Anonyme John Cockerill of Seraing, for the Russian Government, is the installation of water-tube boilers. These are of the Babcock & Wilcox marine type, and have given on the trials very great satisfaction. There are four of these boilers on each hull half, making eight in all, having a total heating surface of 17,200 square feet. In addition to this a small boiler of the same construction is fitted in a stern wheel steamer, which is to act as a work- shop and general tender to the dredger; this boiler has 1000 square feet of heating surface. On the Russian official trials, which took place on the 24th to 29th of May, 1900, the boilers worked throughout without a hitch, giving an abundance of perfectly dry steam. On the full power trial, with all the machinery running, no trouble was experienced in keeping the water level constant, or in getting a sufficiency of steam, although working at a very high rate of evaporation, which would be, judging from the indicated horse-power of the engine, nearly 8 pounds of water per square foot of heating surface per hour. On the stern wheel steamer, with the boiler of 1000 square feet heating surface, the boiler was forced to about double its rated capacity. The boilers are fired exclusively with naphtha ; there are four burners fitted to each boiler in the dredger, and two to the boiler in the stern wheeler. The burners are made so as to swivel out from the furnace when requiring to be cleaned or examined. The spraying of the petroleum into the furnace is accomplished by a jet of steam. The oil by this means is vaporized and made ready for combustion. The temperatures taken of the funnel gases showed these to be very low, i.e., not more than about 500 degrees F. Any soot which may be formed at any time on the tubes can very readily be removed by means of suitable doors, which are provided in the boiler casing for the purpose ; through these doors the whole of the heating surface of the boiler can be scraped or brushed, and as the whole of the interior of the tubes can be cleaned from scale, etc., it will be seen that if ordinary care in cleaning is taken, the boiler can always be relied upon to produce steam as efficiently after it has worked a long time as when first installed. The boilers are constructed in such a manner that repairs can be readily carried out by the engineer's staff on board. 63 o P5 X •«. '", Pi ^ M " W Si cy < M o *• u w 03 o Q p; W >< Pi :n H ^ < < ■^ V^ < H Ol One of the advantages derived from the use of these boilers is the small amount of weight, as compared with ordinary boilers. The weight of the four boilers on one hull half, complete in working order with funnel, up-takes, and all accessories, was .02 tons per indicated horse-power developed on the trial. DREDGERS "HERCULES," "SAMSON" AND "ARCHER" The above vessels are sand-pump dredgers, and were built in 1900 by Messrs. Sir W. G. Armstrong, Whitworth & Co., Ltd., Newcastle-on-Tyne, all three ships being fitted with Babcock & Wilcox boilers, the first two ships with four boilers each, and the last with six boilers, a total aggregate heating surface of 44,300 square feet and grate surface of 1 125 square feet. All three had satisfactory trials on the River Tyne and at sea, afterward proceeding to Australia under their own steam, where they will operate in the service of the Queensland Government. Information received from various ports of call indicated that the boilers were working most satisfactorily. The boilers were made especially large to utilize inferior coals. HOPPER DREDGE " ANTELEON " The trial of this hopper dredge took place at Skelmorlie on August 3d, 1898. The vessel was built by Messrs. Simons & Co., of Renfrew, for the New South Wales Government, and is fitted with twin-screw propelling engines, each having cylinders 10, 15^ and 26 inches diameter by 16 inches stroke, indicating about 650 horse-power at 235 revolutions per minute. Two Babcock & Wilcox water-tube boilers supply steam to the propelling engines, pumping engines, and auxiliary machinery, and the total weight of the main engines and boilers is only 53 tons. Two runs were made in opposite directions at Skelmorlie (the vessel being loaded to full capacity), when a mean speed of over gj4 knots was obtained, the contract speed being only 8 knots. Further sand pumping trials were carried on at Brodick Bay, and on the result of these and the speed trials, Messrs. Simons are to be congratulated. This vessel may be quoted as another instance of the suitability of the Babcock & Wilcox boilers for all classes of vessels, and, as showing the reliance which may be placed upon the boilers, it is intended that this vessel will steam out to Sydney, N. S. W. It may be mentioned that the " Anteleon " is the fourth Scotch-built vessel into which the Babcock & Wilcox boilers have been fitted within the past year or so. — T/ie Steamship. It is interesting to note that the "Anteleon " steamed to Sydney, N. S.W., in eighty days, and on arrival the boilers were found to be in excellent condition. 65 Q ►J W < H ;?; y w u H o <1 U Ph >< 1 (>$ Pi Q o H PQ < O X u C) Q J is < > _ r^ >< ■i< f- ■i4 U c; tn O < pa H < m " UI w o ^2; Q Pi < Q ^. z 1—1 Q .J C/J J < H 66 DREDGE "TEXAS CITY" AND FLOATING DRY DOCK "ALGIERS" The steam dredge "Texas City," built in the spring of 1900, was equipped with a Babcock & Wilcox boiler of the semi-marine type. This style of con- struction is somewhat heavier than the marine and not quite so compact, favoring the land or stationary boiler in appearance ; the tubes forming the heating surface being 4 inches in diameter and from 12 to 14 feet in length. Around the boiler is fitted an air-tight wrought-steel casing, which contains asbestos, magnesia and light fire tile placed against the side tubes. The boiler is supported upon a plate and channel girder, thereby distributing the weight of the structure over a large area. Four boilers of this class have been installed on the United States Government floating dry dock "Algiers." STEAM DREDGE "TEXAS CITY" Capacity, 3500 Cubic Yards of Blue and Red Clay Per Day PONTOON PIPE LINE From Dredge to Dumping Ground DISCHARGE OF 20-INCH PIPE 1000 Feet from Dredge 67 68 FUEL— ITS COMBUSTION AND ITS HEAT VALUE ''HE term "fuel," in its widest sense, may mean any sub- stance which, by its combination with oxygen, evolves heat. It is generally applied, however, to those substances which are in common every-day use for heat -producing purposes. Coal is the fuel most extensively used, and while saw- dust, rice-chaff, bagasse, wood, etc., are not uncommon fuels for making steam on land, coal is practically the only kind that need be considered in marine practice. The nature and quality of coal, in point of view of its heating value, vary considerably. It is a fossil of vegetable origin, and the difference in its nature is attributed to the variation in its origin. Coal from the same stratum does not vary in its nature or characteristics, and generally these characteristics are the same in a certain district, hence the district from which a certain coal is obtained usually determines its commercial designation. Coal is divided into two main classes — anthracite and bituminous. "Anthracite" is a word of Greek origin, meaning "carbon" or " coke," the fuel being so named probably because it is that which contains the largest percentage of fixed carbon. "Bituminous" is of Latin origin, meaning "containing or resembling bitumen." There are various degrees in the nature of these coals, which may be enumerated as follows : Anthracite, or hard coal ; semi-anthracite ; semi- bituminous ; bituminous, or soft coal ; and lignite. Pure anthracite coal — which is said to be the oldest and deepest formation — is found principally in the United States of America. It is also found in the western part of the South Wales coal fields ; in the neighborhood of Swansea ; in some parts of Scotland ; to a small extent in France ; in the South of Russia ; and in the Osnabriick district of Westphalia, Germany. Semi-anthracite coal closely resembles anthracite in its physical characteris- tics and appearance, but contains less fixed carbon and burns more freely. It is represented by what is known as "Welsh anthracite," and by coals from a limited territory in Pennsylvania. Semi-bituminous coal is most largely represented by the "Cardiff" or "Welsh" coals from the enormous fields of South Wales, and in the United States by the rich deposits on the slope of the Appalachian Mountains, extending from Clearfield County, Pa., to the southern boundary of Virginia, the coals in this belt taking the names of "Pocahontas," " George's Creek," "Clearfield," etc. The Belgium coal, known as "Demigras," is also of this class. Bituminous coal is found almost all over the world. The largest known fields, generally speaking, are in Scotland, England and the United States. 69 cja It is found in less quantity, in Germany in the Ruhr district, in Westphalia and Silesia, in the north of France, Austria, Russia, China, Japan, India, Australia, New Zealand and Canada. "Cannel" coal, a variety of bituminous coal, is found in the Midlands of England and in the United States. It is used principally for making illuminating gas and for domestic purposes. The principal lignite fields are in France, Italy, Germany and Austria, but lignite is also found in the United States and in Sweden. The theoretical heating value of fuel is the heat which it develops when consumed under theoretically correct conditions — which are practically only obtained in the laboratory — and it is expressed in heat units or thermal units. In England and the United States of America the British thermal unit is adopted, this being the amount of heat required to raise the temperature of one pound of water one degree Fahrenheit. Steam Drum and Tube Doors of Babcock & Wilcox Marine Boiler, U. S. S. "Atlanta" 71 Arrangement of Babcock & Wilcox Boilers in U. S. S. "Atlanta" Total Heating Surface 7600 Square Feet. Grate, 212 Square Feet 72 On the Continent of Europe the " calorie " is used, and the standard is the heat required to raise the temperature of one kilogram of water one degree centigrade. To convert calories per kilogram of coal into British thermal units per pound of coal, multiply by 1.8. The theoretical heating value of the above-mentioned coals varies between 7000 and 15,500 British thermal units per pound, depending largely on the varying amounts of incombustible matter or ash that the coals contain. The semi-bituminous coals of the Pocahontas and Cardiff varieties are the most uniform in this respect, the ash being only 3 to 8 per cent.; Belgian "Demigras" will run from 5 to 15 per cent., while the residue in Transvaal coal may reach 25 to 35 per cent. The anthracite coals, as mined, contain from 1 5 to 30 per cent, of refuse or slate. Most of this, however, is usually removed when the coal is prepared for the market, so that anthracite, as sold, may contain as little as 3 per cent. On the other hand, the smaller sizes may run very high in ash, and cases have been known where 50 per cent, refuse has been found in boiler tests. Bituminous coals are extremely variable, running from 5 to 35 per cent, ash, while the percentage in lignite is usually considerably under 10. The heat value of the combustible portion of the coal (ash and moisture deducted) is also quite variable, and depends on the quality of the volatile matter, which may be either very rich in hydrocarbons, as in semi-bituminous coals, or comparatively high in oxygen, as in many of the bituminous coals and lignite. So much, in fact, does the amount of oxygen found in lignite detract from the calorific value of the volatile matter, that the combustible portion of lignite is worth only about three-fourths that of semi-bituminous coal. APPROXIMATE CHEMICAL COMPOSITION OF SEVERAL TYPICAL KINDS OF SOLID FUELS Wood, perfectly dry Wood, ordinary Peat , . . Charcoal Straw . . . Coal, anthracite Coal, semi-bituminous Coal, bituminous, Pittsburg . . . , Coal, bituminous, Hocking Valley, O. Coal, bituminous, Illinois . . . . Brown coal. Pacific coast Lignite, Pacific coast Moisture Carbon Hydrogen Oxygen 50 6.0 41-5 20.0 40 4.8 33-2 30.0 40.6 4.2 21.7 12.0 84 I.O 16.0 36 5-0 38.0 I.O 86 I.O 10 I.O 84 4.2 34 1.4 75 5-0 8.0 7-5 67 4.8 1 0.0 I I.O 56 5.0 II. 16.8 50 3-8 136 14.0 55 4.0 150 Nitrogen * Sulphur I.O 0.8 OS 0-5 0.8 0.6 I.O 1.6 1.2 1-5 I.O 3-0 0.9 1.0 1.0 1-5 1.2 3-5 30 5-0 1 0.0 6.0 8.0 8.0 13.0 13-2 5-0 73 =a The elements in the coal from which we derive heat are carbon in its solid state, hydrogen, and sometimes a little sulphur. The hygroscopic water which it contains is injurious, as it absorbs heat for its own evaporation. The heat value of the fuel may be calculated from the analysis by means of Dulong's formula, as follows : B.T.U. per pound equal 146 C+620 (H->^0)+40 S in which C, H, O and S are, respectively, the percentages of carbon, hydrogen, oxygen and sulphur in the fuel, and the constants are the most recent average heat values for carbon, hydrogen and sulphur, each divided by 100. The actual heating value of a coal, as determined by test with an instru- ment known as a "bomb calorimeter" (see page 88), agrees very closely with that calculated from the analysis, usually within 2 per cent., when both the analysis and the calorimeter test are made by a skilled chemist. The analyses given in the foregoing table are called " ultimate analyses," since the constituents of the fuel, except the moisture and ash, are reduced to the ultimate chemical elements. Another kind of analysis, called " proximate analysis," is more commonly used, which separates the coal into four parts, viz. : moisture, volatile matter, fixed carbon and ash. The proximate analysis is of great value for indicating the general charactei' of a coal. By dividing the percentages of volatile matter and fixed carbon each by their sum, we obtain the percentages of each in the "combustible," or coal dry and free from ash. These percentages serve to identify the class to which the coal belongs, as follows : Class of Coal Fixed Carbon oer cent, of Combustible Volatile Matter per cent, of Combustible Anthracite 100 to 92 92 to 87 87 to 75 75 to 50 below 50 to 8 8 to 13 13 to 25 25 to 50 over 50 Semi-bituminous These various kinds of coal act very differently during their combustion in a furnace, and to get the best results each must be handled in the way best suited to its characteristics ; and the size and design of the furnace must also be adapted to the particular requirements of the coal. With anthracite coal disintegration and distillation take place very slowly, with semi-bituminous coal they take place somewhat faster, and with bituminous coal almost instantaneously, the rate depending on the percentage of fixed carbon. For the combustion of one pound of carbon 2.66 pounds of oxygen are necessary, and as the air contains only 23 per cent, of oxygen, it follows that 1 1.6 pounds of air are necessary for the combustion of one pound of carbon. 75 y. < - =5 — O tOH > 00 u ^ '-> PQ o H 5 w >. o o o" z o fH'- The air required for combustion in a boiler furnace has to pass through the spaces between the grate bars, and the layers of fuel on them, the rapidity wiih which it passes through depending on the intensity of the draft and condition of the fire. When the fuel is supplied in too great a quantity, or the supply of air is insufficient, the carbonic acid, formed in the lower layers of the fuel, takes up another portion of carbon in the upper layers, and forms carbonic oxide or carbon monoxide, which passes through the boiler unconsumed, and frequently re-ignites at the top of the funnel, where it comes into contact with sufficient air to enable its combustion to be completed. Thus, flaming at the top of the funnel, or ia the flues beyond the boiler, is generally a sure sign of unsatisfac- tory conditions of combustion. Anthracite coal, and coke, may be called comparatively slow combustion fuels, and to provide that a certain quantity shall be consumed for a given size of boiler, either the grate surface must be increased, as compared with bituminous coal, or the mtensity of the draft — in other words, the velocity of the air supply — must be increased. From this arises the fact that when burning anthracite coal in a boiler furnace proportioned for bituminous coal, either an extra high funnel is required, or an artificial method of intensifying the draft, commonly called "forced draft," must be used. Anthracite and semi-anthracite are the coals for which it is easiest to design a suitable furnace, and experience has shown that with all types of boilers, for these fuels the plain level grate is the most practical ; it is the cheapest in up-keep, and it requires the least skill on the part of the fireman. Naturally, the size of lump, the percentage of ash, the rate of combustion required, and the strength of draft, determine such details as width of bar, extent of grate surface, form of bar, and size of air opening. With semi-bituminous coal, owing to its larger percentage of volatile matter and the rapidity with which this inflammable gas is distilled off, more space must be provided in the furnace and care taken to prevent the burning gases coming in contact with the boiler heating surface and being cooled before combustion is complete. These points are still further accentuated in relation to bituminous coal and lignite, and neglect to observe their importance leads to great loss in the use of these fuels. The best methods of handling semi-bituminous coal and the bituminous coal having the larger percentage of fixed carbon, is to fire it on the front end of the grate, where it is "coked," the volatile gases passing back over the incandescent fuel and burning completely before touching the heating surface. The coke left on the front is then pushed back and a fresh charge of coal fired. With the very volatile bituminous coals and lignite, it is impossible to handle the fuel in this way, as it does not coke and has a tendency to form bad 77 and troublesome clinker when worked with the fire tools. This fuel should be spread in very light charges evenly from the front to the back, covering each half of the grate alternately. Semi-bituminous and the coking variety of bituminous coal may also be fired in this way with no loss in economy if the firing is skillful. The method of firing and the design of the furnace have a material effect on the production of smoke ; but it may be mentioned that while smoke is an indication that the conditions of combustion are susceptible of improvement, an absence of smoke is not by any means a sure sign of proper combustion, for it may be brought about by too much air being supplied, and consequent dilution of the gases ; nor is the production of smoke by any means an indication that much waste takes place, for the quantity of unconsumed carbon sufficient to color the escaping gases from a boiler is an exceedingly small percentage of the total amount of fuel. The Babcock & Wilcox Marine Boiler, here illustrated, is the best of all water-tube boilers, so far designed, for obtaining a high efficiency w^ith bitumi- nous coals. It will be seen that the gases evolved from the fuel, pass under the roof located over the front portion of . the lowest row of tubes, to a high combustion chamber at the rear, and are thoroughly mixed and burned before en- tering the bank of tubes forming the heating surface. Generally speaking, with this boiler and with careful firing and favorable condi- tions, from 70 to 75 percent, of the heat units which a coal is found to contain theoretically, can be transferred to the water and steam. Claims have been made that more than this can be obtained — up to 80 per cent. — with certain classes of boilers ; we do not wish to dispute the possibility of obtaining this, but certainly it is only obtainable under conditions which are so carefully studied as to be impracticable or impossible to maintain in ordinary practice. The remaining 30 per cent, is lost in radiation, in the heat carried away in the waste gases, and in imperfect combustion, due either to unavoidable excess of air in the furnace, or to a lack of sufficient air, depending upon the furnace conditions. A greater proportion of the heat BARTLETT Sl CO , N.Y. I 79 can usually be saved and utilized when anthracite and semi-bituminous coals are employed. And as the volatile matter in the fuel increases, the greater becomes the probable loss from incomplete combustion. Higher evaporative efficiencies can generally be obtained from water-tube boilers than from shell boilers, for the reason, principally, that in the former there are furnaces which are capacious, and in which combustion takes place more quickly than in the furnaces of shell boilers, where not only is the space for combustion confined, but the fuel surrounded by cool boiler surface. Method of Handling a Babcock & Wilcox Boiler into a Steamer 80 HEAT VALUES OF COAL B.T.U. PER POUND OF DRV COAL— CALORIES PER KILO. DRY COAL UNITED STATES Name and Locality of Mine Alabama : Blue Creek, mine run Henry Ellen, lump . Mary Lee .... Pratt, lump .... Old Pratt, No. 4 lump Arkansas : Coal Hill .... Eureka Lignite B. T. U. Colorado : Diamond, Jerome Park New Caste, mine run Illinois: Paisley, screenings Pana, screenings . big Muddy, lump I. add, lump . . . Staunton, lump .Seatonville, lump Streator, lump Streator, screenings Wilmington, screen ings Wilmington, washed screenings I.NDIANA : Brazil, block . . . New Pittsburg . . Brazil, semi-block Indian Territory : McAleester, slack McAleester, washed slack Krebs, lump . . . Kentucky : Vanderpool, lump Maryland : George's Creek . . Eureka Cumberland, mine run Cumberland.mine run Missouri : Hamilton .... Frontenac, lump . . Glen Oak .... II93I 13608 '33'4 12835 14580 • 3452 1 2254 9215 i3«03 1Z069 I^9^2 10565 i34'>' 12450 II 508 12000 12600 12200 9750 1 2 100 13629 12369 12500 10903 12874 14216 13652 13660 '43«3 1 1662 9743 9767 Calo- 6628 7560 7397 7'3i 8100 7473 6808 5"9 7280 6705 6079 5869 7444 6917 6393 6667 7000 6778 5417 6722 7572 6872 69H 5840 6057 7152 7898 7585 7589 7952 6479 5413 5426 n Authority Name and Locality of Mine -W. B. Phillips TheB. &W.Co. St. Louis Sampling Works B. & W., Ltd. J Carpenter i The B. & \V. Co. -Carpente }Noyes, McTaggart and Craven Carpenter St. Louis Sampling " Works Carpenter ■ Barrus •The B. & W. Co. Forsvth ( St. Louis Sampling I Works Ohio : Brier Hill, lump . . Jackson, lump Cambridge .... Hocking Valley, lump Hocking Valley, mine run . . . Palestine Salineville . Yellow Creek Waterford . Pennsylvania : Anthracite Buck Mountain, buck wheat .... Cross Creek . . Honey Brook . . .\vondale . . . Drifton, buckwheat Lackawanna . . Lykens Valley, buck- wheat Scranton Forty Foot and Bituminous Connelsville Duquesne, mine run Catsburg Beaver Creek Carnegie Creedmore . Hoytdale Turtle Creek Pittsburg, nut slack . . . Youghiogheny Tennessee : Glen Mary .... Crooked Fork . . . Virginia and West Virginia : Elk Garden . . . Pocahontas, Flat Top Pocahontas, mine run Thacker .... Fairmont, mine run New River, mine run Nuttalburg, mine run Thermont, mine run B.T.U. Calo- nes 13600 7556 13613 7563 1307s 7264 13 102 7279 12571 6984 13387 7437 13464 7480 13603 7557 13637 7576 12308 6838 1 1520 6400 11732 6518 13219 7344 13722 7623 •237' 6873 11902 6612 13050 7250 13683 7602 14285 7936 13858 7699 13450 7472 14047 7804 13640 7578 13403 7446 13547 7526 13280 7378 12941 7190 12542 6968 12542 6968 13180 7322 14800 8222 14355 7975 14182 7879 13830 7683 14488 8049 14800 8222 "4352 /973 Authority Carpenter The B. & W. Co. "Lord & Haas The B. & W. Co. ' Barms ■Carpenter D. Ash worth Woodman Lord & Haas The B. & W. Co. Barrus Anonymous The B. & W. Co. Barrus The B. & W. Co. [ Lord & Haas The B. & W. Co. ENGLAND, GERMANY, FRANCE, BELGIUM AND AUSTRIA-HUNGARY Coals, Locality of Beds GREAT BRITAIN welsh coals Ebbw Vale, 1848 . . Powell Duff ryn, 1848 Llangennech, 1848 Llangennach, 1871 Graigole, 1848 . . . Nixon's Navigation . B.T.U. Calo- ries 162 14 8998 I57«S 8710 14998 8318 14964 8305 14689 8152 15000 8325 Almost pure anthra- >■ cites, having 84 to 89% of carbon Coals, Locality of Beds GREAT BRITAIN continued Gwaun Cae Gurwen Newcastle .... Derbyshire and York- shire Lancashire .... Scotch B.T.U. i5'23 14820 13860 13918 12870 Calo- ries 8402 8225 7692 7724 7150 Nature Pure, hard anthracite } Bituminous coal, having 77 to 82% of carbon Bitu. coal, having 78% of carbon 81 EUROPEAN COUNTRIES— CONTINUED Coals, Locality of Beds B. T. U. GERMANY Rhenish Prussia : Dortmund, Ruhr coal Witten, Ruhr coal . Bochuin, Ruhr coal . Bommern, Ruhr coal Essen, Ruhr coal Saar-coal .... Saxony: Zwickau Hohndorf . . . . Oelsnitz Lower Saxony, An HALT AND BrUNSW Unseburg Atzendorf Neudorf . Gorzig Halle a. S. Bitterfeld Naumburg Hanover : Osnabriick . . Obernkirchen . Silesia (Prussia) Carlsse^en . . Myslowitz Waterloa . . . Konigshiitte Paulusgrube Waldenburg Brandenburg . Neurode . . . Freienstein . . Maxgrube Bavaria : Hanshamer coal Peipenberg . . Penzberg . . . FRANCE Anthracite de la May enne Anthracite de La mure ^Isfere) . . Bassin du Bas-de- Calais: Maries .... Bully Hessin .... Lens Naux I'Escarpelle . . . les Courrieres . . Bassin de la Saone Blanzy Epinac Bassin db la Loire Rive-de-Gier puits Henry Rive-de-Gier, No. i Rive-de-Gier, Cime- tifere I 14518 J5I-25 «35>4 13212 14985 11511 11964 "343 10674 5769 6444 6093 3853 4165 3830 4563 10789 12718 10422 10758 11412 12247 1242 s 12637 12193 •3393 9651 10087 Calo- ries 15566 13782 14175 15 120 15352 15258 15256 15400 14265 1 548 1 15472 '4493 8066 8403 7508 7340 8325 639s 6647 6302 5930 3205 3580 3385 2 40 2314 2128 2535 5994 7066 379° 5977 6340 6804 6903 7021 6774 7441 5362 5604 5456 4548 4956 8646 7657 787s 8400 8529 8477 84-6 8556 7925 7293 7826 8601 8596 8052 Nature Cannel coal Short flame coal, semi-anthracite Cannel coal Cannel coal ! Brown coal or lig- nite, low grade Semi-anthracite, low grade Bituminous [Long flaming,semi- i bituminous Lignite or brown coal, low grade Anthracite Bituminous, hard coal Bituminous, coking Bituminous, hard coal Bituminous, coking Semi-bituminous coal Semi-bituminous coal, long flame Bituminous coal, long flame Bituminous, hard coal Bituminous, hard coal, long flame Coals, Locality of Beds B.T.U. FRANCE continued Bassin de la Loire: Rive-de-Gier, Cime- tiere 2 .... Rivede-Gier, Cou- son Bassin de l' Aveyron: Lavaysse .... C^ral Bassin d'Alais Roch- belle Bassin de Valen- ciennes : Denain Fosse Renard Denain Fosse Lelvet i Denain Fosse Lelvet 2 St. Wast, Fosse de la Reussite .... St. Wast, Grande Fosse St. Wast, Fosse Tin- chon Anzin, Fosse Chauf- four Anzin, Fosse la Cave Anzin, P'osse St. Louis Fresne, Fosse Honne- parte Vieux-Conde, Fosse Sarteau .... BELGIUM Bassin de Mons : Haut-flenu .... Belle et Bonne, fosse No. 21 .... Levant du flenu . . (Jouchant du flenu . Midi du flenu . . . Grand- Hornu . . . Nord du bois de Bossu Grand- Buisson . . Escouffiaux . . . St. Hortense, bonne veine Bassin du Centre : Haine St. Pierre Bois du Lac La Louviere Bracquegnies Mariemont . Bascoup . . Sars- Longchamps Houssu Bassin deCharleroi St. Martin, Fosse No. 3 Trieukaisin .... Poirier, Fosse St. Louie Bayemont, Fosse St. Charles .... Sacre-Madame . . Sars-les-Moulins, Fosse No. 7 . . Carabinier-fran?aise, No. 2 Roton, veine Greffier Pont-du-Loup . . . 15309 14770 14630 132C3 15643 15244 15 100 15316 i5«oS 15188 15082 •4353 14549 15397 15228 15409 14576 14326 14508 14446 14553 14943 14407 14877 15217 15107 14702 14358 15127 15363 15168 14911 14895 14945 14954 15069 13806 15204 14911 14311 14947 Calo- ries Nature 8505 8206 7335 8691 8469 8389 8509 8392 8438 8379 7974 8083 8554 8460 8561 8098 7959 8060 8037 8085 8302 8004 8265 8454 8393 8168 7977 8404 8535 8427 8284 8275 8303 8372 8012 7670 8447 8403 8284 7951 8304 I Bituminous, hard I coal, long flame Bituminous, hard coal, long flame Semi-bituminous coal Bituminous, coking Bituminous long flame 1 Bituminous I short flame coal, Bituminous , coking I Semi-bituminous 1 coal Semi-bituminous, hard coal I Semi-bituminous, I coking coal J I Bituminous, hard Semi-bituminous, coking , Semi-bituminous, I hard coal 82 EUROPEAN COUNTRIES— CONTINUED Coals, Locality of Beds austria-hun- (;ary Lower Austria : Griinbach . . . Thallern Upper Austria : Wolfsegg-Trannthal Stvria : Leoben Fohnsdorf . . . , Goriach Koflach Wies Trifail Bohemia: Kladno Buschtehrad . . . Libuschin . . . . Schlan Rakonitz-Lubna . . Pilsen Schatzlar Aussig Dux Bilin ...... Brux Moravia : Rossitz M. Ostran . . . . Gaya Gbding B.T. U. Calo- ries 11458 4 6366 7057 9666 9187 6222 6867 7997 7556 10675 8865 9900 7979 7257 93-8 9552 6408 780S 8182 8274 392' 6006 3337 I25S3 6974 12623 7013 4858 2699 5056 I 2809 Natur Semi-bituminous coal Lignite or brown coal Lignite or brown coal 5370 ^ 5104 3457 3815 4443 4198 5931 4925 5500 4433 4032 S'77 5307 3560 4338 4546 4597 Lignite or brown coal Semi-bituminous coal Lignite or brown coal } Lignite or brown coal Coals, Locality of Beds AUSTRIA-HUN- GARY continued Silesia : P. Ostran Orlan-Lazy Poremba Karwin . , Taklowetz , Hungary : Fiinfkirchen Anina . . . Neufeld . . . Brennberg . . Aika .... Salgor-Tarjan Dorog-Annathal Tokod . . . Dalmatia : Siveric . . . . ISTRIA : Transylvania Petrozseny . . . Egeres . ... Bosnia ; B.T.U 12564 12389 1 1057 1302 1 1 1932 10276 "356 5200 8325 6913 7966 7709 8069 8087 10182 Calo. ries 6980 6883 6143 7234 6632 5709 6309 2889 4625 3841 4426 4283 4483 5657 6270 4829 Nature ' Bituminous coal ■ Cannel coal Lignite or brown coal Lignite or brown coal Lignite or brown coal Lignite or brown coal Lignite or brown coal TEMPERATURE OF FIRE The following table, from M. Pouillet, will enable the temperature to be judged by the appearance of the fire : Appearance Temperature Fahrenheit Appearance Temperature Fahrenheit Red, just visible Red, dull Red, cherry, dull Red, cherry, full Red, cherry, clear 977° 1290 1470 1650 1830 Orange, deep Orange, clear White heat White bright White dazzling 2010° 2190 2370 2550 2730 MELTING POINTS OF METALS Substance Temperature - Fahrenheit Metal Temperature Fahrenheit Metal Temperature Fahrenheit Spermaceti . . . Wax, white , . Sulphur .... Tin Bismuth . . . 120° 239 442 Lead . . . Zinc . . . Antimony . Aluminum . Brass . . . 625° 780 842 1 1 60 1650 Silver, pure . Gold coin . . Iron cast, med Steel . . . Wrought-iron 1830° 2156 2010 2550 2910 83 ca EFFICIENCY— USE OF THE COAL CALORIMETER HE term "efficiency," specifically applied to a steam boiler, refers to the proportional amount of heat which is taken from the available supply in the fuel and transferred to the steam generated. In the case of an engine, the efficiency is determined by the amount of heat taken from the steam and transformed into useful work. The efficiency of an entire plant, which includes both engine and boiler and all auxiliary machinery, embodying all their combined efficiencies, appears as the amount of work which can be developed by the engine for each unit of fuel consumed in the furnaces. It is evident, there- fore, that if a poor engine be installed, the efficiency of the plant as a whole will be low, notwithstanding a highly efficient boiler, and vice versa ; and the same thing will also be true, even with a first-class engine and boiler, provided much heat is wasted in the auxiliary machinery. A statement of the efficiency of a plant, therefore, indicates but little, unless something is known of its general design and the type of its various parts. Efficiency is best expressed as a percentage of the total heat supplied. Enough is known of the properties of the steam itself to make the calcu- lation of engine efficiency an easy matter in connection with a careful test, but, in the case of the boiler, the available heat being in the coal, the proposition is of an entirely different character, and a separate test, in addition to that of the boiler, becomes necessary in order to determine the amount of heat that has been supplied by the combustion of the fuel. In fact, so difficult has this accurate determination of the heat value of coal been found, that engineers with any desire to avoid setting up false standards have until recently considered it best to make no report whatever on this point rather than to put forth unreliable or doubtful figures. Still, without a determination of efficiency, we are left to flounder in a sea of ignorance where the only things that keep afloat our desires for comparison, are cut and dried assumptions that nine times out of ten have no counterpart in fact. What right have we to assume that the Ohio coal, or Western Pennsylvania slack, burned under the boilers of the large ore-carrying vessels of the Great Lakes, is the same or equivalent to the Welsh or the Cumberland coal used by the transatlantic flyers } And yet, that is exactly what we do when we com- pare the 1.6 pounds of coal per indicated horse-power of the transatlantic service with the 1.8 pounds of the Lake practice, to the disparagement of the latter. As a matter of fact, the best ships of that remarkable fleet of grain and ore carriers on the Lakes equal or even exceed in the matter of efficiency the larger units of the ocean greyhounds. But, it is only in the light of a reliable 85 / 7^ z Y / '\y p ' Y . y ' ~ 12 / / / y / / y f z Z z Z / / / / ' / Z / y / / y / / y / y / y z ../ / / / / y / / y / y / y y 9 y / z y y / y / y / y y z / Z / -^ / / z z Z y / y y y y y z ji —/. / / / / / / z / y / y y / y y y y y y y y / -^ / z -yL / z z / / y / y y z z y y y ^ / / ^ / z — ^ y / / z y Z y / Z / y y y / z — ^ y ^ y ^ / Z y y y y / y y '^ / y y y y y y z -^ / Z -X / y z —^ y / y y / Z z y y y y y / 11 z -Z Z / / z / / /^ / / z / y y y y y ''> y .^ 71 z ^ z z / / z y y y y / y y y / y / y y y y y -J- / Z ^ / z -^ / z z / / / y / z y y y y y y y y y / / / / / / / / Z / / / z' z y y y y y y y y 5j / / / / ^ z / / / y y y A / y y y y y y y y y y 1- ^/ / / . / / z / / / / / / / / z y y Z y y— y] y- y y y o / z ^ / z v: / z y -^ / z z y J y y y y y y Z y y y— y y < / / z z / / / / y / / z y / / y X- y / y / y y y y y y y o / / / z / / ^ / / y / y y y y y y y y y ^ ^ y u. / / z / / z [/ y y z y / / y / y y y y y y y y y y y <10 o ,/ / / / /' / z z / \y y / / y " Z y y y y y y y y y y / Z / / z Z / /' / z / z / Z y y y y y y y ^ >- / / / /- / / X y y / y / y / y y y y y y y / y^ y o z -X. / z z -^ / / / Z z y / y y y y y y y~ y CO -J / z ,•• z / y y / y z' y -/ / y / y \y y y y y y cc Ul .5 u. .0 / <^ / — ^ / /■ y y / Z Z z y y y y y y y y y y (ij^ y o bJ < ^ z ^o;76 172 369-2 341-5 853.1 1.94.6 0.3778 4 '53' I2I.4 1007.2 1128.6 0.0 1 107 174 370.2 342.5 8523 ..94-8 0.3820 6 170.1 138.6 995-2 1133.8 01622 176 371 J 343-5 851.6 1.95.1 0.3862 8 182.9 151-5 986.2 1137-7 002125 178 372.1 3444 851.0 1.95.4 0.3904 lO 193 -3 161.9 979-0 1 140.9 0.02621 180 373.0 345-4 850.3 1.95.7 0.3945 12 202.0 170.7 972-9 1143-6 03 1 1 1 182 373-9 346.4 849.6 1196.0 0.3987 14 209.6 178.3 967s 1145.8 0.03603 184 374-8 347-3 848.9 1.96.2 0.4029 14.7 212.0 180.9 965-7 1 146.6 0.03760 186 375-7 348-2 848.3 1196.S 0.4070 16 216.3 185.1 962 8 11479 0.04067 188 376.6 349-2 847.6 1196.8 0.4111 18 222.4 191-3 958-5 1 149.8 0.04547 190 377-4 330-1 8470 1197.1 0-4153 20 228.0 196.9 954-6 1151.5 0.05023 192 3783 351-0 846.3 1197-3 0-4194 22 233.1 202.0 951-0 1153.0 0.05495 194 3792 351-9 845-7 1197.6 0.4236 24 237.8 206.8 947.6 1154.4 0.05966 296 380.0 352.8 845-0 1 197.8 0.4278 26 242.2 211. 2 944.6 1155.8 0.06432 298 380.9 353-7 844-4 1198.1 0.4318 28 246.4 2.5-4 941-7 1157-1 0.06899 200 381.7 54.6 843-8 1198.4 0.4359 30 250.3 219.4 938-9 1158-3 0.07360 202 382.6 355-4 843-2 1.98.6 0.4399 32 254.0 223.1 936.3 11594 0.07821 204 383-4 356-3 842.6 1 198.9 0.4441 34 257 5 226.7 933-7 1 160.4 0.08280 206 3842 357-2 841.9 1199.1 0.4482 36 260.9 230.0 931 5 1161.5 0.08736 208 3S5-1 35^-0 841.4 1199-4 0.4524 38 264.1 233-3 929-2 1162.5 0.09191 210 385.9 358.9 840.7 1199.6 0.4565 40 267.1 236.4 927.0 1163.4 009644 2.2 386.7 359-7 840.2 1199.9 0.4607 42 270 I 239-3 925.0 1164.3 0.1009 214 387.S 360.6 839-5 1200.1 0.4648 44 272.9 242.2 923.0 1165.2 0.1054 216 388.3 361.4 839-0 1 200.4 0.4690 46 275-7 245-0 921.0 1166.0 0.1099 218 389-. 362.2 838.4 1200.6 0.4731 48 278.3 247-6 919.2 1166.8 0.1144 220 3898 363.0 837-8 1200.8 0.4772 5° 280.9 250 2 9'7-4 1167.6 0.1188 222 390.6 363 -9 837-2 120.. I 0.4813 52 2833 252.7 9157 1168.4 0.1233 224 391-4 364-7 836.6 .201.3 0.4855 54 285.7 255-1 914.0 1 169.1 0.1277 226 392.2 365- 5 836.1 1201.6 0.4896 56 288 I 257-5 912. .1 1169.8 0.1321 228 39»-9 366.3 835-5 1201.8 0.4939 58 290.3 259-7 910.8 1170.5 0.1366 230 393-7 367 1 834-9 1202.0 0.4979 60 292.5 261.9 9093 1171.2 0..409 232 394-5 367-9 834-3 1202.2 0.5021 62 294.7 264.1 907.7 1171.8 0.1453 234 395-2 368.6 833-9 1202.5 0.5062 64 296.7 266.2 906.2 1172.4 0.1497 236 395-9 3694 833-3 1202.7 0.5103 66 298.8 268.3 904.7 1173.0 0.1541 238 396-7 370.2 832-7 .202.9 0.5.44 68 300.8 270.3 903-3 ■173.6 0.1584 240 397-4 371-0 832.2 1203.2 0.5186 70 302.7 272.2 902.1 '174-3 0.1628 242 398.1 37'-7 831-7 1203.4 0.5226 72 304.6 274-1 900.8 1174.9 0.1671 244 398.9 372-5 83.-1 1203.6 0.5268 74 306.5 276.0 899-4 1175 4 0.1714 246 399-6 373-2 830.6 .203.8 0.5311 76 308.3 277-8 898.2 1 176.0 o.'757 248 400.3 374-0 830.0 1204.0 0-5353 78 310. 1 279-6 896.9 1176-5 0.1801 250 401.0 374-7 829-5 1204.2 0-S393 80 3". 8 281.4 895.6 1177.0 0..843 252 43. -7 375-4 829.1 1204.5 0-54J3 82 3135 283.2 8944 1177-6 0.1886 254 402.4 376.2 828.5 1204.7 0-5475 84 315-2 2850 893-1 ..78.. 1930 256 403 I 376-9 828.0 1204.9 0-5517 86 316.8 285.7 891.9 1178.6 1973 258 403.8 377-6 827-5 1205. 1 0-5559 88 318.5 288.4 8907 1I79-I 0.2016 260 404 5 378.4 826.9 .205.3 0.5601 90 320.0 290.0 889.6 1179.6 0.2058 262 405.2 379.1 8264 1205.5 0.5642 92 321.6 291-6 8884 1 180.0 0.2101 264 405.8 379.8 825-9 1205.7 0.5684 94 323.1 293-2 887.3 1180.5 0.2144 266 406.5 380.5 825.4 1205.9 0.5726 96 324.6 294-8 886.2 n8i.o 0.2186 268 407.2 381.2 824-9 1206.1 0.5767 98 326.1 296.4 8850 1181.4 0.2229 270 4079 381.9 824-4 1206.3 0.5809 100 327.6 297-9 884.0 1 181. 9 0.227. 272 408.5 3826 823-9 1206.5 0.5850 102 329.0 299-4 882.9 1182.3 023.4 274 409.2 383.3 823-4 1206.7 0.5892 104 330.4 300-9 881.8 1182.7 0.2356 276 409.8 384-0 822.9 1206.9 0.5934 106 331.8 302 3 880.8 1183.1 2399 278 410.5 384-6 822.5 1207.1 0.5976 108 333.2 303-8 879-8 1183.6 2441 280 411.1 385.3 822.0 1207.3 0.602 no 334-6 305-2 878.8 1184.0 0.4484 282 411.8 386.0 821.5 1207.5 0.606 112 335-9 306 6 877-8 1.84.4 0.2526 284 412.4 3866 821.1 1207.7 0.610 114 337-2 308.0 876.8 1184.8 2568 286 413.0 387-3 820.6 1207.9 0.6.4 n6 338.5 309-4 875-8 1185.2 0.2610 288 413-7 388.0 820.1 1208.1 0.618 118 3398 3'o-7 874-9 1 185.6 0.2653 290 4143 388.6 819-7 1208.3 0.622 120 341.1 312 874.0 1186.0 0.2695 292 414-9 389.3 819.2 1208.5 0.627 122 342.3 3'3-3 873.0 1185.3 0.2736 294 41S-6 390.0 818.7 1208.7 0.631 124 343-5 314-6 872.1 1186.7 0.2779 20 416.2 390.6 818.3 1208.9 0.635 126 344-7 315-9 871.2 1187.1 2820 298 416.8 391-3 8.7.8 1 209. 1 0.639 128 345-9 317-1 870.3 1187.4 0.2862 300 417-4 391 9 817-4 1209.3 0.644 130 347-1 3184 8S9.4 1.87.8 0.2904 302 418.0 392-5 816.9 1209.4 0.648 132 348.3 3 '9-6 868.6 1 188.2 02946 304 418.6 393-2 816.4 120g.6 0.652 •34 349-5 320.8 867.7 1188.5 0.2988 306 419.2 393.8 816.0 1209.8 0.656 136 350.6 322.0 856.9 1 188.9 03030 308 419-8 394-4 8.5.6 1210.0 0.660 »38 351-/ 323-2 8660 1189.2 0.3072 310- 420.4 3950 815.2 12I0.2 0.664 140 352.9 324 4 865.1 1.89.5 0.3113 312 421.0 395-7 8.4-7 1210.4 0.668 142 354.0 325-6 864.3 1.89.9 03155 314 421.6 3963 814.2 1210.5 0.673 144 355-1 3 '6.7 833. s 1190.2 0-3197 316 422.2 396-9 813.8 1210.7 0.677 146 356-1 327-8 852.8 1190.6 0-3239 318 422.8 397-5 813-4 1210.9 0.681 148 357-2 328.9 852.0 119-5.9 0.3280 320 423.4 398.1 813-0 12... I 0.685 •5° 358.3 330.0 861.2 1.91.2 0.3321 322 424.0 398.7 812.5 1211.2 0.690 «52 359-3 331-1 8604 .I9J.S 03363 324 424.5 399.3 8.2.1 121. .4 0.694 IS4 360.3 332.2 8^96 I 91.8 03405 326 425.1 399.9 811.7 1211.6 0.698 '5^ 361.4 333-3 8589 ..92.2 03447 328 425.7 400.5 8.1.3 1211.8 0.702 'S8 362.4 334-3 858.2 i'92.S 0.3488 330 426 2 • 401. 1 810.8 1211.9 0.707 160 363.4 335-4 8574 1192.8 0.3530 335 427.6 402.6 809.8 1212.4 0.717 162 364.4 336-4 856.7 1193- 1 0.3572 350 431-9 406.9 806.8 12.3.7 0.748 164 3654 337-5 855.9 ..93-4 0.3614 375 438.4 414.2 801.5 1215.7 0.800 166 366.4 338-S 855-2 "93-7 0-3655 400 445. » 421-4 796.3 12.7.7 0.853 168 367-3 339-5 ^54-5 1194.0 0.3695 450 456 2 433-4 787.7 I22I.I 0.959 170 368.3 340-s 853-8 1 194-3 0-3737 500 466.6 444-3 779-9 1224.2 1.065 IP ; 'II ' '(■■ - as r; w ^ Z ■r. ^ ^ o o X 2 < rj- ^ < o < » w < o -^ i^ o w o tM o z . -i w -k ...^ -l^t ti:1 its pressure. It is then called superheated, and the specific heat of superheated steam is .475. The table on page 91 gives the properties of saturated steam at various pressures. It should be noted in using this table that the pressure given is absolute pressure, so that 15 pounds (or more exactly 14.7) should be added to the reading of the gauge. Pressures below the atmosphere, or partial vacuum, are often expressed in inches (of mercury). The following table gives the temperature and pressure of steam for each half inch. TEMPERATURE AND PRESSURE OF STEAM FOR EACH y," OF VACUUM (Calculated from C. H. Peabody's tables) Inches of Vacuum Absolute Pressure Tempera- ture Inches Absolute Pressure Tempera- ture Inches of Vacuum Absolute Pressure Tempera- ture Lbs. per Sq. In. Degrees Fahr. 01 Vacuum Lbs. per Sq. In. Degrees Fahr. Lbs. per Sq. In. Degrees Fahr. 14.697 212.00 10 9.785 192.23 20 4-873 161.25 % 14-451 211.15 io}4 9-539 191.03 20j^ 4.628 159.09 I 14.206 210.29 11 9294 189.81 21 4.382 156.83 I>^ 13.960 209.42 I1Y2 9.048 188.57 21>^ 4.136 154.46 2 13-715 208.54 12 8.803 187.30 22 3-891 151-97 2% 13.469 207.64 I2>^ 8-557 186.00 22Y2 3-755 149-34 3 13-223 206.73 ^3 , 8-311 184.66 23 3.410 146.55 VA 12978 205.80 i3>^ 8.066 183.29 23>^ 3.164 143-59 4 12.732 204.86 14 7.820 181.88 24 2.918 140.42 ^Yz 12.487 203.91 14Y2 7-575 180.44 24Y2 2.673 137-01 5 12 241 202.94 15 7-329 17896 25 2.427 133-32 5^ "•995 201.95 15Y2 7.084 177-44 25Y2 2.172 129.31 6 11.750 200.95 16 6.838 17587 26 1.926 124.89 6>^ 11.504 199-93 16K 6.592 174.26 26>^ 1.680 11994 7 11.259 198.89 17 6-347 172.59 27 1-435 114-34 1% 11.013 197-83 17Y2 6.101 170.86 27>^ 1. 189 107.84 8 10.767 196-75 18 5.856 169.07 28 0.944 100.05 ^Yz 10.522 '95-65 ^8Y2 5.610 167.23 28^ 0.698 90.24 9 10.276 194-53 19 5364 165.31 29 0-453 76.80 9'A 10.031 193-39 '9Y2 5-"9 163-32 29Y2 0.207 54.21 WATER— THE MEASUREMENT OF HEAT Water has a greater capacity for absorbing heat than any other known suDStance — bromine and hydrogen excepted. For this reason and from the fact that it is so commonly found in nature, and can be easily handled in ex- perimental work, it has been adopted as the standard substance for measuring the quantity of heat. Two distinct heat units are used in practice — calories and British thermal units. The latter, usually designated by the letters B. T. U., is the quantity of heat required to raise the temperature of one pound of water, at or near the freezing point, one degree Fahrenheit. The calorie is the quantity required to 93 >< D > e^ > 'H p C) ! ) > 6 u raise a kilogram of water one degree centigrade, and is equal to 3.958 British thermal units. The heat-absorbing capacity, or, as it is called, the specific heat of water, is not exactly constant for all temperatures, but after decreasing very slightly, again increases, and in a gradually increasing ratio, as the temperature is increased. The accompanying table shows the number of British thermal units that will be absorbed by one pound of water, when heated from 32 degrees to various temperatures below 212 degrees. WATER BETWEEN 32 AND 212 DEGREES FAHRENHEIT Temper- Heat Weight, Temper- Heat Weight Temper- Heat Weight, Temper- Heat Weight, ature Units Lbs. per ature Units Lbs. per ature Units Lbs. per ature Units Lbs. per Fahr. per Lb. Cubic Ft. Fahr. per Lb. Cubic Ft. Fahr. per Lb. Cubic Ft. Fahr. per Lb. Cubic Ft. .3,0 0.00 62.42 110° 78.00 61.89 145° 113.26 61.28 179° 147-54 60.57 35 3.02 62.42 112 80.00 61.86 146 114.27 61.26 180 148.54 60.55 40 8.06 62.42 "3 81.01 61.84 M7 II5.2S 61.24 l8l 149-55 60.53 45 13.08 62.42 114 82.02 61.83 148 116.29 61.22 182 150.56 60.50 50 18.10 62 41 "5 83.02 61.82 149 117.30 61.20 183 151-57 60.48 52 20.11 62.40 116 84.03 61.80 150 118.30 61.18 184 152.58 60.46 54 22.11 62.40 117 85.04 61.78 151 119.31 61.16 185 15358 60.44 56 24.11 62.39 118 86.05 61.77 152 120.32 61.14 186 154-59 60.41 58 26.12 62.38 119 87.06 61.75 153 121.33 61.12 187 155.60 60.39 60 28.12 62.37 120 88.06 61.74 154 122.34 61.10 188 156.61 60.37 62 30.12 62.36 121 89.C7 61.72 155 ■23.34 61.08 189 15762 60.34 64 32.12 62.35 122 90.08 61.70 156 124.35 61.06 190 158.62 60.32 66 34-12 62.34 123 91.09 61.68 157 125-36 61.04 191 1 59-63 60.29 68 36.12 62.33 124 92.10 61.67 158 126.37 61.02 192 160.63 60.27 70 38.11 62.31 125 93.10 61.65 159 127.38 61.00 193 161.64 60.25 72 40.11 62.30 126 94.11 61.63 160 128.3S 60.98 194 162.65 60.22 74 42.11 62.28 127 95.12 61.61 161 129.39 60.96 195 163.66 60.20 76 44.11 62.27 128 96.13 61.60 162 130.40 60.94 196 164.66 60.17 78 46.10 62.25 129 97.14 61.58 163 131.41 60.92 197 165.67 60.15 80 48.09 62.23 130 98.14 61.56 164 132.42 60.90 198 166.68 60.12 82 50.08 62.21 131 99.15 61.54 165 133-42 60.87 199 167.69 60.10 84 52.07 62.19 132 100.16 61.52 166 134-43 60.85 200 168.70 60.07 86 54.06 62.17 ^33 IOI.17 61.51 167 135-44 60.83 201 169.70 60.05 88 56.05 62.15 134 102.18 61.49 168 13645 60.81 202 170.71 60.02 90 58.04 62.13 135 103.18 61.47 169 137-46 60.79 203 171.72 60.00 92 60.03 62.11 136 104.19 61.45 170 138.46 60.77 204 172.73 59-97 94 62.02 62.09 137 105.20 61.43 171 139-47 60.75 205 173-74 5995 9^ 64.01 62.07 138 106.21 61.41 172 140.48 60.73 206 174-74 59-92 98 66.01 62.05 139 107.22 61.39 173 141.49 60.70 207 175-75 59-89 100 68.01 62.02 140 108.22 61.37 174 142.50 60.68 208 176.76 59-87 102 70.00 62.00 141 109.23 61.36 175 143-50 60.66 209 177-77 59-84 104 72.00 61.97 142 110.24 61.34 176 144-51 60.64 210 178.78 59.82 106 74-0O 61.95 143 111-25 61.32 177 145-52 60.62 211 179.78 59-79 108 76.00 61.9 J 144 112.26 61.30 178 146-53 60.59 212 180.79 59.76 There are four notable temperatures for pure water, viz.: 1. Freezing point at sea level, 32° F Weight per cu. ft., 62.418 lb.; per cu. in., .03612 lb. 2. Point of maximum density, 39.1° F Weight per cu. ft., 62.425 lb.; per cu. in., .036125 lb. 3. British standard for specific gravity, 62° F. . Weight per cu. ft., 62.355 lb.; per cu. in , .03608 lb. 4. Boiling point at sea level, 212° F Weight per cu. ft., 59.760 lb.; per cu. in., .03458 lb. 95 A United States standard gallon holds 231 cubic inches, and Syi pounds of water at 62 degrees Fahrenheit. A British imperial gallon holds 277.274 cubic inches, and 10 pounds of water at 62 degrees Fahrenheit. Sea water (average) has a specific gravity of 1.028, boils at 213.2 degrees F., and weighs 64 pounds per cubic foot at 62 degrees Fahrenheit. A pressure of i pound per square inch is exerted by a column of water 2.3093 feet, or 27.71 inches high, at 62 degrees Fahrenheit. STEAM PACKET "SANTA ANA" Owners, A. W. Beadle & Co., San Francisco, Cal. Babcock & Wilcox Boilers, 70: Indicated Horse-power 96 EQUIVALENT EVAPORATION FROM AND AT 212° F. OR purposes of comparison, it is usual to reduce the actual evaporative results obtained in practice, to a common standard, known as " equivalent evaporation ft'ont and at 212." This means that the temperature of the feed water is supposed to be «/ 2 1 2 degrees, and that the evaporation takes place at atmospheric pressure, or from 2 1 2 degrees^ the equivalent amount of water being calculated which would be evaporated under such conditions. In both cases the heat imparted to the water is the same, and in order to find the " equivalent evaporation," it is only necessary to find the amount of heat actually absorbed by the water in being converted into steam in the boiler, and divide this by 965.7, the latent heat of steam at atmospheric pressure, which is the heat required to evaporate one pound of water "from and at 212 degrees." For example, suppose that 3000 pounds of water are evaporated per hour at a pressure of 70 pounds, the feed water entering the boiler at roo degrees Fahrenheit. By reference to the steam tables, it is found that steam at 70 pounds gauge pressure (84.7 absolute) contains 1 178.3 British thermal units per pound above 32 degrees; and from the table for heat in the water, it is found that each pound of water, at 100 degrees Fahrenheit contains 68.01 British thermal units above 32 degrees. The boiler will therefore have to impart to each pound of steam generated, the difference between these quantities, or (i 178.3 — 68.01) 11 10.29 British thermal units. This amount, divided by 965.7, gives 1.1497, or, say, 1.15. That is, the same amount of heat imparted to one pound of water at 100 degrees Fahrenheit, in con- verting it into steam at 70 pounds pressure, would evaporate 1.15 pounds FACTORS OF EVAPORATION. From the Tables computed by Mr. Geo. A. Rowell. a-- . 32 40 50 60 70 80 90 100 no 120 130 140 •50 160 170 180 190 200 210 Steam Pressure by Gauge. 50 60 70 80 go 100 110 izo 130 140 150 160 170 180 xgo 200 210 220 230 240 250 260 270 280 290 300 1. 214 1 1.206 1 1.1951 1..851 1.1641 ••1541 1.1441 1.1331 ••1231 '•1131 1. 102 I 1.091 I 1. 081 I 1.070 I 1.060 I 1.050J1 1.039 I 1.029 ' 1.220 1.212 1. 201 1. 191 1. 180 167 1. 170 157 1. 160 1471.150 '36,1-139 ,126,1. I29'I .ii6i.ii8;i ,1051.1 ,095,1.0981 ,084! 1. 087 ,074' 1. 077 I ,063 1 1 .0661 1 ■°53 '•°56! ■043 1 1 •0451 1 ,0321.03511 .222 .214 .204 •193 .183 •173 .162 .152 .142 •131 .121 .110 .100 .090 .079 .069!! .058'!, .048 I, .0371, 225 216 206 196 .65 ■54 144 '33 123 "3 102 092 ,081 071 060 ,0501 040 I .227 1.229 .219 1.220 .20811.210 .198 1.200 .I87JI.I' .1771.179 1. 169 1.158 1. 127 1.117 1. 106 1.096 1.085 1075 1.065 1.054 1.044 1.232 1.224 1.214 1.203 '•'93 '.183 1. 172 1.162 1.152 1. 141 1.130 1. 120 I. no I. too 1.089 1.079 1.068 1.058 1.047 1.236 1.227 1.217 1.207 1. 196 1.186J1 1.165J1 '•'55' '•'45' '•'34 1.124 1.113 1.103 1.092 1.082 1.071 1.061 1 .05 1 ■237 .229 .218 .208 •'97 .187 •'77 .167 ..56 .146 .136 .125 .115 .104 .094 ■083 •073 .0631 .05 2] I 2391 2301 220 210 '99 189 '79 168 158 '47 '37 '27 116 ,106 ■095 ,085 ,074 ,064 •053 .241 ■233 ■223 .212 .202 .192 .181 .171 .160 •'5° .140 .129 "9 .108 .098 .088 .077 .067 .056 .244 .236 .225 .215 •205 • '94 .184 •'74 .i6'< •'53 .142 .132 .121 .III .101 .090 .080 .069 .059 1.247 '•239 1.229 1.218 1.208 1. 198 1.187 1.177 1.167 1. 1 56 1.146 '•'35 1. 125 1. 115 1. 104 1.094 1.083 '■073 1.062 1.240 1.230 1.219 1.209 1.199 1.18 1.178 '•'57 1. 147 1.136 1. 126 1. 116 1.105 1.095 1.08 1.074 1.063 ,2501.251 ,241 1.242 1.232 1.221 1.211 1. 201 1. 190 i.iii 1. 170 1. 159 1.149 '.138 1. 128 1.118 1.107 1.097 1.086 •'37 ■'27 .117 .106 .096 .085 .0751.076 .064 1.065 .252 •243 •233 .222 .212 .202 .191 .i8x .171 .160 .150 • '39 .129 .119 .108 .098 .087 .077 .066 •253 .244 ■234 .223 .213 .203 .192 :.i82 1. 161 1. 151 1.254 1.245 '•235 1.224 1.214 1.204 '■'93 '.'83 '•'73 1. 162 '.'52 140 1. 141 .1301.131 .120 1. 121 ,109 I. no ,099 I. too ,0881.089 078] 1.079 ,067! 1 .068 97 from and at 212 degrees Fahrenheit ; so that 3000 pounds evaporated at actual conditions are cquivalctit to (1.15 X 3000) 3450 pounds from and at 212 degrees. The quantity 1.15 is called the factor of evaporation. It may be H - h . expressed by the following formula : F=^ , m which H equals the total heat in steam above 32 degrees at boiler pressure ; h equals the heat in the feed water above 32 degrees, and 965.7 equals the latent heat in steam at atmospheric pressure. For convenient reference, the table on the preceding page gives these factors for various pressures, and temperatures of feed water. STEAM PACKET " ROBERT DOLLAR Owner: Robert Dollar, San Francisco. Cal. Babcock & Wilcox Boilers, 550 Indicated Horse-power 98 DRY STEAM— USE OF THE STEAM CALORIMETER TEAM without moisture is the essential product of a well- designed steam generator. It may be saturated in quality, or superheated, but it must not be wet. Dry steam, or, as it is called technically, saturated steam (meaning steam saturated with heat), is steam in its natural or normal condition. If any heat is added it im- mediately becomes superheated, and it should be noted that it cannot become superheated until it has first become dry, while if any heat is taken away from saturated steam, a portion of it is at once condensed to the form of moisture. The steam that remains, however, is itself dry, and what we know as wet steam is really a mixture of dry steam and small particles of mois- ture which are mechanically mixed with it and carried along in the current. The question of making dry steam, therefore, is one of properly liberating the bubbles of steam from the surrounding water so that none of the latter shall be entrained with it. As is well known, the immediate predecessor of the water-tube boiler in marine work was the cylindrical or Scotch boiler of large diameters. The Babcock & Wilcox boiler is built with a steam and water drum of less than four feet diameter, and herein is one of its great elements of lightness and safety. But, as a result of this smaller diameter, and consequent reduction of liberating surface, it might at first appear that the quality of the steam would be affected and that considerable moisture would be entrained. That such, however, is not the case, is shown by the following statements of prominent engineers who have obtained their knowledge from actual tests and experience with the boiler : " The moisture m the steam is so infinitesimal as to be entirely negligible in the final results." — Lieutenants B. C. Bryan and IV. W. White, U. S. N. " The calorimetric experiments show the steam to have been perfectly dry." — Chas. E. Emery, Ph. D. "Percentage of moisture in steam — part of i per cent. — .3 to .5." — J. M. Whitham, Mem. Am. Soc. M. E. " At the highest rates of forcing, the moisture entrained in the steam never ex- ceeded ^ of I per cent." — Ernest H. Peabody, Mem. Am. Soc. M. E. " Moisture in steam, 0.48 of i per cent., or practically dry." — Robert Logan, N. A. "The calorimeter showed .72 of i per cent, of moisture at the throttle valve, or practically dry steam."— y. E. Denton, Prof, of Mechanical Engineering, Stevens Institute of Technology. In addition to this testimony, it will be convincing to many to consider that a boiler which made wet steam could scarcely attain the success the Babcock & Wilcox boiler has achieved, or stand the test of continued and varied usage. 99 The following experiment, made several years ago at the works of this company, serves to show the manner in which steam is separated from the water in this type of boiler, and passes in a dry state to the perforated dry pipe connected with the outlet from the drum. It also proves that the size of the drum has little to do with the dryness of the steam, and that a very small liberating surface in connection with a very little thne is all that is needed to insure the proper liberation of the steam from the water. In order to observe the phenomena going on inside the steam drum of a boiler in service, a peep-hole, filled with a stout piece of glass, was made in each drum-head, opposite the space between the return circulating tubes and the baffle plate. By means of an electric arc light placed at one eye piece, the interior of the drum was illuminated and the discharge of each of the circulat- ing tubes distinctly seen. When the boiler was steaming rapidly, with ^-inch air blast in the ash pit, the observations clearly showed that each of the circulatmg tubes was dis- charging against the baffle plate, with considerable velocity, a stream of solid water that filled the tube for half its diameter. There was no spray or mist whatever, showing conclusively that the steam had entirely separated from the water during its passage through the circulating tubes, which, in this boiler, were only 50 inches long by 4 inches in diameter. As a matter of fact, the actual steam liberating surface required for the entire boiler was less than that contained in the circulating tubes, which amounted to about 15 square feet, or i square foot to every 100 square feet of heating sur- face in the boiler. After striking the baffle plate, the water was deflected downward, mixing with the main body of water in the drum, while the steam passed around the ends of the baffle plate into the steam space in which is located the dry pipe. The drum itself is not exposed to great heat in this type of boiler, and the water in it is not agitated in any way, so that there is no possibility of water or spray reaching the dry pipe. In view of this experiment, it is evident that the Babcock & Wilcox marine boiler cannot furnish anything but dry s:earr|. . In any ship or other mstallation of boilers, however, it must 'be' remem- bered that after leaving the generator the steam passes at once into a sycfeiid of piping, which, even if well covered, is always being more or less cooled by the surrounding air. This cooling effect necessarily condenses some of the steam, and it has often happened that samples of steam have been tested which, by accident, contain some of this condensation from the sides of the pipe. Such tests are not only manifestly unfair to the boiler, but are very misleading in their results. METHOD OF TESTING STEAM The method best adapted to insure obtaining a fair sample of steam for test- ing, is to take it from the center of the vertical portion of the steam pipe as near the boiler as possible. Use a straight open-ended nipple, provided with a long thread on one end so that it may be screwed into the steam pipe far enough to bring the open end at or near the center of the current of steam ascending from the boiler, and as far removed as possible from the sides of the pipe, which are always coated with a thin film of moisture. Do not use perforated or slotted nipples, as they have been found to give very inaccurate results. The throttling calorimeter, first devised by Prof. C. H. Peabody, of the Massachusetts Institute of Technology (see "Journal of Franklin Institute," August, 1888), is by far the simplest type of instrument for testing the quality of steam, and, when properly used, gives very accurate results. There have been numerous forms of this instrument, one of the simplest being that designed by Mr. George H. Barrus, of Boston, which is described below : Steam is taken from a }^-inch pipe provided with a valve, and passed through two ^-inch tees situated on opposite ^ sides of a ^-inch flange union, substan- I \ l^"'"^ J'KS- I i 1 ^^W.l. DISK WITH >^ ORIFICE tially as shown in the accompanying sketch. A ther- mometer cup, or well, is screwed into each of these tees, and a piece of sheet-iron, perforated with a ^-inch hole in the center, is inserted between the flanges and made tight with rubber or asbestos gaskets, which also act as non- conductors of heat. For convenience, a union is placed near the valve, as shown ; and the exhaust steam may be led away by a short i^-inch pipe, shown by dotted lines. The thermometer wells are filled with mercury or heavy cylinder oil, and the whole instrument, from the steam main to the I ^-inch pipe, is well covered with hair felt. Great care must be taken that the >^-inch orifice does not become choked with dirt, and that no leaks occur, especially at the sheet-iron disc, also that the NOT PERFORATED THERMOMETER CUP exhaust pipe does not produce any back pressure below the flange. Place a thermometer in each cup, and, opening the 3^ -inch valve wide, let steam flow through the instrument for ten or fifteen minutes ; then take frequent readings on the two thermometers and the boiler gauge, say at intervals of one minute. The throttling calorimeter depends on the principle that dry steam when expanded from a higher to a lower pressure, without doing external work, becomes superheated, the amount of superheat depending on the two pressures. If, however, some moisture be present in the steam, this must necessarily first be evaporated, and the superheating will be proportionately less. The limit of the instrument is reached when the moisture present is sufficient to prevent any superheating. Assuming that there is no back pressure in the exhaust, and that there is no loss of heat in passing through the instrument, the total heat in the mixture of steam and moisture before throttling, and in the superheated steam after throttling, will be the same, and will be expressed by the equation H—^ — = 1 146.6 + .48(/- 212) 100 H — \\ 46.6 — .48 (/ — 212) or X— ^ ^X 100 in which x = percentage of moisture ; H = total heat above 32° in the steam at boiler pressure ; L — latent heat in the steam at boiler pressure ; 1 146.6 = total heat in the steam at atmospheric pressure ; t = temperature shown by lower thermometer of calorimeter ; 2 1 2 = temperature of dry steam at atmos- pheric pressure. Theoretically the boiler pressure is indicated by the temperature of the upper thermometer ; but, owing to radiation, etc., it is usually too low, and it is better to use the readings of the boiler gauge, if correct, or better still to have a test gauge connected on the ^-inch pipe supplying the calorimeter. If the instrument be well covered, and there is as little radiating surface as possible, the above assumption that there is no loss of heat in passing through the instrument may be nearly, though never quite, correct. On the other hand it is more than likely to be very far from correct, and, to eliminate any errors of this kind, Mr. Barrus recommends a so-called "calibration" for dry steam. This, again, involves an assumption which is open to some doubt, which is that steam, when in a quiescent state, drops all its moisture and becomes dry. No other practical method, however, has been proposed, and this is, therefore, the only method used at the present time. Some engineers, however, refuse to make any calibration, but, instead, make an assumed allow- ance for error. To make the calibration, close the boiler stop valve, which must be on the steam pipe beyond the calorimeter connection. Keep the steam pressure exactly the same as the average pressure during the test, for at least fifteen 103 SIX PROTECTED CRUISERS "TACOMA," " CLEVELAND," " DEN'VKK," " GALVESTON," •' CHAT PANOOGA " AND "DES MOINES" All Fitted with Babcock & Wilcox Boilers Arrans;evient of Boiler Rooms: Total Heating Surface . 13200 sq.ft. Total Grate Surface . 300 sq. ft. Ratio H. S. to G. S.,44: i FRAME 42 LOOKING FORWARD minutes, taking readings from the two thermometers during the last five min- utes. The upper thermometer should read precisely the same as during the test, and the lower thermometer should show a higher temperature ; this read- ing of the lozvcr thermometer is the calibration reading for dry steam, which we will call T. Calculation of results, allowing for radiation by calibration method : — .48 {T— i) Formula, x ■=. j X 100 in which x — percentage of moisture ; T = calibration reading of lower ther- mometer ; t — test reading of lower thermometer ; L — latent heat of steam at boiler pressure. The method of taking a sample of steam from the main is of the greatest importance, and more erroneous results are due to improper connections than to any other cause. Use only a plain, open-ended nipple projecting far enough into the steam pipe to avoid collecting any condensation that may be on the sides of the pipe. Take care that no pockets exist in the steam main near the calorimeter, in which condensation can collect and run down into sampling nipple. Remember you are ascertaining the amount of moisture in the steam and not measuring the condensation on the walls of the steam piping. Make connections as short as possible. As mentioned above, there is a limit in the range of the throttling calo- rimeter which varies from 2.88 per cent, at 50 pounds pressure to 7.17 per cent, at 250 pounds. When this limit is reached a small separator may be interposed between the steam main and the calorimeter, which will take out the excess of moisture. By weighing the drip from the separator and ascertaining its per- centage of the steam flowing through, and adding this to the percentage of moisture then shown by the throttling calorimeter, the total moisture in the steam may be ascertained. It is seldom, however, in a well-designed boiler, that any but a throttling calorimeter becomes necessary. los ECONOMY DUE TO THE HEATING OF FEED WATER HE importance of heating feed water before delivering it to a boiler can best be realized by considering exactly what takes place during the generation of steam. As explained on page 89, the total heat in steam consists partly of sensible heat, which marks the boiling point of the water, and partly of latent heat, which converts the water into steam. Therefore, in generating steam in a boiler, the water must first be heated to the boiling point and then enough heat added to evaporate it at the required pressure. The rate at which water absorbs heat varies slightly as its density decreases, but for rough calculations it can be assumed that the number of degrees Fahrenheit which a pound of water is heated, represents the number of British thermal units it has absorbed. Suppose, therefore, that a boiler is making steam at 180 pounds gauge pressure and is being fed with water at 60 degrees Fahrenheit. By reference to the steam tables, we find that the boiling point at 1 80 pounds gauge pressure is about 380 degrees Fahrenheit, and the latent heat equals about 845 heat units. When the water goes into the boiler, therefore, it has first to be heated from 60 degrees to the boiling point, which requires approximately (380 — 60) 320 heat units. This, with the latent heat afterwards added to convert it into steam, makes a total of (320+845) 1 165 heat units which must be added to each pound of water entering the boiler to make one pound of steam. If instead of entering the boiler at 60 degrees, the feed water were heated to 200 degrees Fahrenheit, only (380 — 200) 180 heat units would have to be added to bring it to the boiling point instead of 320 as before, and the total heat added per pound of steam would be (180 + 845) 1025 instead of 1165 PERCENTAGE OF FUEL SAVED BY HEATING FEED WATER 0) 2 & 2 I. e« Temperature of Water Entering Boiler 1 (Steam Pressure 60 Pounds) Initial Entei < \ 120° 140° 160° 180° 200° \ 202" 204° 206° 208° 210° 212° 214° 216" .32° II75 ' 749 9.19 10.89 12.59 14.30 14.47 14.64 14.81 i 14.98 15.15 15-32 15.49 1566 40 I 167 6.86 «-57 10.28 1200 13.71 13.88 14.05 14.22 14.40 14.57 14.74 ! 14.91 15.08 SO "57 6.05 7.78 9.51 11.24 12.97 13-14 1332 1349 13.66 13.83 14.00 ! 14.18 14-35 60 1 147 .S-23 6.97 8.72 10.46 12.21 12.38 12.55 12.73 12.90 : 13.08! 13.25 13.43 13.60 70 1 137 4.41 6.16 7.91 9.67 "43 II. 61 11.78 11.96 12.14 ; 12.31 12.49 1 12.66 12.84 80 1127 ! 3-44 ,S-32 7.10 8.87 10.65 1 10.82 11.00 II. 18 11.36 1 11.53 1 1. 7 1 1 11.89 12.07 qo 1117 , 2.68 4-47 6.26 8.06 9.85 10.03 10.21 10.38 10.56; 10.47 10.92 1 1. 10 11.28 100 1 107 [ 1.80 3.61 542 7-22, 903 9-21 9-39 9-.S7 9-75 9-93 lo.ii 10.29 10.47 no 1097 .91 2-73 4-55 6.38 8.20 8.38 8.56 8.74 8.93 9.11 9.291 9.47 9.66 120 1087 — 1.84 3-67 5-51 7-35 7-54 7-77 7.90 8.09 8.27 ' 8.45 : 8.64 1 1 i 8.82 107 heat units. In other words, to each pound of water converted into steam the boiler would now have to add only 88 per cent, of the amount of heat it did before, and 12 per cent, of the coal might be saved, or, providing the same amount of coal was burned on the grates, it would make nearly 14 per cent, more steam than it did with feed water at 60 degrees. The table on page 107 shows the saving that may be expected by heating feed water various amounts. Another very convincing way of looking at this matter is from the view of engine efficiency. The best engine yet designed, with all the modern improvements of high steam pressure, multiple expansion, condensers, etc., cannot possibly use more than one-fifth of the heat contained in the steam. This is because all the latent heat is necessarily wasted without doing work. How very much more wasteful then must be the pumps, blower engines and other auxiliary machinery on board ship, even if, as is often the case, they exhaust into the condenser. It is the general impression that auxiliaries will take much less stearn if the exhaust is turned into the condenser, thereby reducing the back pressure. As a matter of fact, vacuum is rarely registered on an indicator card taken on auxiliary cylinders unless the exhaust connection is short and without bends, long pipes and many angles vitiating the effect of the condenser. On the other hand, if the exhaust steam in the auxiliaries can be used for heating the feed water, all the latent heat of this steam, except what is lost by radiation, goes back to the boiler and is saved instead of being thrown away in the condensing water or wasted with the free exhaust. Taking the whole plant into consideration, this makes the auxiliary machinery more efficient than the main engine. For illustration, take the first of the series of tests of the steamship "Pennsylvania," as found on page 146. The total amount of steam furnished per hour was 20,407 pounds, of which 17,252 pounds were used in the main engine and 3155 in the auxiliaries, i.e., the auxiliaries required 15.46 per cent, of the total steam. Of the 3155 pounds of auxiliary steam, 139 pounds were used by the stoker engines and exhausted into the ash pits, leaving 3016 pounds that exhausted into the heater. The feed water w^as taken from the hot well at a temperature of 99.3 degrees Fahrenheit and pumped through a closed feed water heater, where it was heated to 222 degrees Fahrenheit by means of the exhaust steam from the auxiliary machinery. From this heater it passed to the boilers and was converted into steam at a pressure of 242 pounds. The auxiliaries exhausted into the heater at about 3 pounds back pressure. By referring to the steam tables, it will be found that the 3016 pounds of steam supplied to the auxiliary machinery contained 3,634,280 British thermal units (1205 x 3016). At 3 pounds back pressure the same amount of steam consumed would contain 3,467,797 British thermal units. The 109 o '-' in X i I < 3 ^ da o o u difference between these amounts — 166,483 British thermal units — is all that is available for doing useful work, and as no engine can use all of this without waste, it will be seen that the proportion of heat that is converted into work is very small indeed. If the exhaust steam from the auxiliary machinery had been turned into the condenser, it is true that not quite so many pounds would have been required each hour, but ail the latent heat would have been thrown away in the condensing water, while as a matter of fact, by sending it into the feed water heater, over three-quarters of the entire 3,467,797 British thermal units were saved. This is shown by the heat units absorbed by the feed water which was heated from 99.3 degrees to 222 degrees, a difference of 122.7 degrees Fahrenheit. This multiplied by the number of pounds heated gives (20,407 X 122.7) 2,503,939 British thermal units as the actual amount of heat taken from the exhaust steam of the auxiliaries each hour and returned to the boiler. Of the remaining 963,858 British thermal units, part is lost in radiation, condensation in the pipes, etc., and part, amounting to nearly 600,000 British thermal units, is wasted in the drips from the heater, on account of the impossibility of cooling the condensed steam much below 222 degrees Fahrenheit. It may be noted, further, that each pound of coal burned contained 1 1,790 British thermal units, of which 75.7 per cent, or 8923 British thermal units were utilized in making steam. If, therefore, 2,503,939 heat units had not been saved by heating the feed water, it would have been necessary to have heated the same by an additional expenditure of 280 pounds of coal per hour, thereby increasing the total coal burned in the plant, per indicated horse- power, to 2.15 pounds instead of 1.92 pounds, as shown by the test. There is another reason for heating feed water, aside from the obvious saving of heat units, and that is the fact that the boiler steams more econom- ically when using hot feed water than when using cold. This was demonstrated experimentally by Kirkaldy, of England, and the theory advanced by M. Nor- mand seems very plausible, namely, that cold water checks the circulation in the boiler, and in re-establishing this a certain amount of heat disappears in mechanical work, with a consequent loss in evaporation. Water-tube boilers with their rapid and uniform circulation are not liable to injury by the use of cold feed water, but the above points make it clear that cold water should never be used by the engineer who wishes to obtain the highest economy from his plant. =a m REBOILERING THE UNITED STATES MONITORS T the breaking out of the war with Spain, the United States Gov^ernment found it necessary to commission every available ship then in ordinary ; among these vessels were the old single turret monitors, which were capable of doing good service as harbor defence vessels, provided they could be reboilered at once. The contract for this work on the " Canonicus," " Mahopac " and " Manhattan," stationed at League Island Navy Yard, Philadelphia, was awarded to The Babcock & Wilcox Company, and the first two vessels were made ready for steam in thirty days and the third in forty-two days after the order to proceed with the work was received. As the boilers were built in sections, the Government saved much time and expense by passing them into the vessels through the seven-foot armored funnel. Cutting of the decks was thereby entirely avoided. Originally, each monitor was fitted with two flat-sided Stimer fire-tubular boilers, one on either side of a fore and aft fire room. As soon as one old boiler was cut up and removed, the work of installing the new boilers began, so that construction progressed on one side of the ship while the second boiler was being demolished on the other. The new boilers contained a total of 6000 square feet of heating surface and 200 square feet of grate. Steam was supplied to a pair of horizontal, crank and lever Ericsson engines, having cylinders 48 inches in diameter and 24 inches stroke. To economize space and obtain a low center of gravity, the cylinders were placed athwartships on the same axial line, and as both were fitted with 16-inch trunk pistons, the effective annular area of the crank end was equivalent to that of a circle 45 inches in diameter. In order, therefore, to equalize the power developed on each side of the piston, it was necessary to allow the steam to follow further on the trunk end than on the head end. As the engines were constructed before the advent of high pressures, only 50 pounds initial could be carried in the cylinders, although the boilers were constructed for a working pressure of 175 pounds. It is conceded by the best authorities that the time employed in building and installing the boilers is the quickest on record, and, as to steaming, the Navy Department states : " It-is a source of satisfaction that the performance of these vessels with the new boilers exceeded that obtained when the vessels were first built." li% EXAMPLES OF DURABILITY— COST OF REPAIRS N the introduction of marine water-tube boilers, the chief, although unwarranted, objection to their use was the " cost of repairs"; those wedded to the Scotch or tank type pre- dicting the necessary renewal of the tubes every two years. Persons interested in the advancement of engineering and anxious to install water-tube boilers have been deterred from so doing by the continued cry, "cost of repairs." The steamer " Zenith City," equipped with Babcock & Wilcox boilers in the spring of 1895, had, at the completion of the season of 1900, traveled a total of 300,000 miles. The total cost of repairs to each boiler at the end of the fourth year amounted to '$35.00, which sum was expended as much on repairs to boiler fittings as to the boiler proper. At the end of the fifth and sixth seasons no repairs were needed. The steamer "Charles Nelson" is fitted with these boilers, and the owner states that the steamship " has been in constant and active service at sea upwards of 34 months, and the boilers have given good satisfaction. There has been no expense whatever for repairs, and the boilers are in good condition. i / \ -j]/ I JA^l \^K ^^ ^ 1 STEAM PACKET "CHARLES NELSON" Owner; Chas Nelson, San Francisco, Cal. Babcock & Wilcox Boilers, 850 Indicated Horse-power H4 They have shown an excellent economy and furnished plenty of steam, using the various Pacific Coast coals. The 'Nelson' has made good passages to and from Manila, on two occasions equaling the average time made by the United States Army transports." Concerning the steamer " Dirigo," boilered at the same time as the " Nelson," her owners say that she has been in active service for the same number of months, and the results obtained warranted their installing two similar boilers in the steamship "John S. Kimball," one in the steamer "Archer" and ordering another for a new steamer under construction. At the expiration of a 12,000-mile voyage from Boston to Cavite, the boilers of the United States gunboat "Marietta" needed only a few grate bars. This run was in addition to the war service of this little vessel, and the memorable trip around the " Horn" in company with the battle ship " Oregon." (See page 37.) After spending the winter and spring of 1899 on the Atlantic Coast, the cruiser " Chicago " made a trip around Africa, returning to New York via South America and stopping at Rio Janeiro. The total distance traveled was 35,000 miles, and, on arrival, she was able to proceed at once to Buenos Ayres, as there was nothing to do to her boilers. The gunboat " Annapolis " has steamed 60,000 miles, and no repairs have been made. The steamer "Queen City" completed at the end of the season of 1900 a total of 250,600 miles, and no repairs have ever been made on her boilers. The steamers "Alex. McDougall " and " Presque Isle" have each carried about 430,000 tons of iron ore, steaming a distance of 1 30,000 miles. One tube, due to an original imperfection, has been renewed in the boilers of the "McDougall." The "Presque Isle" has needed nothing. It is a significant fact that vessels equipped with Babcock & Wilcox marine boilers never find it necessary to call in the services of the shop boiler maker. "5 M H CORROSION— CAUSES AND PREVENTIVE MEASURES S the life of a boiler mainly depends upon the rate of progress of the corrosion of its pressure parts, the pre- vention or delay of this destructive action is one of the most important duties of the intelligent engineer. Not only should the subject be studied in its various aspects, but the greatest care and watchfulness are necessary in order to successfully stay the advances of this subtle force. The principal causes of corrosion of iron and steel boilers, in sea-going vessels, can be classified as follows : 1st. Use of sea water. 2d. Acidity — the use of animal or vegetable oils in the steam cylinder. 3d. Admixture of air with the feed water. 4th. Galvanic action. Each of these causes of corrosion, and means of preventing or remedying them, will be considered separately. USE OF SEA WATER Salt water is known to be a solvent of iron or steel, and when boiled under high pressure the magnesium chloride, about 250 grains of which are contained in every gallon, becomes highly corrosive. ANALYSIS OF SEA WATER Carbonate of lime Sulphate of lime Sulphate of magnesium Chloride of magnesium Chloride of sodium Total solids 9.79 grains per gallon 1 14.36 grains per gallon 134.86 grains per gallon 244.46 grains per gallon 1706.00 grains per gallon 2209.47 grains per gallon Under certain conditions, particularly in the process of corrosion, the water becomes acid by the dissociation of magnesium chloride into hydrochloric acid and magnesia ; the acid, in contact with iron not protected by scale, forms an iron salt which, at the very moment of formation, is neutralized by the free magnesia in the water, thereby precipitating oxide of iron and reforming magnesium chloride. Thus it is easily seen that free iron is never found in solution in boiler water. The black and red deposits formed in boilers which have had an excess of sea water in them are generally iron oxides. The red is found when there is much air allowed to get into the boiler ; the black when little or no air is present. Just here comes in one of the most astonishing neglects of marine engineering. It is the neglect of modernizing the condensers of sea-going ships. 1.17 To deliberately install an expensive and .well-constructed boiler, and as deliberately permit the use, in connection therewith, of condensers known to be subject to leakage, and constructed so as to make quick and efficient repair extremely difficult, is at least commercially criminal. There is far more room for improvement in design and construction of the condensers than in marine boilers, and the great importance of the former is most obvious when the first cause of corrosion is properly considered. Preventive. — To prevent salt feed, the condensers must be tight, and an ample provision made for fresh water " make-up " either by carrying a supply in bulk or by installing an adequate evaporating plant, designed and located so as to operate without priming. If salt feed does enter the boiler, the quantity must not be increased by "blowing off" water from the boiler, at least not until the saturation has reached /j. A high saturation is preferable to a continuous renewal of salt feed, aside from the heat loss of blowing off. A light scale will reduce the evaporative efficiency of a boiler, in spite of statements to the contrary, and a heavy scale will induce the burning out of parts exposed to the flames. Remedy. — A small amount of salt water is bound to get into the boilers, even under favorable conditions, through priming in the evaporator and slight leakage from the condenser, and it is an excellent plan to constantly use a small quantity of milk of lime to neutralize it. One or two pounds per looo indicated horse-power fed per day, in the manner below mentioned, may suffice. The lime used is the ordinary unslaked lime of commerce, and it should be finely powdered and kept in a dry place ; for instance, on the up-take gratings. Milk of lime is a mixture of about one pound of lime to a gallon of water, and should be added at times to the water in the filter box. The Use of Lime. — When starting with new boilers on a voyage for the first time, ten pounds of lime should be put into the boilers for every looo horse-power (dissolve in water and put in through man hole) ; and four to six pounds of lime per day for every lOOO horse-power should be passed through the hot well (as milk of lime) for about six days. At the end of the voyage the boilers should be examined to see if they have a thin coating of lime scale on their interior surface. If this is not the case and the water shows an improper color, the use of the lime should be continued. The rationale of the use of lime is the conversion of magnesium chloride, which is corrosive in effect on iron and steel, into magnesia and chloride of calcium, neither of which is corrosive ; and the light scale on the surface also prevents the corrosive elements from coming into contact with the iron. Further precautionary methods must be employed by the marine engineer in order to conquer corrosion. The boiler water should be tested daily, and if ii8 found to be acid or to contain a larger amount than 50 grains of chlorine per gallon, a remedy must be applied. ACIDITY This cause of corrosion may arise from salt feed, or from the introduction of animal or vegetable oil with the feed water by reason of using such oils in the steam cylinders, the exhaust steam entraining much of it to the condensers. This oil, containing fatty acids, will decompose and cause pitting wherever the sludgy deposit can find a resting place in the boilers. Preventive. — Next in importance to the total exclusion of sea water, is the necessity of keeping oil out of the boiler. Only the highest grade of hydrocarbon oil should ever be used in the steam cylinders, and of this the least possible amount. Also, in lubricating piston rods and valve stems, this same precaution should be observed. For, apart from the evil effects of acidity, the hydrocarbon deposited upon the heating surfaces is most harmful, as a thin film of this deposit forms a complete non-conductor, thereby preventing the heat from passing through into the water, and causing the surfaces to burn, blister and crack. Where surface condensers are used, the feed water should be purified on its way to the boiler by passing it through a cartridge filter, which must be kept clean. A large amount of impurities are thereby caught, and the condition of the feed water materially improved. Remedy. — If the boiler water is strongly acid, a solution of carbonate of soda should be added to the feed at the rate of a bucket of soda solution per hour until the water just turns red litmus paper blue, after which daily additions of soda will suffice to keep the water in a safe or alkaline state. Carbonate of soda has also been found effective in cases where scale of sulphate of lime is formed, as it possesses the property of changing the sulphate of lime to sulphate of soda, which is soluble, and, therefore, harmless. Carbonate of lime, which is also formed, may be easily blown or washed out. To sum up, oil and salt water should never be allowed to enter any kind of a steam generator, and, where surface condensers are used, the feed water should be purified as much as possible before entering the boiler. Graphite can be used in place of oil as a cylinder lubricant with equally satisfactory results. In fact, graphite is superior to oil when the steam pressure is carried from 200 to 275 pounds, corresponding to a temperature in the neighborhood of 400° F. Oils containing animal fats produce rapid corrosion and should never be used in the cylinder of a steam engine. Many steam vessels are running without a particle of oil ever being injected into either their main or auxiliary cylinders, the slushing of the piston rods being found ample for piston lubrication. "9 =y ADMIXTURE OF AIR WITH FEED WATER Air has been a well-recognized cause of corrosion for many years, and instances of rapid corrosion have been proved to have been caused by the feed pumps sucking air from the hot well, and the feed being delivered at a level considerably below the water line. The boilers that have been most free from this kind of corrosion are those in which the best means have been adopted to keep out air. Small bubbles of air expelled from the water on boiling, attach themselves tenaciously lo the heating surfaces. The oxygen in this air at once begins war on the iron or steel and forms iron rust ; making a thin crust or excrescence which, when washed away by the circulation or dislodged by expansion and contraction, leaves beneath a small hole or pit. Pitting, once started, progresses rapidly, as the indentations form ideal resting places for the bubbles of air, and at the same time present increased surfaces to be attacked. * Thorpe states that " nearly all natural waters contain oxygen in solution,, and can only be freed therefrom by prolonged boiling in vacuo." * Spenmath states that water absorbs oxygen as follows : At 32° Fahrenheit it will absorb 4.9 per cent, of its own bulk At 50° Fahrenheit it will absorb 3.8 per cent, of its own bulk At 68° Fahrenheit it will absorb 3.1 per cent, of its own bulk * Stromeyer states that under i 50 pounds pressure, cold feed water absorbs 3.2 pounds of oxygen per ton. With independent feed pumps there is less liability for air to get into the boilers than when the pumps are worked off the engines. Air or oxygen is most corrosive in its action, and this is the reason for the boiler feed delivery pipes being fixed either in the steam space or near the water line. Preventive. — Where possible, the hot well water should be pumped to a filter tank situated eight to ten feet above the feed pump suction valves. By so doing, a large amount of air rises and is liberated from the surface of the water, and a head of water at the suction valves of the pump is assured. Remedy. — Salt water absorbs more air than fresh water. Care should be taken to keep the pump glands tight, and to eflficiently entrap free air in the air vessels. GALVANIC ACTION Formerly, nearly all corrosion in boilers was attributed to this cause, and zinc slabs were suspended everywhere possible within the water space. The position of zinc relative to that of iron in the scale of electro-positive metals, causes it to be attacked instead of the metal of the boiler when galvanic action takes place. Preventive. — To afford protection by the use of zinc, however, there must be positive metallic contact between the zinc and iron. Practically, it is impossible to maintain this contact with the usual methods of installation, * " Corrosion of Boiler Tubes in U. S. Navy," Lt. Com. Walter F. Worthington, U. S. N., "Journal of the American Society of Naval Engineers,'' Vol. XII. and it has been shown that no galvanic current exists after a few hours of steaming, in the arrangements ordinarily employed. Remedy. — The use of zinc, however, should not be abandoned on this account, as it appears still a very important element of protection against corrosion due to air in feed water. Its suspension in drums, and points within the boiler near the entrance of the feed, is recommended as of positive benefit, and, indeed, as long as zinc slabs continue to disintegrate and oxidize in a boiler, they deflect to themselves from the iron just that amount of harmful action. METHOD OF TESTING WATER FOR CORROSIVENESS The first thing in testing, as is well known, is to see that the color of the water, as shown in the gauge glass, is neither black nor red. The only color STEAM WHALER "SHELIKOF" Owners : Pacific Whaling Co. Babcock & Wilcox Boilers, 450 Indicated Horsk-power admissible is slightly dirty gray or straw color, unless the water is transparent. So long as the water is red or black, corrosion is going on, and it must imme- diately be neutralized by freely using lime or soda, and frequently scumming and blowing off, the make-up being provided by the evaporator. The salinometer is not a very accurate instrument for determining the quantity of sea water in boiler water, but the apparatus here described gives a convenient and accurate method of ascertaining the exact number of grains of chlorine per gallon in the water tested. It is based on the scheme for the volumetric determination of chlorine devised by Fr. Mohr, an eminent chemist, and requires one graduated bottle, one bottle of silver solution containing 4.738 grams of silver nitrate to 1000 grams of distilled water, and one bottle of chromate indicator, which is a 10 per cent, solution of pure neutral potassium chromate. To* Make Test. — Fill the graduated bottle to the zero mark with the water to be tested ; add one drop of the chromate indicator ; then slowly add the silver solution ; keep shaking the bottle. On nearing the full amount of silver solution required, the water will turn red for a moment, and then back to yellow again when shaken. The moment it turns red and remains red, stop adding the silver. The reading on the graduated bottle at the level of the liquid will then show the amount of chlorine in grains per gallon. For example, if a per- manent red color is shown when the level is midway between 1 50 and 200, there are 175 grains of chlorine per gallon. The principle of the process depends upon the fact that if some of this silver solution be dropped into water containing a chloride, a curdy white precipitate of chloride of silver will be formed. If there is also present in the water enough potassium chromate to give a yellow color, the white precipitate will continue to form as before, owing to the silver having a greater affinity for chlorine than for the chromic acid in the chromate. But, at the moment when all the chlorine in the sample has been converted, the silver will attack the yellow potassium chromate, and chromate of silver will be formed, which is red in color. The amount of chlorine present is, therefore, shown by the amount of silver solution required to convert it all to silver chloride, and the determination of the exact point at which the chloride precipitate ceases to form is greatly facilitated by observing when the chromate indicator turns from yellow to red. It is not necessary to add the silver solution until the color becomes very red, as the delicacy of the reaction would be destroyed, but the change from yellow to """ v- yellowish red must be distinct and must not change on shaking. The sample of water to be tested should be neutral, as free acids dissolve the silver chromate. If it should be acid, neutralize by adding sodium carbonate. Slight alkalinity does not interfere with the reaction, but should the sample be very alkaline, it may be neutralized with nitric acid. Graduated Bottlk 650 123 Should it happen that the color does not change within the limits of the graduations, the sample may be tested by diluting with distilled water. For example, add three parts of distilled water to one part of the sample. If then, on testing the mixture, the color changes at 200, the number of grains per gallon in the original sample will be four times this reading, or 800 grains. The chlorine should be kepi down to the least possible amoiuit — say below ^o grains per gallon — as the nearer the boiler water is to fresh water the safer the boilers are against corrosion. If the water is so corrosive as to be acid, blue litmus paper, which has not been allowed to become deteriorated through exposure to the atmosphere (keep in a bottle with a glass stopper), will turn slightly red. If a change in color is not apparent at once, it should be allowed to remain in the solution a few minutes and then carefully dried and compared with an unused sample. Another method is to put into it a few drops of a chemical called methyl- orange. This methyl-orange gives a yellow color so long as the water is alka- line, but if turned pink, it shows that the water is acid, and therefore highly corrosive. This latter test is more sensitive than the litmus paper test, and should be used in preference. A testing kit containing the graduated bottle and the solutions referred to, also strips of blue and red litmus paper, neatly packed in a padded box, is supplied by The Babcock & Wilcox Company with all boiler installations intended for salt water service. Steam .\nd Water Drum. Babcock & Wii.cox Boiler, Details of Construction 125 :^ .-- Q o w m CARE OF BABCOCK & WILCOX MARINE BOILERS FIRING. — The correct manner of firing boilers depends largely upon the class and quality of the fuel. Coal can be divided roughly into three classes — anthracite, or hard coal ; semi-bituminous ; and bituminous, or soft coal. When anthracite coal is burned it should be spread evenly over the grate and a fire of uniform thickness maintained, which may be from 3 to 8 inches, depending on the intensity of the draft and size of the fuel. When stoking, half the grate should be covered at a time. In this way, complete combustion is promoted by the fire on the bright half of the grate. Semi-bituminous coal, that is high in fixed carbon and low in volatile matter, can be fired evenly on the grate or coked just inside the fire door under the reverberatory roof, and then spread back over the incandescent fuel beyond. The coking of the coal at the front of the furnace distills off the volatile gases which burn under the furnace roof before passing among the tubes forming the heating surface. Bituminous coal, which contains a large percentage of volatile matter and a relatively small amount of fixed carbon, is best burned by stoking light and often and covering about one-quarter of the grate at a time. The fire should be from four to seven inches thick to obtain the best results. Cleaning. — The efficiency of boilers must be preserved by keeping the heating surfaces clean, both externally and internally. By means of a steam lance and a flexible hose, provided with the boilers, the soot may be almost entirely removed from the tubes, the lance being inserted through the dusting doors in the side casing. In this way the boilers may be cleaned without interfering with the stoking. On arriving in port, the boilers should be swept out, and all deposits of soot removed. When time in port will permit, the hand hole plates opposite the tubes in the vicinity of the furnaces should be removed, and the interior surfaces examined and washed out ; and, if any undue accumulation of scale has taken place, it should be removed by the spoon scrapers or wire brush. Tubes have been known to blister and crack, and upon removal found to contain only an eggshell of scale thinly deposited over their entire inner surface. Had these tubes been closely examined, before removal, by means of an electric lamp or torch, a small laminated hummock of scale would have been discovered directly over the blister or crack. These small bunches are composed of flakes of scale that have become loosened from other parts of the boiler and carried with the circulation until dammed in some portion of the tube. As these bunches are loose, they may be easily dislodged by 127 washing out with a hose. Scale burns are most likely to occur when the feed water contains sulphate of lime or when salt water is used for make-up feed. If the water has a tendency to form a hard scale, such a scale should be removed with the tube scrapers provided. One thirty-second of an inch of scale is the maximum thickness that should be allowed upon the heating surface. STEAM TUG "EDNA G" Owners : Duluth & Iron Range Railroad. Babcock & Wilcox Boilers, 550 Indicated Horse-power. Breaking Ice in Duluth Harbor Blowing Off. — Boilers should be blown through the bottom blow valves, at least twice a day, and through the surface blow valve, or scummer, once a watch. Opening these valves wide and immediately closing them is usually sufficient. Bottom blows should be used freely after the boilers have been standing with banked fires or quietly steaming. At such times blowing should be more frequently attended to, as the circulation is less active and there is more opportunity for scale-producing deposits to settle on the heating surface. 128 PLUG EXTRACTOR Repairs. — In order to remove a tube, select a narrow ripping chisel from the tool box furnished with all instal- lations, and slit both ends of the tube lengthwise to a depth a short distance beyond the tube seat ; close the expanded portions in, and, after loosening, the tube can be driven out. Care should be taken not to mar the seat in the wrought-steel header into which the tube is expanded. The process of removing and renewing tubes is the same as that employed in Scotch boilers, but avoids the necessity of beading over, as the ends are not exposed to the action of the flames, nor the tubes used as stays. To save time in cases of emergency, tubes may be stopped with a conical cast-iron plug supplied for the purpose. As the plug fits the tube, only a few raps with the hammer are necessary to make it tight. The large end of the plug is drilled and tapped, and may be easily withdrawn by the extractor, consisting of wrought steel bridge, bolt and nut, furnished with the boiler. When tubes become defective, they are generally renewed, as the time required is but a trifle longer than that of plugging. The expanding of the tubes is performed in the usual manner with expanders and mandrils provided. In re- placing any of the short tubes, or nipples, between the headers and mud drum, or headers and steam and water drum, care should be taken that the projecting ends are swelled with the expander. All tubes and nipples should extend beyond their expanded seats one-half an inch. EXPANDER IN POSITION URK Docks at Two Harbors, Minn. 129 TESTS OF BABCOCK & WILCOX MARINE BOILERS ^^^^^^I^^^^THE object of testing a steam boiler is to determine the ^M quantity and quality of steam it will supply continuously ^^ and regularly, under specified conditions ; the amount of ^/ fuel required to produce that amount of steam, and some- ^? times sundry other facts and values. In order to ascertain ^f these things by observation, it is necessary to exercise great care and skill, and employ the most perfect appa- ratus, or errors will creep in sufficient to vitiate the test and render it of no value, if not actually misleading. The principal points to be noted in a boiler test are : 1st. The type and dimensions of the boiler, including the area of heating surface, steam and water space, and draft area through or between tubes. 2d. The style of grate, its area, with proportion of air space therein ; height and size of funnel ; area of up-take, etc. 3d. Kind and quality of fuel ; if coal, from what mine, etc. ; percentage of refuse and percentage of moisture in fuel. The latter is a more important item than is generally understood, as in adding directly to the weight, it intro- duces an error in the final results directly proportioned to the per cent, of the fuel. 4th. Temperature of feed water entering boiler, and temperature of escap- ing gases. The temperatures of fire room and of external air may be noted, but are usually of slight importance. 5th. Pressure of steam in boiler, draft pressure in furnace, at boiler side of damper, in up-take connection with funnel, and the pressure of the blast, if any, in the ash pit or stoke hold. 6th. Weights of feed water, of fuel and of ashes. Water meters are not reliable as an accurate measure of feed water. 7th. Time of starting and of stopping test, taking care that the conditions are the same at each, as far as possible. 8th. The quality of the steam, whether "wet," "dry" or superheated. From these data all the results can be figured, giving the economy and capacity of the boiler, and the sufficiency or insufficiency of the conditions, for obtaining the best results. For purposes of comparison with other tests, the water actually evaporated under the observed conditions per pound of coal and combustible and per square foot of heating surface per hour are reduced to " equivalent evaporation " from and at 212 degrees. (See page 97.) The standard boiler horse-power is equal to 34)^ pounds of water evapo- rated per hour from and at 2 1 2 degrees. The modern marine engine, however uses only about half a boiler horse-power for each indicated horse-power, and any calculation of the former quantity is of little use for marine purposes. 131 TESTS OF EXPERIMENTAL MARINE BOILER BUILT BY THE BABCOCK & WILCOX COMPANY AND INSTALLED FOR EXPERIMENTAL PURPOSES AT THEIR WORKS The following tests were made on this boiler under the conditions noted: By the late Chas. E. Emery, Ph. D., October 29TH, 1897 : Anthracite egg coal; closed stoke-hold blast. By Jay M. Whitham, Mem. Am. Soc. M. E., May 7TH, 1895: Pocahontas coal; closed ash-pit blast. By Ernest H. Peabody, Mem. Am. Soc. M. E., March 25, 1899 : Keystone coal with mechanical stoker ; natural draft. Engineer conducting test Date of test . C. E. Emery Oct. 29tli, 1897 Duration of test, hours .... Heating surface : 1337 in boiler 215 in li eater, sq. ft Grate surface, sq. ft. .... . Ratio of heating surface to grate surface Kind of fuel J Steam pressure by gauge, average, lbs. Force of draft in inches of water, closed stoke hold Force of draft in inches of water, closed ash pit Force of draft in inches of water at base of funnel, average Force of draft in inches of water in furnace, average Temperature of feed water, average deg. Fahr. Temperature of water from heater, average deg. Fahr Temperature in upper part of closed fire room, average deg. Fahr. .... Temperature of flue gases ... -j Per cent, of refuse in coal .... Quality of steam (by Barrus calorimeter with caJibration) ...... Average water per hour evaporated into dry steam under actual conditions, lbs. .Water evaporated per pound of coal, from and at 212°, lbs. Water evaporated per pound of combustible, from and at 212°, lbs Coal per sq. ft. of grate per hour, lbs. . Water evaporated per sq. ft. of heating surface per hour, under actual conditions, lbs. Water evaporated per sq. ft. of heating surface per hour, from and at 212°, lbs Water evaporated per sq. ft. of grate per hour, from and at 212°, lbs 7K 1552 33-25 46.67 Lackawanna egg. Woodward Mine 200 +0.99 —0.49 +0.14 108.8 230.8 95-2 Antimony did not melt* 7.98 Dry 9619 8.36 9.08 40.29 6.20 7.21 33672 J. M. Whitham May 7th, 1895 24 1552 38.5 40.03 Pocahontas run of mine 154 +0.98 —0.54 —0.04 66.0 117.9 By Pyrometer 607° F. 5-38 Dry 12,493 8.29 8.76 46.9 8.05 9.67 3897 E. H. Peabody Mar. 25th, 1899 6.0 1552 457 33-96 Keystone run of mine "3 Natural draft — 0-35 —0.15 61.3 151.0 Bismuth melted* Lead did not 12.6 Dry 5270 10. II 11.65 137 3-39 4.07 138.2 • Antimony melts at 840^^ F.; lead at 625^ F., and bismuth at 510^ F. ARRANGEMENT OF BOILERS OF U. S. S. "ALERT" TESTS OF A BABCOCK & WILCOX BOILER BUILT FOR THE U. S. S. "ALERT"* TESTS CONDUCTED BY A BOARD OF NAVAL ENGINEER OFFICERS CONSISTING OF LT.-COM. GEO. W. McELROY, LT. W. W. WHITE AND LT. EMIL THEISS The "Alert"' will have two boilers placed side by side in the ship, with a passage- way between them, facing an athwartship fire room. The dimensions, over all, of the boilers are : Length at bottom of ash pit, 1 1 feet I inch; distance from boiler front to perpendicular from center of drum, ig}i inches; length at top from back end to center of drum, lo feet 5^ inches; width of boiler, 8 feet 9 inches; height from bottom of ash pit to center of drum, 10 feet 8^ inches. Heating surface, outside of tubes, square feet . . . . 2012 Heating surface in boxes, square feet ...... 93 Heating surface in drum, square feet 20 Total heating surface 2125 Grate surface (length of grate, 6 feet 4 inches) square feet . . 48 Ratio heating surface to grate surface 44 : i Air heater : Number of tubes (each 3 inches diameter and 6 feet long) . . 102 Heating surface in tubes, square feet 48 1 Area through tubes, square feet 4.3 Least area between tubes for up-take gases, square feet , . 7.25 Smoke pipe : Diameter, feet and inches . 3-6 Height, feet 48 Boiler : Weight of boiler, dry-weighed on car, complete, pounds . . 46488 Total weight of boiler and water, pounds 54638 The weight of water necessary to fill this boiler to 5 inches in gauge glass (which is at the middle of the drum), is 8833 pounds, or 8150 pounds for same level at tem- perature due to boiling water under 225 pounds pressure. DESCRIPTION OF TESTS Four separate tests were made, on April 11, 12, 13 and 14. The first was with cold air, closed ash-pit draft, and a steam jet in the smoke pipe. This test was intended to demonstrate the performance, under the conditions stated, of the boiler with the maximum consumption of coal that it is expected to reach in naval practice. The second test was with open ash pit, a steam jet being used in the chimney to produce a partial vacuum about equivalent to that due to the height of smoke pipe as on the ship, viz., about 0.45 inch of water. The third was with heated air, closed ash-pit draft, and a steam jet in the chimney. The blower drew the air through the heater tubes and discharged it into ■■' Extracts from the annual report for 1899 of Admiral Geo. W. Melville, Ex-Engineer-in-chief of the United States Navy. the back of the ash pit. The conditions as to draft, method of firing, and temperature of feed were as nearly as possible the same as in test No. i, the object being to establish the effect due to the heating of the air. In all the three preceding tests Cumberland coal was used. During the first and the greater part of the second test it was George's Creek coal. During the latter part of the second test, and throughout the third test, another shipment of coal, also Cumberland, was used. This last coal contained less slack and less surface moisture than the first, but all was of excellent and presumably of very similar quality. The fourth test was with cold air, closed ash-pit draft, and a steam jet in the chimney, and was undertaken to show the efficiency of the boiler using hard coal under moderately strong forced draft. Attention is especially directed to the comparative results of tests made Apni i^ in presence of the Board, and on April 19 by the firm. These two tests were made under nearly identical conditions as to draft, temperature of feed, and method of firing, except that during the test of April 13 the air heater was in use, while on April 19 it was not, and would seem to show that with the ratio of grate to heating surface, and the circulation of gases secured in the boiler under test, the up-take gases escape at so moderate a temperature that the air heater is of little value. The data of the tests, bearing on this point, are given in the table on the following page. The results of the parallel tests, with and without air heaters in use, made by the Board on April 11 and on April 13, are somewhat vitiated by the fact that the coal used was not from the same shipment in the two cases ; and, while from the same coal region, and presumably of very similar heating value, the first lot contained about 4.09 per cent, of surface moisture, and was composed of nearly 75 per cent, slack, while the second lot contained 2.77 per cent, of surface moisture, and contained much less slack — about 50 per cent. The following experiment, made April 22, in the presence of Lieut, (then Chief Engineer) G. W. McElroy, United States Navy, gives the time required for raising steam under the conditions stated. Fires were started with wood and oily waste in front. About one-half shovelful of kerosene was thrown on just after lighting the fires. Soft coal was used toward the end. The boiler was at atmospheric temperature when fires were lighted, the water at the temperature of 54° F. Its height in the gauge glass on starting fires was i^ inches. Almost immediately after the fires were started the circulation of the water began, as evidenced by the temperature of the different parts of the boiler. RECORD OF RAISING STEAM Time Lighted fire, i^ inches water in boiler gauge glass. Natural draft 11.42 Began to make steam. No pressure on steam gauge 11.44^ 5 pounds pressure on steam gauge 11.45 ^° pounds pressure on steam gauge 11.46X 20 pounds pressure on steam gauge 11.47 25 pounds pressure on steam gauge 11.48^ 40 pounds pressure on steam gauge 11.49^ 50 pounds pressure on steam gauge 136 w , iz: '/^ 1— ( Pi u, < o^ ^ o Ol, X X (J H u s u pa ^ < N 1— 1 ^ J C^:] t^ u h o < o — — ~ "^ = = =«= 3 .,- i-^g - f I ?S - r f : r^S-H 00 - - q ■«■ d 00 d d t^o r^ >D o c* ^ CO tn - OvOOO : ^ S. ^r *? 'i °. - • p^cc "— a»oo Oso o t^t^i . 00 tnC-S ■*«' " ' '*H3 2,g;g: _ VO.O - ' 2 vo - S'— -^"^ CQ^- « 4j« U— - C. . ^5 c^ ) - - 11 • t^oo ■ •^ - ■* q q doodCNOt^cqcioo c< - - ^ ,^ ^.s o „ M 01 ^2^ lo "* N vD \0 O _^ ^ I« ir> -o ui • • g N — sC .1 = N30 2-1 1+ : : - oo -00 nO O (^ r^ -* r^ ^00 t^ -^sO • O C p ".OO O O N ■* S r^oo "- « "■ •o m ^ c ^ o <^ o^n'S „ _ 00 O O ■» fO ^ 1-F t> insO N N ■^■gs^^S"^?; -■ ti <; 3 « - r^O -» u "^ — TJ c> q -_ - f«^ c o o — . ';^ 9 c y. O pnoo - m - S5 w o moo o 00 - M^ T :+ : :S: K ; C» O rood in r^ <> C O ^-.i n3 ts eic*' « e.S '£ ?. « ^•■2. ■3-£ •■s. ■ I I ■ ? ".S E fo o f^ • mi M) Do C CD o£s gS-t: »n o »n ■» moo N ■* I Q O' t^oo' d E S 3 « «« > E O rt 03,?' E >< IE 137 RECORD OF RAISING ^TE\M— Continued Time 1 1. 51 65 pounds pressure on steam gauge. ii-5^M^ 75 pounds pressure on steam gauge 11.52^ 100 pounds pressure on steam gauge 11.53 105 pounds pressure on steam gauge 11.53^ 125 pounds pressure on steam gauge •'•54M^ 150 pounds pressure on steam gauge 11.553^ 175 pounds pressure on steam gauge 11.56^ 200 pounds pressure on steam gauge "•57^ 225 pounds pressure on steam gauge. 4)^ inches water in boiler gauge glass. Put on blower 5^ inches water in boiler gauge glass. Safety valve blowing. Stopped blower The table contains the calculated results and final averages. The evaporation has been figured out on the basis of dry coal and combustible consumed, and water evaporated into steam of the calculated quality. On the completion of the tests the boiler was thoroughly examined inside and outside. The grate bars and bearers had not suffered the least injury, nor did the fire-brick back, or the fire-brick baffles supported upon the row of 4-inch tubes over the furnace, show signs of distress. The entire outer casing plates opposite the tubes were removed on one side and the magnesia and fire-brick lining taken down, exposing the tubes and making possible an examination of the sectional vertical baffles. These, as well as the inclined deflector in the space above the tubes, were found in perfect condition. The edges were sharp and no warping was noticeable. The 4-inch tubes immediately above the furnace were perfectly straight. Generally speaking, the tests conducted must be regarded as most satisfactory. The boiler did its work under natural and under forced draft with good economy and without distress. The comparatively low temperature of the up-take gases during all the tests both with and without the air heater in use seems to indicate that the air heater is not a necessity in combination with a boiler of the design in question, and can not be considered a desirable adjunct except possibly when working at very high rates of combustion. 138 C/3 h O en Z 1—1 O z o OS CO < h < C/3 o a: <« O ■a 1 O 3 65 •^ o r-» VO V 00 o t- O -^ O r>. 8n o t 7 ro C\ 1 fO 1 00 \o ro a:s cn o >- N VO vp o VO Cn 00 VO ri ON _« 05 fO rj- VO o VO 1 lO VO ■!■ t^ o 1 1 4- O vq 00 O t^ to S 1 N N o VO ro 1 On ro 00 VO •1- o ? ro N I PJ \o PJ o 00 o - ro VO 00 o p« r *^ ro ro 1 ro o% "" ■^ io S ^ c^ S "b 00 1 > V — : S vO lO »o -* J?l 1> „ o 00 o o 00 to pj NO o 1 * O Tj- ro fO ■<*• 1 r< o ■^ o On M ro M On o 1 M N ?is o TT ■^ •o M M X r^ ro 1 :^ 00 ro ro is <" T 00 ^ 1 ro VO r^ O \o VO VO 4) is « O o r^ o M taM 00 O VO ro o %. Ov NM fO fO r^ 1 N o i_^ o r^ 00 pj t^ o ero 1 T M t^ ? ro ro VC VO N 2 r^ ^ 3 00 > " ' „ to m ■o 00 NO VO " t^ o M r- ^ X. o\ ^ ' N ' t^ fO ■. 8n VO 0) r^ 00 00 o VO 00 M " to VO o VO s T N "" ro ro tT VO V i IS N i Z u t: JS I>» ro ^ VO o r^i tfi t^ N \q o 00 M vq ro ^^ VO o s» Cs VO ■ ^ a. (U • C tn 3 ■£ o -a • u V is 9- O 0) •J. ■6 o 73 d o O [3 0) 1) 60 V ^ ■S w £- IS 0) c c ■J? 1 tr. ' o u ■a 0) (A o 4J o S ■Ji CJ 73 60 c 'c 0) a, O 2 (U c S O c c _o g VM o _5 IS 0) a IS o tti o 1 *>> o S ,o -5 s 0) O 60 S 4J 5 "o .2 c 5 Q c/3 yj 73 o ^ 5 r" '^ E o a: 23 fe 73 -/ 73 139 ARRANGEMENT OF BABCOCK & WILCOX BOILERS IN LARGE LAKE CARGO STEAMERS 140 CO OeS W S < tti H V) "x" u W 'o t^ ^N^ < U ^ ■^ o H o u U~\ ^ \o <^ b .^ O o o u >• :^ oi W iz; ^ f— t ■f re T3 o H CD to -0 g§5> •^ -.s spsssA JO psads CO 00 00 fc ■*• :? =■ 00 1 ? •id 'bs "d d 'H 1 !> ? i • - §8 o ^ ^ o d d H I l«»oi o 1 so o oo o t^ i 00 ? cc IN. « O ^3 pUE XUOJJ SUOI) JEtHDV xiuQ -Sua "•BIM d H I aad •jfi jad iajB^V a. I. ^ V &• « 3 3 ^ oa, ■3u3 uiEjv d H I ■"3d l«JOX 00 00 o dH I ■■3d ajEJO •U'>S-"d IBJOX I saaiiog I SUU3} -«■ o ■«■ I* \0 t^ t^ 3}nat]^ jad 'SAa>{ sai(3ui uinnDE\ 3 — E§ d T «I d IP^ni ■aan sjanog IV sjnoH jsax }o nopcana «l V E « oo 00 o r^ O TESTS OF MACHINERY OF S. S. "PENNSYLVANIA" At the request of Mr. A. B. Wolvin, of Duluth, the Babcock & Wilcox Company installed its testing apparatus on board the Minnesota Steamship Company's new steamer " Pennsylvania "* for the purpose of making a series of tests of that steamer's machinery. Advantage was also taken of this opportunity by the Navy Department to secure exact data regarding the economy of the boilers, the steam consumption of the main engine and auxiliary machinery, and the working of the mechanical stoker with which the ship was fitted. Accordingly, Lieutenants B. C. Bryan and W. W. White were detailed by the Bureau of Steam Engineering to make a trip with the ship and conduct the trials. The results obtained were published in Vol. XL, Part 3, of the "Journal of the American Society of Naval Engineers," from which we quote the following : " The main propelling engine is of the vertical, direct-acting, inverted, jet-condens- ing, quadruple-expansion type, designed for a maximum horse-power of about 2000. Number of cylinders, unjacketed . . . . . . . 4 36>^ f High-pressure J First intermed I Second intern (^ Low-pressure Diameter of cylinders,! First intermediate-pressure in inches j Second intermediate-pressure Stroke, inches .... Diameter of piston rods, inches 56 40 4K " Steam is supplied by two boilers of the Babcock & Wilcox water-tube marine type, built for a pressure of 250 pounds. Each boiler is 9 feet 3 inches long, 12 feet 6 inches wide, and 16 feet 8 inches high, containing 3000 square feet of heating surface and suitable for 65 square feet of grate surface. Weight of boilers, dry, pounds ....... 145,860 Weight of water contained, pounds ...... 33,492 Total weight of boilers and water, pounds 179,352 "All steam-generating tubes are 2 inches in diameter, No. 10 B. W. G. in thickness and 7 feet 3 inches long, the connecting tubes being 4 inches in diameter and No. 6 B. W. G. in thickness. The sides of the boilers are formed by 2-inch tubes inclined the same as the generating tubes, but placed one above the other and expanded into straight manifolds or corner boxes. " Three mechanical underfed stokers are fitted to each boiler. These were installed by the American Stoker Company. " The particular coal handled on these trials was from the Essen mine, in western Pennsylvania. It contained a large percentage of refuse, and therefore afforded an excellent opportunity of illustrating any superiority in stoking which a mechanical device would give over hand firing. A test of a sample of the coal used gave, by a Mahler bomb calorimeter, 1 1,790 B. T. U. per pound of dry coal. * The name of this vessel has since been changed to " Mataafa." 143 "In all, eight tests of the main engine were made. No. i, No. 2, and No. 5 are similar, and representative of the usual power developed under ordinary steaming conditions of the vessel. Test No. 3 was made with almost maximum high-pressure cut-off ; test No. 4, cutting off very nearly as short as the high-pressure valve gear would permit. "■ Tests No. 6 (a, b, c) were undertaken with the sole aim of ascertaining the economy of the main engine when working under reduced boiler pressures, no account of the coal used being recorded. "The results of these tests are not strictly comparable, on account of the irregular operation of the air pump, causing, as will be seen from an inspection of the tables, considerable variation in the vacuum obtained on the different tests. A more satisfactory comparison would have been possible had the vacuum carried been about the same at all times. " Previous to beginning the above tests the dead plates of the furnace were thoroughly cleaned of clinker. The same operation was repeated about an hour before each test ended, particular attention being given to have the fires, as nearly as could be judged by the eye, in the same condition at both the beginning and the end. Each test was begun and finished with the stoker hoppers entirely filled ; coal fired during the interval covered by the test was accurately weighed on a platform scales. " During the tests all water fed to the boilers was delivered by the air pump through a 4-inch pipe connection from the overboard discharge of the (jet) condenser, into the upper of two tanks in the engine room, which latter were specially installed for the tests. The upper tank was mounted upon platform scales, and water flowing into it could be regulated or shut off, as desired, by means of a valve. Each tank of water, after weighing, was dropped by gravity to the lower tank, from which a suction pipe of about 8 feet in length led to the feed pump. " All tests began with the lower or feeding tank full, and ended in the same way, " A Barrus throttling calorimeter attached to the main steam pipe near the high- pressure cylinder was used to determine the quality of steam supplied by the boilers, and readings of the upper and lower thermometers were recorded. " The moisture in the steam, as figured, after making due allowance for condensation in the instrument, is so infinitesimal as to be entirely negligible in the final results. The assumption has been made, therefore, that dry steam was furnished during all the tests. " The method adopted to determine the amount of steam used by the auxiliary machinery was to condense the exhaust steam therefrom and weigh the resultant water. This condensation was accomplished by means of a cylindrical exhaust feed- water heater, of the surface condenser type, containing thirty-eight 2-inch tubes 9 feet long. The feed water on its path to the boilers passed through these tubes and condensed the exhaust steam from the auxiliaries, which was directed into the shell, and at the same time elevated its own temperature proportionately. In order to reduce the temperature of the drain from the feed heater, it was led to a coil contained within a barrel. A stream of cooling water ran into the barrel and overflowed into the bilge. Mounted upon platform scales, was another barrel which received, by gravity, MS 1 - \D 00 O-OO OS iz; Oh o u CO h CO < O CO O fa o CO h CO H fa O D CO ■^ C O Q tri u^ (^ 00 ro T 0*nO ^ ■* -^f-NO t^ ^ 00 « 00 sD vO O t^co -I ^;s 1^ T> c t ■% H . -^ M I-. fo ^ O (^ « « - », HH O "- O • • • r5 C 3 -00 O C ™ aTJ r^ tl£ - « « ^ moo N O 00 w t>. t^ o -"t o ■^fOM fot>.m-00' fesllh^» 00 MOO t^ m — i« -s D. o -E-s N •SiiSs3^3? I"^.E^"S- »o\D t^ ■* r>. ( r> 00 ■* 5> rOsO t^ O^-JD "* "* < * t^ ■* O^ ■* O inoo 00 00 d M rt 2" :? "^ ''' ^ 2 O O^ O h* « ' mO ro O m ► ■^ in o^ "^ 55^ C 3 O'O' H^ Ofi 146 the condensed exhaust steam from the auxiliaries. As soon as the weighing barrel was filled the inflow was momentarily stopped, the weight taken, and then the con- densed water rapidly discharged into the bilge. "On May 28, three special tests were run, with the view of fixing the steam consumption of the fire-room blower and air pump, and incidentally the total steam necessary to operate the several auxiliary pumps and the steering engine, which were in use during all the tests. The power developed by the main engine, and the average weight of coal burned were about as shown in test No. i. STEAM CONSUMPTION OF AUXILIARY MACHINERY Auxiliary Steam Consumed per Hour (Pounds) Air pump ........... 721 715 828 613 Feed pump 487 468 595 350 Bilge pump 275 275 320 240 "Water-service pump 146 154 156 150 Auxiliary pump 330 Starboard dynamo 480 480 Port dynamo 671 Steering engine 125 125 125 125 Fire-room blower 622 692 2909 725 550 Total . 3377 3229 2028 " To determine the amount of steam used in operating the stokers, the exhaust from one was led into a barrel containing a previously weighed quantity of water, and there condensed. Two tests, similarly made, gave 22.5 and 23.7 pounds, respectively, or an average of 23.1 pounds, as the hourly consumption. For all stokers the steam used per hour would, therefore, amount to 138.6 pounds. " The cost of operating all stokers and the blower is found to be 4.29 per cent, of the total steam generated. By reason of the blower exhaust passing through the feed heater, however, the actual net cost of the stoker installation is equivalent only to 1.68 per cent, of the steam made." Attention of the reader is particularly called to the high evaporation obtained from and at 212"^ per pound of coal, the average result of five tests being 8.86, which is especially good when it is remembered that the coal burned contained only 11,790 B. T. U. per pound. The average eflficiency of the boiler is therefore 72.6 per cent. Again, the coal consumption per indicated horse-power would have been materially reduced had it been possible to maintain a better vacuum, the highest reading recorded being only 24.35 inches, while the average was only 23.5 inches. 147 c o S < TESTS OF MACHINERY OF S. S. "ALEX. McDOUGALL"* Under direction of the Bureau and by the courtesy of the officials of the Minne- sota Steamship Co., two tests were made by Lieuts. B. C. Bryan and W. W. White, U. S. N., of this Bureau, of the main machinery of the steamer " Alexander McDougall," at present the largest whaleback in service on the Great Lakes. The main engine was designed for a maximum horse-power of about 2500 and is similar in arrangement and all essential features to the engine of the " Pennsylvania." The auxiliary machinery, however, differs from that of the " Pennsylvania," in that the air, water service (cooler), and bilge pumps are attached to the low-pressure cross-head of the main engine ; the feed pump (Deane), is independent, duplex, of the horizontal compound tandem-plunger type, having steam cylinders of 8 and 12 inches, respectively, with water cylinders of 5 inches, and a common stroke of 10 inches. Much of the other auxiliary machinery is practically the same on both ships. Data of Main Engine Diameter of cylinders, inches (all rods 5X-ir>ch diameter) Stroke, inches ......... Xet piston areas, square inches Ratios of net piston areas ...... Clearances, per cent. . High- First Inter- Second In- mediate- termediate- pressure pressure 19 28;^ 43 40 40 40 272.7 627.12 1441.38 I : 12.51 I : 5.42 I : 2.36 15 II 10 Low- pressure 66 40 3410.38 I 9 Steam is supplied by two boilers of the Babcock & Wilcox marine water-tubular type, built for a pressure of 250 pounds, containing 7000 square feet of heating and 128.8 square feet of grate surface. Two small one-cylinder (5 by 5) blowers, one for each boiler, with an inlet through heaters in the up-take and delivering at the back of the ash pits, supply the necessary air under forced draft for combustion of the fuel, which latter is hand- fired. Two tests were made on the down trip, one on Lake Superior and the other on Lake Huron. The vessel was loaded with a cargo of 6407 tons (2240 pounds each) of iron ore, and had in tow the barge " Constitution," laden with 5164 tons of the same material. The method of weighing the total water fed to the boilers, and ascertaining the steam used by the auxiliaries was, substantially, the same as in the tests of the ma- chinery of the " Pennsylvania." A summary of results obtained appears on page 151. At the beginning of the test on July 2 i, the following auxiliary machinery was in operation : Feed pump, steam-steering engine and both fire-room blowers. By reason of the feed-water heater being entirely too small, excessive back pressure resulted, and the fire-room blowers were stopped (in use one and one-fifth hours) after it became evident that steam could be readily and easily maintained at the usual pressure with- out their aid. The average hourly weight of condensed exhaust steam collected during five hours of the test, with the feed pump and steering engine only in use, amounted to 1685.4 pounds. For the purpose of fixing the steam economy of the feed pump during the last two and one-fourth hours of the test, the steam steering engine was thrown out and the ship steered by hand. Under the latter conditions, an average of 1 174.7 pounds of condensed exhaust steam per hour resulted. During the entire test on July 23 the only auxiliary machinery in operation was the feed pump and fire-room blowers. * Extract from the annual report for i8gg of Admiral Geo. W. Melville, Ex-Engineer-in-chief, U. S. N. 149 SUMMARY OF TRIALS— S. 8. "ALEX. McDOUGALL" Date of trial, 1899 Duration of trial, hours Speed of vessel, miles Draft of vessel during trial, forward, feet Draft of vessel during trial, aft, feet Revolutions of engines Piston speed, feet per minute f Boiler I At engine . Pressures per gauge . -i First receiver Second receiver [ Third receiver Vacuum in condenser, inches of mercury Opening of throttle .... C High-pressure Steam cut-off in fractions J First intermediate-pressure of stroke . Mean pressure ders . cylin- Indicated horse-power I Second intermediate-pressure [ Low-pressure Nominal ratio of expansion 'High-pressure First intermediate-pressure Second intermediate-pressure Low-pressure Equivalent reduced to low-pressure f High-pressure I First intermediate-pressure ■^ Second intermediate-pressure Low-pressure [Total Per cent, of total indi- C High-pressure cated horse-power de- J First intermediate-pressure veloped in each cylin- | Second intermediate-pressure der . . . . [ Low-pressure C Injection .... Temperature, in degrees! Hot-well .... Fahrenheit . . j Feed water after passing heater [ Escaping gases at base of smoke pipe Double strokes of feed pump Revolutions of the \ Port . blowers . / Starboard . Air pressure, boiler ash pits, inches of w^ater Kind of coal Total amount of coal consumed, pounds Moisture in coal, per cent. . Dry coal consumed, pounds . Total refuse in coal, pounds . Total combustible consumed, pounds . Quality of steam ..... Weighed water pumped to boilers, pounds Water evaporated per pound of dry coal, boiler conditions, pounds Water evaporated per pound of combustible, boiler conditions, pounds Equivalent evaporation, per pound of dry coal from and at 212° . Equivalent evaporation, per pound of combustible, from and at 212 Dry coal burned per hour per square foot of grate surface, pounds Total steam used by main engine, pounds ..... Total steam used by auxiliary machinery, as weighed, pounds Steam used by main engine per hour, per indicated horse-power developed pounds ........... Total steam used (all machinery in use) per hour, per indicated horse power developed by main engine ...... Dry coal used per hour per indicated horse-power to generate necessary to run main engine only, pounds .... Dry coal used per hour per indicated horse-power, developed by engine to generate steam required to operate all machinery in use steam 18.00 75-4 502.7 247.8 245 96.8 331 2.09 22.35 Wide •53 .56 •63 •66 20.04 93-4 36.1 iS-5 6.85 27-57 388.15 345^29 342.85 357 1 433^29 27.08 24.09 23.92 24.91 46 117 170.6 543^6 26.1 * * t t 27200 5 25840 2967 22873 Dry 223996 8.67 9-79 9-58 10.82 20.06 207764 1623: 14.50 15-63 1.67 1.80 July 23 6 9-75 1783 18.00 81.7 544-7 244 240.7 107.5 35-2 3-2 22.4 Wide .685 .625 •655 .725 16.39 1 00.90 4456 18.88 8.3 1 32.60 456.94 459 55 452-52 466.94 • 835^95 24.89 25-03 24.65 25-43 64 "5 157.8 526 29.7 391 383 .25 t 19500 5 18525 1710 1 681 5 Dry 165980 8.96 9.87 10.02 ir.03 23-97 157346 8634 14.28 15.07 1.59 1.68 • Not in operation, t Natural draft, t Run of mine, Pittsburg bituminous. 151 < I— I t; - o c/5 ?, TESTS OF A BABCOCK & WILCOX BOILER BUILT FOR THE U. S. S. " CINCINNATI" =^ In the annual report of the Chief of the Bureau of Steam Engineering there is published a report of tests made on one of eight new boilers built by The Babcock & Wilcox Company for the " Cincinnati," by a board composed of Lieutenant-Commander A. B. Willits and Lieutenant B. C. Bryan, U. S. N. These tests were made June 15 to 22, 1900, at the works of the builders, Elizabethport, N. J., and the following synopsis includes all but the detailed tabulations from which the important data given was deduced." DESCRIPTION OF BOILER AND APPURTENANCES The boiler is of the Babcock & Wilcox new marine type, composed entirely of wrought steel, the point of difference between it and the older type of this make of boiler being in the arrangement of baffle plates (as shown in the sectional view on the following page) which compel the products of combustion to pass three times across the tubes before entering the up-take. The small tubes are 2 inches outside diameter, while the bottom tube in each section or element, is 4 inches outside diameter. The total heating surface is 2640 square feet. The grate is an undivided area of 63.25 square feet, and is fired through four properly spaced doors. BOILER DATA Kind of boiler, Babcock & Wilcox — " Alert " type. Diameter of top drum, 42 inches, inside. Length of top drum, 12 feet. Tubes: total number, 565 ; length, 8 feet (525, 2 inches outside diameter, and 40, 4 inches outside diameter). Grate surface : length, 6 feet Sj^ inches ; width, 9 feet 5}^ inches ; area, 63.25. Grate surface reduced in tests Nos. 5 and 6, to 5 feet 6 inches; 52 square feet area. Heating surface: area, 2640 square feet; ratio to grate, 41.74:1. Per cent, water-heating surface, 100. Grate bars: kind, fixed. Smoke pipe: area, 7.876 feet; height, 48 feet above grate; ratio to grate, 1:8.03. Weight of boiler and all fittings except up-takes and smoke pipe : Without water, jjounds ...... Water, 5 inches in glass ; steam at 215 pounds, pounds Total with water, pounds Total weight per square foot of grate surface, pounds Total weight per square foot of heating surface, pounds 53304 9498 62802 992.9 2379 Blower: kind, 60-inch Sturtevant, driven by belt from shop engines. Area of blower inlet, 9.62 square feet; outlet, 6.89 square feet. Feed water: kind, feed water heated by steam jet. Air heater: kind, two-pass; 3-inch tubes. Area of surface, 495 square feet. Feed pumps: kind, Worthington duplex; dimensions of cylinders, 7^ by 4; 6-inch stroke. Other boiler appurtenances: steam jet. The boiler was erected in a wooden structure built especially for the test and having the following dimensions : Length, 29 feet 2 inches ; width, 17 feet 2^ inches ; ' •Extracts from the " Journal of the American Society of Naval Engineers," Volume XII. height, 2 1 feet. This was made as nearly air-tight as possible, but contained several windows that could be opened or closed to regulate the amount of draft pressure. The blower was driven by belting from the main shop engines and ran continually. An air heater was built in the up-take by means of which the waste gases imparted heat to the air on its passage to the ash pit. This heater could be placed in and out of service at will by the use of a by-pass flue. "Cincinnati's" Builer — B. & W. "Alert" Type. Section Showing Path of Gases DESCRIPTION AND OBJECT OF TESTS Seven tests were made in all. Six of these consisted of three pairs, in which the tests of each pair were made under similar conditions in every way except that of using the air heater, one being with and the other being without this heater, in order to define the economy due to its use. The last or seventh test was for maximum capacity, and was made without the air heater and with the full grate. Two pairs of tests, one at a consumption of about 20 pounds of coal and the other at about 35 pounds of coal per square foot of grate per hour, were made with the full grate surface in use. These tests will be found in tables of results numbered i, 2-H, 3-H, 4, the letter H signifying that the air heater was in use during the tests. The grate surface was then reduced to 52 square feet, by a course and a half of bricks, seven courses in 154 height, at the back of the furnace, and tests Nos. 5 and 6-H were made, burning about 50 pounds of coal per square foot of grate per hour. Tlie bricks were then removed from the furnace and test No. 7 was made, burning nearly 60 pounds of coal per square foot of grate per hour. The data and results of these tests will be found in the table on pages 158 and 159. COAL AND FIRING The fuel used was Pocahontas, Flat Top, coal. It contained considerable slate and clinkered badly. On tests Nos. i and 2-H run-of-mine coal was used ; on tests Nos. 3-H, 4, 5 and 6-H the coal was screened, using a screen with a i-inch mesh. On test No. 7 the screenings from the former tests were run over a ^-inch mesh screen, and the coal thus screened was mixed with the screened coal used in other tests. The firing was good and very regular. Two alternate doors were fired in rapid succession. The other two sections of fires, in wake of the other two doors, were sliced through the slicing door, and then leveled with a hoe, and then coaled, the average time between coalings of the same two furnaces being from eight to ten minutes. The furnace doors were open about twenty-five seconds when coaling and about ten seconds in leveling. The coal made comparatively little smoke except when firing or working fires. The data in regard to smoke was taken by using Ringelmann charts. DESCRIPTION OF APPARATUS The water was weighed in two tanks, each supported on a platform scales and run into a third tank below, from which the feed pumps drew water. All pipes were above ground and in plain sight, and wherever connected to other piping or boilers plugs were left out of T connections to show that there was no leakage. The gross and tare weights of each tank were taken, and the temperature was taken at the lower tank just as each upper tank drained into it. The feed water was heated by steam injection before entering the weighing tanks. The coal was weighed in barrows on platform scales in the fire room and dumped on the floor. The time was taken when each lot of barrows were fired. A sample shovelful of coal was taken from each lot of barrows and thrown into a barrel, and from this, mixed and quartered, the final samples for analyses, calorim- eter and moisture determinations were taken. The gases for analyses were drawn from near the center of the base of smoke pipe by means of a pipe inserted therein connected with an inspirator and a small Orsat instrument. All draft pressures were taken outside the building, pipes being led there from the different places where pressure determinations were required. Temperatures were taken at the back and front of the up-take just above the heater ; in front by a mercurial pyrometer, and at the back by a metallic pyrometer. When the air heater was used the temperature was taken in addition just below the heater by means of a mercurial pyrometer. The moisture in the steam was determined by a Barrus universal calorimeter. The steam was found practically dry in all cases. The steam was partly used in the shop and partly blown off into the atmosphere, the pressure being controlled by regulating a small stop valve by hand. 15s BARTLETT 4 CO., N.Y. June 19, 1900. — Without air heater, full grate. Coal per square foot of grate per hour, 35.08 pounds. Water per square foot of heating surface, from and at 212°, 8.75 pounds. June 20, igco. — Without air heater, reduced grate. Coal per square foot of grate per hour, 30.38 pounds. Water per square foot of heating surface, from and at 212°, io.o7 pounds. Al. — Aluminum melts at . . . . . ii6o^ F. Sb. — Antimony melts at 840° F. Zn. — Zinc melts at 780° F. Pb. — Lead melts at 625° F. June 22, 1900. — -Without air heater, full grate. Coal per square foot of grate per hour, 59.2 pounds. Water per square foot of heating surface, from and at 212°, 13.67 pounds. June 25, 1900. — Without air heater, full grate. Coal per square foot of grate per hour, 20.18 pounds. Water per square foot of heating surface, from and at 212°, 5.42 pounds. TEMPERATURE OF GASES PASSING THROUGH BOILER AS SHOWN BY MELTING POINT OF METALS— TESTS OF "CINCINNATI" BOILER 156 Experiments to show the heat of the gases at various points were made by noting the points at which different metals melted. A small piece of metal was wired to a piece of 5^ -inch pipe, and pushed in carefully through the dust doors at the side of casing to about the middle of the boiler ; by noting where such metal would melt, and again introducing a piece of the same metal at another hole further along in the path of the gases until a position was reached when the metal would not melt, and by the use of various metals with known melting points, the temperature of the gases was determined and is plotted on the diagrams on the opposite page. Before making test No. 6-H, on June 2 ist, all water was drained from the boiler and the contents of boiler noted for each i-inch mark of the water gauge glass, with the following results : WEIGHT OF WATER CONTAINED IN BOILER Temperature of Water, 72 Degrees Fahrenheit Height of Water in Gauge Inches Total Water Pounds Difference Height of Water in Gauge Inches Total Water Pounds Difference I 2 3 4 9312 9498 9662 99' 2 10137 186 164 250 225 1 7 8 10368 10672 10943 II175 231 304 271 232 Fires were started in the boilers with light wood, and blower in use, at 9:40 A. M. Temperature of water in boiler, 72 degrees; height in gauge glass, i inch. The following is a record of the time required to raise steam to 215 pounds pres- sure from cold water : RECORD OF RAISING STEAM Time Time Steam Pressure Pounds Steam Pressure Pounds By Watch Elapsed By Watch Elapsed 9:40 Fires started 9:51 1 1 mins. sees. 125 9:45 5 mins. sees. Steam formed 9:51:10 1 1 mins. 10 sees. 135 9:46:30 6 mins. 30 sees. 25 9:51:15 1 1 mms. I 5 sees. 145 9:47:30 7 mins. 30 sees. 35 9:51:30 II mins. 30 sees. 155 9:48 8 mins. sees. 45 9:51:40 II mins. 40 sees. 165 9:48:30 8 mins. 30 sees. |5 9:51:5s 1 1 mins. 55 sees. 175 9:49 9 mins. sees. 65 9:52:10 12 mins. 10 sees. 185 9:49:30 9 mins. 30 sees. 75 9:52:20 1 2 mins. 20 sees. 195 9:50 10 mins. sees. 85 9:52:30 1 2 mins. 30 sees. 205 9:50:30 10 mins. 30 sees. 95 9:52:40 12 mins. 40 sees. 215 9:50:45 10 mins. 45 sees. "5 An examination of the boiler after this test showed no injury or change in its condition in any respect. In addition to the tests made for the Navy Department, three tests were made for The Babcock & Wilcox Company by E. H, Peabody, Mem. Am. Soc. M. E. The data and results of these tests are included with the others in the following table : 157 t^ •«• ro O^ \ \ \ ■ O k- lU Q ^ ^ ►-1 < « I 1 .a c » « O 0) c.S SB. M 00 ■* O^CO o 00 -r m^o t^ 5 fa o c CO E- co < u z t— ( "++ * O m bs ro O S N a I- a « ' -. < ^ 00 2; '+ + 4> vO ^- OJ - •^ -+. ++ 00 00 • • 00 00 vO ,2++ ++ • in fo m 00 Q^ ' to O fO Q v2 « ^ M \0 "'I art " "^ "oo e^ o ^- d vD (++ rSn^i 1"^ I+++ 4) ^ y C WM_ fc- re u u re (fl O ^ 'I' 3 rt o "o-S o'o c •"'c rt 3.S rt u E rt o - *j n ■" *- u ^ O^o o o B Q U V V V £ « £i Si H y rt S o o o o CQcA>x.fafafa -a = 3 o *j O.C s «* u u . 0) c 2 n, i_ •S " o^^ b JJ V. y oj -^ CI. « a-^^l - w . o e 3 « , c: "^ c- o r; o ><^ c " o "i~ o &> O p. CI c o ,„ i- "rt 5 Sis o o o o u u Co >,>^ >^ rs8 : S :§; .a 6 „ 6 U MS t) V 3 O-QO •^ m 00 00 00 00 00 O i-i o^ 00 m m 00 00 O S- o o - »o f*^ r^ 00 00 00 00 00 - »A0O _ o *, a- •V ^ o ft-O - 1* CO - o oo m »^ = = s. ■ o o "• « OJ u . OJ U i- ^ i .2 ^, is I. o a ^ 3 « > * « M „ tots n-c T3 n c u C IS be ;. c hT3 •^ o 5-i O j: ^ c o o u * o d. n. i! u c ^ o 1 o a o 5, 3 4) U) ., a ^ f^' 4) = V > 3 M u O a s > 3 > V 3 3 F w =->3 o 5 "_*<"- rt 3-3 pS = h P >i > P 8v? If a •3 •HZ Z « SB c 3 T a « ■s :S "5 o m 1=^. ;5 ^ K -r rt u • = U- IS t^ c o V', cs -a z o o be "^ !C '^- "^ S ^ ■5 C 4J u c 3 11 4> J! H c S ^ 2 2 ^ ;z a c 3 s bO bO >^ IC erf 3 '■^ 60 j= E >^.; - X - Ml be .- _ o vM s u: 3 S - tac O -« 2 -:: n p V c u V P y*^ Is-Q V, •X. T3 bt ^ iS 3 ^3 >. u < a S" 3 - - > be 2 ^ ^ 0) ^g * X ^ ^^ < •< < Id •Ei£ 1 a" 3 a UH 159 ANALYSES OF WASTE GASES MADE DURING TESTS OF U. S. S. " CINCIN- NATI" BOILER, ELIZABETHPORT, N. J., JUNE, 1900 Date Time Condition of Fire when Sample was Taken CO 2 CO Pounds Dry Gas per Pound Carbon 1900 f June 15- 4^S8 5-'5 5-30 5-55 6.16 6.27 7.05 "•45 12.50 1.50 3^50 11.25 12.40 12.50 12.58 1.03 10.10 10.25 10.28 io^35 11.00 2.20 2.40 10.25 11 .00 11.04 II. 13 12.25 12.36 11.00 II. 03 ".13 11.50 "•55 "•59 II. 21 "•4S 12.38 2.26 2.30 243 10. 16 10.21 II. 10 II. 13 11.47 Just before firing One minute after firing Just after raking Two minutes after firing Three minutes after raking and just before firing .... Average Just after firing Just after slicing . • Just after slicing Average One-half minute after firing While slicing • . . . . Just after slicing Just before slicing One minute after firing While slicing While slicing (all samples except ii o'clock collected through H-inch iron pipe) Just after raking One minute before firing While slicing (sample collected through glass tube) Just after raking Just after firing Average While slicing While slicing Just after firing Two minutes before raking . Just after raking Just after raking Just after raking One minute before raking Just after firing Just after raking One minute before raking Just before raking Average ........... Two minutes before firing Two minutes before firing Just before leveling and firing . . .... Just after firing Just after firing . Two minutes before firing Average Just before firing One minute before firing Just after leveling [ Just after firing Just after firing Average 15.2 »4^3 i 130 12. s «4-3 12.7 16.0 33 30 6.7 3-7 6.6 2.0 I.O 2.0 0.0 0.8 I.O 0.7 2.0 y 16.8 June i6-< 14.0 13-4 12.0 12.0 I3^2 4-S 6.4 5^o 6.6 4.8 I.I 0.0 I.O 0.2 0.7 J - 19. 1 June iS-i 12^7 12.3 14.2 •25 I3-0 '35 $•7 3-4 4.0 4^3 4.0 54 0.5 2.7 O.I 1.2 34 0.2 . i7^3 June 19- i3-« 15.0 13^8 14.4 13.2 13.0 10.2 10.2 4^2 32 5-2 3-1 5.6 5-6 8.3 9.0 15 1.2 0.6 0.9 0.4 0.6 0.5 0.3 1 - 18.8 June 20- 12.8 i3^S II. 2 10.4 9.2 12. 1 14.2 $•7 5^7 8.4 8.1 9.9 5-4 4.0 0.6 0.0 0.3 o^5 0.0 0.7 0.8 I 20.6 f June 2I-' II. 8 iS-7 13.0 JS^4 i3^6 13^0 16.0 6.9 4.6 6.0 3-0 5-6 53 4.2 0.4 0. 1 0.0 0.6 0. 1 0.4 0.0 ' 17-7 June 23-| ^•5 14^3 II. I'i'.'s i3^3 14.2 4^8 4.2 9.0 7-9 4.2 3.8 0.2 1. 1 0.0 0.4 I.O 1.0 - 18.6 June 25-^ 12.9 I5^3 13.0 >3^7 14.0 9.0 5^8 4^1 6.0 6.6 52 11.2 0.7 I.O I.O 03 0.8 0-3 - 18.S 130 6.6 o^7 , 161 TESTS OF A BABCOCK & WILCOX MARINE BOILER, BUILT FOR A SEA-GOING DREDGER FOR THE INDIAN GOVERNMENT (The tests were made at the Babcock & Wilcox Works, Renfrew, Scotland) Date, 1899 December 28 December 29 December 30 Duration of test, hours Heating surface, square feet Grate surface, square feet Kind of fuel used Kind of draft Amount of draft at root of funnel, inch .... Average gauge pressure, pounds per square inch Average temperature of feed water, degrees Fahrenheit . Mean temperature of gases in funnel, degrees Fahrenheit Total coaJ fired, pounds Total refuse, pounds Percentage of refuse ....... Coal fired per hour, pounds Refuse per hour, pounds ....... Combustible per hour, pounds ..... Coal consumed per square foot grate per hour, pounds Water evaporated per hour under actual observed con- ditions, feed water 40 degrees Fahrenheit, pressure 180 pounds, pounds ....... Equivalent weight of water evaporated per hour with feed at no degrees Fahrenheit, pounds Water evaporated per pound coal per hour, actual ob- served conditions, feed water 40 degrees Fahrenheit, pressure 180 pounds, pounds ..... Water evaporated per pound coal per hour, from and at 212 degrees Fahrenheit, pounds ..... Water evaporated per pound of combustible per hour, actual observed conditions, pounds .... Water evaporated per pound of combustible per hour, actual observed conditions, from and at 212 degrees Fahrenheit, pounds ....... Water evaporated per square foot heating surface, assum- ing feed at 1 10 degrees Fahrenheit, pounds . Water evaporated per square foot of grate area, assum- ing feed at 1 10 degrees Fahrenheit, pounds . Theoretical total heat value of fuel by Thompson's calorimeter, British thermal units Efiiciency of boiler, per cent ...... 8 8 8 2835 2835 2835 77 77 77 S Hetton (Newcastle) Natural Waynes, Merthyr (Welsh) Natural Black Ban (Scotch) Natural •35 180 -45 180 •4 180 45 635 15600 800 40 643 15600 1680 40 620 15600 2496 5-1 10.7 16 1950 1950 '95° 100 210 312 1850 1740 1638 25.32 25-32 25-32 16112 17700 15625 18013 19877 17546 8.26 9.08 8.01 lO.II II. 15 9-85 8.7 10.17 9-54 10.65 12.5 11-73 6.3 7 6.19 234 258 227 13460 13660 12870 72.6 78.9 74 Note. — The evaporation obtained showed the boiler to be of a capacity suitable for a 1200 indicated horse-power triple- expansion engine of economical construction, using 14 to 15 pounds of steam per indicated horse-power per hour. COAL CONSUMPTION TESTS OF S. S. " JOHN W. GATES "* Between October 10 and 15, 1900, tests were made on the lake steamer "John W. Gates," owned by the American Steamship Co., by Lieutenant-Commander J. H. Perry and Lieutenant B. C. Bryan, U. S. N. Four tests in all were made, of ten, four, eight and six hours' duration, respec- tively. During the tests indicator cards were taken from the main engines, and the usual observations of pressures and temperatures recorded. The coal was carefully weighed and logged on each test. * Extracts from " Journal of the American Society of Naval Engineers," Vol. XII. 163 Tests Nos. I and 2 were made with the vessel light, on the up trip, in Lakes Huron and Superior, respectively. Test No. i was made under the usual running speed of the vessel when light, and amounted to merely weighing coal and taking observations for ten hours out of the run. Test No. 2 was made using a steam jet in the smoke pipe to increase the draft. Tests Nos. 3 and 4 were made on the down trip, after having loaded at Two Harbors, Minn., with about 7000 tons of ore, the vessel drawing about 17 feet 10 inches of water. Test No. 3 was made at the usual running speed, and Test No. 4 with draft increased by steam jet in smoke pipe. The machinery of this ship was built under the supervision of the able Chief Engineer of the American Steamship Co., Mr. Joseph F. Hayes, and the great economy obtained is largely due to his care in the design and arrangement of the plant. The ratio of the high to low-pressure cylinder area is i to 13.22. Joy valve gear is used on the high and intermediate-pressure cylinders, giving in the high-pressure cylinder an admission of steam almost perfect, as is shown by the indicator cards therefrom. The cylinder ports are made large, while the clearance is reduced as much as possible. A feed heater is provided, into which all the auxiliaries necessary for heating the feed water are exhausted. The dynamo when running exhausts into the third receiver of the main engine, and all precautions have been taken to make these engines economical, and with great success, as is shown by the results. The type of Babcock & Wilcox boiler adopted, known as the "Alert" type, is one that the recent tests made by Government officials show to be exceedingly economical under various conditions. It is provided with baffle plates directing the products of com- bustion three times across the tubes before leaving the boiler. Each of the two boilers installed is 10 feet long, 11 feet 8 inches wide, and 13 feet 10 inches high, containing 3000 square feet of heating surface and suitable for 65 to 70 square feet of ordinary grate surface for hand firing. The total grate surface of all stokers is 108 square feet. The weight of the two boilers dry is io9,26opounds, and with water, 132,590 pounds. The bottom and top rows of tubes are 4 inches in diameter and all others are 2 inches in diameter. All tubes are of seamless cold-drawn steel, the 4-inch tubes being No. 6 B. W. G., and the 2-inch tubes No. 10 B. W. G. in thickness. The lengths between headers is 9 feet. The main propelling engine is of the vertical, direct-acting, inverted, jet-condens- ing, quadruple-expansion type. Number of cylinders f High-pressure Diameter of cylinders, J First intermediate-pressure in inches j Second intermediate-pressure [ Low-pressure . . . . Stroke, inches ........ Diameter of piston rods, inches 4 25 60 40 4H Order of cylinders from forward : (i) high pressure, (2) first intermediate pressure, (3) second intermediate pressure, (4) low pressure. Sequence of cranks : high pressure, low pressure, first intermediate, second intermediate. The high pressure and first intermediate pressure are at 1 80 degrees, as are the second intermediate pressure and low pressure, the former being at 90 degrees with the latter. There is one four-bladed propeller, 14 feet in diameter with 15 feet 6 inches pitch. Two mechanical stokers of the Crowe pattern were fitted to each boiler. This stoker consists, essentially, of a set of bars carried from front to back of the furnace, over a number of fair leaders, by two chains, one on each side of the furnace. At the back of the furnace the chains and bars pass over a drum and thence back over fair leaders to the front of the furnace again. 164 During the entire trip the stokers worked satisfactorily. During most of the time little or no smoke was emitted from the pipe except while the fires were being worked from the back, or when an additional amount of coal worked in under the plate in the front of the furnace. The air pump worked regularly and quietly, but for some reason, probably due to the large clearance required in the cylinders of this type of pump, the vacuum carried was not much in excess of 23)^ inches. Lead did not melt during any of the tests when suspended in the up-takes just over the top row of 4-inch tubes or practically where the gases leave the boiler proper. Lead suspended in the boiler where the gases leave the last row of 2-inch tubes melted on the test of October 15, but only softened on the tests of October 10 and 13. A proximate analysis of the coal used, gave results as follows: Fixed carbon . Volatile mattei Moisture Ash Per cent. 57.00 37.00 2.00 4.00 Heating value of coal by calorimeter The following table gives the data and results of the tests 100.00 13,180 B. T. U. COAL CONSUMPTION OF S. S. ' •JOHN W. GATES." Number of test I 2 3 4 Date, 1900 Oct. 10 Oct. II Oct. 13 Oct. 15 Duration of test, hours .... 10 4 8 6 Steam f At boiler 244 244 248 250 1st receiver .... 70= V"d'».-" .... ^ [3d receiver .... 107.8 324 "3-9 34-1 107.7 32-9 108.7 34-0 7-5 7-9 6.5 9.0 Vacuum, inches 24 23-3 233 23.0 Temper- f Engine room .... 83-5 82.7 80.0 76.2 ature, Injection water .... 61.3 53-6 50.0 61.3 degrees ) Hot well feed water entering heater "3-5 "3-9 "7-3 "5-3 F. [ Feed water leaving heater . 186.0 1797 187.0 186.5 Links in from f High-pressure . . . 30 -75 3-25 •75 f ., , . J 1st intermediate-pressure . 35 1.5 to 2.25 3-75 1. 00 ^. , ^' 1 2nd intermediate-pressure •"^^^^ [Low-pressure . . . 3-5 1.75 to 2.25 3-75 1.50 4-5 1-75 3-75 2.25 High-pressure cylinder 340.1 425.6 330-2 437-8 1st intermediate-pressure cyl- Indicated inder .... 388.5 516.6 354-2 490.7 horse-power o 1907 United States Navy Fireboat "James Duane" 2 1650 1907 City of New York Fireboat " Thomas Willett" 2 1650 1907 City of New York S. S. " Daisy" I 600 1907 W. A. Mitchell & Co., San Francisco, Cal. S. S. " H. P. Bope" . 2 2500 1907 Standard S. S. Co., Duluth, Minn. Revenue Cutter " Itasca " 2 1624 1907 U. S. Revenue Cutter Service S. S. " Shoshone " I 600 1907 C. R. McCormick & Co., San Francisco, Cal. Battleship " Michigan" 12 16500 1907 United States Navy Battleship " South Carolina " 12 16500 1907 United States Navy Revenue Cutter " Bear" I 800 1907 U. S. Revenue Cutter Service Tug " Ajax" I 825 1907 Southern Pacific Co., San J"rancisco, Cal. Collier " Prometheus " 6 6000 1907 United States Navy Collier " Vestal " 6 6000 1907 United States Navy Tug"E. P. Ripley" . I 900 1907 Atchison, Topeka & Santa Fe Railway Tug ' ' Navigator " 2 1300 1907 Associated Oil Co., San Francisco, Cal. S. S. .... 2 800 1907 Ira J. Harmon, San Francisco, Cal. Fireboat "Cornelius W.Lawrence" 2 1250 1907 City of New York Revenue Cutter " Snohomish " I 850 1907 U. S. Revenue Cutter Service Ferryboat " Camden " . 2 IIOO 1907 Pennsylvania Railroad Co., Philadelphia, Pa. Supply Ship " Celtic " . 4 2500 1907 United States Navy Battleship . i8 23000 1907 Brazilian Navy Battleship i8 23000 1907 Brazilian Navy Tug .... 2 500 1907 Italian Navy Battleship " San Marco" 14 20000 1907 Italian Navy s. S. . I 100 1907 Yokohama Engine & Iron Works, Japan Battleship " Capitan Prat " . lOOOO 1907 Chilian Navy 172 LIST OF VESSELS IN WHICH BABCOCK & WILCOX BOILERS ARE FITTED OR ARE ON OKDEK— Continued No. Indi- Name ot Boil- cated Horse- Year Owner ers power Steam Yacht " lolanda " 2 1350 1907 Morton F. Plant, New York Tug .... 1000 1907 J. P. Rennoldson & Sons, So. Shields S. S. " Gunga" . 500 1907 East Indian Railway S. S. " Saras vati " 500 1907 East Indian Railway S. S. "Koombana" 4200 1907 Adelaide S. S. Co. S. S. " Marco Tolo " . 4200 1907 Navigazione Generale Italiana S. S. " Cristoforo Colombo". 4200 1907 Navigazione Generale Italiana S. S. .... 1500 1907 Adelaide S. S. Co. Floating Dry Dock 1000 1907 Japan Tug .... 1000 1907 London & India Docks Co. Battleship " Delaware " 14 25000 I90S United States Navy Battleship " North Dakota " 14 25000 1 90S United States Navy Battleship " St. Vincent" . 24500 1908 British Navy * Battleship "Vanguard" 24500 1908 British Navy Revenue Cutter " Acushnet " 2 1500 1908 U. S. Revenue Cutter Service Revenue Cutter '' Tahoma " . 2 1750 1908 U. S. Revenue Cutter Service Revenue Cutter 2 1750 1908 U. S. Revenue Cutter Service Steam Yacht " Idalia" I 800 1908 W. D. lloxie. New York U. S. BATTLESHIP "NEW HAMPSHIRE" Babcock & Wilcox Boilers, 17200 Indicated Horse Power. 173 INDEX A PAGE Advantages of the Babcock & Wilcox Marine Boilers 31 Acidity of feed water, dangers of and remedy for 119 "Alert" boiler, tests of 135 "Alert" type of Babcock & Wilcox Boiler 20 Alban water-tube boiler 10 Algiers floating Dry Dock, boiler for 67 Analyses of fuels 73 Analyses of waste gases from boiler . 137, 161 Analysis of sea water 117 Anderson water-tube boiler .... 11 "Annapolis," U. S. Gunboat ... 41 War service of 37, 46 Boilers in 35 Repairs ........ 115 Trial of 43 "Anteleon," Steam Dredger ... 65 "Archer," Steam Dredger .... 65 Auxiliary machinery of Lake steamers, tests of 147, 149 B Babcock & Wilcox Boilers Advantages and salient points . 31 "Alert" type 20 In U. S. Gunboat "Annapolis" . 35, 43 In U. S. S. "Chicago" ... 35 In Steam Dredgers 63 In U. S. Gunboat "Marietta" . 35,41 In S. S. "Pennsylvania'' . . . 143 In H. M. S. "Sheldrake" . . 55 Care of 127 Circulation in 24, 100 Construction of casing .... 28 Corrosion 117 Description of 23 Designs of 1S68, 1873, 18S1 . . 15 Design of 18S1 16 Designs of 1895 and 1896 ... 19 Drum head 27 Durability 114 Dusting door 29 Economy of 35 Foundation of 27 Liberating surface lOO Man-hole plate 27 Repairs I14, 129 Riveted joint 27 Semi-marine 67 Sizes of (outside dimensions) 41, 55, 67, 135, 143. 153 Tests of 131-165 Weight of 31.135,143.153 Weight of water in . . 135, 153, 157, 164 Barrus throttling calorimeter . . . loi Battle of the boilers 49 Battle of Santiago, lessons of , . . 35 Belleville boilers in the S. S. "Ohio" 51 Belleville boilers, reasons for not adopting in U. S. N 53 Brief history of the water-tube boiler 8 British Admiralty tests of H. M. S, "Sheldrake" .... . . 55 B PAGE British imperial gallon, contents and weight 96 British thermal units, value of . . . 71, 93 British thermal units, per pound of dry coal 8 c Calories, value of • . . 73, 93 Calories per kilogram of dry coal . . 81 Calorimeter for coal 87 Calorimeter for steam 99 "Canonicus," reboilering of Monitor 33, 113 Carbonates of soda and lime, use of 119 Care of Babcock & Wilcox Marine Boilers Firing 127 Cleaning 127 Blowing off 128 Repairs 1 14, 129 Chemical composition of fuel ... 73 "Chicago," U. S. Cruiser, boilers in 35 "Chicago," repairs to boilers of . . 115 Chlorine in feed water, testing for . 123 "Cincinnati" boiler, tests of . . . 153-161 Circulation in Babcock & Wilcox Boilers icx) Coal, classes of 75, 127 Coal calorimeter 85-88 Coal, combustion and heat value of 69-83, 127 Construction of the Babcock & Wilcox Marine Boiler 23 Corrosion, causes and preventive measures 117 Corrosiveness, testing water for . . 122 Cost of repairs 114 Cylindrical and water-tube boilers, economy of 35 D Description of the Babcock & Wilcox Marine Boiler 23 Details of construction of the Babcock & Wilcox Marine Boilers . 23, 29 "Dirigo," repairs to boilers of S. S. . 115 Dredgers tit ted with Babcock & Wil- cox Marine Boilers Russian Government dredgers for the River Volga .... 63 "Hercules" 65 "Samson" 65 "Archer" 65 "Anteleon," Hopper Dredge . 65 "Texas City" 67 Dry Dock "Algiers," floating ... 67 1 >ry steam gj Durability of Babcock & Wilcox Bf'ilers 114 Dulong's formula 75 E Economy of cylindrical and water- tube boilers 35 Economy due to heating feed water . 107 Economy of Lake cargo steamers . . 85, 141 175 ^ PAGE Efficiency, use of coal calorimeter . 85 Engineers' reports of sea trials ... 139 Equivalent evaporation from and at 212° Fahrenheit .... 97 Ericsson engines for U. S. Monitors . 113 Evaporation, factors of 97 Evaporation from and at 2 1 2° Fahr. . 8, 97 Eve water-tube boiler 9 Exhaust steam used for heating feed water 107 Experimental marine boiler, tests of 133 Expanding tubes, method of . . . 129 F Factors of evaporation, table of . . 97 Feed water, heating of 107 Field water-tube boiler 10 Firing, methods of 77. 79- '27 Floating Dry Dock " Algiers "... 67 Fuel, its combustion and heat value . 69 Fuel saved by heating feed water . . 107 G Gallon, contents and weight of . . 96 Galvanic action 117, 121 " Gates, John W.," coal consumption of S. S 163 Generation of steam 89 Graphite for lubrication 119 Griffith water-tube boiler 9 H Heating of feed water 107 Heat value of coals 81 " Hercules," Steam Dredger ... 65 " Hero," boilers and voyages of S. S. 49 History of water-tube boilers ... 8 K Kelly water-tube boiler 12 L Lake cargo steamers, tests of . . . 141 Lane water-tube boiler 11 Laws of generation of steam ... 89 Liberation of steam from water . . 100 Lime, use of, for preventing corrosion 1 18 List of vessels in which Babcock & Wilcox Boilers are installed 167 M " McDougall, Alex.," boilers of S. S. 149 " McDougall, Alex ," repairs to boilers of S. S 115 Mahler bomb calorimeter .... 88 " Mahopac," reboilering of Monitor . 33> 1 13 " Manhattan," reboilering of Monitor ^3 Man-hole plate 27 " Marietta," U. S. Gunboat .... 41 Boilers in 35 War service of 37 Repairs to boilers of .... 39, 1 1 5 Coal consumption of ... . 41 Marine water-tube boiler, require- ments of 21 ^ pa(;b Measurement of heat 93 Melting point of metals 83,156 Melville, Admiral, U. S. N., on water- tube boilers ...... 33 Metals, melting point of 83, 1 56 Method of expanding tubes .... 129 Method of firing 77,79,127 Method of removing tubes .... 129 Method of testing Babcock & Wilcox Boilers 131 Method of testing water for corrosive- ness 122 Miller water-tube boiler 11 Monitors, reboilering U. S 113 Morrin water-tube boiler 12 N Naphtha used as fuel 63 " Nelson, Charles," repairs to boiler of S. S 114 " Nero," boiler of S. S 17 " Nero," boilers and voyages of S. S. 4S o Oil for cylinder lubrication .... 119 Oil for fuel 63 " Orlando," voyages of Steamship . 49 " Otto," voyages of Steamship . . 49 P Peabody throttling calorimeter . . loi " Pennsylvania," trial of steamship and tests of boilers . . . 143 Perkins water-tube boiler .... 9 " Presque Isle," repairs to boilers of Steamship 115 Properties of steam 89, 93 Proximate analyses of coal .... 75 Q " Queen City," repairs to boilers of Steamship 115 R Raising steam, record of "Alert" boiler 136 " Cincinnati " boiler 157 Reboilering U. S. Monitors .... 113 Removal of tubes 129 Repairs to boilers of U. S Gunboats " Marietta" and "Annapolis" 39 Repairs, cost of 114 " Reverie," Steam Yacht, and boiler for 16 Requirements of a marine water-tube boiler 21 " RoUo," voyages of steamship . . 49 Russian Government dredgers . . 63 S " Samson," Steam Dredger .... 65 Santiago, lessons of the battle of . 35 176 Sea-going dredgers fitted with Bab- cock & Wilcox Boilers " Hercules " " Samson " " Archer " " Anteleon " For Indian Government, tests of boilers of Sea trials from engineers' reports, steamships fitted with B.&W. Boilers Sea trials H. M. S. " Sheldrake " . . .Sea water in water-tube boilers . . Semi-marine Babcock & Wilcox Boiler " Sheldrake " tests and sea trials . . Soda, use of, for preventing corrosion Status and history of water-tube boilers Steam calorimeter Steam — properties and laws of genera- tion Stevens' boat Stevens' water-tube boiler, 1804 . . Stevens, John Cox, water-tube boiler, 1805 Stimer fire-tube boilers in U. S. Monitors Stokers used with B. & W. Marine Boilers . . . . 133, 143. Stokers, cost of operating .... Superheated steam, specific heat of . T 65 65 65 65 1 6-, 139 59 '17 67 55 119 5 99 14 113 [46, 164 147 93 Tables Analyses of waste gases, U. S. S " Cincinnati " boiler . . Approximate chemical composi tion of solid fuels . . . Classes of coal Factors of evaporation . . . Heat values of coal .... List of vessels fitted with B. & W Boilers Melting point of metals . . Percentage of fuel saved by heat ing feed water .... Properties of saturated steam Record of raising steam . . Relative economy of cylindrical and water-tube boilers Results of tests U. S.S. "Alert" . U. S. S. "Annapolis" Auxiliary machinery of Lake vessels, steam consump tion of U. S. S. " Cincinnati " 1 57, 1 58, 1 59, 161 Cylindrical boilers vs. water tube boilers Experimental marine boiler Steamship "John W. Gates" Lake cargo steamers . . . U. S. S. " Marietta" . . . " Alex. McDougall "... Steamship " Pennsylvania " Sea-going dredger for Indian Government .... 163 H. M. S. " Sheldrake " . . 58, 59, 61 161 73 75 97 167-169 83, 156 107 91 •36,157 35 137 43.45 147 35 133 .65 141 41 149, 151 146 T * PACK Tables — continued Temperature and pressure of steam for each ]4. inch of vacuum 93 Water between 32° and 2 1 2° Fahr. 95 Weight of water contained in boiler 157 " Tasso," voyages of Steamship . . 49 Temperature of fire 83 Temperature of gases passing through boiler, " Cincinnati " tests . 156 Tests Tests of boilers, methods of making 131 "Alert " boiler, tests of . . . 135 " Annapolis," trial of ... . 43 Auxiliary machinery of Lake vessels, tests of .... 147, 149 " Cincinnati " boiler, tests of . 1 53-161 Cylindrical boilers vs. water-tube boilers 35 Experimental boiler at B. & W. works 133 " John W. Gates," coal consump- tion of Steamship .... 163 Lake cargo steamers, tests of . 141 " Marietta," coal consumption of 41 " Alex. McDougall," tests of machinery 149 " Pennsylvania," trial of steam- ship and tests of boilers . . 143 Sea-going dredger for Indian Government, tests of boilers of 163 H. M. S. " Sheldrake," sea trials and tests of boilers ... 55 Water-tube boilers at the Impe- rial Experimental Station at Charlottenburg, tests of . . 53 Testing steam, method of ... . loi Testing water for corrosiveness . . 122 " Texas City," boiler of Steam Dredger 67 " Trophy," boiler of yacht .... 17 " Truro," voyages of .Steamship . . 49 Tubes, expanding and removal of . 129 u United States Navy, adoption of water-tube boilers in . . . 33, 51 U. S. Monitors, reboilering of ... 113 U. S. standard gallon, contents and weight 96 Use of lime and soda for preventing corrosion 118-119 Use of zinc for preventing corrosion 122 Vessels in which Babcock & Wilcox Boilers are installed . . . w Ward water-tube boiler War service of the U. S. Gunboat "Annapolis" 167 13 46 177 w •* PAGE Water, weight and temperature of 93, 96 Water-tube boilers at the Imperial Experimental Station, Char- lottenburg, tests of ... In the United States Navy . . Requirements for marine service Status and history With closed-end tubes .... With tubes connected at both ends Weight of Babcock & Wilcox Boil- ers 135, 143, 153, 164 Weight of water in Babcock & Wil- cox Boilers .... 135, 153, Weight and specific heat of water Weight of gallon of water .... 53 33.51 21 5.8 8-13 14-20 157 95 96 W Wiegand water-tube boiler .... Wilcox water-tube boiler Wilson, Thomas, Sons & Co., Ltd. Ships of, fitted with B. & W. Boilers Boilers of Wolvin, A. B., first instalment of water-tube boilers on Great Lakes z " Zenith City," boilers for Steamship " Zenith City," repairs to boilers of Steamship Zinc, use of, for preventing corrosion INDEX TO ILLUSTRATIONS " Alert," arrangement of boilers in U. S. S 134 " Alert " type of Babcock & Wilcox boiler, 1899 20 " Alert " type of Babcock & Wilcox boiler, section showing path of the gases 79,154 " Alex. McDougall," Steamship . . 148 " Algiers," boiler for floating Dry Dock 66 " Atlanta," U. S. Cruiser 70 Boiler 71 Boilers, arrangement of ... . 72 " Annapolis," boilers 42 U. S. Gunboat 44 "Anteleon," Hopper Dredger ... 68 " Archer," Steam Dredger .... 64 B Babcock & Wilcox Boilers Babcock & Wilcox designs, 1868 and 1873 15 Babcock & Wilcox design, 1881 16 Babcock & Wilcox design, 1895 '7 Babcock & Wilcox " Alert " type 79,154 Of U. S. S. " Alert," arrange- ment of 134 In large lake cargo steamers, arrangement of 140 Of U. S. S. " Atlanta," front view showing tube doors ... 71 Of same, arrangement of . . . 72 Of U. S. S. " Chicago," arrange- ment of 36 Of U. S. S. "Denver," arrange- ment of 104 Of U. S. S. "Marietta" and " Annapolis " 42 Of Yacht " Reverie " .... 17 Of Dredger " Samson " . . . . 22 Of H. M. S. "Sheldrake" ... 56 Of U. S. S. "Wyoming" ... 32 Of S. S. " Zenith City " . . 18 B.abcock & Wilcox Co., works, Bay- onne, N. J 132 B Babcock & Wilcox Compagnie Fran- caise, works, Paris, France Babcock & Wilcox, Ltd., works, Renfrew, Scotland .... Barrus throttling calorimeter . . . Boilers, rail shipment to Pacific coast Boiler tube, Diirr Montupet Niclausse " California," U. S. Armored Cruiser Calorimeter for coal For steam " Canonicus," U. S. Monitor . . . Casing, construction of, B. & W. boiler " Charles Nelson," Steam Packet . . " Chicago," boiler room U. S. Cruiser " Cincinnati," boiler, temperature of gases passing through boiler as shown by melting point of metals U. S. Cruiser Circulation of water in B. & W. boilers, section showing discharge from circulating tubes . . " City of Nanaimo," Steam Packet . Compagnie Francaise, Babcock & Wilcox, Paris, France, works of the " Cornell," S. S D December on Lake Superior " Denver," U. S. Cruiser . . Arrangement of boilers . " Dirigo," Steam Packet . . Dredger for the River Volga Drum — details of construction . Drum fittings — front view of boiler Drum head — forged steel Durr boiler tube Dusting panels, Babcock & Wilcox Boiler PAGB 12 IS 49 17 19 19 114 122 160 162 lor 47 13 13 13 126 88 lOI 38 24, 28 114 4 34 156 152 100 94 160 108 iSo 102 104 144 62 125 26 27 13 29 178 E " Edna G," Steam Tug Efficiency diagram . . Expander in position . PAGE 128 86 129 R " Reverie," boiler, 1889 . . . Yacht Riveted joint " Robert Dollar," Steam Packet 17 16 27 98 Floating Dry Dock " Algiers," boiler for Forged steel drum head Forged steel header Forged steel section Foundation and structural iron of casing, B. & W. Boiler . . G •♦Grattan, W. S.," Fire Boat . . . H Header, forged steel . " Hermes," II. M. S. " Hotspur," Steam Tug K " King Edward VII " M Mahler calorimeter for fuel . . . . " Mahomet Ali," Nile Passenger Steamer .... " Mahopac," U. S. Monitor . "Manhattan," U. S. Monitor " Marietta," U. S. Gunboat Boilers of ... • Order for fire brick Methods of installing B. & W. Boilers in vessels N " Nanaimo, City of," Steam Packet . " Nebraska," U S. Battle Ship . . " Nero," S. S Niclausse boiler tube " Nome City," Steam Packet . . . o Ore Docks at Two Harbors, Minn. . P " Pennsylvania," S. S Plug extractor Pontoon pipe line for Dredger " Texas City " " Presque Isle," S. S Pressure parts, boilers for Dredger " Samson " Pressure parts, boiler for H. M. S. " Sheldrake " R Rail shipment of boilers " Rainier," Steam Packet .... " Raleigh," U. S Protected Cruiser . 66 27 21 23 24 106 21, 23 52 78 150 88 no 174 112 40 42 39 80, 166 94 84 48 13 116 129 142 129 67 76 22 56 47 90 120 Cargo '<■ St. Louis," U. S. Protected Cruiser Section, forged steel Semi-marine boiler . . . . . Semi-marine boiler for "Texas City" " Sheldrake," H. M. S Boiler " Shelikof," Steam Whaler . . . Shipment of boilers by rail . . . Ships fitted with Babcock & Wilcox " Alex. McDougall " . . . . "Annapolis," U. S. Gunboat . "Atlanta," U. S. Cruiser . . "Augustus B. Wolvin" . . "California," U. S. Armored Cruiser "Canonicus," U. S. Monitor " Charles Nelson," Steam Packet "Chicago," U. S. Cruiser . "Cincinnati," U. S. Cruiser "City of Nanaimo, "Steam Packet " Cornell," Lake Cargo Steamer "Denver," U. S. Cruiser " Dirigo," Steam Packet " Edna G," Steam Tug " Empire City," Lake Steamer " Hermes," British Cruiser "Hotspur," Steam Tug . " King Edward VII," British Battleship " Mahomet Ali," Nile Passenger Steamer "Mahopac," U. S. Monitor . "Manhattan," U. S. Monitor "Marietta," U. S. Gunboat " Nebraska," U. S. Battle Ship " Nero," English Freight Steamer " Nome City," Steam Packet ♦' Paraguay," Lake Cargo Steamer " Pennsylvania," Lake Cargo Steamer " Presque Isle," Lake Cargo Steamer " Rainier," Steam Packet . . . " Raleigh," U. S. Cruiser . . . " Robert Dollar," Steam Packet "St. Louis," U. S. Protected Cruiser " Santa Ana " Steam Packet . . " Sheldrake," British Gunboat " Shelikof," Steam Whaler . . " Spokane," Passenger Steamer . "Superior City," Lake Cargo Steamer "Truro," English Freight Steamer " Wyoming," U. S. Monitor . . "Zenith City," Lake Cargo Steamer Steam calorimeter Stevens' boat, machinery of . . . Structural iron of casing , B. & W. Boiler boilers 130 23 60 66 54 56 122 47 148 44 70 124 126 38 114 34 152 94 108 102 144 128 124 52 78 150 no 174 112 40 84 48 n6 106 142 76 90 120 130 96 54 122 no 92 50 74 30 lOI 8 24 179 l PAGE *' Texas City," boiler for .... 66 " Texas City," Dredger 67 Torpedo Boat 46 "Truro," S. S 50 w Water-tube boilers Alban, 1843 ^° Anderson, 1S75 11 B. & W., " Alert " type .... 20 B.&W, 1868-73 15 B & W , 1881 16 B. & W., 1895 17 B. & W, 1896 19 Eve, 1825 ■ . 9 Field, 1866-7 10 Griffith, 1821 9 Kelley, 1873 12 Lane 11 Miller, 1870 it W Water-tube boilers — continued Morrin. 1S85 12 Perkins, 1832 9 Stevens, 1804 8 John Cox Stevens, 1805 ... 14 Chas. Ward, 1887 13 Wiegand, 1872 12 Wilcox, 1856 15 " Wolvin, Augustus B.," S. S. . 124 Works of The Babcock & Wilcox Co., Bayonne, N. J 132 Works of Babcock & Wilcox, Ltd., Renfrew, Scotland .... 162 Works of the Compagnie PVancaise Babcock & Wilcox, Paris, France 160 " Wyoming," boiler for 3- " Wyoming," U. S. Monitor ... 74 z " Zenith City," boiler 18 " Zenith City," Steamship .... 30 December on Lake Superior 180 The Knickerbocker Press New York 909015 W'^-f/f 5 Libira:#y IS. THE UNIVERSITY OF CALIFORNIA LIBRARY