The Iron Age 1891-11-12: Vol 48

‘THE IRON AGE THURSDAY, NOVEMBER 12, 1891. The New Pennsylvania Ferry Boat | houses at each end of her passage. She is | lights are placed on silvered brackets with Cineinnati. | propelled by two screws, placed upon one | opalescent shades around the sides, with | shaft running longitudinally through the two large irridescent electroliers opposite On last Saturday the new screw propel-| center of the boat, driven by two steeple the landing of the stairs. The floor is ler ferry boat Cincinnati made her trial' compound engines. handsomely carpeted. The mahogany ae = hs fs i = il STEEPLE COMPOUND ENGINES OF NEW PENNSYLVANIA FERRY BOAT CINCINNATI. trip and may be now considered as having | Cabin Arrangement. seats are fitted with bent wood seat arms been placed in commission, plying on the| The upper cabin is one spacious saloon, | secured by silvered fittings. The cabin North River between Jersey City and | 87 feet long and 38 feet wide, and is on a| has a seating capacity for 166 persons. The New York. The boat is a double- decker, level with these stations. The walls and | stairs to the lower cabins are inclosed with this construction having been adopted in | ceilings are finished in delicate pink tints, | leaded glass partitions of handsome design. order to couform with the two-story ferry ' relieved with aluminum leaf; the electric! Thetwo lower cabins are each 144 feet long Jatt 822 and 15 feet wide. The adoption of the screw propeller gives an unobstructed view of the entire cabin, the handsome mahogany stairs being the grand central feature. These cabins are decorated in light pearl gray tints, with papier-maché festoons on the frieze and roughen«d can vas panels relieved with aluminum leaf, producing a most harmonious effect. The floors are entirely covered with mosaic tiling, ard the central domes over the stairs leading to the upper saloon are lighted by leaded glass. Mahogany seats, similar in design to those in the upper saloon, afford a seating capacity for 304 persons. The electric lights, which are arranged along the sides of the cabins, are of the same style and finish as those in the upper saloon, with the exception of around the stairways, were they are in clusters. The total number of lights in all the cabins is 112, making it one of the most brilliantly lighted boats in ferry service. Heating and Ventilating. All the cabins are heated and ventilated by the Sturtevant system, by which the entire volume of air is renewed every five minutes. The supply of fresh air is drawn down anair duct 38 incaoes in diameter from above the upper deck and passed through a heat’ r which brings it up to the desired temperature and delivered into tue cabins near the ceilings at a pressure which forces the foul air through ventila- tors located under the seats, which are connected by ventilating ducts with reg- isters opening into the team gangway, The temperature is governed by electro- thermostats which control the valves that regulate the hot and cold air supply at the beater, thereby maintaining a uniform temperature. Hull Arrangement, The principal dimensions of the hull are as follows: Length over guards, 206 feet; length of hull, 200 feet; beam over guards, 65 feet; beam of hull, 46 feet; depth from deckto keel, 17 feet; draft, 10 feet 10 inches; displacement, 890 tons. The hull is of iron, built by the Samuel L. Moore & Sons Company, of Elizabeth. port, N. J., from plans and specifications furnished by the Pennsylvania Railroad Company. Its general arrangements and the location of the machinery are shown in the accompanying plan and transverse sections. It has five complete transverse bulkheads and two longitudinal bulk- heads extending from collision bulkhead to collision bulkhead at eitherend, mak- ing in all 14 water-tight compartments. All the deck beams are of iron and cov- ered with ,',-inch iron plates the entire length and breadth of the boat. The amidship house is also of iron and extends 9 inches above the hurricane deck, mak- ing the boat entirely fire proof from any cause which may originate in the hold. Steam Steering Engines. This boat is equipped with two Williamson steam steering engines of a type that was originally designed by the manulacturers for the Pennsylvania Railroad Co. and was first placed in service on their ferry boat Chicago, June 17, 1886. These engines are placed in the hold almost directly under the pilot houses, which gives direct connections from the steering wheels to the engines, and uniform leads for the tiller ropes. There is attached to the bell gear a specially designed indicator con- nected with the engine room, which shows the engineer from which pilot house the signals are being given. This is arranged so that the handles connected with this indicator have to be raised before the pilot can ring the ‘‘ go-ahead” bell, thereby preventing any mistakes or neglect on his part to operate the indicator. There is also in front of the pilot a dial indicator showing the direction in which the engines THE IRON AGE. November 12, 1891 are working, so that he will always be advised whether his signals are being answered promptly. The engines each have cylinders 18 inches and 36 inches in diameter and 26- inch stroke. These engines were designed and constructed at the Pennsylvania Rail- road Company’s shops at Hoboken and are fitted with Canfield’s balanced piston valve. This valve, as shown in the verti- cal sectional elevation of the engine, is of the piston type. It is operated by Joy valve gear. The valve consists essentially of a hollow steel cylinder formed with shrunk-on piston rings made of wrought iron. Each of these rings is provided with annular channels into which metal packing strips are fitted. The port open- ings extend through this cylinder between certain of the piston rings. As shown in the drawing, a steam chest is located opposite the lower or high-pressure cylin- der, another steam chest being opposite the low-pressure cylinder. Provision is made for admitting live steam between each head of the valve casing and the ends of the valve in order to establish an equal pressure at both ends of the valve and thereby maintain a perfect balance. It will be noticed that the tail rod is of larger diameter than the valve rod, thus reducing the bearing area at the upper end aa) ia TL FERRY BOAT CINCINNATI. SIDE ELEVATION OF THE NEW PENNSYLVANIA November 12, 1891 THE IRON AGE. 823 f | “ale + Ste iictcchsheteiecbubachacae oO STEERING 20 4] f 00d) 4 ss 4 } wearin] pore | $ ENGINE ae « w z > @ 4 “ ¢ ° j++4+--4+-++ ENGINE tl |} AIR PUMP CONDENSER of the valve in order to compensate for the weight of the valve and valve rod. The steamways provided for the entrance of steam to the high pressure cylinder for its exhaust into the low-pressure cylinder are shown clearly in the drawings, the arrows indicating the direction of the flow. The engine is about to start on the down stroke, steam being admitted to the upper side of each cylinder. Tae accompanying cards from the en- gines were taken with steam at 105 pounds; vacuum, 24,4, inches; revolutions, 94, the indicated horse- power being 736. The shafts are coupled between the two engines, so that in case of accident to either engine or line of shafting they can be disconnected and used independently. The shaft extends the entire length of the boat, with sectional propeller wheels at each end; these wheels are 8 feet 9 inches diameter and 13 feet 6 inches pitch, and work together in either direction. At120 pounds steam pressure and 106 revolutions -; o < Z Zz — Oo Z = ~ o = 3 e 5 . <= 3 = 6 © a 2 z 2 ma = 2AM by 3 2 3 . = - s > fon ost a = _ \! = ~S t < — A = f - rs — — | —— b v be HI =H x es 2 Z ’ - 7 h « < fi = a beat r yy os <¢ ou iy wf > 3 | g & 5 \ ; p >" S | » je} | o % 2 § A } . > | = $ t ~* >} | «3 = = al NS fx ~ ~ Z. < 3 oe Quy a minute these engines have developed 1016 indicated horse-power, giving a speed of 14 miles per hour. The con- denser is detached from the main engines, and has independent air and circulating pumps. A grease extractor is connected with the exhaust pipes from the various engines to prevent the oil used in lubricating the cylinders passing with the feed water into the boilers. In a separate compartment adjoining the engine room are situated the heating and ventilating apparatus, ap in- candescent electric-light plant of 200 lights capacity of 16 candle-power each, and also one of the steam steering engines. In addition to this large electric-light plant there is one of 35-light capacity in the engine room, which is connected by a special circuit to all the signal lamps, and to a number of the cabin lights, to be used in case of accident to the larger plant. This is a novel feature which will be of great practical value in case of emergency. Bollers. In another compartment situated to the right of the engineer, as he stands on the working platform, is the boiler room, in which are two tubular boilers built of steel of 60,000 pounds tensile strength with shell plates ,°, inches in thickness and tested to carry 120 pounds working press- ure; each boiler is 10 feet in diameter, 10 feet long, and has 49 square feet of grate surface and 1750 square feet of heating surface. There is in addition a donkey boiler 42 inches in diameter and 6 feet 9 inches in hight. A circulating apparatus is fitted in connection with this boiler by which a uniform temperature is maintained throughout the main boilers, while steam is being raised. At the rear of the boilers is another compartment in which is located the other steam steering engine and a fresh water tank. All the floors and platforms in the hold are iron, no wood being used below decks, except the insulating strips for the electric light wires, so there is absolutely no danger from fire. The joiner work in all its details was built by John E. Hoffmire & Son, from plans furnished by the well-known architects, Furness, Evans & Co. of Philadelphia, and «mbodies many new features, both in construction and ornamentation. The Collapse of the Fly Wheel at Manchester. The Providence Journal presents the following data in regard to the collapse of the fly wheel of the engine running the Amoskeag Mill at Manchester, N. H. The engine was built by the George H. Corliss Steam Engine Works, and was a double 36-inch condensing engine, with 6-foot stroke, and normally ran at 61 revolutions per minute. The fly wheel was of the built-up type, 30 feet in diameter, 110 inches face, was made of 12 sections and had a contract weight of 68 tons. The fly wheel had but one set of arms. There were five bolts 1% inches in diameter in each section of the fly wheel, and there were about 170 square inches in a cross section of the fly wheel rim. The engine furnished power through three belts from this wheel, one of 24 inches and two of 40 inches each. The engine was fitted with the new type of Corliss valve gear similar to the engine which burst its wheel in Lynn. The receiving pulleys, three in number, were all 12 feet in diameter; one was about 26 inches wide and two about 42 inches wide. All were of finer grained iron than the fly wheel proved to be, and were quite differently constructed. Each of the 42-inch face pulleys was made of two separate pulleys, bolted together. These two combined had a cross section of 50 square inches, and each pulley had two sets of arms. The engine was used to- gether with water power to drive four mills. Its greatest horse. power ever indi- cated was 2000, and C. H. Manning, superintendent of the Amoskeag Mills, testified at the inquest that this was its maximum load. At the time of the col- lapse the engine was running at 1900, pos-. sibly 1950, horse-power. The engine was installed in 1883, and was run only at times of low or high water, averaging, perhaps, three months in a year. The superin- tendent considers that the engine had had the equivalent of three years of ordinary service. The belts were heavy double belts, the same as were put on when the engine was first started. They were first quality at that time, and had been in- spected within 48 hours of the time of the accident. The manner of operation in connection with the water power is interesting in re- lation to the theory of racing which has been advanced to explain the catastrophe. The engine can be run connected with seven 1286 824 THE IRON AGE. November 12, 1891 water wheels. It bas never been operated with all seven at once, is not ordinarily run with more than three, and at the time of the collapse it was connected with two wheels in such manner as to indicate a very light water-power connection. The wheel upder No. 4 mill had at the time one-tenth FORWARD ENGINE HIGH PRESSURE CYLINDER SCALE 50 1H. P. 174,90 M. PRESSURE 67.92 LBS. LOW PRESSURE CYLINDER SCALE. 16 AFTER ENGINE “iGH PRESSURE CYLINDER SCALE 50 1.H.P. 177.90 M. PRESSURE 58. 95 LBS, LOW PRESSURE CYLINDER SCALE 20 Steam, 105lbs. Vacuum, 24.3 in. Rev., 94. Cards from Engines of the Cincinnati. gate open, that under No. 7 mill had four- tenths gate open. At times of back water it has been run with four wheels, with full gate or all except one, which was kept partly closed to keep sufficient load on the engine to make it manageable. The engine would, of course, regulate closer when running independently. It is stated, however, that the water power in use at the time of the collapse would not perceptibly affect the speed of the engine, as it was not sufficient to start the shafting if at rest. On the ‘morning of the accident, October 15, an irregularity of speed was noticed in the mills connected with the engine, mills 4 | and 5 running very slowly and mills 7 and 8 with increased speed. A few minutes | before the disaster the superintendent of carding noticed a slackness of speed in No. 5 mill, and as is customary in such cases, ordered the machinery to shut down, and went to the engine house to make inquiries. It is from this shut down that the theory of the failure of the governor to act and the engine racing takes its rise. The varying and increased speed, due in some measure to the sudden shutting down of No. 5 mill, being noticed in the other mills, caused them to shut down also at about the same I H. P., 736. time, thus throwing the whole load off the | inquire about the increase of speed, the engine, which a moment before was | engineer was at his desk and said he had nearly fully or over loaded. This relief | heard of nothing wrong. The engineer from load might have stimulated the | started to descend into the wheel pit, when engine to racing, but the function of |the engine began to race. Quickly; re- the governor is to control the speed. | tracing his steps, he began to close tie Theoretically, the governor would respond | throttle of the right-hand cylinder, direct- see — a VERTICAL SECTION OF ENGINES OF THE CINCINNATI. to such an increase of speed in such a|ing his assistant to close the left-hand manner as to absolutely prevent a particle| throttle. The assistant had closed his of steam from entering the cylinders of the | throttle, and the throttle of the right-hand engine—that is, that the valve would be/| engine was closed to within one-third of an tripped before its lap was uncovered. |inch, when the fly wheel burst, a flyin According to testimony, when the super-| piece striking the engineer on the head, intendent reached the engine room to! causing instant death and knocking him November 12, 1891 THE IRON AGE. 825 into the wheel pit, where he was found. The superintendent says the engine was running at normal speed when he left the engine room, and he was not 15 seconds out of the room when the explosion occurred. The engine was supplied through a 20-inch pipe, and the pressure recorder at almost 9.30 exactly shows a drop from 95 to 54 pounds pressure when the main stop valve had been closed. An examination showed that the cylinders, condenser and bed-plate were all right. The fly wheel had disappeared, the jack shaft pulleys were broken, although their hubs still remained fast on the shaft, but the main shaft was not sprung’ The fly- ing masses of iron demolished the engine room, cutting a clean swath through the pump room adjoining and the drawing-in room overhead, and huge pieces were carried hundreds of feet into the river and into other buildings. The unfortunate occupants of the drawing-in room, without any premonition, felt the floor give way beneath them, and all were plunged into the wreck below and more or less badly injured. If the engine raced, the fault is attrib- uted, and with reason, to the governor. This had worked satisfactorily up to the time of the breaking of the fly wheel. The water power employed at the time was not snfficient to continue the accelerated speed of the engine which would result if one- half the load was taken from the engine and the governor failed to work, provided the valves were closed at the same moment the one-half load was thrown off, not be- ing sufticient to continue the work attached in its immediate neighborhood. If the fly wheel was running at normal speed, and the valves were closed, its speed would begin to slacken when the stop valves were about three fourths closed, and the fly wheel would come to rest in about 15 to 20 revolutions from the time the stop valves were fully closed. The governor must have failed to do its work at the time of the accident if the engine attained a high rate of speed. Itis said, however, that engineers have made a practice of set- ting valves to cutoff at least one-sixteenth of the stroke when the governor is against the upper stops. The slighest amount of steam admitted to an engine suddenly relieved of its load is sufficient to cause dangerous racing in a few seconds. Both the other prominent makes of stationary slow-speed engines of large size, built in this city, have attached a safety device which stops the engine if the governor fails to act. If the assumption that the engine raced is to be accepted, the action of the governor is the key to the situation, as admitted by Mr. Manning in his testimony. But the superintendent, who went to inquire what the trouble was, says the engine was running at the normal speed 15 seconds before the crash, and an expert mechanical engineer who visited the mill directly after the ccllapse finds reason to doubt that the engine raced, and some evidence to support another theory of the cause of the failure. Some trouble had been noted with one of the jack shafts, and this may have been responsible for the slackening of speed in the mill which it drove. The direction in which the frag- ments of the wheel were thrown, and in which the force of the bursting was spent, is such as to suggest that this trouble with the jack shaft induced a twisting, or side pull, upon that part of the rim of the wheel, which its broad face of 110 inches supported by only a single set of arms was unable to sustain. The making of a wheel of this size face with but a single set of arms is open to criticism and is con trary to the practice of other prominent builders. The William A. Harris Steam Engine Company limit the width of face of a fly wheel with a tingle set of arms to 96 inches; for anything wider than that this concern uses two sets of arms. But whether one cause or the other led to the collapse, the makers are confronted with the discovery of flaws in the wheel due to defective foundry work which would have condemned the wheel if they had been known, but which the method of sounding, a discredited method, although still practiced, failed to reveal. Superin- tendent Manning testified that the rem- nants of the fly wheel show very many in- ternal flaws, where the iron is drawn badly by shrinkage in cooling, all of which is impossible to discover without destroying the wheel. There were enough flaws in the casting to have condemned it in the superintendent’s mind, if they had been discoverable, and he would not have al- lowed it to run a day. With perfectly sound castings at the normal speed of 61 revolutions, he considered the wheel 15 times as strong as necessary to do the work. He does not feel positive that the accident was due to the defect in the castings, but is certain had the fly wheel been sound no damage ,would have been done. It has been the intention to give in this review the facts without prejudice, and space has been tendered the builders of the engine for the publication of any state- ment they care to make in the matter. They write as follows: The Amoskeag wheel differed in no essential proportions from many others now in active service. It had been running successfully since October, 1883. The first wheel made from tuis pattern is now at Merchant’s Manu- facturing Company, Fall River, Mass., and was started in the early part of 1868. The regulato: and its belt having been found in- tact, we do not consider the accident due to engine racing, but rather to the crushing of the jack pulleys, which were 12 feet in diam- eter, with S arms—not of our manufacture. In this connection Mr. Gould testifies that he found one of these ‘‘ 42” jack pulleys too hot to lay his hand on, and Mr. Reardon says that shorly after ‘“‘ there was a sheet of fire, like that from an emery wheel, coming from the top of the south belt box, shooting toward the west "—i.e., toward the large wheel. All this took place while the engines were running quietly and before the engineers had come up toom the jack wheel pit ‘‘in a hurry ” to shut off the steam. The jack shafts were not par- allel with engine shaft, and consequently guide pulleys were resorted to—a system to be avoided, if possible, in prime movers, and one always requiring the closest inspection and facility of adjustment. That the wheel did not ‘‘ explode” in the sense in which the word is ordinarily used—i.e., from the action of centrifugal force—is proven by the fact that the fragments were not thrown to greater dis- tances than would be theoretically due to the normal rim speed after fracture. If an ex- perience of 23 years in the construction and successful running of large driving pulleys counts for anything, we are justified in our conviction that this deplorable accident was not due to erroneous proportions nor to an in- sufficient factor of safety. As regards quality of material, our clients are aware that we use, and have always used, high priced irons ex- clusively. CorRLIss STEAM ENGINE COMPANY, Per William B. Sherman, Secretary. oo —— The Philadelphia Foundry Associa- tion.—Forty representatives of firms en- gaged in the casting of metals within a radius of 100 miles of and in Philadelphia have formed the ‘‘ Foundry Association.” The new organization includes firms oper- ating iron or brass foundries or casting metals of any description. Its object is for the advancement of foundry interests and the mutual enjoyment of the members. The meeting was held at the Manufact- urers’ Club. The officers elected were Francis Scbumann, president; Thomas Devlin, vice-president ; Joseph Thompson, treasurer, and Howard Evans, secretary. The members include firms in Philadelphia, York, Wilmington and other towns and cities. The movement has been for some time under consideration. ‘‘ The organ- ization has nothing to do with the fixing of prices,” said Secretary Evans, ‘‘or the regulation of trade matters, It may be- come a national organization, with head- quarters in Philadelphia. It is an orgar- ization on the plan of the Builders’ Ex- change.” i New Torpedo Boats. Engineering of London states that Thornycroft & Co. have entered into an agreement with the Société des Forges et Chantiers de la Méditerraree for the con- struction in France of two torpedo boats similar to the Comeur, recently built at Chiswick for the French Government, and nearly identical with the boats recently built by the English firm for the Brazilian Government, and which gave such remark- able results as regards speed. In the yard at La Sayne three somewhat larger boats than the Comeur class are also being con- structed, and these are likewise fitted with the Thornycroft boilers. These boats are 143 feet long, 14.7 feet broad and 8.23 feet draft aft, with a speed of 20.5 knots at 104 tons displacement. There are two boilers in each boat working at a pressure of 200 pounds per square inch, and each boiler has 29.8 square feet of grate sur- face, 1825 square feet of heating sur- face and weighs complete with water 9.83 tons. The boilers supply steam to a single three cylinder compound engine of about 1200 indicated horse power, having cyl- inders of 17.3 inches, 25.2 inches and 39.3 inches in diameter, with a stroke of 164 inches. The first of these boats is at pres- ent undergoing her trials at Toulon. The society has further contracted to build for the French Gove: nment a large fast seagoing torpedo boat called the Mousquetaire, which has a contract speed of 244 knots per hour, and will be fitted with two of the Thornycroft type of boil- ers. These boilers are among the largest constructed of the Thornycroft type, hav- ing a grate surface of 41.2 square feet, and weighing complete with water about 16 tons each. These boilers generate steam for two three cylinder engines having cyl- inders of 15.8 inches, 23.6 inches and 35.5 inches in diameter, with 15.8-inch stroke, and exerting collectively 2100 indicated horse-power. The boilers and engines are so arranged that one boiler supplies steam to one engine, and the other boiler to the remaining engine, both systems bein kept entirely separate, but are so arrange that should occasion require it either boiler can be worked with either engine, or one boiler can supply both engines, The length of the boat between perpen- diculars is 154 feet, and 15.4 feet broad, with a draft aft of 6.2 feet, and a displace- ment when fully loaded of 125 tons. She carries two 17.8-inch torpedo tubes on deck, and two 37-mm. quick-firing guns, and is divided altogether into nine water- tight compartments. ec The long strike of the railroad coal miners in the Pittsburgh district has been settled, the men returning to work at the old rate of wages. The strike was caused by the miners demanding an advance of 10 cents per ton, which was refused by the operators. The strike was inaugurated about October 1, and was participated in by about 12,000 men, who are said to have lost nearly $1,000,000 in wages, having been idle about five weeks. Many of the miners’ families are in destitute circum- stances, having suffered for the neces- saries of life. As stated above, the men returned at the old rate of wages, which is 79 cents per ton for mining. The elaborate and thoroughly artistic manner in which the October souvenir of the Memphis (Tenn.) Zvening Scimitar, the leading Democratic paper of that city, is gotten up isa good example of Southern enterprise. The souvenir is a 56-page magazine, 24x18 inches in size, full of descriptions of all the undertakings, public and private, of that much-adver- tised and booming Southern city, a ‘i. 4 ee aur 4 ~ + 826 THE IRON AGE, November 12, 1891 Fire-Proof Construction. BY JOHN JAMES WEBSTER. (Continued from page 783.) Structural Combination of Materials. Having now briefly considered the fire- resisting properties of the principal build- ing materials, a short description will be given of the way in which they have been combined by various makers to form fire- proof structures. Most attention appears to have been given to the floors; but there are other portions of the building which have to be considered with equal care—viz., the walls, columns, partitions, roof, &c. As bricks are undoubtedly the best fire- resisting materials, they should be used for all internal walls; while to obtain any desired architectural effects stone can be employed on the external faces. In fact, the nearest approach to a fire-proof struct- ure would be a building of brick walls and columns, with brick-groined ceilings and roofs. Such a building, however, would be costly, and in most cases unre- munerative, and would occupy so large and the first known example of this was in the cotton mill of Messrs. Phillips & Lee of Manchester, erected in 1801. The beams were of cast iron and placed about 10 feet apart. This system was very gen- erally adopted in cotton mills and ware- houses, and js even followed at the pres- more approved methods can be substi- tuted. Messrs. Woodhouse & Potts modi- fied the system by casting pockets on the sides of the beams, on which rested rolled joists, about 2 feet 6 inches apart, carry- ing segmental brick arches, Fig. 1. An- other form is that of Mr. Scott, Fig. 2. Woodhouse & Potts. Fig: TG 3 Toy SA NLFESS ° “* OTTO oan hci RIORLELCL MAORI IIS COOMBLRAMEDIIEIDIGI. VOSIVEGIA. TTT aT TN TTT ITAL ¥ Ti Scott. nn cr nt A A AAPL ADIL ALIA GLP ADA CLL LILLE — - : . —_ - , * * Sir W. Fairbairn. Fig 5 VIIL LIC Oe LOGI TOTTI TTI Mihi CUE Radda nna CaUMen MnO Ma 7 —s : an amount of space that only a small area would be available for the storage of goods. To economize space, it is neces- sary to use iron and steel in the construc- tion of the columns, floors, roofs, &c. For most warehouses and public buildings it will be found to be more economical to employ cast iron for the columns, as it is seldom necessary to have the length more than 24 or 25 diameters. Although the hollow cylinder is one of the most econom- ical forms, it will be found that a column of cruciform section, although considerably weaker theoretically, can frequently be used to greater advantage for carrying ordivary warehouse loads; for practice often demands an excess of metal beyond the theoretical requirements of a cylin- drical column, which would seldom be the case with one of a cruciform section. The latter section has also the advantage of adapting itself to the in- ternal fittings of a building, and is less costly in construction. For the main and cross girders for carrying the floors it de- pends eutirely upon local conditions whether built or rolled beams are more economical, but in most cases it will be found advantageous to use steel in prefer- ence to iron. The earliest form of fire-proof floor was the brick arch springing from iron beams, Fig +. (ZZ a a da oe » I id Je eee é . ye ey nee ag ea SIT OPTED LT IL TT IO TVET IF Suss0HGRRBOURORO! Fox & Barrett. FIRE-PROOF CONSTRUCTION, ent time to a large extent, with the ex- ception that rolled iron beams have superseded cast-iron beams. In the build- ing regulations and by-laws of many cities and large towns in England this descrip- tion of fire-proof floor is still specified, and it is only by an evasion of the by-law by an ingenious rendering of the clauses that The bays were generally 10 feet long, and on the columns were cast brackets to re- ceive rolled joists, which were tied to- gether by means of cast-iron beams, and upon them brick arches were turned, Al- though there is a saving of brick work in this system, a large amount of the iron work appears to be exposed, which would be a November 12, 1891 THE IRON AGE. 27 A modification of this system was intro- duced by Mr. Moreland, in which corru- gated iron was used in place of the flat plates, Figs. 5 and 6. The objection in both cases is the exposure of so much iron. Owing to the great weight of the ordinary serious defect in a fire. Sir William Fair- bairn introduced the form of floor, Figs. 3 and 4, in which the intrados of the arch consisted of plate iron } inch thick, in widths of 3 feet, riveted together by means of T-irons 4 x 2 inches by 5, inch. Tie Fig : 13. Fiq 14. Yarra ry ee pedadedeniaebnhehoe hahah ini WN NN ee sige he hi huh ded sadddcididdieg Dawnay. the hollow bricks shown in detail, Fig. 8, are 9 inches deep at the springing and 4} inches at the crown. The space above to the floor level is filled with lime and ashes and paved with flags or tiles. The advantage of hollow bricks has been known for a long time to both English and French builders, but the first patent taken out for their manufacture appears to be that of Benford Denton, in 1812. The bricks up to this time were all made by hand, but in 1842 Mr. Collar, a French- man, obtained a patent for making them by machinery. The machinery, however, was not successful, and Robert Beart of Godmanchester took out a patent on April 24, 1845, which has since worked satisfactorily. These two patents led to a long and interesting law suit between the French and English inventors, the former asserting that the latter had infringed his patent. ARCH POTS. Hollow bricks known as ‘arch pots” were excensively used at one time, the floors of Buckingham Palace and some of those of the National Gallery, the Treasury build- ings, the United Service Club, the dome of the Bank of England, &c., having been con- structed with them, Fig. 9. An enlarged view of the pots is shown in Fig. 10. The span of the arches was generally about 6 feet and never more than 7 feet, the rise never exceeding 6 inches. The pots were about 8 inches high, 43 inches square at the top, and the same diameter at the bot- tom; the sides and bottom were scored, and a small hole was made in each to act as a key for the mortar. Homan & Rodgers (Figs. 23 to 26 Inclusive). FIRE-PROOF CONSTRUCTION. bars, at distances of 9 feet, were fixed to the top of the rolled iron beams, which were 10 feet apart, the space between the plates and the floor line being filled with concrete. The floors were then laid as de- sired, in either flags, tile, wood or cement. brick-arch floors, Sir William Fairbairn iutroduced in the design of the Saltaire Mills, built in 1854, hollow brick-arch floors, Figs. 7 and 8. The beams are of cast iron, spaced 10 feet apart. The arches have a rise of 12 inches to the crown, and Vaux & Thuasne. The first departure from the brick-arch floor appears to be that designed by Dr. Fox of Bristol, and improved by Mr. Bar- rett, known now asthe ‘‘ Fox and Barrett” system. This consists, Figs. 11 and 12, of small rolled joists, placed about 20 segues + hE Ae RMA hb foc ee A i SO thls TT A, ay ee, 828 THE IRON AGE, November 12, 1891 inches apart, and resting upon the main girders, strips of wood about 1} inches square being laid upon the bottom flanges about 14 inches apart. Upon these strips and between the joists the concrete was laid, the ceiling being plastered as usual, and the floor laid as desired with wood, flags or tiles. This was the first system in which any attempt was made to protect the iron joists. It was adopted in the Liverpool Exchange buildings, the cellars of which extended under the whole of the large space known as ‘‘ The Flags,” and are used as bonded vaults. In the con- struction of the roof which forms the floor of the ‘‘ Flags ” a modification of the Fox and Barrett system was suggested by one of the foremen. Instead of the strips of wood, he placed hollow tiles of triangular section, Figs. 13 and 14, which decreased the weight, increased the strength and offered greater resistance to fire, both on account of the nature of the material and of the inclosed air space; in addition to this the concrete above could be laid with- out the use of the flat centers beiow. Mr. Barrett gives the following comparative weights: Wooden floor, 35 to 40 pounds per square foot; Barrett’s, 78 pounds per square foot; 44 inch brick arch, 70 pounds per square foot; 9-inch brick arch, 120 pounds per square foot. The floor designed by Clark Bunnett is a flat floor of concrete somewhat similar to the Fox and Barrett system, the wood fillets being fixed to the top flange with clips, and the concrete filled in on the top of a flat centering to the level of the fillets. A layer of mastic is spread over the con- crete, and the flooring boards or blocks secured to the fillets. In 1862 Mr. Allen took out a patent for a special concrete composed of Portland or other cement mixed with cinders, slag coke or clinkers, in the proportions of 1 of cement to 6 of the other materials for strong and of 1 to 8 for ordinary concrete. This he used in place of stone for arches of flooring and for other portions of buildings. At the large fire in the six-storied premises of Messrs. Waterlow of Finsbury, in 1871, when all the iron and stone work were de stroyed, lintels made of Allen’s concrete were not affected by the intense heat. Mr. Bunnett designed a special flooring, con sisting of hollow bricks joggled at the sides, somewhat similar to those used by Sir William Fairbairn in the Saltaire mills. Wrought-iron tie rods were incased in the brick work and locked the bricks together, each being supported by those adjoining. it to a fierce fire for 14 hours, and a slow j flanges of the binding joists, which, for a fire for 27 hours, and then quenching by|7-foot bay, would be 5 inches deep; means of a jet froma hose. The results| flat centering is then placed below were very satisfactory, the fire bricks be-| the joists, and concrete, consisting of ing uninjured, and the iron joists per-| Portland cement and broken fire clay, is fectly straight and sound. Archibald! filled in, effectually protecting them on the The floors of the Grosvenor Hotel and of - the Victoria Station, Pimlico, are built on EE SECC NEES Tr yt this system. An experimental arch of 15 YS = 000 feet span with a rise of 2 feet 3 inches withstood satisfactorily a load of 267 pounds per foot superficial, the deflection being about ,% inch. One of the earliest to fully realize the importance of protecting the iron work of the girders was Mr. Whichcord, who, in 1878, devised a special fire brick casing which inclosed the web and lower flange of the iron girder, as shown in Fig. 15. The blocks were about 9 inches long, and so designed as to form a skewback to re- ceive the arch bricks; the bricks and blocks were set in cement, allowance being made for expansion. He constructed an experimental furnace, 15 feet long by 10 by 5 feet, in which he placed the joist incased in fire bricks, from which sprung side arches to the walls of the furnace, to represent as nearly as possible a floor. It was loaded with 64 tons distributed, be- ing one fourth of the actual breaking weight. A fierce fire was then kept up for 24 hours, when the bricks were suddenly quenched with water. The beam having eflected 14 inches when hot regained its Hyatt. FIRE-PROOF CONSTRUCTION. Dawnay, Assoc, M, Inst. C. E., introduced | under side. The flooring and ceiling can a system consisting of a solid block of| be made as desired, the different arrange- normal position when cool, and, beyond| concrete between the joists, with a flat | ments being shown in Figs. 16, 17 and 18. the bricks being vitrified, no damage was | ceiling. Either 4-inch square iron bars, |The weight for a 12-foot bearing is 40- done. A second experiment was made, | 12 inches apart, or 3-inch iron joists, 1| pounds per square foot, and it is capable after rebuilding the furnace, by submitting! foot 6 inches apart, rest on the lower! of bearing a safe load of 2 hundredweight November 12, 1&91 THE IRON AGE, 829 en per square foot. A modification of Fux and | adopted. The former consists of flat plates Barrett’s system, designed by Mr. Phil- lips, was introduced by Measures Brothers, in 1862. It consisted of a concrete floor having T-iron bars spaced about 9 inches apart in place of the wooden ones, Figs. 19 and 20. In more recent designs, Figs. 21 and 22, light rolled iron joists are im bedded in the concrete. The flooring boards are laid upon light wooden joists secured to the upper surface of the con- crete, leaving an air space between, which, it is claimed, prevents dry rot and deadens thesound. The disadvantage of this sys- tem appears to be that there is so much iron work unprotected. Homan and Rod- gers have obtained several patents for fire- proof floors, the first being in 1865 for a concrete arch of a normal span of 10 feet. The objection to this system was the weight—about 1 hundredweight per square foot—and the cost of the centering. The next patent, taken out in 1871, was for the flat type, Figs. 23 and 24, having steel or iron joists imbedded intheconcrete. The weight per square foot of such a floor, 20 x 10 feet, capable of sustaining a load of 2 hundredweight per square foot safely, would be 56 pounds. The third patent, taken out in 1885, Figs. 25 and 26, claimed the use of special hollow bricks, carried on rolled joists which supported the coke breeze or other concrete, the latter being lsid without the use of centers. This system is similar to the one adopted under the ‘‘ Flags” at Liverpool, Figs. 13 and 14. Any of these floors can be finished on the surface with granolithic, asphaltic, tiles, wood blocks or any otber material used for this purpose, and as the bricks are molded with longitudinal grooves underneath, they make a good key for plaster. They have been used by the London School Board, General Post Office, the People’s Palace, Queen Anne’s Mansions and other large buildings. W. H. Lindsay & Co. of Paddington adopt an effective combination of iron and con- crete, the floor and ceiling being flat. The size and distance apart of the rolled joists of iron or steel depend upon the load and span. They are strengtheped by means of trussed rods passing under and over the joists alternately, at intervals of about 18 inches. The whole of the iron work is then embedded in ‘‘pumice concrete,” consisting of coke breeze, sand and Port- land cement, and weighing about 80 ponnds per cubic foot. The advantage of this plan 1s that the tryss rods, besides giving additional strength, sustain the concrete in position. Another form of flooring is adopted by these makers in which the truss rods are dispensed with, and the pumice concrete is fixed in the form of slabs, and not in sit#. Both sys- tems, with the different methods of fixing the flooring boards, are shown in Figs. 27 and 28. Provisional protection was granted to Richard Moreland, Jr., in 1866, for the invention of a form of floor shown in Fig. 29. It consisted of iron-framed girders resting on each side of the column and continuous to the end of the building. Cross girders in the form of bow string girders, and made of angle bar with flat- bar connections, were fixed one over each column and others spaced about 3 feet 9 inches apart, The whole was then incased ina solid block of concrete, forming a floor of great strength; with the main girders 12 feet apart and 10 feet 9 inches long and 15 inches deep, the floor would carry safely a load of 3 hundredweight per square foot. The advantage of this system was that the concrete was continuous and not broken into sections by webs of cross girders. It is reported that a strike among the carpenters of Paris in 1840 induced the master builders to substitute iron and con- crete for timber flooring, the systems of Vaux and Thuasne being those generally or bars bent at the end, as shown in Fig. 31, and resting on the walls; upon these bars are bent square iron rods, which carry cross rods. Flat centers are — underneath, and the concrete thrown down, imbedding the iron work completely. In the Thuasne system rolled iron joists are used, slightly arched and placed 2 feet apart center to center. They are con- nected at about every 3 feet by flat-iron ties, the ends being turned over the top flange of the girder, and upon them are placed the square rods as in the Vaux sys- tem, the concrete being also laid in a simi- lar manner. The ceilings in both cases are finished in plaster, and the floors can be laid with any material desired. This system was adopted at the Louvre in Paris. Another floor very generally used in Paris consists of an arch of hollow bricks springing from rolled joists, the sofiit of which is finished in plaster of paris to form a flat ceiling. The size and distance apart of the joists depends upon the loads to be borne and upon other con- ditions. An ordinary wooden floor is laid on the joists. A system introduced many years ago by Dennett and Ingle of Notting- ham has been adopted in many im- portant buildings, including the new Foreign Office, Home and Colonial Offices, the Town Hall, Manchester, and Her Majesty’s Theater. arch of concrete, having sulphate of lime or gypsum for its base, the other constitu- ents being broken bricks, stone refuse, furnace dross, &c. The concrete is spread upon specially constructed centers, and the spandrels are either left open or filled up to the floor level, as shown in Fig. 32. A section through the ceiling over the Cabinet Council Room of the New Foreign Office is shown in Fig. 33, the dome being 36 feet diameter, and with a thickness of 9 inches at the haunches. A section through the domed vault over the ladies’ dressing room, at Her Majesty’s Theater, is shown in Fig. 34. This dome is 30 feet by 20 feet by 5feet. Many experiments have been made with these floors with very good results, the 8 foot span of Her Majesty’s Theater bearing safely a load of 3} tons per square foot. Experiments by impact are, however, useless when the load is applied to one spot; for it is possible to send a shot through a pane of glass without shattering it, and yet the same bal) would probably not stand on a similiar piece of glass without breakingit. A floor patented by Joseph Bunnett in 1858 was formed of hollow bricks having two sides each composed of two parallel inclines half the depth of the block; tie rods bound the bricks to the angle iron wall plates, and formed a slight arch. The construction is shown in Figs. 35, 36, 37, 38 and 39. Arches of this design have been made with a span of 21 feet and a rise of only 24 inches. An experimintal arch of 15 feet span and 2 feet 3 irches wide carried a distributed load of 267 pounds per square foot with a defection of ,% inch; each brick was 104 inches long by 9} inches wide by 6 inches thick, and weighed 21 pounds; they were joined together with Portland cement and sand. Thaddeus Hyatt has obtained several patents for fire-proof floors in which iron is used in combination with concrete. One system substitutes flat bars 2 inches by + inch for the small rolled joists. In another system angle irons are riveted to the underside of the girders to carry the ¢-inch wires crossways, which act as a key for the concrete; ceiling holders 24 inches deep, and notched at the ends to slip on the flanges at the joists, are placed 2 or 3 inches apart, and the concrete is then laid, light timbers being used to which the flooring can be attached. Another system, Figs. 40 and 41, is the subject of a later patent. In addition to the vertical bars imbedded in it, the concrete is arched It consists of an | from one bar to the other, and kept in position by tie rods incased in a mixture of either plaster of paris, concrete, or other fire-proof material. blocks of glass of various forms are placed in it at intervals to illuminate the space below and so dis- pense with windows, which Mr. Hyatt con- tends are a source of danger ina fire. This system is claimed to be a “ self supporting illuminating beam arch.” (To be continued.) = ——$————_$__— The Armor-Plate Trials. BY A NAVAL OFFICER. In the recent armor-plate trials at the Naval Ordnance Proving Ground at Indian Head, the three plates used, as has al- ready been stated by The Irun Age, were a Bethlehem nickel, a Carnegie, Phipps & Co. nickel and a Bethlehem simple steel, which had been put through a process in- vented by a Mr. Harvey for hardening the face of the plate. This hardness is in- tended to penetrate the plate for several inches, }eaving the remainder in its origi- nal condition. Each plate received four 6-inch Holtzer steel projectiles at the cor- ners and one Firth 8-inch shell at the cen- ter. The 6-inch bolts weigh ed 100 pounds each, and wepe fired with a charge that at the distance from the target would give them 2075 feet per second as their striking velocity. These shells were of the armor- piercing type, had a length of 17} inches und were fired from a gun 40 calibers in length. The 8-inch shells weighed 210 pounds each, were 21 inches long and had a striking velocity of 1850 feet per second. All three of the plates were of the same dimensions—namely, 8 feet high, 6 feet wide and 104 inches thick. They were placed side by side on the arc of a circle having its center at the gun. The firing resulted as follows: The Bethlehem nickel kept out allcf the 6-inch projectiles, but was rather badly cracked by the 8-inch projectile, which, as in all of the trials, was not fired until after the plate had re- ceived all four of the 6-inch projectiles. The Carnegie nickel plate let the upper two 6-inch and the 8-inch through into the backing and kept out the two lower 6-inch, which were the third and fourth shots fired at the plate. The 8-inch, in addition to its penetrating the target, cracked it considerably, although not to the same extent as the Bethlehem nickel plate suffered. When this shot was fired it was the general opinion that deeper penetration would be obtained than by any of the previous shots. Subsequent measurements, however, failed to bear out this notion. The shell remained in the hole, its base being sunk not quite 1 inch below the face of the plate, giving thus a total penetration of 22 inches. ~— The Bethlehem Harveyed plate kept out and broke up the first and second 6-inch shells that were fired at its upper corners and the fourth 6-inch fired at one of the lower corners. The third 6-inch and the 8-inch got through into the backing fur- ther than any shell succeeded in doing in the other plates. The 6-inch getting through was decidedly an unexpected re- sult. The hole made was larger in diam- eter than those made by the two previous shots in this target, and the shell was wholly imbedded until the base was almost 10 inches from the face of the plate. It was concluded as a result of this penetration that enough power having been given to th