The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

1902.] MARINE REVIEW AND MARINE RECORD, = lished between the boats using coal and those using oil, and this would be another incentive to cause systematic and careful study a. the subject upon the part of all connected with the torpedo eet: The data which have been secured by the liquid fuel board will be exceedingly appreciated in maritime and industrial circles. A careful analysis of these data will show how complete it is and how carefully it has been collected. -Although the experiments have only been in progress for a short time, practically every en- gineering principle that enters into the oil-fuel question has been touched upon by the board. The tests that have been conducted have been of such a diversified nature, and so many deductions can be made, that other experiments will now be enabled to ascer- tain in what direction research should be carried on to secure further definite information. The completeness and character of the experimental plant has probably never been surpassed, and it is due to this fact that the data collected will command attention in the engineering world. While the information secured may not hasten the introduction of oil as a fuel in arrnored cruisers and battleships, it will materially increase oil-fuel installation in ships of the merchant marine and in shore establishments. It is the engineering or mechanical feature which is of com- manding importance in the industrial or mercantile marine world. The structural disadvantages which are so serious as regards naval development will only be encountered in a less degree in ships of the mercantile marine. The structural disadvantages that may prove so serious in the navy will not be encountered in the installation of liquid fuel appliances in shore establishments. The insuring of a reserve supply of the fuel ought also to be a less serious problem for industrial plants. It should therefore be understood that the naval problem is distinct unto itself, and that while the experiments so far conducted show that an instal- lation on a battleship is a serious question, the tests also prove that for manufacturing purposes crude petroleum is in many re- . spects an incomparable fuel. Probably not over a fraction of I per cent. of the oil used as fuel would be consumed by the navy; and therefore, while further investigation may be necessary to show the adaptability of oil for large war vessels, the tests already conducted will be of great value and afford considerable information to all present consumers of liquid fuel, as well as to those contemplating the installation of oil-fuel appliances. The engineering information which is being obtained by the liquid fuel board will secure increased efficiency of the motive power of the naval stations in the future, and also conduce to the benefit of the torpedo boat flotilla. It will also afford another illustration of the manner in which the industrial world has been aided by naval experimental research. The data collected during the official oil tests should be compared with the results secured under the same boiler when coal was used. 'The evaporative efficiency, as well as the ability to force the boiler with two kinds of fuel, can thus be com- pared and the engineering advance that has been made of late can best be appreciated. It will be mainly by reason of the fact that this comparative data is obtainable that important conclu- sions can be drawn from the information already secured. The bureau submits a copy of the report of Lieut. Ward P. Winchell, as to the performance of the steamer Mariposa, when using oil exclusively under her boilers in making the round trip between San Francisco and 'I'ahiti. The bureau also submits a copy of the preliminary report of the liquid fuel board. VOYAGE OF THE STKFAMSHIP MARIPOSA USING OIL FUEL. The following is a description of the steamer Mariposa, of the Ocean Steamship Cco., as fitted for oil-fuel burning, with an account of the preliminary trial trips of the vessel as witnessed by Com'dr. H. N. Stevenson, United States navy; also the re- port of Lieut. Ward P. Winchell, United States navy, who officially represented the department on the round trip of the steamer between San Francisco and Tahiti: The Mariposa is a single-screw iron steamer, built at the yard of William Cramp & Sens, Philadelphia, in 1883. She has just had new engines and boilers installed by the Risdon Iron Works, San Francisco. The oil-burning plant has just been in- stalled by the same company. 'This vessel has been employed in the Pacific trade, and is now running to Tahiti from San Fran- cisco, making the round-trip voyage of 7,320 knots each month. Gross tonnage .<2-x55-- das eee ae ob oaieelte OO) 3,160 Length between perpendiculars, feet............ 314 Beami,:. feet 5 vied anies «oe le: res ae AI Mean: dratight,, f€€foc2 -5-s0) <3 Hes sche Heed 22 Depth of -hold, feet... 555). -svet iim ngs eee oe rr 3/12 There is a single bottom with four watertight athwartship bulkheads, and two masts, square-rigged on the foremast. The total crew was formerly eighty-one, but since the change from coal to oil burning sixteen men have been taken out of the engineer's force, reducing the crew to sixty-five men and making the engineer's force for oil burning twenty men, as follows: One chief engineer, three assistant engineers, three oilers, one electrician, one attendant for ice machine, one attendant for air compressor, three water tenders, six firemen, one storekeeper. There is one triple-expansion engine of the inverted direct. acting type, with cylinders 29 in., 47 in. and 78 in. by 51-in. stroke, designed for 2,500 I. H. P., fitted with piston valves on the high- " pressure and intermediate-pressure, and slide-valve on the low- pressure cylinders, all driven by link motion. The condenser is part of the back framing. The cylinders are not jacketed. 'The air, feed and bilge pumps, of which there are two sets, are driven from the forward and after crossheads. The centrifugal circulat- ing pump.1s driven by a separate engine. The four-bladed pro- peller is 16 ft. .6 in. diameter and has a pitch of 23 ft, There are three cylindrical tank boilers placed fore and aft in the line of the ship--two are double ended, 15 ft. 3 in. diameter by 17 ft. 3 in. long, and one single ended, 14 ft. diameter by 9 ft. 9 in. long, the latter placed amidsnips forward of and worked from the forward fire room. Each double-ended boiler has: six corrugated furnaces. The double-ended boilers have a common combustion chamber for opposite furnaces, while the single-ended one has a common combustion chamber for its three furnaces. There is one smokestack for all the boilers. 'The combustion chambers of. the double-ended boilers have a brick bridge wall, and the back. sheet of the single-ended one is covered with fire brick. 'The decision to use oil in place of coal was not made until the changes in engines and boilers were well under way, and it was decided to. put the ship on the route to Tahiti. The steam pres-~ sure is 180 lbs. There is one auxiliary boiler, two-furnace return- tube type, in upper fire-room hatch, and fitted to burn coal only. THE OIL TANKS. These were constructed out of the old coal-bunker space forward of the boilers, and as the steamer is intended to carry oil for the round trip of about 7,320 miles some additional space had to be taken from the fore hold. They are arranged as fol- lows: Just forward of the boiler space a solid watertight bulk- head, well braced, was built from the berth deck to the single bottom of the ship, extending to the single skin of the ship, from side to side; 4 ft., or two frame spaces, forward of this was also built another similar solid bulkhead, which formed the after ends of the oil tanks; 48 ft. farther forward another similar solid bulkhead was built to form the forward ends of the oil tanks, and 4 ft. forward of this another solid bulkhead. The spaces of 4 ft..at each end of the tanks being a cofferdam space to catch any oil from leakage or accident, these cofferdam spaces can be filled with water if necessary. The tank space is divided into six tanks by a middle bulkhead and two side partitions. Splash plates to break the impact cf rolling are placed in each tank, a small opening at the top allowing any accumulation of gas to pass off to ventilating trunk. Small openings at the bottom allow free communication for the oil. Along the top of the tanks is provided an expansion head or trunk, being 4% ft, high and 414 ft. wide. Over each a ventilating trunk connecting with the top of each tank extends up to about 5 ft. above the hurricane deck, fitted with cowls, one tube reaching to near the bottom to carry off any heavy gas that might accumulate there. From the upper deck the sounding pipes to each tank are reached. There are no pipes in or through the tanks except those connected with the oil service. The total capacity of the tanks, exclusive of ex- pansion trunk, is 6,338 lbs. of oil--about 905.43 tons. One barrel of oil equals 42 gallons. To fill the tanks, on the port side outside the ship a 6-in. hose connection is fitted; from this a pipe leads to'/the forward fire room where the tank oil pump is placed. This pump, hori- zontal duplex, steam cylinders, 9 in., oil cylinders 8% in., stroke 10 in., can be used to draw its supply from the pipe and deliver into each of the tanks, or by using by-passes, which are provided, the oil barge alongside can fill all the tanks; an overflow pipe from each tank, carried at height of the deck above them, leads to an overflow outside the ship near the supply hose coupling. There are two service or settling tanks placed in pockets formed on either side of the single-ended boiler. 'They are reached by doors from the forward fire rcom; each of these tanks. holds about twelve hours' supply. 'They are filled by the oil-tank pump and have overflows back to the main tanks, ventilating tubes lead from near the bottom of the pockets in which they are placed to the smoke stack. Each service tank is provided with glass gauges by means of which the amount used every hour or watch can be easily measured. Each settling tank has two suction pipes, one at bottom to draw off water if necessary, the other at a height of about 2 ft. for the oil supply to the service pumps. All the tanks are provided with manholes to reach the interior. ~ PUMPS, AIR COMPRESSOR, ATOMIZER, ETC. The oil-service pumps, of which there are two, horizontal duplex, steam cylinders 6 in., oil cylinders 4 in., and stroke of 6 in., one being large enough to supply all the burners, are placed in the forward fire room on either side. They draw their supply from the settling or receiving through removable strainers placed so they can be easily changed for cleaning, and discharge into the bottom of the small heating tank near them where the oil is heated by a steam coil to not more than 150° Fahr., and thence by a pipe to the burners. The air from the compressors, under a pressure limited to 40 lbs., discharges into the top of the heater tank on its way to the burners, so that the oil and the air go to the burners under the same pressure. The heater tank is pro- vided with glass gauges, also a float to work a telltale and auto- matic control of oil-supply pump. The air compressor is placed in a pocket off the upper engine room platform, and consists of duplicate steam and air cylinders connected to a crank shaft carrying a fly wheel turning between the cylinders. Either set is large enough to supply all the air necessary. The air compressor is horizontal, _double-acting, 7