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464 Parsons Geared Turbines The British warship Badger, which rammed and sank a German subma- rine boat, is the first British warship which was fitted with geared turbines, and this "good service', to quote the admiralty telegram expressing official pleasure with the crew, as well as the general excellence of her work during the war, is further proof of 'the efficiency of this latest system of ship propulsion. One -of 'the 'ob: THE MARINE REVIEW sion. The step to the geared tur- bines of the Transylvania was not so momentous, since the marine installa- tions in use or in process of construc- tion represent collectively about 1,000,000 shaft horsepower. The Transylvania, however, is the largest ship completed with the sys- tem. She has been built by the Scotts Shipbuilding & Engineering Co., Ltd., of Greenock, and is 567 feet in length, 66 feet 6 inches in beam, and 45 feet ee "e Cre: | << 20 S % 3 a ~~ N orl Rate. Lbs. per Hour per Horse Power es, 8 2 Steam Corns PRE Sip . (4201 1000 L000 3000 © 4000 5000 000 12 Horse Power.Each Set. jections urged against the turbine system generally was that it did not conduce to easy handling or maneu- vering of a vessel. Were further proof required to dispose of this idea, it is to be found in the operation of war vessels, not only at the "Fight of the Bight", but in ramming. An- other incident of the week, indicative of the increasing favor of the system, is the 'successful trial of the 'first Atlantic liner fitted with geared tur- bines--the Cunard liner Transylvania. This is only another indication of the commendable enterprise shown by our premier steamship company in recent years, for it will be remem- bered that they were the first to place on the New York express service a turbine-driven ship--the Carmania, which, under the command of Captain Noel Grant, R.N., won such renown as an armed cruiser by sinking the (ap. brararear. Lhe success of. the Lusitania and Mauretania, too, has had great influence on ship propul- in depth, and has accommodation for 2,475 passengers, including 350 in the first-class and 125 in the second-class rooms. The machinery is arranged to drive twin-screws, there being for each propeller-shaft a high-pressure and low-pressure Parsons' reaction Dis- place- ment. tons. Channel ssteameri) go a eee 2,030 CateG "COasteh iw ee eu 2,020 Cargo strain oy 11,900 Passenger and: cargo steamer... .2.. 11,520 hi S ei IMeRe ya ot ee ei ee 13,560 Oo Se Sr liner ee ee 35,500 Paddle: steamers so es: 494 _ SCrews. December, 1914 revolution of the propellers is 130 per minute, the ratio being 12% to 1. The full power is 9,500 shaft horse- power, and the speed 16% knots. The steam consumption of the turbines . is only 11% pounds per hour per shaft horsepower. These figures rep- resent the maximum power without the use of the by-pass valves. Either the high-pressure or low-pressure tur- bines can be worked independently, the steam-leads being arranged ac- cordingly, so that the derangement of any one turbine does not interfere with the driving of the ship by twin ! Incorporated with each low- pressure ahead turbine is an astern turbine of Parsons impulse. reaction type, of adequate power for rapid ma- neuvering. Further interest in geared turbines is raised at the moment by a paper read last Tuesday at the Institute of Engineers and Shipbuilders in Scot- land by WD. McLaren: and :G..M. Welsh. \ln it they gave outline par- ticulars of the machinery for a' num- ber of vessels typical of. various classes, and for the same ships de- signs, weights, etc., of geared-turbine installations were set out for com- parison. In dealing with perform- ances, actual and probable, the authors estimated the resistance, plotting curves of effective horsepower on a speed base, along with thrust deliv- ered, shaft and indicated horsepowers and the estimated steam consumption. The data are more or less empirical, but doubtless assumed from a large mass of material in the possession of the authors. Without entering into the methods of computation adopted, it is permissible to indicate generally the deductions made as regards com- parative steam consumption for differ- ent types of machinery. The authors admit the difficulties in setting out precise data, but give in the diagram annexed, Fig. 1, representative pet- formances which may be accepted as Heating surface. Weights : Recip- Geared tur- Recip- : rocating bine ma- rocating. Turbines. machinery. chinery. sq. ft. Sq. it. tons, tons. 9 900 7,890 580 470 2,130 1,930 145 152 8,200 6,610 570 500 21,520 17,540 1,280 1,030 30,740 27,670 2,120 1,560 83,850 83,850 5,550 4,200 4,230 3,550 240 195 *This is combination machinery against geared turbines, ahead turbine, placed side by side, the former on the inner and the latter on the outer line, both engaging with a gear-wheel on the propeller-shaft. The size of the installation. is sug- gested by the diameter of the gear- wheel, 10 feet, and its breadth, 5 feet. At full power the turbines run at 1,630 revolutions, while the speed of correct within reasonable limits. They direct attention to the point that the consumption rates for engines with dependent pumps is less than for en- gines with independent pumps; but in the latter case the power for these auxiliaries is not recorded, and the heat in their exhausts is generally utilized for feed-heating. Compound