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¢ THE Marine. REVIEW Development of the Marine Steam Turbine. BY THE HON, C. A. PARSONS AND R, J. WALKER. During the last few years the steam turbine has formed the subject of many papers read before various leading in- stitutions, and its different applications have often been referred to. It is hardly within the scope of this - paper to deal in detail. with the earlier experiments and trials which have led up to the present satisfactory position of the turbine. It may be of interest, however, to briefly describe the various steps that have been made from time to time in the development of same. In 1894 the first Parsons compound steam turbine engine was built and was applied to the driving of a dynamo. This engine was designed for 10 H. P., with a modified high-speed dynamo, and for a working speed of 18,000 revolutions per minute. It ran for some years, do- ing useful work, and is now in South Kensington museum. Subsequently, efforts were made to- wards the construction of engines of larger sizes, which resulted, in the year 1888, in several turbo-alternators of 120 _H. P. being supplied for the generation of current in electric light stations, and- at that period the total H. P. of turbines at work reached in the aggregate about 4,000, all of which were of the parallel flow type and non-condensing. In 1892 the steam turbine was first adapted to work in conjunction with a condenser. This engine was capable of developing 200 H. P at a speed of revo- lutions of 4,800 per minute, and drove an alternator of 150 kilowatt output. It was tested by Prof. Ewing, F. R. S.,, and the result of the test showed a consumption of steam of 27 lbs. per kilowatt hour, which is equivalent to about 16 lbs. per I. H. P., with steam moderately superheated and a vacuum of 28 in. Since then various improvements have been made, until at the present time the steam turbine is generally recog- nized to be an efficient and practical engine, which, in the larger sizes, has attained a high degree of economy in steam. The following table shows the ad- vance made in sizes and increased econ- omy in steam consumption as applied for electrical purposes: Steam Super- Steam Capac- per kil- heat _pres- ity kil- - owatt Vacs, Deg. sure per owatts. hour, inches. EB. <. sq; in, Date. Ibs. lbs. 1887 75 50 Mase Rae 120 1892 100 27.00 27 50: sas 1898 1250 18.81 28 180 130 1901 1000 17.30 27 198 150 1902 3000 14.74 27 235 138 ' 1904 4000 15.40 28.7 150 200 Superheating of the steam has been adopted in the case of land _ turbines, and it has been found by experiments that for every ten degrees F. of super- heat, the steam consumption is reduced by about one per cent. Fig. 1, which is based upon a large number of tests, shows the steam con- sumption of different sized plants per kilowatt hour without superheating, from which it will be noted that the efficiency increases steadily as the size grows larger. Turbine engines are also used for gen- erating electrical current for the trans- mission of power, the working of elec- tric tramways, railways, electric pump- ing, coaling and similar purposes. They are also used for coupling direct to and driving fans for producing forced and induced draft for general ventilating purposes; also for driving centrifugal and screw pumps, and also for the more important work of driving blowers for supplying air under pressure for blast furnaces and other purposes. Land turbines have been very largely adopted in the past few years for the generating of electricity, judging from the fact that these machines are running in the power stations of some forty cor- porations and of twenty-five public elec- tric supply companies. One of the largest power stations in England, now ap- proaching completion, contains two units of 3,000 H. P. and six units' of 6,000 i. Ps each. The total horsepower of turbines of the Parsons type delivered and on or- der, including turbines at work and un- der construction by licensees on the Continent and in the United States at the present time for land purposes - is nearly 2,000,000 H. P.. The. installa- tions now on order include units of up- wards of 10,000 H. P. The application of the steam turbine to the propulsion of ships has attracted a great deal of attention in the ship building world within the last few years. It was not until the year 1894 that the idea of propelling a vessel by means of a steam turbine was put into prac- tical form. The Turbinia, as is now generally known, was the first vessel to be fitted with turbine engines, and be- tween the years 1894 and 1898 many experiments were made with the Tur- binia, niecessitating radical changes in the design and arrangement of the ma- chinery. The first engine which was "Paper read before the Institute of Marine Engineers in London, tried was the radial flow type, giving about 1,500 H. P. to a single screw. The results, however, were far from satisfac- tory, a speed of only 18 knots being obtained. Several different propellers were tested with this engine, and the results compared with the power reg- istered by a dynamometer showed in every case a very low propeller effi- ciency. The original turbine engine was removed, and the engines finally adopted consisted of three turbines in series-- high pressure, intermediate pressure, and low pressure--each driving a separate shaft, with three propellers on each shaft. A reversing turbine was coupled with the low pressure turbine to the central shaft. Very exhaustive trials were car- ried out by Prof. Ewing in 1807. A full account of these trials will be found in the "Transactions of the Institution of Naval Architects," Vol. XLV (1903). Following the success of the Tur- binia, the torpedo boat destroyers Viper and Cobra were built and fitted with turbine machinery for the royal navy, and achieved remarkable speeds, the Viper taking the position of being the fastest vessel in the world, having at- tained the phenomenal speed of 36.86 knots per hour. Unfortunately, how- ever, the Viper ran on the rocks of the Channel islands in a fog, and ultimately became a total wreck. The Cobra foun- dered in a storm. Thus, after two or three years of hard work the Turbinia was the only vessel afloat fitted with turbine engines. ' About this period very great difficulty was experienced in endeavoring to in- duce railway companies and owners of mercantile vessels to build a_ turbine boat. Each company appeared anxious that someone else should make the first experiment. The marine turbine was first adopted for commercial purposes in the Clyde steamer King Edward to the order of Capt. Williamson in the summer of 1901. So successful was this vessel during the first season's running on the Clyde (the year of the great exhibition at Glasgow) that an order was placed for a second vessel, Queen Alexandra, and the per- formance of these two vessels running on the Firth of Clyde demonstrated the commercial advantages accruing from the adoption of the turbine system. Other vessels quickly followed the King Edward and Queen Alexandra until there are at the 'present time 31 turbine vessels in service for commer- cial purposes, representing a total of