All About Engines

Engines for Ships 293 to be used. The one illustrated is made in sizes to produce from 20 to 80 tons of distilled water per day; the largest is 9 ft. 8 in. high and occupies a floor space of 5 ft. 6 in. by 4 ft. 3 in. But that is only a small fraction of the space which would be required for the water. The Machinery of Great Ships The steam turbine was first used for marine pro- pulsion about twenty years ago, when a small vessel, the Turbinia, which was about 100 feet long, accom- plished a speed of 32 knots, beating by 8 knots the fastest vessel then afloat. After this experiments were made on both war ships and fast passenger vessels leading to a considerable increase of speed as well as economy. The greatest triumph of all, perhaps, was secured by the sister ships Mauretania and Lusitania, of the Cunard Line. Since they were launched in 1907 these vessels have been surpassed by other vessels of the mercantile marine in size, but never in speed, and the Mauretania's 26 knots still remains a record for a merchant ship. This wonderful vessel has twenty-five boilers, twenty-three double-ended, the other two being single- ended as in Fig. 35. The former have eight and the latter four furnaces each, so that there are 192 furnaces altogether, and these require 192 stokers and 120 trimmers, work- ing in shifts to keep them fired. This duty is not left to the men to do or not as they think fit. On many ships the orders for firing are sent from the