Engineering Wonders of the World
Volume I

36 ENGINEERING WONDERS OF THE WORLD. the crank-shaft, an important consideration where machinery space is limited. In the diagonal or inclined direct-acting type of engine the cylinders are placed diagonally at an angle to suit the height of the shaft, and the piston and connecting . Diagonal rojs are jjrectly coupled to the acting crank_g]iaft will therefore Engines. be seen that this type of engine takes up a larger amount of space in a fore and aft direction than the oscillating engine. It is, however, a very convenient form when considerations of space are not important factors in the design, and, being better adapted for working at higher steam pressures than the oscillating engine, it is used largely in modern paddle-wheel ships. It is no exaggeration to say that the advent of the marine steam turbine has, during the last ten or fifteen years, completely revolu- tionized fast ocean travel, and The Marine jiag j far _ reaching, effects Steam Turbine. on warshlP design. Among the advantages offered by the turbine as compared with the triple-expansion piston engine for high-speed vessels are : (1) freedom from vibration ; (2) reduced cost of working, maintenance, and supervision; and (3) diminished space and weight required. The success of the new form of propulsion is in a very great measure due to the inven- tive genius and the unceasing labour of the Hon. Charles Algernon Parsons. Other types of turbine, notably the Curtis, Rateau, and Zoelly, have been, or are being, applied to marine propulsion ; but of the total number of turbine-driven vessels so far constructed, by far the larger proportion are fitted with Parsons turbines. The Curtis turbine, the invention of Mr. Charles Gordon Curtis, is of the impulse type, with revolving wheels, each carrying two or more rows of blades. After the Parsons type, the Curtis turbine has been most largely- adopted for marine work. The American pas- Curtis, Rateau, and Zoelly Turbines. senger steamer Creole, and the scout-cruiser Salem of the United States Navy, are pro- pelled by this type of turbine, as will also be the battleship North Dakota, now under construction for the same Power. In the Japanese Navy the Curtis turbine has been the battleship Aki and the armoured cruiser Ibuki. The Rateau turbine is represented in several French and Russian destroyers and torpedo boats ; while Zoelly turbines have been ordered for the new German adopted for cruiser Ersatz Schwalbe, and for a tor- pedo-boat destroyer for the same navy. In 1894 a pioneer syndicate founded by Mr. Charles Parsons built the Turbinia (see Fig. 2) to demonstrate the suitability of the turbine principle for marine propulsion. Prior to that date History of turbines had been employed ^ar^°ns largely for electric lighting, bine, and in this tiny vessel they were for the first time used to revolve pro- peller shafts. The Turbinia, with her speed of 34 knots, proved herself the fastest steamer in the world, and those who wit- nessed her capabilities at the Naval Review at Spithead in 1897 will not soon forget the interest she created. The British. Admiralty was not slow to see the advantages offered by the new means of propulsion, and an order was placed with the Parsons Company for the construction of turbine machinery for a torpedo-boat destroyer, followed shortly after- wards by another order for a second set. These two destroyers each attained a speed of 36 knots on trial. Cross-Channel boats, river steamers, ocean yachts, and pas- senger vessels of moderate dimensions fol- lowed, proving the suitability of the turbine for high-speed merchant steamers. Then came the important experiments carried out with H.M.S. Amethyst fitted with turbines and similar third-class cruisers with piston engines,