Engineering Wonders of the World
Volume I

42 ENGINEERING WONDERS OF THE WORLD. The combination of piston and turbine engines has also been adopted for Atlantic work in the new White Star- The Triple- Dominion liner Laurentic. This screw Atlantic , , . . , , , . vessel, which has a gross ton- Liner “Lau- c rentic.” nage of about 14,500, is pro- pelled by two sets of four- crank triple-expansion “ balanced ” engines driving two outer screws, and a low-pres- sure turbine driving the centre screw. The Megantic, a sister vessel, with the exception less speed—no wunder construction by Messrs. Harland and Wolff. Any forecast as to the future development of marine propulsion must take into account the internal-combustion engine using either gas or oil fuel. The application of this engine for marine work has made great strides during the last few years in vessels of moderate size and power, and it would seem that its adoption in ships of large dimensions and high speed is only a question of time. Fig. 17.—MOTOR CARS PASSING THROUGH THE FUNNELS OF THE “ MAURETANIA.” that she will be fitted with twin-screw pro- pelling machinery of the piston type, has also been constructed at Belfast, so that soon a comparison of the efficiency of the two systems will be made under exactly similar conditions in Atlantic work. The sea performance of the Laurentic and Megantic will be watched closely by the shipping world, for it is known that the combination of piston and turbine machinery will also be adopted in the two great White Star liners—larger than the Lusitania and Mauretania, but of much Internal- combustion Engines. The chief reasons why internal-combustion machinery commends itself are (1) the ab- sence of boilers, funnels, etc., and (2) the economy effected in fuel consumption. This form of machinery is able to convert the greatest percentage of heat units in the fuel used into mechanical work, and consequently it is not surprising that many experiments are being conducted, and that marine engineers generally are eagerly awaiting developments. One of the