Compound Locomotives

Abstract

THE present position of locomotive engineering in this country is of a very interesting nature; owing to the gradual increase of weight of trains hauled and the higher speeds now in use, it has been necessary to increase the power of the locomotive by leaps and bounds to cope with these demands. This naturally has not been done without great scheming on the part of the designers, for, with the standard gauge of railway of 4 feet 8½ inches, the engines are tied down to certain dimensions between the frame plates; in total length, to a certain extent, by the turntables in use; and in height of boiler for reasons of stability. These questions of design are interesting because they are intimately connected with the economical working of the engines, especially in the consumption of fuel, a question which of late years has taken a prominent position in the economical management of locomotives. For several years the highly economical results obtained at sea with the use of high pressures coupled with the compound or triple expansion engine have caused engineers to look in that direction for further improvements, with the result that two different types of compound locomotives were designed, and are considerably past the experimental stage. These engines are now working successfully on two of the English railways, and are being adopted on many foreign ones.