Diesel-electric locomotives of the British Railways

The paper gives a brief history of the attempts made to utilize the Diesel engine for railway traction, and the trend towards electric transmission for larger-powered units. The entirely different considerations in the application of Diesel-electric motive power to shunting and to main-line work are treated separately. The Diesel-electric shunting locomotive must be capable of meeting a fairly definite set of operating requirements, and these practically determine the main features of design. The basis of the design of the main-line Diesel-electric locomotive is that it shall perform the duties of one of the existing traffic classes of steam locomotives. A comparison between the operating characteristics of steam and Diesel locomotives is difficult, because of the different speed/tractive effort characteristics and other variables. The dominating problem in the design of the main-line locomotive is to compromise between the restricting limits of space and weight, and yet have an engine which will operate at a high load factor, at the same time giving reliability and economical running. The scope for Diesel-electric traction for main-line locomotives in this country must depend upon the extent to which its potential availability can be utilized.