138 Book of Engineering 



a system as this and that it would save the 

 heavy cost of electrifying the remainder of 

 the Metropolitan system. It is suggested 

 that the train might draw its current from 

 the live rail up to the point where it ends, 

 and then the Diesel engine should be coupled 

 up to provide power for the rest of the 

 trip. 



There are, of course, some difficulties in 

 the way of the adoption of such a scheme, 

 and there are some engineers who contend 

 that the Diesel-electric unit will have to 

 have considerably longer testing than it has 

 so far been possible to give it. The great 

 point, however, is that the Diesel-electric 

 system could be profitably employed on 

 lines which need electric traction, but for 

 which the cost under present conditions is 

 certainly prohibitive. 



In comparison with steam, the balance 

 is very largely in favour of the Diesel 

 engine, nor has progress in the development 

 of the high speed Diesel engine been in 

 any way exhausted. So far from that being 

 the case, these engines are now being made 



