140 Book of Engineering 



It may be of interest to mention here 

 that the petrol-electric coach, and the petrol- 

 electric locomotive, are by no means new, 

 since a large number of both kinds of 

 vehicles were sent out to France during the 

 War and used with great success behind 

 the lines on the light railways which were 

 built for transport of munitions and stores. 



Now to consider the problems involved 

 in connection with Diesel-electric traction. 

 At the outset the power vehicle, whether 

 it is a locomotive or a motor coach, bears a 

 resemblance to the steam engine in that 

 each is self-contained; in addition, the out- 

 put of its prime mover has a definite limit. 

 In the second place the transmission of 

 power, being electric, is capable of high 

 overloads for limited periods. 



Owing to the enormous capacity of a 

 power station when compared with the 

 rating of the rolling-stock motor, ordinary 

 electric stock permits the full advantages of 

 the electric motor to be utilised to the 

 utmost limit. It has been the aim of the 

 designers of the Diesel-electric equipment 



