Challenger of Locomotive 137 



considerable running it was seen that the 

 difficulties of providing a suitable change 

 gear transmission were almost insurmount- 

 able; it was therefore determined to have 

 an alternative scheme by which electric 

 transmission took the place of the gear 

 drive. 



Many possibilities are envisaged in such 

 a combination as the Diesel engine with 

 electric drive. In the first place there would 

 be nothing to prevent such a combination 

 being employed on lines already electrified. 

 Take, for instance, the Metropolitan Rail- 

 way which has to depend upon steam and 

 electric locomotives for some miles. The 

 train from the city is hauled by an electric 

 locomotive but there comes a point where 

 the electrification of the system ceases. At 

 this station the locomotive must be changed, 

 which, even in the best circumstances, 

 means some slight delay; this delay in the 

 aggregate is quite a serious factor, especially 

 upon such crowded metals as these. 



It is claimed by the expert that the Diesel- 

 electric unit would serve admirably for such 



