AIR COMPRESSORS 

 TABLE (Continued) 



The main reservoir varies in size according to the kind of 

 service freight or passenger in which the engine is employed. 

 In the best practice, a main reservoir of not less than 40,000 cu. 

 in. capacity for passenger, and from 50,000 to 70,000 cu. in. 

 for freight, service is used. For freight service the following 

 schedule is recommended. 



Main -Reservoir 



Pump Capacity Capacity 



Cubic Inches 



One 9*-in 50,000 



Two 9i-in 65,000 



One 11-in 60,000 



Two 11-in 70,000 



One 8J-in. cross-compound 70,000 



If the train is long and the main reservoir small, a high 

 pressure must be carried in the latter in order that it may 

 equalize with the brake pipe at a sufficiently high pressure to 

 promptly release the brakes and recharge the auxiliaries. 

 When the main reservoir is large, a much lower reservoir 

 pressure can be carried, and the pump can also store a greater 

 quantity of air while the brakes are applied. When, there- 

 fore, the main reservoir is small, the pump must work both 

 *These sizes are always in stock. 



