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ELECTRIC AUXILIARIES ON MERCHANT SHIPS. 



The greater part of the electrical machinery below deck is naturally located in the engine 

 room. The following table gives a list of below-deck auxiliaries suitable for a cargo ship 

 of about 8,000 to 10,000 dead-weight tons and equipped with 2,500 to 3,000 shaft horse- 

 power steam turbine. A motor ship requires somewhat fewer auxiliaries, and slightly less 

 power is necessary for driving them. Tankers require a number of motor-driven pumps 

 for discharging the cargo. These may be installed either in a special pump room or arranged 

 with the motors on deck with vertical shafts to the pumps below. It will be noted that in 

 the list there are only five sizes of motors. That is with the intent of simplification and to 

 reduce the number of spare parts to be carried. A study of particular cases may show that it is 

 possible to satisfactorily arrange the engine-room equipment so as to have still fewer sizes. 



Below-Deck Auxiliaries. 



Motors for these auxiliaries should be designed for continuous running, because, while 

 certain pumps may be started and stopped frequently, the service cannot be considered 

 intermittent. 



In the engine room, and in fact even if placed in the lowest part of the ship, totally en- 

 closed motors are not recommended. For continuous operation they would have to be ex- 



