158 ELECTRIC AUXILIARIES ON MERCHANT SHIPS. 



the future and maintain such advantage as we have secured due to the large increase in Ameri- 

 can registry, it would seem that the opportunity afforded by this joint meeting should prove 

 of inestimable value, as engineering advancement can only be secured when a thorough 

 knowledge and understanding of all conditions are recognized by both the manufacturers and 

 users of machinery. 



The problem is entirely an economic one. It is only because investigations show that 

 the electrically equipped ship can be operated more economically and can earn more that the 

 question is being discussed. It is the intention of the writer to endeavor to show why this is 

 the case. 



Not much information has been published relating to the details of costs of operation of 

 ships. Studies indicate that on new ships electric auxiliaries will show a marked improvement 

 in the economy of operation and will increase the net earning capacity. The future will show- 

 that many existing ships can be operated profitably by the substitution of electric for steam 

 auxiliaries. The reasons for expecting such big savings are not at once apparent. Investi- 

 gations indicate that the losses are partly due to innumerable small leaks and to radiation ; 

 in other words, it is the steam which is generated in the boilers but not put to useful work 

 that, in a great measure, accounts for the high fuel consumption of many steam-driven ships. 

 When it is recognized that steam is kept on hundreds of feet of piping from the boilers to 

 the steering engine all the time, and in many ships it is always on all deck lines, to avoid losses 

 and leaks incident to expansion strains from alternately heating and cooling, and in the win- 

 ter time there are often considerable extra losses incident to keeping steam on deck ma- 

 chinery to prevent freezing, it can be seen that it is not by any means entirely due to the in- 

 efificiency of steam auxiliaries themselves that we get a poor showing, but to the very nature 

 of their application, which cannot be altered. The size of the evaporators fitted in many 

 steamships is proof of the amount of steam that is made by the boilers and passed off into 

 the atmosphere. 



Auxiliary machinery on ships can be readily subdivided into two broad types: (a) For 

 deck use; (&) for below-deck use. The motors most suitable are enclosed, weather-proof for 

 above deck, and ventilated for below deck. 



It is not the intention to describe a number of different pieces of electric machinery for 

 ships. A study of the technical papers shows an ever-increasing amount of space being 

 given to such descriptions. Thoroughly reliable, simple and substantial machinery of vari- 

 ous designs has been developed. 



DECK MACHINERY. 



Deck machinery (Plates 29, 30 and 31), properly speaking — that is, all machinery which 

 is exposed to the elements and which must be built with this in view — consists generally 

 of cargo winches, anchor windlass, a certain number of capstans, mooring winches and 

 sometimes special machinery on particular ships. It is true that the steering machinery is 

 not generally exposed to the elements, but is, however, very often housed in an extremely 

 damp compartment. Continuous operation is vital to the safety of the ship. It will be 

 evident that only machinery designed and built for the service should be considered for 

 the application. The sei-vice of deck machinery is of an intermittent nature except in some 

 special ships, that is, certain tankers where the motors for driving the cargo pumps are 

 mounted on deck. 



Electric deck machinery has been developed along two fundamentally distinct lines : one 

 in which the motor is mechanically geared to the drums, and the other where some form of 



