70 THE DETERMINATION OF THE RESISTANCE OF SHIPS. 



I have worked very hard to bring about this trial of electrical propulsion, and finally I 

 have succeeded in doing so. It has taken about eight years to do it. Whether there will 

 be any more electrically propelled vessels, I do not know. I believe the California is still 

 regarded as an experiment, but when she is fully equipped and running the installation 

 of electrical propulsion may popularize itself and electrical propulsion have the use which 

 I think it is entitled to. 



When I began the proposed electric propulsion there was no geared propulsion — that is, 

 I had never heard of it, although I dare say there may have been some beginnings made — 

 and when good engineers began to propose geared equipment I bethought myself very care- 

 fully as to whether the electric method was justified in the light of possibilities demonstrated 

 or imagined in connection with gears. I had been fortunate enough to limit my recom- 

 mendations to very definite purposes in my advocacy of electric drive; that is, I said in my 

 first statements on the subject that it was something suited to very large vessels where large 

 powers would be involved, and particularly suited to vessels in which economy at variable 

 speed was desirable, such as warships. Wonderful work has been done in connection 

 with gear drives, and the speed-reduction problems, which are the primary object of electric 

 propulsion, have to a great extent been solved in that direction. The exact limit of geared 

 driving is something which I do not know about, but I know that many experiences indicate 

 that the limit is high. 



This drawing of Sir Charles Parsons' design which I show here (Plate 39) is a couple 

 of years old. It shows a very complicated arrangement, but it does not show any of the 

 piping. This arrangement is designed for separate cruising turbines with a view to getting 

 high economy at cruising speeds; it involves a certain degree of complication, and the 

 different turbines are more or less tied together and dependent upon each other. One of 

 the greatest advantages of electric drive is that you have a lot of units which are indepen- 

 dent, two or more generating units and several motors; you are not dependent upon any 

 mechanical connection which may be broken or impaired, you do not have to carry steam 

 across from one turbine to another, you have a relatively simple unit, and electricity is used 

 as a means of transmission. Another great advantage is that you can run at low speed with 

 one unit instead of using two and make your electrical connections so that the speed is right 

 and the electrical efficiency is always high. 



In the large number of ships now being proposed in the Navy, I believe that a great field 

 opens for electric propulsion, and that, if electric machinery is designed to drive some of 

 these large ships, better results can be obtained than in any other way. Although the devel- 

 opments in connection with geared turbines are very important, they have not changed my 

 opinion one iota as to the expediency of electric drive in the types of ship for which I 

 originally recommended it. 



