ELECTRIC PROPULSION OF MERCHANT SHIPS. 295 



I trust tliat my remarks will be taken only as constructive criticism, in that we may 

 not, in the development of this new propelling drive, pass through such unpleasant and 

 costly experimentations that we have had with the reduction gear drive. 



It is quite unwise to consider installing the electric drive in more than a few vessels, 

 until sutificient time has elapsed to have thoroughly tested it out in actual operation, to per- 

 mit it being boiled down to a practical operating unit; and while the advocates of the elec- 

 tric drive may be fully convinced that it will be a perfect running unit, still they assumed 

 the same position at the beginning of the reduction gear drive, with the results of which 

 you all are aware. 



The President: — Is there any further discussion on the paper? If not, we will ask 

 Mr. Emmet to make such reply as he desires. 



Mr. Emmet: — A good deal has been said on which I will not undertake to comment. 

 Much of the criticism brought against electric propulsion on board ships I have been familiar 

 with for thirty years in every branch of the art to which electricity has been applied. The 

 same things have been said over and over again in connection with other uses where it has 

 been proposed to use electricity. The fact remains that, wherever electrical apparatus goes, 

 it popularizes itself. It involves simple rotation, and rotation is much more simple than 

 mechanical reciprocating movements. 



Mr. Smith has been quoted as saying that the electric drive was much more expensive, 

 while other shipbuilders have made comparisons similar to those which were made by Mr. 

 Smith and found that it was cheaper, so' that there was a difference of opinion. 



The suggestion that the Diesel engine was the solution is another thing that I will not 

 go into; it is' rather complicated, but I have been informed by very good authorities that the 

 best Diesel engines were the big, slow ones, that the high-speed ones had generally not 

 proven so reliable, and that if you are going tO' put a Diesel engine on a ship you had better 

 connect it directly vi^ith the propeller. I do not know whether that is true or not, but that 

 opinion is held by people who are very good authorities on Diesel engines. 



I think that the Diesel engines might be operated in connection with electricity under 

 certain circumstances of speed and power, and I believe that some such installations have 

 been successfully carried out. 



The comparison shown in my paper is of the engine instead of the gear, but, in point 

 of fact, if I had put in the gear, it would have taken up almost exactly the same space. It 

 happens that I had the weights and particulars of an engine, and since there are many types 

 of gears, I thought best to make comparison with the engine, which is still in extensive use, 

 for the propulsion of such ships, and which fact now seems to be quite generally preferred 

 to the gear drive. 



No investigation of the oil used in these determinations of gear efficiency was made. 

 We were running with a rather thin oil, such oil as is generally used, and it was heated to 

 normal temperature, that is, the gears had been running a long time, and the oil had taken 

 its normal temperature, so that this test was not peculiar in the matter of the viscosity of 

 the oil. 



One gentleman suggested that pitting was well known, and that it was generally on the 

 pitch line, or always so. I suggest he look at Plate 119 of my paper, which is a photograph 

 of the gear, which shows pitting all over the face and very large chunks of metal removed. 



