38 DISCUSSION ON MAY MEETING PAPERS. 



very violent nature, pieces being projected in all directions, a steam pipe of Ij^ inches diam- 

 eter being cut in two about 8 feet away from the explosion by one of the pieces of the spray 

 valve body. 



Fortunately this explosion was not attended by fatal results, but I think most practical 

 engineers will agree it is better to get rid of a system where there is liability of 

 such occurrences. 



The authors do not seem to realize that the mechanical injection of fuel is obtained by 

 the use of very small and simple pumps and fuel pipes, which are also very small, and have 

 an enonnous factor of safety. 



With regard to the high-speed Diesel engines for the electric drive, the consumption of 

 these engines is as small as that on the larger type. On looking through the official trials of 

 over twenty submarine engines running at 380 revolutions per minute, the figures are in the 

 neighborhood of 0.382 to 0.386 per brake horse-power per hour; therefore I think that part 

 of the disadvantage under the heading of 3 on page 8 should be eliminated. 



Of course everyone must quite agree with the authors that, if American shipowners 

 desire to run their ships in competition with European companies, they must employ internal- 

 combustion engines. 



Mr. Edgar D. Dickinson, Member: — Many of the thoughts that had occurred to me 

 have been expressed so much more ably by others, especially one remark Mr. Femald made 

 about what we are doing to develop apparatus, that I will not say anything on the subject. 



There are, however, a few points in the paper read by Mr. Shaw which I think we should 

 mention here. Referring to page 6 saving on auxiliaries, possible only with electric trans- 

 mission of power : The alternative, as I read this paragraph, would mean — ^I cannot believe 

 the authors meant it — to recommend a separate Diesel engine for each winch, capstan, start- 

 ing engine, pump and compressor. In practice, the advantage of the oil-engine driving auxili- 

 aries can only be secured by the use of electrical means. Regarding the auxiliaries, I am 

 glad to see that this has been given prominence, because the same means and therefore the 

 same saving can be realized on any ship, and it is in no way affected by the kind of propul- 

 sion machinery. 



On page 7 the argument in favor of more than two sets of auxiliary Diesel engines — 

 that is, the aitxiliary engines — applies to an even greater extent when considering Diesel elec- 

 tric propulsion with several generating sets as compared with direct drive. I will not go into 

 detail here; of course there is a loss in transmission with Diesel electric drive and there are 

 arguments pro and con that we cannot touch on. 



Trade Routes. — The field for merchant ships is wherever a cargo can be profitably car- 

 ried. The long trade should be the favored route, in that the percentage of time in port is 

 less, but it is sometimes the case that the short route is the more profitable. 



On page 7 I note that cheaper oils are not recommended for oil engines. That, of 

 course, is of interest in making comparison with other drives. I do not know of any par- 

 ticular troubles now being experienced with Diesel engines of the best types applied to the 

 duties for which they are designed. 



I would like to inquire what the authors mean by high speed. The studies of Diesel 

 electric drives with which I am familiar are based on using engines of established design, 

 moderate speed, rugged construction, and of design and general proportion that long experi- 

 ence has shown to be the most reliable. In that particular connection, on the Fordonian, 



