222 THE SUBMARINE OF TO-DAY AND TO-MORROW. 



cubic feet of free air for its combustion. In the low-pressure type of engine which I am 

 designing for the Navy Department, the clearance will be about 17 per cent, and in a cylin- 

 der with the same bore and stroke there will be 1.17 cubic feet of free air at the beginning 

 of compression. I think that Mr. Donnelly will agree with me in my contention that the 

 output of power in my type of engine will be over 8 per cent greater than in the Diesel of the 

 same size. When I first proposed this type around 1905 the objection of the original Diesel 

 manufacturers was that this engine would have some good points, but it would be more 

 bulky than the Diesel. This proves the contrary to be the case. 



Mr. Donnelly did not bring up the matter of efficiency, nor did Mr. Sperry. For this 

 reason I will not say much on this point. It will be sufficient to say that this engine which I 

 have originated will avoid the slow feeding of the fuel and in this way will gain in efficiency 

 over the Diesel. The Diesel idea of slow feeding was originated as a result of the Diesel 

 fallacy, which has since been abandoned by the engineers who have made a study of the 

 oil engine. The slow-feeding doctrine is the vermiform appendix of the oil engine. 



There is a feature which has been brought into my engine in order to produce the 

 desired result in regard to obtaining a low-pressure type of engine, and this feature has 

 other uses. For instance, it is necessary to warm the engine in order to use low-compression 

 pressures. The only practical way to accomplish this seems to be by the use of steam in the 

 jackets of the engine. This steam must be first produced by the combustion of fuel. The 

 supply of steam can be maintained by the waste heat of the engine. Now we have a supply 

 of heat on the submarine. Is this steam of any use? Mr. Spear and his engineers say 

 "No." I say "Yes." Perhaps there has been a change of heart in the submarine builders in 

 the last five years since this proposition was put up to them. At that time I do not believe 

 they even dreamed that submarines would cruise 1,000 miles. They do, however, and have 

 developed into real ships in the broadest sense of the word and are no longer dispatched for 

 a short dash to perform a special mission and return to their base. A military element must 

 be capable of performing its function regardless of conditions. Can the crew do their best 

 work if they are confined in a cold, damp vessel? Will it not be a godsend to the crew if 

 they can have properly heated quarters, and will not the result of this physical comfort be 

 manifested in their spirit and accomplishments? I believe this will be tTie case. Then again, 

 might it not be advisable to give the submarine the ability to make a short spurt of extreme 

 speed while submerged? This could be of use either for the ofifensive or for seeking safety. 

 This can be done if there is a steam supply, by running the oil engines as steam engines from 

 the steam supply at the same time the motors are nmning. In this way the maximum 

 speed of the submarine while submerged can be greatly increased. When I was a student 

 in the naval architectural course at the Massachusetts Institute of Technology I was taught 

 that the limit of speed of a ship was caused by the wave-making resistance. I was taught 

 that up to a certain point the power needed practically depended upon skin friction, but that 

 above a certain point the wave-making resistance came into consideration, and the result 

 was that further speed was at the expense of an excessive amount of power. Certainly a sub- 

 marine should eliminate this wave-making resistance to a certain degree, at least while sub- 

 merged. Might it not be possible to attain a greater speed submerged than on the surface ? 

 This speed could be maintained for only a short time and it might not be a valuable factor. 

 This is a problem for the strategist and not for the engineer. The engineer can give the 

 strategist the burst of speed if it is desired. 



There is another point in connection with the present submarine engines. They are 



