88 ENGINEERING PROGREvSS IN THE U. S. NAVY. 



Mr. McFarland: — There is no question of changing the gearing, which, as 

 already stated, is giving entire satisfaction. 



Mr. Edwin A. Stevens, Jr., Member: — Mr. Anderson, in his discussion, 

 compares the Birmingham with the other scouts. I agree that for such ships as 

 the scouts, cruisers, and destroyers, there is much to be said in favor of the turbine, 

 especially for the latter. 



We all know that the advantages of the reciprocating engine, compared with 

 the turbine, fall off decidedly in short-stroke high-speed engines such as those 

 that have been fitted in destroyers in the past. Due to a large percentage of clear- 

 ance the economy is poor, and also due to the inertia of the moving parts the high- 

 speed reciprocating engines do not give satisfaction. Where Captain Dyson in 

 his paper speaks in favor of the reciprocating engine, it is for a different type, 

 namely, battleship engines, where about 126 revolutions have been the highest 

 obtained, as in the Delaware. The engines in the Birmingham were designed 

 for 200 revolutions, although I believe the piston speed is about the same as the 

 Delaware. 



In comparing the engines of the Utah with those of the Delaware and the Wyo- 

 ming, I might call attention to the fact that the Wyoming is about 25 per cent 

 larger than the Delaware, and has considerably more horse-power, while the Utah 

 is only about 10 per cent larger, and her engines were designed for about the same 

 horse-power as the Delaware, although she (the Utah) developed considerably 

 more speed. Mr. Anderson complains that the Utah and Delaware is not a fair 

 comparison, and then takes a much larger ship, namely, the Wyoming. The 

 advantage due to size, if anything, would lie decidedly with the latter, as we all 

 know the larger the power we build an engine, the weight per horse-power decreases. 



The room for the machinery of the scout is, as Mr. Anderson says, the same, 

 but how about the Delaware and Utah? Captain Dyson points out differently 

 there. Another thing, in both Mr. Curtis' and Mr. Anderson's remarks about 

 increasing the economy of turbine, the question of increase of weights has been 

 avoided. If the increase in economy that Mr. Curtis speaks of in the improved 

 North Dakota is realized, what will be the increase in weight? 



Mr. Anderson mentions the Connecticut, Idaho, Nebraska, and Mississippi as 

 being laid up at navy yards with broken crank shafts and other troubles. I would 

 like to call attention to the larger number of ships there are in the Navy fitted with 

 reciprocating engines than those fitted with turbines. Taking the proportion of 

 time that the reciprocating-engine ships have actually spent in the navy yard for 

 repairs, and comparing that with the time that the turbine-engine ships have spent, 

 I think that the reciprocating-engine ship will be found to show up to advantage. 

 The North Dakota, for the major part of last summer, was in the navy yard, and 

 the Chester spent all of one summer in the navy yard for repairs. 



If any ship with a broken crank-shaft is kept in a yard for any considerable 

 time for repairs, it would probably be waiting for a new forging, which should 



