STRUCTURAL STEEL STANDARDIZED CARGO VESSELS. 109 



per cent of the total weight of the hull. The plates to be rolled are shipped flat 

 from the fabricators, punched and shaped to size, and rolled at the shipyard. As 

 many as 175 tons of plates have been rolled in a single day. Furnace plates, of 

 which there are only eighteen, requiring hot forgings, are pressed hot in hydraulic 

 presses at outside fabricating shops and shipped to the yard in blank form where 

 they are punched and worked to size to correct metal templates. 



Exclusive of the rolled plates, these shops with their limited equipment have de- 

 livered 460 tons of frame material per week, working night and day shifts, which, we 

 believe, will compare most favorably with other shipyards. 



Rivet driving being the barometer of production has gradually increased from 

 30,000 per day during July to about 75,000 a day for October, with an average 

 drive of 32 rivets per gang hour. As the men become more experienced and accus- 

 tomed to their task, we believe that a higher average hourly rate will be obtained. 



For the last two months we have employed an average of about 12,000 men and 

 have been assembling at the rate of six ships per' month; 18,000 men will ultimately 

 be required to fully man the yard, when a production of twelve ships per month may 

 be expected. 



We are a little over a year old in our enterprise, having broken ground on Sep- 

 tember 14, 19 1 7, and during this period, through an unusually severe winter, we 

 have completed the shipyard, delivered our first ship, the Agawam, classed Ai by 

 both the American Bureau of Shipping and Lloyd's — this being the first fabricated 

 ship built of structural steel to be delivered — and launched in all fifteen ships, which 

 conclusively proves the soundness of the fabricated construction and how this method 

 which we have employed has been the only one that could have been followed in the 

 emergency to build the bridge of ships to Pershing and victory. 



Note. — On actual measurement these ships have a deadweight carrying capa- 

 city of 5,350 long tons. 



DISCUSSION. 



The President : — Mr. Sutphen is entitled to your thanks for his paper and the illus- 

 trations. 



The next paper this morning is No. 8, entitled, "On Vibrations of Beams of Variable 

 Cross-Section," by Mr. N. W. Akimoff, Member. 



Mr. Akimoff presented the paper. 



