NOTES ON LAUNCHING. 95 



DISCUSSION. 



The President : — This paper, No. 5, entitled "Notes on Launching," is now before 

 you for discussion. 



Mr. E. H. Rigg, Member:— The question of launching ships has assumed greater im- 

 portance in recent years, due to the increase in the size of ships. The Society is to be con- 

 gratulated upon the fact that Mr. Gatewood has given us this interesting paper. 



The question of way-end pressures is one to which the big yards have been forced to 

 pay more and more attention, and particularly such yards as are situated here, in the neigh- 

 borhood of Philadelphia, where we are, roughly speaking, 100 miles from the ocean. 



We are subjected to considerable variation in height of tide at the time of launching, 

 and although we settle the launching date to fit in with a time when high tide is to be ex- 

 pected, nevertheless, if the wind is in the wrong quarter, it is possible that the launching 

 may have to be postponed. It is not exceptional to have a variation of 4 or 5 tons per square 

 foot in way-end pressure, if you have even a foot less of tide than you expect, which con- 

 dition we have fovmd frequently in the launching calculations for battleships in this district. 

 Mr. Gatewood's plan to eliminate elaborate internal shoring is an excellent one and, though 

 it will need some experimentation on a small scale before trying out on a large one, I feel 

 that the Society and the profession in general are indebted to him for his investigation and 

 interesting presentation of the matter. 



The President: — Does any other gentleman wish to continue the discussion? If not, 

 I think a motion for a vote of thanks would be in order. 



Mr. Spencer Miller, Member of Council: — I so move, Mr. President, that we extend 

 a vote of thanks to Mr. Gatewood. 



The President: — All in favor of the motion say "Aye"; contrary-minded "No." The 

 motion is unanimously carried. 



We will now pTOceed to paper No. 6, entitled "Side Launchings of Ships on the Great 

 Lakes," by Mr. Frank E. Kirby, Honorary Vice-President, and Mr. Edward Hopkins, Mem- 

 ber. In the absence of both of the authors, the paper will be presented by Prof. Herbert C. 

 Sadler. 



Professor Sadler presented the paper and, in connection therewith, said: — 

 "I might say, Mr. President, that I think it is perhaps familiar to most of the mem- 

 bers that the principal danger in a side launching is in giving the longitudinal ways too small 

 a declivity. Provided you give a large enough declivity to the ways, there is practically little 

 or no danger. 



The reason for that is, of course, when the vessel first lands in the water she has a heel 

 towards the water side, shortly after reaching the water, and when she picks up buoyancy, 

 she tends to roll back towards the dock, and the danger is in her bilge catching on the edge 

 of the dock before the vessel is bodily clear. I have seen numerous launchings, big 600-foot 

 vessels, and as a rule there is very little, or practically no danger experienced in the launching. 



