88 PROGRESS IN TURBINE SHIP PROPULSION. 



In connection with his comments concerning the piping diagram shown in Plate 32, which 

 permits one of the two turbines of the cross- compounds set to be quickly disconnected, the 

 ship proceeding on its way with the other turbine, it should not be necessary to explain that 

 ordinary gate and globe valves are quite sensible of being found in perfectly good order 

 after long periods of desuetude. 



The President: — A vote of thanks is due to Mr. Hodgkinson for his paper, which 

 we appreciate very much. All in favor of such a vote of thanks say "Aye" ; contrary- 

 minded "No." The vote of thanks is duly given to Mr. Hodgkinson for the paper. 



Mr. Hodgkinson : — I thank you, Mr. President and gentlemen. 



The President : — We will now take up paper No. 5, entitled "Notes on Launching," by 

 Mr. William Gatewood, Member. 



In the absence of Mr. Gatewood, the paper will be presented in abstract by Mr. Homer 

 L. Ferguson. 



Mr. Ferguson, in presenting the paper, said: — "I will state that this paper, in essence, 

 is the application of crushing strips between the bottom of the vessel and the sliding ways, 

 where the heavy pressures come as the bottom of the vessel passes over the outboard end of 

 the groundways. 



"The importance of this is illustrated by the laiuiching of a number of heavy ships, 

 usually battleships, when deformation of the bottom occurred. That condition has been 

 taken care of by fitting shores inside the double bottom, to prevent deformation, this shor- 

 ing being carried on to the upper deck. At first it was assumed that the cause of these ex- 

 cessive pressures was unevenness of the ways, but later it was found out that excessive pres- 

 sure over the end of the groundways was the cause, and not any unevenness in the ways at all, 

 and that actually in launching large ships this is a more important feature than the crushing 

 of the ship forward due to heavy fore poppet pressures in that it results in distinct damage 

 to the vessel. To distribute these pressures, Mr. Gatewood worked up the idea of using 

 strips carried practically throughout the length of the launching ways. 



"This plan can be applied not only to large vessels, but it can be used successfully in 

 the launching O'f small vessels ; and I think it has another effect, in that it provides consid- 

 erable elasticity of the launching ways so that any unevenness in either the ground support 

 or groundways is automatically taken care of. 



"We have recently launched a good many destroyers with pressures as low as half a 

 ton to the square foot, and the launching has been entirely successful in every particular. 

 The ways are provided with light crushing pieces throughout the length, and we think that 

 the absolute uniformity of distribution of pressure which has taken place prevents any Httle 

 unevennesses in the groundway from having any particular effect, and has assisted most ma- 

 terially in the successful launchings of these vessels. We have launched with lighter pres- 

 sures than we have launched with before, and in all kinds of weather, and quite successfully." 



