LAUNCHING DATA FOR A BATTLESHIP. 



By Naval Constructor John G. Tawresey, U. S. N., Member. 



[Read at the twenty-second general meeting of the Society of Naval Architects and Marine Engineers, held in 



New York, December 10 and 11, 1914.] 



The launching of a great ship is always a matter of interest to the profession, 

 and one of anxiety to those responsible. The experience from an unbroken series 

 of successful launches, backed by the knowledge that every condition has been in- 

 vestigated and every precaution taken, is not sufficient to entirely banish the thought 

 that there may be some unusual factor for which allowance has not been made. 

 The data for some previous vessel, especially one of corresponding dimensions and 

 weight, are the basis of the launching arrangements adopted for a new vessel, and 

 the great value of such data, when full and reliable, is considered sufficient reason 

 for adding the following notes on the launching of a battleship to the valuable 

 papers on launching already contained in the Transactions of the Society. 



Papers on launching are published in the Transactions for the years 1894, 

 1900, 1903 and 1904; they give full data for a great variety of vessels and for a 

 considerable range of launching weights. The tables and plans herewith for the 

 U. S. S. Oklahoma, a 27,500-ton battleship, 575 feet long and 11,965 tons launch- 

 ing weight, will serve to bring the r,ecorded data up to date and to extend it to 

 larger and heavier vessels. 



The Oklahoma was launched at the New York Shipbuilding Company's yard, 

 Camden, N. J., on March 23, 1914. Much of the following data is taken from 

 the regular report prepared by Naval Constructor E. G. Kintner, U. S. N., for the 

 records of the Bureau of Construction and Repair, Navy Department. Through 

 the courtesy of the New York Shipbuilding Company, I am able to include the 

 launching plan and the launching curves, prepared by the Company's naval archi- 

 tect, Mr. E. H. Rigg, one of our members. 



The launching was considered entirely successful, and the statement of data is 

 presented as showing regular practice for large vessels, not as an example of novel 

 methods. All of the arrangements had been used for previous launchings. The ar- 

 rangement of cradle, packing, shoring, etc., is shown on the plate of launching plan. 

 Dog shores were used as preventers and safety devices ; the vessel was actually re- 

 leased by means of the hydraulic triggers now generally used for large vessels. The 

 arrangement for distributing the pressure at the fore poppets when the vessel lifts 

 is worthy of note — a rocker or segment of trunnion of 50 feet radius. It was first 

 used for the U. S. S. Arkansas, and has now been used for a number of vessels and 

 is effective. 



