AN ANALYSIS OF TESTS OF WATER-TIGHT BULKHEADS WITH 

 PRACTICAL RULES AND TABLES FOR THEIR CONSTRUC- 

 TION. 



By Professor William Hovgaard, Member. 



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



New York, November 17 and 18, 1910.] 



This paper is a continuation of last year's paper on the "Strength of 

 Water-tight Bulkheads." While that paper was of a purely theoretical 

 nature, the present paper contains an analysis of bulkhead tests, followed 

 by practical rules and tables based on this analysis. 



The majority of tests here recorded and analyzed, in fact all except 

 the last two, have been carried out in American battleships and cruisers. 

 Probably rio other navy has undertaken so great a number of scientifically 

 conducted tests as the United States Navy, and it is at least certain that 

 no other navy has been so generous as to permit a publication of the results. 

 As far as the author is aware, no reliable and exhaustive information on 

 bulkhead tests had been published anywhere prior to 1898, when the late, 

 eminent Naval Constructor J. J. Woodward, U. S. Navy, published his 

 valuable paper on this subject in the Transactions of this Society, and 

 very little has come to light since that time. The careful and scientific 

 methods in carrying out the tests, which were originated by Mr. Woodward, 

 have been used ever since in the United States Navy. 



During the present analysis new theoretical problems have occurred, 

 and improved methods of solution of problems, already discussed, have 

 suggested themselves in some cases. This paper shall therefore begin with 

 an extension of the theoretical treatment given in last year's paper. 



I. Further Devei^opment op the Theory. 



a. BRACKETS. 



In last year's paper the effect of a bracket was considered equivalent 

 to a bending moment exerted at the end of the stiffener, and the stiffener 

 was regarded as carrying this bending moment without being structurally 

 reinforced by the bracket. This is the ordinary theoretical view of the 

 case, but is correct only if the bracketing is effected by extending the 

 stiffener down below the top of the floors, connecting it to a floor plate or 

 longitudinal as indicated in Fig. i, o, and provided we consider the stiffener 



