144 BUOYANCY AND STABILITY OF TROOP TRANSPORTS. 



1. The standard of subdivision should be the highest consistent with the 

 floodable length and with the adopted minimum spacing of the bulkheads. If 

 nso = f = (n -\- i) So, the n-compartment standard should be adopted. 



2. Within the given standard of subdivision, the spacing of the bulkheads should 

 be the greatest possible consistent with that standard, provided no practical consid- 

 erations stand in the way of such spacing. With the n-compartment standard the 



spacing should closely approach — . In other words, the factor of subdivision ac- 



n 



cording to this rule is practically either unity or some simple fraction: — Vz, Vs, H, 

 etc.* It should be observed that the same ship may be, at the same time, subdivided 

 to different standards, depending on the value of the floodable length at various 

 points. Frequently ships, which may be subdivided to the three-compartment stand- 

 ard at amidships and at the extreme ends, can be subdivided only to the two-compart- 

 ment standard on the quarter length, where the floodable length is a ininimum, and 

 such vessels will be referred to as two-compartment ships. 



(/) In troop transports, which are liable to be loaded more deeply than ordi- 

 nary passenger vessels, the floodable lengths are relatively small. In the following 

 table are given the average minimum values of / as found in troop transports of 

 good design used during the war by the United States Navy. The minima occurred 

 as usual on about one-quarter of the length of the ships from the ends. In the third 

 column are given what are considered appropriate values for the corresponding 

 spacing of the bulkheads at the points when the floodable length is a minimum. 



Table I. 



Ships of less than 500 feet in length cannot, according to this table, be sub- 

 divided in a satisfactory manner to the two-compartment standard throughout their 

 length and are not, therefore, suitable for the transport of troops. Ships of more 

 than 500 feet in length may be subdivided according to the two-compartment stand- 



I'This rule differs from the recommendations of the Board of Trade Committee on Subdivision of Merchant 

 Ships in that the factor of subdivision, according to the committee, bears no definite relation to the floodable 

 length, being obtained from a continuous curve plotted pji the length of the ship as abscissae. 



