RULES ADOPTED AT INTERNATIONAL CONFERENCE. IS 



It must be proved that the spaces just enumerated are practicable for the pur- 

 pose intended and that they are in fact to be so used. The same permeability shall 

 not be assigned to any other space without the approval of the Administration. 



(b) Ninety-five per cent in passenger and crew spaces, peaks, trimming tanks 

 exclusively so used, double bottoms, and all other spaces not specifically appropri- 

 ated to one of the purposes indicated in the foregoing Section (a). 



If in a 'tween-deck space inclosed by complete transverse permanent steel 

 bulkheads any portion thereof is appropriated to passengers, the whole of that space 

 shall be regarded as passenger space; and, similarly, 'tween-deck spaces appropri- 

 ated for the carriage of either passengers or cargo shall be regarded as passenger 

 spaces. 



Where the space before or abaft the machinery space below the margin line 

 consist partly of spaces mentioned in Section (a) and partly of spaces mentioned 

 in Section (b), the average percentage of permeability shall be determined sepa- 

 rately for each end by the formula 95 — 35^, where r is the ratio between the 

 volume of the spaces mentioned in Section (a) and the total volume of the space 

 in the portion of the ship under consideration. 



Article VIII. — Permissible Length of Compartments. 



1. The maximum permissible length of one compartment having its center at 

 any point in the vessel's length is obtained from the floodable length (Article VI) 

 by multiplying that length by an appropriate factor, called the factor of subdivision. 



2. This factor of subdivision depends on the length of the vessel, and, for a 

 given length, varies according to the nature of the service for which the vessel is 

 intended. This factor decreases in a regular and continuous manner — 



(a) As the length of vessel increases; and 



(b) As, for a given length, the vessel departs from the type of vessel engaged 

 in a mixed cargo and passenger service, and approaches to the type of vessel pri- 

 marily engaged in the transportation of passengers. 



3. For each of the two types of vessels referred to in the previous paragraph 

 2, (b), the variation of the factor of subdivision may be expressed by a curve, of 

 which the co-ordinates represent the length of the vessel and the value of the fac- 

 tor. The following table gives certain points on two curves the higher of which 

 corresponds to the minimum requirements for the "mixed" type, and the lower to 

 the minimum requirements for the "passenger" type. 



