563 



(5) In order not to exceed the volume limits established by para- 

 graphs (2), (3) and (4) of this Regulation and irrespective of the 

 accepted type of cargo transfer system installed, when such system 

 interconnects two or more cargo tanks, valves or other similar closing 

 devices shall be provided for separating the tanks from each other. 

 These valves or devices shall be closed when the tanker is at sea. 



(6) Lines of piping which run through cargo tanks in a position less 

 than tc from the ship's side or less than Vc from the ship's bottom shall 

 be fitted with valves or similar closing devices at the point at which 

 they open into any cargo tank. These valves shall be kept closed at sea 

 at any time when the tanks contain cargo oil, except that they may be 

 opened only for cargo transfer needed for the purpose of trimming of 

 the ship. 



REGULATION 2 5 



Subdivision and Stability 



(1) Every new oil tanker shall comply with the subdivision and 

 damage stability criteria as specified in paragraph (3) of this Regula- 

 tion, after the assumed side or bottom damage as specified in para- 

 graph (2) of this Regulation, for any operating draught reflecting 

 actual partial or full load conditions consistent with trim and strength 

 of the ship as well as specific gravities of the cargo. Such damage shall 

 be applied to all conceivable locations along the length of the ship 

 as follows: 



(a) in tankers of more than 225 metres in length, anywhere in 

 the ship's length ; 



(b) in tankers of more than 150 metres, but not exceeding 225 

 metres in length, anywhere in the ship's length except involving 

 either after or forward bulkhead bounding the machinery space 

 located aft. The machinery space shall be treated as a single flood- 

 able compartment ; 



(c) in tankers not exceeding 150 metres in length, anywhere in 

 the ship's length between adjacent transverse bulkheads with the 

 exception of the machinery space. For tankers of 100 metres or 

 less in length where all requirements of paragraph (3) of this 

 Regulation cannot be fulfilled without materially impairing the 

 operational qualities of the ship. Administrations may allow re- 

 laxations from these requirements. 



Ballast conditions where the tanker is not carrying oil in cargo tanks 

 excluding any oily residues, shall not be considered. 



(2) The following provisions regarding the extent and the character 

 of the assumed damage shall apply : 



(a) the extent of side or bottom damage shall be as specified in 

 Regulation 22 of this Annex, except that the longitudinal extent 

 of bottom damage within 0.3L from the forward perpendicular 

 shall be the same as for side damage, as specified in Regulation 22 

 (1) (a) (i) of this Annex. If any damage of lesser extent results 

 in a more severe condition such damage shall be assumed. 



(b) where the damage involving transverse bulkheads is en- 

 visaged as specified in sub-paragraphs (1) (a) and (b) of this 

 Regulation, transverse watertight bulkheads shall be spaced at 



