564 



least at a distance equal to the longitudinal extent of assumed 

 damage specified in sub-paragraph (a) of this paragraph in order 

 to be considered effective. Wliere transverse bulkheads are spaced 

 at a lesser distance, one or more of these bulkheads within such 

 extent of damage shall be assumed as non-existent for the purpose 

 of determining flooded compartments. 



(c) Where the damage between adjacent transverse watertight 

 bulkheads is envisaged as specified in sub-paragraph (1) (c) of 

 this Regulation, no main transverse bulkhead or a transverse bulk- 

 head bounding side tanks or double bottom tanks shall be as- 

 sumed damaged unless : 



(i) the spacing of the adjacent bulkheads is less than the 

 longitudinal extent of assumed damage specified in sub-para- 

 graph (a) of this paragraph; or 



(ii) there is a step or a recess in a transverse bulkhead of 

 more than 3.05 metres in length, located within the extent of 

 penetration of assumed damage. The step formed by the 

 after peak bulkhead and after peak tank top shall not be 

 regarded as a step for the purpose o,f this Regulation. 



(d) If pipes, ducts or tunnels are situated within the assumed 

 extent of damage, arrangements shall be made so that progressive 

 flooding cannot thereby extend to compartments other than those 

 assumed to be floodable for each case of damage. 



(3) Oil tankers shall be regarded as complying with the, damage 

 stability criteria if the following requirements are met : 



(a) The final waterline, taking into account sinkage, heel and 

 trim, shall be below the lower edge of any opening through which 

 progressive flooding may take place. Such openings shall include 

 air pipes and those which are closed by means of weathertight 

 doors or hatch covers and may exclude those openings closed by 

 means o.f watertight manhole covers and flush scuttles, small 

 watertight cargo tank hatch covers which maintain the high 

 integrity of the deck, remotely operated watertight sliding doors, 

 and side scuttles of the non-opening type. 



(b) In the final stage of flooding, the angle of heel due to un- 

 symmetrical flooding shall not exceed 25 degrees, provided that 

 this angle may be increased up to 30 degrees if no deck edge im- 

 mersion occurs. 



(c) The stability in the final stage of flooding shall be investi- 

 gated and may be regarded as sufficient if the righting lever curve 

 has at least a range of 20 degrees beyond the position of equi- 

 librium in association with a maximum residual righting lever of 

 at least 0.1 metre. The Administration shall give consideration 

 to the potential hazard presented by protected or unprotected 

 openings whjch may become temporarily immersed within the 

 range of residual stability. 



(d) The Administration shall be satisfied that the stability is 

 sufficient during intermediate stages of flooding. 



(4) The requirements of paragraph (1) of this Regulation shall 

 be confirmed by calculations which take into consideration the design 

 characteristics of the ship, the arrangements, configuration and con- 



