469 



oxcopds linlf tlio lioight of the double bottom, hi shall be taken equal 

 to tlio double bottom height minus the well height. 



Piping serving such wells if installed within the double bottom 

 shall bo fitted with valves or other closing arrangements located at 

 the ])oint of connection to the tank served to i^revent oil outflow in 

 the event of damage of the piping during stranding. Such piping shall 

 bo installed as high from the bottom shell as possible. 



2.3.3 In the case where stranding damage simultaneously involves 

 four centre tanks, the value of 0, may bo calculated accoiding to the 

 formula 



0,=|(SZ,1^< + SZ,CO (3) 



A VII/Res.246 



2.3.4 An Administration may credit as rechicing oil outflow in case 

 of stranding, an installed carpjo transfer system having an emergency 

 high suction in each cargo oil tank, capable of transferring from a 

 breached tankor tanks to segregated ballast tanks or to available 

 cargo tankage if it can be assured that such tanks will have sufficient 

 ullage. Credit for such a system would bo governed by ability to 

 transfer in two hours of o])eration, oil equal to one half of tlie largest 

 of the breached tanks involved and by availability of e(iuivalent 

 receiving cai)a('ity in ballast or cargo tanks. 'J'he credit shall be con- 

 fined to ])ermitling calculation of 0^ according to foi-nnda (3). The 

 ])ipes for such suctions shall bo installed at least^ at a heiglit not less 

 than the vertical extent of the stranding danuige i\. 



The A<lministra(ion shall su])ply the Organization witli the informa- 

 tion concerning tho arrangements accei)tod by it, for circulation to 

 other governments. 



3. Limitations oj Size of Cargo Oil Tanks 



3.1 Limitation oj hypothetical oil outflow 



The hypothetical oil outflow Oe or 0, calculated in accordance with 

 the formjdae in Section 2 shall not exceed 30,000 cubic metres or 400^ 

 D\V, whichever is tho greater but subject to a niaxinuim of 40,000 

 cubic metres, where £>iy= deadweight of the ship in metric tons. 



3.2 Limitation oj volume oj single tank 



The volume of a wing tank shall not exceed seventy-five ])crcont of 

 the limits of hy|)othetical oil outflow referred to in 3.1. The volume of 

 a centre tank shall not exceed 50,000 cubic metres. 



3.3 Limitation oj tank length 



The length of each tank shall not exceed 10 metres or one of the 

 following values, whichever is the greater: 



(a) where no longitudinal bulkhead is provided: O.lZ 



(b) where a longitudinal bvdkhead is ])rovidc(l at the centreline 

 only: 0.15/^ 



(c) where two or more longitudinal bulkheads are i)rovi(le(l: 



(i) for wing tanks: 0.2£ 

 (ii) for centre tanks; 



(1 ) if -A is equal to or greater than 1/5 : 0.2/, 



-418 0-75-31 



