282 



(2) If a void space or sej^regated water ballast tank of a Iciigth less than d- 

 as defined in Regulation 22 of this Annex is located betweeft wing oil tanks,** Oc 

 in formula (I) may be calculated on the basis of volume Wi being tlie actual 

 volume of one such tank (where they are of equal capacity) or the smaller of the 

 two tanks (if they differ in capacity) adjacent t~o such space, nuiltiplied by Si as 

 defined below and taking for all other wing tanks involved in such a collision 

 the value of the actual full volume. 



where : fi=lengtli in metres of void space or segregated ballast tank under con- 

 sideration. 



(3) (a) Credit shall only be given in respect of double bottom tanks which are 

 either empty or carrying clean water when cargo is carried in the tanks above. 



(b) Where the double bottom does not extend for the full length and width 

 of the tank involved, the double bottom is considered non-existent and the 

 volume of tlie tanks above the area of the bottom damage shall be included in 

 formula (II) even if the tank is not considered breached because of the installa- 

 tion of such a partial double bottom. 



(c) Suction wells may be neglected in the determination of the value hi pro- 

 vided such wells are not excessive in area and extend below the tank for a mini- 

 mum distance and in no case more than half the height of the double bottom. If 

 the depth of such a well exceeds half the height of the double bottom, hi shall 

 be taken equal to the double bottom height minus the well height. 



lUping serving such wells if installed within the doulile bottom shall be fitted 

 with valves or other closing arrangements located at the point of connexion to 

 the tank served to prevent oil outflow in the event of damage to the piping. Such 

 piping shall be installed as high from the bottom shell as possible. 



(4) In the case where bottom damage simultaneously involves four centre 

 tanks, the value of Os may be calculated according to the formula 



0,= ^(SZiWi + 2ZiCi) (III) 



(5) An Administration may credit as reducing oil outflow in case of bottom 

 damage, an installed cargo transfer system having an emergency high suction in 

 each cargo oil tank, capable of transferring from a breached tank or 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 be governed 

 by ability to transfer in two hours of operation, oil equal to one half of the 

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

 capacity in ballast or cargo tanks. The credit shall be confined to permitting 

 calculation of Os according to formula (III). The pipes for such suctions shall be 

 installed at least at a height not le.ss than the vertical extent of the bottom 

 damage Vs. 



The Administration shall supply the Organization with the information con- 

 cerning the arrangements accepted by it. for circulation to other Contracting 

 Governments. 



KBGULATIOX 24. LIMITATION OF SIZE AXI) AKI!AX(;EMKNT OF CARGO TANKS 



(1) Every new oil tanker shall comply with the provisions of this Regula- 

 tion. Every existing oil tanker shall be required, within two years after the date 

 of entry into force of the present Convention, to comply with the provisions of 

 this Regulation, where such a tanker falls into either of the following categories: 



(a) a tanker, the delivery of which is after 1 January [1977] : or 



(b) a tanker to which both the following conditions apply : 

 (i) delivery is not later than 1 January fl977] and 



(ii) the building contract is placed after 1 January [1072], or in cases where 

 11(1 building contract has previously been placed, the keel is laid or the tanker is 

 at a similar stage of construction after 30 June [1972].'' 



■"> One delegation suggested to extend the formula in this paragraph to supply also to 

 centre tank void spaces. 



*' The dates sliown in this sub-paragraph require further examination, particularly In 

 view of the fact that some of these dates will be prior to the 1973 Conference. 



