553 



(2) Where abnormal conditions or the need to carry large quan- 

 tities of oil fuel render it necessary to carry ballast water which is 

 not a clean ballast in any oil fuel tank, such ballast water shall be dis- 

 charged to reception facilities or into the sea in compliance with Regu- 

 lation 9 using the equipment specified in Regulation 16(2) of this 

 Annex, and an entry shall be made in the Oil Record Book to this 

 effect. 



(3) All other ships shall comply with the requirements of para- 

 graph (1) of this Regulation as far as reasonable and practicable. 



REGULATION 15 



Retention of Oil on Board 



(1) Subject to the provisions of paragraphs (5) and (6) of this 

 Regulation, oil tankers of 150 tons gross tonnage and above shall be 

 provided with arrangements in accordance with the requirements of 

 paragraphs (2) and (3) of this Regulation, provided that in the case 

 of existing tankers the requirements for oil discharge monitoring and 

 control systems and slop tank arrangements shall apply three years 

 after the date of entry into force of the present Convention. 



(2) (a) Adequate means shall be provided for cleaning the cargo 

 tanks and transferring the dirty ballast residue and tank washings 

 from the cargo tanks into a slop tank approved by the Admin- 

 istration. In existing oil tankers, any cargo tank may be designated 

 as a slop tank. 



(b) In this system arrangements shall be provided to transfer 

 the oily waste into a slop tank or combination of slop tanks in 

 such a way that any effluent discharged into the sea will be such as 

 to comply with the provisions of Regulation 9 of this Annex. 



(c) The arrangements of the slop tank or combination of slop 

 tanks shall have a capacity necessary to retain the slops generated 

 by tank washing, oil residues and dirty ballast residues but the 

 total shall be not less than 3 per cent of the oil carrying capacity 

 of the ship, except that, where segregated ballast tanks are pro- 

 vided in accordance with Regulation 13 of this Annex, or where 

 arrangements such as eductors involving the use of water addi- 

 tional to the washing water are not fitted, the Administration 

 may accept 2 per cent. New oil tankers over 70,000 tons dead- 

 weight shall be provided with at least two slop tanks. 



(d) Slop tanks shall be so designed particularly in respect of 

 the position of inlets, outlets, baffles or weirs where fitted, so as to 

 avoid excessive turbulence and entrainment of oil or emulsion 

 with the water. 



(3) (a) An oil discharge monitoring and control system approved 

 by the Administration shall be fitted. In considering the design of 

 the oil content meter to be incorporated in the system, the Admin- 

 istration shall have regard to the specification recommended by 

 the Organization. [^] The system shall be fitted with a recording 



1 Reference is made to Recommendations on International Performance Speeiflcations 

 for Oily-Water Separating Equipment and Oil Content Meters adopted by tlie Organization 

 by Resolution A.233(VII). 



