Annex - Recommendation Concerning Tonnage Measurement of Segregated Ballast Tanks in Oil Tankers
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Statutory Documents - IMO Publications and Documents - Resolutions - Assembly - IMO Resolution A.747(18) – Recommendation Concerning Tonnage Measurement of Segregated Ballast Tanks in Oil Tankers – (Adopted on 4 November 1993) - Annex - Recommendation Concerning Tonnage Measurement of Segregated Ballast Tanks in Oil Tankers

Annex - Recommendation Concerning Tonnage Measurement of Segregated Ballast Tanks in Oil Tankers

 In order to use a unified base for the application of tonnage measurement of segregated ballast tankers, Administrations are recommended to accept the following principles;

  1 The ship is certified as a segregated ballast oil tanker as stated in paragraph 5 of the supplement to the International Oil Pollution Prevention Certificate and the location of the segregated ballast tanks is indicated under paragraph 5.2 of that supplement.

  2 Segregated ballast tanks are those tanks exclusively used for the carriage of segregated water ballast, as defined in Regulation 1(17) of Annex 1 of MARPOL 73/78. The segregated ballast tanks should have a separate ballast pumping and piping system arranged for the intake and discharge of ballast water from and to the sea only. There should be no piping connections from segregated ballast tanks to the fresh water system. No segregated ballast tank should be used for the carriage of any cargo or for storage of ship's stores or material.

  3 In the International Tonnage Certificate (1969) under “Remarks” an entry is made for the tonnage of segregated ballast tanks in oil tankers as follows:

  • "The segregated ballast tanks comply with Regulation 13 of Annex 1 of the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating thereto, and the total tonnage of such tanks exclusively used for the carriage of segregated water ballast is ...”

    The reduced gross tonnage which should be used for the calculation of tonnage based fees is ..."

  4 The tonnage of segregated ballast tanks mentioned above should be calculated according to the following formula:

K1× Vb

where:
k1 = 0.2 + 0.02 log 10V (or as tabulated in Appendix 2 of the International Convention of Tonnage Measurement of Ships, 1969);
V = the total volume of all enclosed spaces of the ship in cubic metres as defined in Regulation 3 of the International Convention on Tonnage Measurement of Ships, 1969;
Vb = the total volume of segregated ballast tanks in cubic metres measured in accordance with Regulation 6 of the International Convention on Tonnage Measurement of Ships, 1969.

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