(Jan 2006) (Rev.1 July 2006) (Rev.2 Apr 2007) (Rev.3 Jan 2008)
IACS UNIFIED INTERPRETATION MPC 85, REV.3
Regulation 22(5), Annex I of MARPOL 73/78 as amended by resolution MEPC.117(52)
Regulation 22, Pump-room bottom protection
Regulation 22 (entering into force on 1 January 2007) reads:
—1. This regulation applies to oil tankers of 5,000 tonnes deadweight and above constructed on or after 1 January 2007.
2. The pump-room shall be provided with a double bottom such that at any cross-section the depth of each double bottom tank or space shall be such that the distance h between the bottom of the pump-room and the ship‘s base line measured at right angles to the ship‘s base line is not less than specified below:
h = B/15(m) or h = 2 m, whichever is the lesser.
The minimum value of h = 1 m.
In case of pump-rooms whose bottom plate is located above the base line by at least the minimum height required in paragraph 2 above (e.g. gondola stern designs), there will be no need for a double bottom construction in way of the pump-room.
Ballast pumps shall be provided with suitable arrangements to ensure efficient suction from double bottom tanks.
Notwithstanding the provisions of paragraphs 2 and 3 above, where the flooding of the pump-room would not render the ballast or cargo pumping system inoperative, a double bottom need not be fitted.“
The term —pump-room“ means a cargo pump-room. Ballast piping is permitted to be located within the pump-room double bottom provided any damage to that piping does not render the ship‘s pumps located in the —pump-room“ ineffective.
The double bottom protecting the —pump-room“ can be a void tank, a ballast tank or, unless prohibited by other regulations, a fuel oil tank.
Bilge wells may be accepted within the double bottom provided that such wells are as small as practicable and the distance between the well bottom and bottom shell plating is not less than 0.5h.
MEPC 57/5/3 Page 2 ANNEX
room is required to be protected by a double bottom.
Rev.1 of this UI is to be uniformly implemented by IACS Members and Associates for ships subject to this regulation.
Rev.2 of this UI is to be uniformly implemented by IACS Members and Associates for ships subject to this regulation.
Agenda for the CTC #32Page 32 of 39
To be held in Panama City on the 09 April 2008 Issue No. 1
Our Ref.: AGO-22713/1000003Approved by: H.N. Snaith