MARPOL Consolidated Edition 2017

Annex I: Regulations for the prevention of pollution by oil
Regulations 22, 23
8.2 Subject to the provisions of international law, a Party to the present Convention shall be entitled to deny
entry of oil tankers operating in accordance w ith the provisions of paragraph 5 or 6 of this regulation into the
ports or offshore terminals under its jurisd iction, or deny sh ip-to-ship transfer of heavy grade oil in areas under
its jurisdiction except w hen this is necessary for the purpose of securing the safety of a ship or saving life at
sea. In such cases, that Party shal l communicate to the Organization for circulation to the Parties to the present
Convention particulars thereof for their information.
Regulation 22
Pump-room bottom protection
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 sha ll 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
shi p's baseline measured at right angles to the ship's baseline is not less than specified below:
h = ,i (m ) or
h = 2 m, w hichever is the lesser.
The minimum value of h = 1 m.
3 In case of pump-rooms w hose bottom plate is located above the baseline by at least the minimum
height required in paragraph 2 above (e.g. gondola stern designs), there w ill be no need for a double bottom
construction in way of the pump-room.
4 Ballast pumps sha ll be provided w ith suitable arrangements to ensure efficient suction from double
bottom tanks.
5 Notwithstanding the provisions of paragraphs 2 and 3 above, w here the flooding of the pump-room
would not render the ballast or cargo pumping system inoperative, a double bottom need not be fitted.
SEE INTERPRETATION 49
Regulation 23
Accidental oil outflow performance
1 This regulation shall apply to oil tankers delivered on or after 1 January 2010, as defined in regulation 1.28.8.
2 For the purpose of this regulation, the following definitions shall apply:
.1 Load line draught (ds) is the vertical distance, in metres, from the moulded baseline at mid-length
to the waterl ine corresponding to the summer freeboard to be assigned to the ship. Calculations
pertaining to this regulation shou ld be based on draught d 5 , notwithstanding assigned draughts that
may exceed ds, such as the tropical load line .
. 2 Waterline (d 8 ) is the vertical distance, in metres, from the moulded baseline at mid-length to the
waterline corresponding to 30% of the depth 0 5 .
. 3 Breadth (8 5 ) is the greatest moulded breadth of the ship, in metres, at or below the deepest load
line draught d 5 .
. 4 Breadth (8 8 ) is the greatest moulded breadth of the ship, in metres, at or below the waterline d 8
.
. 5 Depth (0 5 ) is the moulded depth, in metres, measured at mid-length to the upper deck at side .
. 6 Length (L) and deadweight (OW) are as defined in regulations 1.19 and 1.23, respectively.
80 MARPOL CONSOLIDATED EDITIO N 2017