The Merchant Shipping (Cargo Ship Construction) Regulations 1997

Location of spaces

22.—(1) Machinery spaces shall be positioned aft of cargo tanks and slop tanks and shall be separated from them by a cofferdam, cargo pump room, oil fuel bunker tank or permanent ballast tank and shall be positioned aft of such cofferdam or cargo pump room except that the lower part of a cargo pump room may be recessed into a machinery space of Category A in order to accommodate pumps subject to the crown of the recess being not more than one third of the moulded depth above the keel; provided that, in the case of a ship not exceeding 25,000 tonnes deadweight where a recess of such height is not practicable for reasons of access and arrangement of piping, the recess may be increased to a height not exceeding one half of the moulded depth above the keel. Pump rooms, other than cargo pump rooms, containing pumps and fittings for ballasting spaces adjacent to cargo tanks and slop tanks and pumps and fittings for oil fuel transfer may be considered equivalent to a cargo pump room for the purpose of this regulation provided that the fire protection arrangements and fire extinguishing arrangements of those pump rooms are in accordance with the requirements for cargo pump rooms.

(2) Except as otherwise permitted by paragraphs (3), (4) and (5) accommodation spaces, control stations, main cargo control stations and service spaces other than isolated lockers for cargo handling gear shall be positioned aft of cargo tanks and slop tanks and pump rooms or cofferdams which separate cargo tanks and slop tanks from machinery spaces except that such spaces may be positioned over the recess of a pump room to which paragraph (1) refers.

(3) Accommodation spaces, control stations, main cargo control stations and service spaces may be positioned forward of the cargo area provided that they are separated from the cargo tanks and slop tanks by a cofferdam, pump room, or the whole or part of an oil fuel bunker tank or permanent ballast tank except that such spaces may be positioned over the recess of a pump room to which paragraph (1) refers.

(4) Navigating spaces may be positioned above the cargo tanks and slop tanks provided that they are used only for navigating purposes and are separated from the upper deck by means of an open space the height of which shall be not less than 2 metres.

(5) Where accommodation spaces, control stations, cargo stations, and machinery spaces other than machinery spaces of Category A are located over part of an oil fuel bunker tank the horizontal separation of such spaces from cargo tanks or slop tanks shall be to the satisfaction of the Certifying Authority.

(6) Means shall be provided to isolate oil spills on the upper deck from accommodation and service spaces and shall take into account stern cargo handling facilities where these are provided.

Additional requirements for ships constructed on or after 1st September 1984

(7) Notwithstanding paragraph (1) machinery spaces containing internal combustion machinery having an output greater than 375 kilowatts (other than main propulsion machinery) and provided for the safety of the ship and machinery spaces other than machinery spaces of Category A may be positioned forward of the cargo area provided that they are separated from the cargo tanks and slop tanks in the manner specified in paragraph (1) for machinery spaces positioned aft of such tanks.

(8) In combination carriers when the slop is carried on dry cargo voyages the slop tanks shall be surrounded by cofferdams except where the boundaries of the slop tanks are the hull, main cargo deck, cargo pump room bulkhead or oil fuel bunker tank. Such cofferdams shall not be open to a double bottom, pipe tunnel, pump room or other enclosed space and shall be provided with means of being filled with water and of being drained. Where the boundary of a slop tank is the cargo pump room bulkhead the pump room shall not be open to any double bottom, pipe tunnel or other enclosed space except that bolted gas-tight access covers may be permitted.

(9) The piping between the slop tanks and the pump room on combination carriers shall be provided with isolating arrangements located adjacent to the slop tanks or, where such an arrangement is impracticable, within the pump room at the position where the piping penetrates the bulkhead. The isolating arrangements shall be either a valve and a spectacle flange or a spool piece and blank flanges.

(10) A separate pumping arrangement shall be provided on combination carriers for discharging the contents of the slop tanks to a connection located above the main deck.

(11) The slop tank hatches and cleaning openings on combination carriers shall be on the open deck and, unless such openings are closed by bolted watertight plates, shall be provided with locking arrangements which shall be under the control of a ship’s officer.

(12) Cargo oil pipes installed below deck on combination carriers shall be located within wing cargo tanks except that when cargo wing tanks are not provided the Certifying Authority may permit the installation of such pipes in ducts which shall be capable of being adequately cleaned and ventilated.