The Merchant Shipping (Cargo Ship Construction) Regulations 1997

PART VI CONSTRUCTION—TANKERS

General

21.—(1) This Part applies to United Kingdom and other tankers the keels of which were laid, or were at a similar stage of construction, on or after 25th May 1980; and to United Kingdom and other tankers converted into or adapted to be tankers on or after 25th May 1980.

(2) This Part applies to tankers designed to carry crude oil and petroleum products which have a closed flash-point not exceeding 60°C and a Reid vapour pressure below atmospheric pressure, or other liquids having a similar fire hazard, except chemical tankers and gas carriers which comply with the constructional requirements specified in the Codes referred to in the definitions of such ships in regulation 2.

(3) In this Part “fire protection arrangements” and “fire extinguishing arrangements” mean requirements for those matters, so far as relevant, contained in the Merchant Shipping (Fire Appliances) Regulations 1980(1), the Merchant Shipping (Fire Protection) Regulations 1984(2), and (notwithstanding their revocation by these Regulations) the Merchant Shipping (Cargo Ship Construction and Survey) Regulations 1981(3).

(4) The hull, superstructures, structural bulkheads, decks and deckhouses shall be constructed of steel or other equivalent material except that the crowns and casings of machinery spaces of Category A and the exterior boundaries of superstructures and deckhouses which are required to be insulated to “A-60” standard shall be constructed only of steel.

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.

Cargo tank ventilation Requirements for tankers constructed on or after 1st September 1984

23.—(1) The cargo tank venting systems shall be independent of the ventilation arrangements for any other compartments. The arrangement and position of the openings in the cargo tank deck from which the emission of flammable vapours can occur shall be such as to minimise the possibility of flammable vapours being admitted into enclosed spaces containing a source of ignition or collecting in the vicinity of machinery and equipment which may constitute an ignition hazard.

(2) The cargo tank venting arrangements shall be in accordance with the provisions of Schedule 2 in Merchant Shipping Notice MSN 1671.

Ventilation of pump rooms and other enclosed spaces Requirements for tankers constructed on or after 25th May 1980

24.—(1) Cargo pump rooms and pump rooms having a similar hazard shall be mechanically ventilated and discharges from the exhaust fans shall be led to a safe place on the open deck. The ventilation of these rooms shall have sufficient capacity to minimize the possibility of accumulation of flammable vapours. The number of changes of air shall be at least 20 per hour, based upon the gross volume of the space. The air ducts shall be arranged so that all of the space is effectively ventilated. The ventilation system shall be of the exhaust type, using fans of the non-sparking type.

(2) Ventilation inlets and outlets and other deckhouse and superstructure boundary space openings shall be located clear of the cargo pump room openings. Openings for machinery space ventilation shall be located as far aft as practicable taking into consideration the location of any stern loading and discharging facilities provided.

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

(3) The cargo spaces and their adjacent enclosed spaces in combination carriers shall be capable of being ventilated by permanently installed or portable fans. A fixed gas detection system shall be provided in cargo pump rooms, pipe ducts and the cofferdams adjacent to slop tanks. Arrangements shall be provided to detect the presence of flammable vapours in all other spaces within the cargo tank area from the open deck or other easily accessible positions.

Inerting, ventilation and gas measurement Requirements for tankers constructed on or after 1st October 1994

25.—(1) Double hull and double bottom spaces shall be fitted with suitable connections for the supply of air.

(2) On oil tankers required to be fitted with inert gas systems—

(a) double hull spaces shall be fitted with suitable connections for the supply of inert gas;

(b) where hull spaces are connected to a permanently fitted inert gas distribution system, means shall be provided to prevent hydrocarbon gases from the cargo tanks entering the double hull spaces through the system;

(c) where such spaces are not permanently connected to an inert gas distribution system, appropriate means shall be provided to allow connection to the inert gas main.

(3) Suitable portable instruments for measuring oxygen and flammable vapour concentrations shall be provided. In selecting these instruments, due attention shall be given to their use in combination with the fixed gas-sampling line system referred to in paragraph (4).

(4) Where the atmosphere in double hull spaces cannot be reliably measured using flexible gas-sampling hoses, such spaces shall be fitted with permanent gas sampling lines. The configuration of such line systems shall be adapted to the design of such spaces.

(5) The materials of construction and the dimensions of gas sampling lines shall be such as to prevent restriction. Where plastic materials are used, they shall be electrically conductive.

Access to spaces in the cargo tank area of oil tankers Requirements for oil tankers constructed on or after 1st October 1994

26.—(1) Access to cofferdams, ballast tanks, cargo tanks and other spaces in the cargo area shall be direct from the open deck and be such as to ensure their complete inspection. Access to double bottom spaces may be through a cargo pump-room, deep cofferdam, pipe tunnel or similar compartments, provided adequate ventilation for safety can be ensured.

(2) For access through horizontal openings, hatches or manholes, the dimensions shall be sufficient to allow a person wearing a self-contained breathing apparatus and protective equipment to ascend or descend any ladder without obstruction and also to provide a clear opening to facilitate the hoisting of an injured person from the bottom of the space. The minimum clear opening shall be not less than 600 millimetres×600 millimetres.

(3) For access through vertical openings, or manholes providing passage through the length and breadth of the space, the minimum clear opening shall be not less than 600 millimetres×800 millimetres at a height of not more than 600 millimetres from the bottom shell plating unless gratings or other footholds are provided.

(4) For oil tankers of less than 5,000 tonnes deadweight smaller dimensions may be approved by the Certifying Authority in special circumstances, if the ability to traverse such openings or to remove an injured person can be proved to the satisfaction of the Certifying Authority.

(1)

S.I. 1980/544, to which there are amendments not relevant to these Regulations.

(2)

S.I. 1984/1218; relevant amendment is S.I. 1993/1193.

(3)

S.I. 1981/572, to which there are amendments not relevant to these Regulations.