Openings in watertight bulkheads and internal decks
(1) (a) The number of openings in the boundaries of watertight compartments shall be the minimum compatible with the design and proper working of the ship.
(b) Where penetration of watertight bulkheads and internal decks is necessary for access, piping, ventilation, electrical cables, or for any other purpose, arrangements shall be made to maintain watertight integrity at each such point of penetration.
(c) The Administration may permit openings in compartment boundaries above the freeboard deck to be weathertight rather than watertight where it is demonstrated that any progressive flooding resulting therefrom can be easily controlled and the safety of the ship would not be impaired.
(2) (a) Doors provided to ensure the watertight integrity of internal openings which are used while the ship is at sea shall be of the sliding watertight type and capable of being remotely closed from the bridge and capable also of being operated locally from each side of the door without the door closing automatically.
(b) Indicators shall be provided at the bridge position showing whether the doors are open or closed, and an audible alarm shall be provided when the door closes.
(c) The power for operating and controlling the doors, indicators and alarms shall be supplied from the emergency switchboard required by regulation 51.
(d) The control system shall be so designed that if the system fails, closure by hand will not be prevented or impeded.
(e) Each power-operated sliding watertight door shall be provided with an individual hand-operated opening and closing mechanism. Means shall be provided at the door itself to open and close the door safely by hand from both sides and from an accessible position above the bulkhead deck.
(3) (a) Access doors and access hatch covers normally closed at sea and intended to ensure the watertight integrity of internal openings, shall be provided locally and on the bridge, with indicators to show whether these doors or hatch covers are open or closed.
(b) A notice shall be affixed to each such door or hatch cover stating that it is not to be left open at sea.
(c) Such doors and hatch covers shall not be used except where access is necessary and is authorised by the officer of the watch.
(4) (a) Watertight doors or ramps of satisfactory construction may be fitted to subdivide large cargo spaces internally where the Administration is satisfied that such doors or ramps are essential.
(b) These watertight doors or ramps may be of the hinged, rolling or sliding type, but shall not be remotely controlled
(c) They shall be closed before the voyage commences and shall be kept closed throughout the voyage and the time of opening such doors or ramps when the voyage has ended and of closing them before the voyage commences shall be entered in the log book.
(d) Any doors or ramps which may be accessible during the voyage shall be fitted with a device which prevents unauthorised opening.
(5) Every closing appliance which is required to be kept permanently closed at sea to ensure the watertight integrity of a compartment shall be provided with a notice affixed to it stating that it is to be kept closed, except that manholes secured by closely bolted covers need not be so marked.
External openings
(1) All external openings which lead to compartments assumed intact for the purposes of calculating the subdivision index "A", and which are below the final waterlines, shall be watertight.
(2) External openings required to be watertight in accordance with subregulation (1) shall be of sufficient strength and, except in the case of cargo hatch covers, shall be fitted with indicators on the bridge.
(3) Openings in the shell plating below the deck limiting the vertical extent of damage shall be kept permanently closed while at sea. Any of these openings which may be accessible during the voyage, shall be fitted with a device which prevents unauthorised opening.
(4) Notwithstanding the requirements of subregulation (3), the Administration may authorise the opening of specific doors, at the discretion of the master, if it is satisfied that such opening is necessary for the operation of the ship and provided that the safety of the ship would not be thereby impaired.
(5) Every watertight closing appliance which is required to be permanently closed at sea to ensure the integrity of an external opening shall be provided with a notice affixed to it stating that it is to be kept closed at sea; provided that manholes secured by closely bolted covers need not be so marked.
