Hull Construction Regulations (C.R.C., c. 1431)

Watertight Subdivision

9 Every ship shall be subdivided into compartments by bulkheads that are watertight up to the bulkhead deck, the maximum length of which compartments shall be calculated in accordance with such of the provisions of Schedule I as apply to that ship; every other portion of the internal structure that affects the efficiency of the subdivision of the ship shall be watertight, and shall be of a design that will maintain the integrity of the subdivision.

Peak, Machinery Space and Shaft Tunnel Bulkheads

• 10 (1) Subject to subsection (1.1), every ship shall be equipped with a collision bulkhead

  • (a) that is watertight up to the bulkhead deck, and

  • (b) that is fitted at a distance abaft the ship’s forward perpendicular of not less than 5%, and not more than 3.05 m + 5%, of the length of the ship.

• (1.1) In the case of a ship that has a forward superstructure, the collision bulkhead shall be extended weathertight to the deck next above the bulkhead deck and this extension shall

  • (a) be fitted directly over the collision bulkhead below, unless

    • (i) the collision bulkhead is fitted at a distance from the ship’s forward perpendicular of 5% or more of the length of the ship, and

    • (ii) the part of the bulkhead deck which forms the step is made weathertight, and

  • (b) have a plating and stiffeners of such strength and construction as to be capable of supporting the pressure of a head of water up to the margin line, as if the extension formed part of a bulkhead immediately below the bulkhead deck.

• (2) Every ship shall be provided with a watertight afterpeak bulkhead and with watertight bulkheads dividing the space appropriated to the main and auxiliary propelling machinery, boilers, and the permanent coal bunkers, if any, from other spaces; such bulkheads shall be watertight up to the bulkhead deck; provided that the afterpeak bulkhead may be stopped below the bulkhead deck if the safety of the ship is not thereby impaired.

• (3) The stern gland shall be situated in a watertight shaft tunnel or other watertight space separate from the stern tube compartment and of such a volume that if the tunnel or space is flooded the margin line will not be submerged; the stern tube shall be enclosed in a watertight compartment, the volume of which shall be the smallest compatible with the proper design of the ship.

Double Bottoms

• 11 (1) Every ship of 50 m in length or more shall be fitted with a watertight double bottom that

  • (a) in ships of no less than 50 m but less than 61 m in length, extends at least from the forward end of the machinery space to the collision bulkhead, or as near to that bulkhead as is practicable;

  • (b) in ships of no less than 61 m but less than 76 m in length, extends at least from the forward end of the machinery space to the collision bulkhead and from the aft end of the machinery space to the afterpeak bulkhead, or as near to those bulkheads as is practicable; and

  • (c) in ships of 76 m or more in length, extends at least from the collision bulkhead to the afterpeak bulkhead, or as near to those bulkheads as is practicable.

• (1.1) Ships of no less than 24 m but less than 50 m in length that carry berthed passengers below the bulkhead deck shall be fitted with a watertight double bottom for the full length of compartments in which passenger spaces are located.

• (2) When a double bottom is required by this section to be fitted in a ship, the inner bottom shall be continued out to the ship’s sides in such a manner as to protect the bottom to the turn of the bilge; the inner bottom shall be deemed to be adequate for this purpose if the line of intersection of the outer edge of the margin plate with the bilge plating is not lower at any point than a horizontal plane passing through the point of intersection with the frame line amidships of a transverse diagonal line inclined at 25 degrees to the base line and cutting it at a point one half of the ship’s moulded breadth from the middle line.

• (3) Wells constructed in the double bottom for the purpose of drainage shall not be larger or extend downwards more than is necessary for such purpose, and shall not be less than 460 mm from the outer bottom or from the inner edge of the margin plate, provided that a well extending to the outer bottom may be constructed at the after end of a shaft tunnel.

• (4) Wells for purposes other than drainage shall not be constructed in the double bottom; the Board may exempt any ship from the requirements of this subsection in respect of any well it is satisfied will not diminish the protection given by the double bottom.

• (5) Nothing in this section shall require a double bottom to be fitted in way of watertight compartments used exclusively for the carriage of liquids, if the safety of the ship will not be impaired in the event of bottom or side damage by reason of the absence of a double bottom in that position.

• (6) The Board may exempt any ship, other than a ship of Class I, from the requirements of a double bottom in any portion of the ship that is subdivided by application of a factor of subdivision not exceeding 0.5 if it is satisfied that the fitting of a double bottom in that portion of the ship would not be compatible with the design and proper working of the ship.

Stability in Damaged Condition

• 12 (1) Every ship shall be so constructed as to provide sufficient intact stability in all service conditions to enable the ship to withstand the final flooding of any one of the main compartments into which the ship is subdivided in accordance with the provisions of section 9; if two of the main compartments, being adjacent to each other, are separated by a bulkhead that is stepped, the intact stability shall be adequate to withstand the final flooding of those compartments; if the ship’s factor of subdivision is 0.5 or less, the intact stability shall be adequate to withstand the final flooding of any two of the main compartments that are adjacent to each other.

• (2) For the purposes of this section, the sufficiency of the intact stability of every such ship shall be determined in accordance with the provisions of Schedule II.

• (3) Every ship shall be so constructed as to keep unsymmetrical flooding when the ship is in a damaged condition at the minimum consistent with efficient arrangements; if cross-flooding fittings are provided in any such ship, the fittings and the maximum heel of the ship before equalization shall be such as will not endanger the safety of the ship.

• (4) Where the margin line may become submerged during the flooding assumed for the purposes of the calculation referred to in Schedule II, the construction of the ship shall be such as will enable the master of the ship to ensure

  • (a) that the maximum angle of heel during any stage of such flooding will not be such as will endanger the safety of the ship; and

  • (b) that the margin line will not be submerged in the final stage of flooding.

• (5) In every ship the owner shall provide a document for the use of the master of the ship containing information as to the use of any cross-flooding fittings provided in the ship.

• (6) In every ship the owner shall provide a document for the use of the master of the ship containing

  • (a) information necessary for the maintenance of sufficient intact stability under service conditions to enable the ship to withstand damage to the extent referred to in Schedule II; and

  • (b) information as to the conditions of stability on which the calculations of heel have been based, together with the information that excessive heeling may result if the ship sustains damage when in a less favourable condition.

Construction of Watertight Bulkheads

• 13 (1) Every part of a ship required to be watertight shall be of such strength and construction as to be capable of supporting the greater of whichever of the following pressures that the part might have to sustain in the event of damage to the ship:

  • (a) the pressure of a head of water up to the margin line; or

  • (b) the pressure of the maximum head of water.

• (2) In every ship all tanks, including double bottoms, peak tanks, settling tanks and bunkers, forming part of the structure of the ship and used for the storage of oil fuel or other liquids, shall be of a design and construction adequate for that purpose.

Openings in Watertight Bulkheads

• 14 (1) In every ship the number of openings in bulkheads and other structures required to be watertight shall be the minimum compatible with the design and proper working of the ship.

• (2) So far as practicable, trunks installed in connection with ventilation, forced draught or refrigeration systems in any ship shall not pierce such bulkheads or structures.

• (3) Every tunnel above the double bottom, if any, in a ship, whether for access from the crew space to the machinery space, for piping or for any other purpose, which passes through a bulkhead, shall be watertight; the means of access to at least one end of such tunnel, if it may be used as a passage at sea, shall be through a trunkway extending watertight to a height sufficient to permit access above the margin line; the means of access to the other end of the tunnel shall be through a watertight door; no tunnel shall extend through the first subdivision bulkhead abaft the collision bulkhead.

• (4) Not more than one doorway, other than a bunker or tunnel doorway, shall pierce a watertight bulkhead in the machinery space in any ship; if any such bulkhead is pierced by a doorway the doorway shall be placed so as to have the sill as high as possible in the ship.

• (5) Doorways, manholes and access openings shall not be fitted in the collision bulkhead below the margin line of any ship or in any other bulkhead that is required to be watertight and divides a cargo space from another cargo space or from a permanent or reserve bunker; the Board may permit any such ship to be fitted with doorways in bulkheads dividing two between deck cargo spaces if it is satisfied that

  • (a) the doorways are necessary for the proper working of the ship;

  • (b) the number of such doorways is the minimum compatible with the design and proper working of the ship, and the doorways are fitted at the highest practicable level; and

  • (c) the outboard vertical edges of such doorways are situated at a distance from the ship’s shell plating which is not less than one fifth of the breadth of the ship, such distance being measured at right angles to the centre line of the ship at the level of the deepest subdivision load water line.

• (6) In every ship

  • (a) bulkheads outside the machinery space that are required to be watertight shall not be pierced by openings that are capable of being closed only by portable bolted plates; and

  • (b) where portable bolted plates are permitted in machinery space bulkheads, the master and persons in charge of the navigation and engine room watches shall ensure that such plates are in place before the ship leaves port and are not removed during navigation except in the case of urgent necessity, and the master shall ensure that notices to this effect are posted in the Chart Room and at the openings on each side of the bulkhead.

• (7) In every ship

  • (a) valves and cocks not forming part of a pipe system shall not be fitted in any bulkhead required to be watertight;

  • (b) where a watertight bulkhead is pierced by pipes, scuppers, electric cables or other similar fittings, provision shall be made that will ensure that the watertightness of the bulkhead is not thereby impaired; and

  • (c) the collision bulkhead shall not be pierced below the margin line by more than one pipe, provided that if the forepeak is divided to hold two different kinds of liquids the collision bulkhead may be pierced below the margin line by not more than two pipes; any pipe which pierces the collision bulkhead shall be fitted with a screwdown valve capable of being operated from above the bulkhead deck, the valve chest being secured to the forward side of the collision bulkhead.

Means of Closing Openings in Watertight Bulkheads

• 15 (1) In every ship efficient means shall be provided for closing and making watertight all openings in bulkheads and other structures required to be watertight.

• (2) Every door fitted to any such opening shall be a sliding watertight door, provided that, in a ship that is not required by section 9 of Schedule I to have a factor of subdivision of 0.5 or less, hinged watertight doors may be fitted

  • (a) in passenger, crew and working spaces above any deck the underside of which at its lowest point is at least 2.13 m above the deepest subdivision load water line; and

  • (b) in any bulkhead, not being a collision bulkhead, that divides two cargo between deck spaces; for such cases a notice shall be posted in the Chart Room stating that these doors shall be closed before the voyage commences and shall be kept closed during navigation; similar notices shall be posted at the doors, on each side of the bulkhead.

• (2.1) The master and persons in charge of the navigation and engine room watches shall ensure that the doors fitted in accordance with paragraph (2)(b) are closed before the voyage commences and are kept closed during navigation, and the master shall ensure that the notices to this effect required by that paragraph are posted in the Chart Room and at the doors on each side of the bulkhead.

• (3) Hinged watertight doors shall be fitted with catches capable of being worked from each side of the bulkhead in which the door is fitted.

• (4) All doors required to be watertight shall be secured by means other than bolts, and shall be closed by means other than gravity or a dropping weight.

• (5) Watertight doors fitted in bulkheads between permanent and reserve bunkers, other than the doors referred to in subsection 16(3), shall always be accessible.

Means of Operating Sliding Watertight Doors

• 16 (1) Where in a ship not required by section 9 of Schedule I to have a factor of subdivision of 0.5 or less, any sliding watertight door in a bulkhead, other than a door at the entrance to a tunnel, is in a position that may require it to be opened at sea and the sill thereof is below the deepest subdivision load water line, the following provisions apply:

  • (a) if the number of such doors exceeds five, all such doors and all tunnel doors shall be operated by power and shall be capable of being simultaneously closed from a central control situated on the bridge; and

  • (b) if the number of such doors does not exceed five,

    • (i) if the criterion numeral of the ship does not exceed 30, such doors and tunnel doors shall not be required to be operated by power, and

    • (ii) if the criterion numeral of the ship exceeds 30, all such doors and all tunnel doors shall be operated by power and shall be capable of being simultaneously closed from a central control situated on the bridge, provided that, if there is only one such door and one tunnel door in the ship, both of which are in the machinery space, they shall not be required to be operated by power.

• (2) In every ship, other than ships of Class I, required by section 9 of Schedule I to have a factor of subdivision not over 0.5, all sliding watertight doors shall be operated by power and shall be capable of being simultaneously closed from a central control situated on the bridge, provided that, if there is only one such door and it is in the machinery space, it shall not be required to be operated by power.

• (3) Where a sliding watertight door that may be opened at sea for the purpose of trimming coal is fitted between bunkers in the between decks below the bulkhead deck, such door shall be operated by power.

• (4) Where a trunkway that is part of a refrigeration, ventilation or forced draught system, is carried through more than one transverse watertight bulkhead and the sill of the opening of such trunkway is less than 2.13 m above the deepest subdivision load water line, the sliding watertight door at the opening shall be operated by power.

• (5) Where a sliding watertight door is required to be operated by power from a central control, the power system shall be so arranged that the door can also be operated by power at the door itself; the arrangement shall be such that the door will close automatically if opened at the door itself after being closed from the central control, and will be capable of being kept closed at the door itself notwithstanding that an attempt may be made to open it from the central control; handles for controlling the power system shall be provided at both sides of the bulkhead in which the door is situated and shall be so arranged that any person passing through the doorway will be able to hold both handles in the open position simultaneously.

• (6) Where these Regulations require that the opening and closing of the sliding watertight doors of a ship be operated by power,

  • (a) there shall be at least two sources of power for opening and closing all such doors simultaneously;

  • (b) an indicator shall be fitted at the central control site for such doors, to show whether there is any disruption in the power available to operate them;

  • (c) any fluid used for the purpose of operating such doors shall be incapable of freezing at the temperatures likely to be encountered on the voyages the ship makes;

  • (d) there shall, in the case of an electro-hydraulic operating system, be two sources of hydraulic power fitted, consisting of two pumps or their equivalent, in addition to the main and emergency sources of power.

• (7) Every sliding watertight door that is operated by power shall be provided with efficient hand-operating gear that can be operated both at the door itself and at an accessible position above the bulkhead deck; at the position above the bulkhead deck the hand-operating gear shall be operated with an all-round crank motion.

• (8) Where a sliding watertight door is not required to be operated by power, it shall be provided with efficient hand-operating gear with an all-round crank motion, both at the door itself and at an accessible position above the bulkhead deck.

• (9) The hand-operating gear for operating the sliding watertight door in the machinery space from above the bulkhead deck shall be placed outside the machinery space unless such a position is inconsistent with the efficient arrangement of the necessary gearing.

• (10) The master and persons in charge of the navigation and engine room watches shall ensure that all sliding watertight doors are kept closed during navigation except when necessarily opened for the working of the ship, in which case such doors shall always be ready to be immediately closed and the master shall ensure that notices to this effect are posted in the Chart Room and at the doors on each side of the bulkhead.