4.14 Peak and Machinery Space Bulkheads, Shaft Tunnels, etc.:

(1) A collision bulkhead shall be fitted which shall be watertight up to the bulkhead deck and this bulkhead shall be located at a distance from the forward perpendicular of not less than 0.05L or 10 metres, whichever is the less, and, except as may be permitted by the Administration, not more than 0.08L or 0.05L + 3 metres, whichever is the greater.

(2) Where any part of the ship below the waterline extends forward of the forward perpendicular, e.g., a bulbous bow, the distances stipulated in subsection (1) shall be measured from a point either-

• (a) at the mid-length of such extension;

• (b) at a distance 0.015L forward of the forward perpendicular; or

• (c) at a distance 3 metres forward of the forward perpendicular,

• whichever gives the smallest measurement.

(3) The bulkhead may have steps or recesses provided they are within the limits prescribed in subsections (1) or (2).

(4) No doors, manholes, access openings, ventilation ducts or any other openings shall be fitted in the collision bulkhead below the bulkhead deck.

(5) The collision bulkhead shall comply with the following provisions-

• (a) except as provided in paragraph (b), the collision bulkhead may be pierced below the bulkhead deck by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a screw-down valve capable of being operated from above the bulkhead deck, the valve chest being secured inside the forepeak to the collision bulkhead, provided that-

  • (i) the Administration may, however, authorise the fitting of this valve on the after side of the collision bulkhead where that the valve is readily accessible under all service conditions and the space in which it is located is not a storage space;

  • (ii) all valves shall be of steel, bronze or other approved ductile material; and

  • (iii) valves of ordinary cast iron or similar material are not acceptable.

• (b) If the forepeak is divided to hold two different kinds of liquids the Administration may allow the collision bulkhead to be pierced below the bulkhead deck by two pipes, each of which is fitted as required by paragraph (a), provided the Administration is satisfied that there is no practical alternative to the fitting of such a second pipe and that, having regard to the additional subdivision provided in the forepeak, the safety of the ship is maintained.

(6) Where a long forward superstructure is fitted-

• (a) the collision bulkhead shall be extended weathertight to the deck next above the bulkhead deck;

• (b) the extension need not be fitted directly above the bulkhead below provided it is located within the limits prescribed in subsection (1) or (2) and that the part of the deck which forms the step is made effectively weathertight; and

(7) The number of openings in the extension of the collision bulkhead above the freeboard deck shall be restricted to the minimum compatible with the design and normal operation of the ship and all such openings shall be capable of being closed weathertight.

(8) Bulkheads shall be fitted separating the machinery space accommodation spaces forward and aft and made watertight up to the bulkhead deck and in passenger ships an afterpeak bulkhead shall also be fitted and made watertight up to the bulkhead deck, provided that the afterpeak bulkhead may, however, be stepped below the bulkhead deck, providing the degree of safety of the ship as regards subdivision is not thereby diminished.

(9) In all cases stern tubes shall be enclosed in watertight spaces of moderate volume and the stern gland shall be situated in a watertight shaft tunnel or other watertight space separate from the stern tube compartment and of such volume that, if flooded by leakage through the stern gland, the bulkhead deck will not be immersed.