Chapter 5 - Weathertight Integrity

5.1 Virtual Freeboard Deck

(1) For the purposes of this section only, where actual freeboard to the weather deck exceeds that required by ICLL by at least one standard superstructure height, openings on that deck, abaft of the forward quarter, may be assumed to be in Position 2. This shall be taken, unless otherwise stated, as defined in ICLL.

(2) For vessels up to 75 metres load line length, a standard superstructure height shall be taken as 1.8 metres. For vessels over 125 metres load line length, this shall be taken as 2.3 metres. Superstructure heights for vessels of intermediate lengths shall be obtained by interpolation.

5.2 Hatchways and Skylight Hatches

(1) General Requirements

• (a) All openings leading to spaces below the weather deck not capable of being closed weathertight, shall be enclosed within either an enclosed superstructure or a weathertight deckhouse of adequate strength meeting with the requirements of the Recognised Organisation assigning the Load Line.

• (b) All exposed hatchways which give access from Position 1 and Position 2 shall be of substantial weathertight construction and provided with efficient means of closure. Weathertight hatch covers shall be permanently attached to the vessel and provided with adequate arrangements for securing the hatch closed.

• (c) Hatches which are designated for escape purposes shall:

  • (i) be provided with covers which shall be openable from either side and in the direction of escape they shall be openable without a key. All handles on the inside shall be non-removable^footnote;

  • (ii) be readily identified and easy and safe to use, having due regard to its position; and

  • (iii) not be required to have a coaming provided:

    • (ba) the hatch cover is weathertight; and

    • (bb) the hatch shall be closed at sea and marked accordingly and shall be provided with open/close indication at the navigating position.

(2) Hatchways Which are Open at Sea

• (a) In general, hatches shall be kept closed at sea. However, hatchways which may be kept open for access at sea shall be as small as practicable (a maximum of 1 square metre in clear area), and fitted with coamings of at least 300 millimetres in height in positions 1 and 2 Hatchways shall be as near to the centreline as practicable, especially on sailing vessels. Covers of hatchways shall be permanently attached to the hatch coamings and, where hinged, the hinges shall be located on the forward side.

5.3 Doorways and Companionways

(1) Doorways Located Above the Weather Deck

• (a) External doors in deckhouses and superstructures shall be weathertight. Doors opening directly onto staircases which are located in the following positions, shall have coaming heights of at least:

  Location	Unrestricted Yachts	Short Range Yachts
  A	600mm	300mm
  B	300mm	150mm
  C	150mm	75mm

  Location A	The door is in the forward quarter length of the vessel and is used when the vessel is at sea.
  Location B	The door is in an exposed forward facing location aft of the forward quarter length.
  Location C	The door is in a protected location aft of the forward quarter length, or an unprotected door on the first tier deck above the weather deck.

• (b) Weathertight doors shall be arranged to open outwards and when located in a superstructure side, be hinged at the forward edge. Alternative closing arrangements shall be considered providing it can be demonstrated that the efficiency of the closing arrangements and their ability to prevent the ingress of water shall not impair the safety of the vessel.

• (c) An access door leading directly to the engine room from the weather deck shall be fitted with a coaming of height of at least:

  Location	Unrestricted Yachts	Short Range Yachts
  Position 1	600mm	450mm
  Position 2	380mm	200mm

• (d) Construction and securing standards for weathertight doors which are provided for use only when the vessel is in port or at anchor in calm sheltered waters and are locked closed when the vessel is at sea, may be considered individually. Coaming heights need not meet 5.3(1)(a)

• (e) Proposals to reduce the coaming heights required by 5.3(1)(a) and 5.3(1)(c) shall be subject to special consideration and approval by the Administration, having regard for the protected location of the weathertight door, the space to which it serves, increased freeboard and increased water freeing arrangements.

(2) Companion Hatch Openings

• (a) Companionway hatch openings which give access to spaces below the weather deck shall be fitted with a coaming, the top of which is at least 300 millimetres above the deck, or 150 millimetres in the case of Short Range Yachts.

• (b) Washboards may be used to close the vertical opening. When washboards are used, they shall be so arranged and fitted that they shall not be dislodged readily. Whilst stowed, provisions shall be made to ensure that they are retained in a secure location.

• (c) The maximum breadth of an opening in a companion hatch shall not exceed 1 metre.

5.4 Glazed Openings & Skylights

General

(1) Glazed openings & Skylights shall:

• (a) be made from toughened safety glass. In case of chemically toughened glass, it shall be qualified by testing in accordance with EN 1288-3, based on the requirements given in ISO 11336-1. Regular inspections of the glazed openings, with particular reference to the surface condition, shall form part of the operational procedures and annual surveys;

• (b) not be fitted in such a position that their sills are below a line drawn parallel to the freeboard deck at side and having its lowest point 2.5% of the breadth (B), or 500 millimetres, whichever is the greatest distance, above the design waterline;

• (c) be attached to the ship in such a manner, that they are capable of fulfilling their role in the application of ICLL requirements;

• (d) follow the requirements of Chapter 18 where they are for glazed openings in the navigating position;

• (e) not be fitted in the hull in the way of the machinery space; and

• (f) be of the non-readily opening type which shall be securely closed when the vessel is in navigation and indication provided on the bridge that they are closed.

(2) When glazed openings are fitted by bonding, the following provisions shall be observed:

• (a) proposals shall include measures to ensure the integrity of the bond line taking into account environmental and ageing effects; and

• (b) when required to be fire rated, arrangements shall be such that glazed openings and doors cannot fall from their mounting should the bond line fail, except where the glazed opening or door assembly has successfully passed the standard fire test without the need to provide any additional means of fastening.

(3) Where glazed openings protect buoyant volumes, they shall be designed using the pressure heads derived from a recognised International Standard such as ISO 5780 or ISO 11336-1.

(4) Where glazed openings do not protect buoyant volumes, they shall be designed using the pressure heads rules of a Recognised Organisation or a recognised International Standard such as ISO 11336-1.

Deadlights

(5) In all cases, it shall be ensured that any limitations (i.e. aspect ratio, maximum window size, etc) included in the Rules of the Recognised Organisation or International Standard being used are observed and complied with.

(6) Glazed openings within the buoyant part of the hull shall be provided with deadlights so arranged that they can be easily and effectively closed and secured watertight.

(7) Deadlights may be portable provided these are stored in an easily accessible location and are readily mountable in a seaway. Instructions to the Master as to when deadlights shall be applied to portlights shall be provided.

Storm Covers

(8) For all vessels other than Short Range Yachts, Storm covers shall be required in the following locations, where deadlights are not already required by Section (6):

• (a) glazed openings in the front and sides of Level 1;

• (b) glazed openings in the front of Level 2; and

• (c) where storm covers are interchangeable between port and starboard, a minimum of 50% of each size shall be provided.

(9) Where required by Section (8), if the glazed openings meet an enhanced structural standard, in accordance with Recognised Organisation rules, a recognized International Standard, or a factor of 1.5 applied to the design pressure of the glazed opening, then storm covers are not required provided the glazing is of laminated construction. The ratio between the thicknesses of the plies in the laminate shall not exceed 4/3.

(10) A and B Class Cabin Bulkheads and Doors are accepted in place of deadlights or storm covers fitted to glazed openings, except in the following locations where deadlights or storm covers are to be provided:

• (a) In Levels 1 and 2 when considered buoyant in the Stability Calculations

• (b) In Levels 1 and 2 when above the buoyant part of the Hull and separating fwd facing glazed openings from a direct access leading below

• (c) In Level 1 when above the buoyant part of the Hull and separating side facing glazed openings from a direct access leading below

Skylights

(11) Fixed or opening skylights shall-

• (a) have a glazing thickness appropriate to their size and position as required for glazed openings;

• (b) be provided with protection from mechanical damage to the skylight load-bearing glazing in any position;

• (c) except where the arrangements comply with (12), when fitted in Level 1 or 2, be provided with deadlights or storm covers that can be easily and safely mounted in a seaway; and

• (d) if designated for escape purposes, be provided with a means of opening from either side of the skylight provided that in the direction of escape they are able to be opened without a key.

(12) the Administration may permit the storm covers specified in Sections (11)(c) to be omitted provided the glazing meets Section (9)

Strength

(13) Glazed openings, together with their frames, deadlights and storm covers, if fitted, shall meet an appropriate national or international standard or the rules regarding side scuttles and windows of a Recognised Organisation^footnote.

(14) Where the glazing material, glazing thickness, or fixing of the glazed opening do not meet the requirements of a recognised standard^footnote they may be tested^footnote, to the satisfaction of the Administration, in accordance with the following provisions:

• (a) the glazed opening shall be tested to a minimum test pressure of 4 times the required design pressure derived from an appropriate national or international standard, provided that as a minimum, the calculated thicknesses shall meet the Recognised Organisation requirements; and

• (b) the testing shall be witnessed by an Recognised Organisation.

5.5 Ventilators and Exhausts

(1) Adequate ventilation shall be provided throughout the vessel. The accommodation shall be protected from the entry of gas and/or vapour fumes from machinery, exhaust and fuel systems, where machinery exhaust systems pass though accommodation they shall be fitted in a gas tight trunk or each space shall be fitted with a carbon monoxide detector, having an alarm provided locally and at a continuously manned station.

(2) Ventilators shall be of efficient construction. Generally, ventilators serving spaces below the freeboard deck or an enclosed superstructure, shall have a minimum coaming height of:

(3) Ventilators shall be kept as far inboard as practicable and the height above the deck of the ventilator opening shall be sufficient to prevent the ingress of water when the vessel heels.

(4) The ventilation of spaces such as the machinery space, which shall remain open, requires special attention with regard to the location and height of the ventilation openings above the deck, taking into account the effect of down flooding angle on stability standard (See Chapter 11) and alternative ventilation for use in bad weather.

The means of closure of ventilators serving the machinery space shall be selected with regard to the fire protection and extinguishing arrangements provided in the machinery space.

(5) Engine exhaust outlets which penetrate the hull below the freeboard deck shall be provided with means to prevent back flooding into the hull through a damaged exhaust system. For vessels operating on unrestricted service a positive means of closure shall be provided. The system shall be of equivalent construction to the hull on the outboard side of the closure. For Short Range Yachts, where the fitting of a positive closure is not practicable, the exhaust shall be looped up above the waterline on the outboard side of the system, to a minimum height of 1000 millimetres, and be of equivalent construction to the hull.

(6) Ventilators shall be provided with permanently attached means of weathertight^footnote closure. Where the full coaming heights of 5.5(2) are met, permanently attached means of closure may be omitted if it can be shown that the open end of a ventilator is afforded adequate protection by other structure(s) which shall prevent the ingress of water.

(7) Proposals to reduce the coaming heights required by 5.5(2) may be subject to special consideration and approval by the Administration, having regard for their protected location, means to prevent the ingress of water, excess freeboard and impact on stability.

5.6 Air Pipes

(1) Air pipes serving fuel and other tanks shall be of efficient construction, led to above the bulkhead deck and provided with automatic closing devices. Where the full coaming heights of 5.6(2) are met, automatic closing devices may be omitted if it can be shown that the open end of an air pipe is afforded adequate protection by other structure(s) which shall prevent the ingress of water.

(2) Air pipes shall be kept as far inboard as practicable and be fitted with a coaming of sufficient height to prevent inadvertent flooding. Generally, air pipes to tanks shall have a minimum coaming height of:

(3) Air pipes to fuel tanks shall terminate at a height of not less than 760 millimetres above either, the top of the filler pipe for a gravity filling tank or, the top of the overflow tank for a pressure filling tank.

(4) Proposals to reduce the coaming heights required by 5.6(2) may be subject to special consideration and approval by the Administration, having regard for their protected location, means to prevent the ingress of water, excess freeboard and impact on stability.

5.7 Scuppers, Sea Inlets and Discharges and Other Hull Penetrations

(1) The standards of ICLL shall be applied to every discharge led through the shell of the vessel as far as it is reasonable and practicable to do so, and in any case, all sea inlet and overboard discharges shall be provided with efficient shut-off valves arranged in positions where they are readily accessible at all times.

(2) Underwater lights and associated penetrations fitted in the hull shall be approved by the Recognised Organisation.

5.8 Materials for Valves and Associated Piping

(1) Valves which are fitted below the waterline shall be of steel, bronze or other material having a similar resistance to impact, fire and corrosion. Non-metallic valves shall not normally be considered equivalent.

(2) The associated piping shall, in areas as indicated above, be of steel, bronze, copper or other equivalent material. Non-metallic piping shall not normally be considered equivalent.

(3) Where the use of plastic piping is proposed, it shall be specially considered and full details of the type of piping, its intended location, and use, shall be submitted for approval; with regard to watertight integrity, any plastic piping shall be above the waterline. Due regard shall be paid to the Fire Test Procedures Code, and 14A.2.3.4 or 14B.2.11.6.

(4) The use of flexible piping in any location shall be kept to a minimum compatible with the essential reason for its use. Flexible piping and the means of joining it to its associated hard piping system shall be approved as fit for the purpose.

5.9 Additional Equivalence Considerations

(1) Openings to be kept closed at sea

(2) Enhanced Bilge Pumping capacity and additional bilge alarms

(3) Compliance with damage stability if not already a requirement (see Section 11)

(4) Provision of dorade boxes or baffle systems to prevent direct ingress of water

(5) Alternative ventilation for use in bad weather

(6) Consideration of down-flooding angle and reduced risk of green sea loads, i.e. protected position

(7) Enhanced survey inspection regime

(8) Operational Limitations