Regulation 17 – Internal Watertight Integrity of Passenger Ships Above the Bulkhead Deck

General – Steps in the bulkhead deck

For the treatment of steps in the bulkhead deck of passenger ships see explanatory notes for regulation 13.

Regulation 17.1

This explanatory note only applies to passenger ships for which the building contract is placed on or after 1 January 2020 and which are constructed before 1 January 2024.

1 Sliding watertight doors with a reduced pressure head that are located above the bulkhead deck and which are immersed in the final or during any intermediate stage of flooding should comply fully with the requirements of regulation 13. These types of sliding watertight doors tested with reduced pressure head must not be immersed at any stage of flooding by a head of water higher than the tested pressure head. See figure 1 below. These sliding watertight doors shall be kept closed during navigation in compliance with the requirements of regulation 22 and this should be clearly indicated in the damage control information required by regulation 19.

2 If watertight doors are located above the worst final and above the worst intermediate waterline in damage cases contributing to the attained subdivision index A, but within the area where the door becomes intermittently immersed (fully or partly) at angles of heel in the required range of positive stability beyond the equilibrium position, such doors are to be power-operated and remotely controlled sliding semi-watertight doors complying with the requirements of regulation 13, except that the scantlings and sealing requirements could be reduced to the maximum head of water caused by the waterline being intermittently immersed (see figure 1 below). These doors should be closed in case of damage and this should be clearly indicated in the damage control information required by regulation 19.

3 The use of sliding watertight doors above the bulkhead deck affects the escape provisions of regulation II-2/13. When such doors are used above the bulkhead deck, there should be at least two means of escape from each main vertical zone or similarly restricted space or group of spaces, at least one of which should be independent of watertight doors and at least one of which should give access to a stairway forming a vertical escape. Sliding watertight doors that will be used frequently by passengers must not create a tripping hazard.

4 Doors fitted above the bulkhead deck which are required to meet both fire protection and watertight requirements should comply with the fire requirements in regulation II-2/9.4.1.1 and the watertight requirements in paragraphs 1 and 2 above. Notwithstanding regulation II-2/9.4.1.1.3, watertight doors fitted above the bulkhead deck should be insulated to the standard required by table 9.1 and regulation II-2/9.2.2.1.1.1 or by table 9.3 and regulation II-2/9.2.2.1.1.2 as appropriate. The door must be capable of operation using both the remote fire door control circuit and the remote watertight door control circuit. If two doors are fitted, they must be capable of independent operation. The operation of either door separately must not preclude closing of the other door. Both doors must be capable of being operated from either side of the bulkhead.

Regulation 17.2

This explanatory note only applies to passenger ships constructed on or after 1 January 2024.

1 Doors fitted in internal watertight subdivision boundaries located above the bulkhead deck that are immersed at either the final equilibrium or worst intermediate stage of flooding waterlines should be sliding watertight doors that comply fully with the requirements of regulation 13. They should not be immersed at any stage of flooding by a head of water higher than their design scantlings or their tested pressure head. These sliding watertight doors should be kept closed during navigation in accordance with the requirements of regulation 22 and this should be clearly indicated in the damage control information required by regulation 19.

2 The use of sliding watertight doors above the bulkhead deck affects the escape provisions of regulation II-2/13. When such doors are used above the bulkhead deck, there should be at least two means of escape from each main vertical zone or similarly restricted space or group of spaces, at least one of which should be independent of watertight doors and at least one of which should give access to a stairway forming a vertical escape. Sliding watertight doors that will be used frequently by passengers must not create a tripping hazard.

3 Doors fitted above the bulkhead deck which are required to meet both fire protection and watertight requirements should comply with the fire requirements in regulation II-2/9.4.1.1 and the watertight requirements in paragraph 1 above. Notwithstanding regulation II-2/9.4.1.1.3, watertight doors fitted above the bulkhead deck should be insulated to the standard required by table 9.1 and regulation II-2/9.2.2.1.1.1 or by table 9.3 and regulation II-2/9.2.2.1.1.2 as appropriate. The door must be capable of operation using both the remote fire door control circuit and the remote watertight door control circuit. If two doors are fitted, they must be capable of independent operation. The operation of either door separately must not preclude closing of the other door. Both doors must be capable of being operated from either side of the bulkhead.

Regulation 17.3

This explanatory note only applies to passenger ships constructed on or after 1 January 2024.

1 To be considered capable of preventing the passage of water when intermittently immersed in the required range of positive stability, these doors should meet a watertight standard for a minimum 1 m head of water. These doors may be hinged or sliding, provided they comply with the design requirements applied from both sides of the door. Consideration should be given to the opening direction for hinged doors, so that they do not open against the intended direction of escape. These doors should be closed in case of damage and this should be clearly indicated in the damage control information required by regulation 19.

2 These doors are required to meet the fire protection requirements in chapter II-2. Because these doors are not watertight doors that comply with the requirements in regulation 13, the exclusions for watertight doors in chapter II-2 do not apply. In addition to operation using the fire door control circuit, these doors should be provided with a separate remote closure control circuit located on the navigation bridge with the central operating console for the power-operated sliding watertight doors that is required by regulation 13.7.1. A diagram showing the location of each door, with visual indicators to show whether each door is open or closed, should also be at the central operating console. A red light should indicate a door is fully open and a green light should indicate a door is fully closed. When the door is closed remotely, the red light should indicate the intermediate position by flashing. The indicating circuit should be independent of the control circuit for each door. Indication should also be provided to the onboard stability computer, if installed in accordance with regulation 8-1.3.1.

3 These doors should also be capable of being remotely closed with the ship listed 15 degrees either way.

Regulation 17.5

For passenger ships for which the building contract is placed on or after 1 January 2020 and which are constructed before 1 January 2024, this is regulation 17.3.

This paragraph is intended to ensure that progressive flooding through air pipes of volumes located above a horizontal division in the superstructure, which is considered as a watertight boundary when applying regulation 7-2.6.1.1, will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.