3.1 Arrangements above the bulkhead deck
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1320 – Guidelines for the Drainage of Fire-Fighting Water From Closed Vehicle and Ro-Ro Spaces and Special Category Spaces of Passenger and Cargo Ships – (11 June 2009) - Annex – Guidelines for the Drainage of Fire-Fighting Water From Closed Vehicle and Ro-Ro Spaces and Special Category Spaces of Passenger and Cargo Ships - 3 Drainage Arrangements for Passenger Ships - 3.1 Arrangements above the bulkhead deck

3.1 Arrangements above the bulkhead deck

  3.1.1 Above the bulkhead deck, except as provided in paragraph 1.1.2 above, an adequate number of properly-sized drains should be provided on each deck to ensure that the combined water flow from the fixed fire-extinguishing system and the required number of fire hoses can be rapidly discharged overboard or drain to a bilge system with a reservoir tank fitted with a high water level alarm.

  3.1.2 At least four drains should be located on each side of the protected space, uniformly distributed fore and aft. Freeing ports should not be installed in enclosed superstructures, as defined by regulation 3.10 of the ICLL 66.

  3.1.3 The drainage system on each side of the deck should have an aggregate capacity of not less than 125% of the maximum flow rate of the fixed fire-extinguishing system water pumps plus the flow from two fire hoses (four if required by SOLAS regulation II-2/19.3.1.2). In case an automatic deep well or submersible pumping system is installed, the bilge pump capacity can be subtracted from the required drainage capacity.

  3.1.4 Minimum capacity of drains

 The minimum capacity of scuppers, freeing ports or a combination thereof should be determined in accordance with the provisions of paragraphs 3.1.4.1 or 3.1.4.2, respectively.

  3.1.4.1 The minimum required area of scuppers and connected piping should be determined by the following formula:

where:

A is the total required sectional area of the drains on each side of the deck in m2;

Q is the combined waterflow from the fixed fire-extinguishing system and the required number of fire hoses in m3/s;

h is the elevation head difference between the bottom of the scupper well or suction level and the overboard discharge opening or highest approved load line in m; and

∑ hl is the summation of head losses corresponding to scupper piping, fittings and valves in m.

 In no case should the area of each individual drain be less than 0.0078 m2 or 125 mm diameter piping.

  3.1.4.2 The minimum required area of freeing ports should be determined by the following formula:

where:

A is the total required sectional area of freeing ports on each side of the ship in m2;

Q is the combined waterflow from the fixed fire-extinguishing system and the required number of fire hoses in m3/s; and

h1-h2 is the depth of water on the deck determined in accordance with paragraph 4.2.

 If the cross-sectional area of freeing ports required by the ICLL 66 is equal to or greater than determined above, additional freeing ports are not required.

Parent topic: 3 Drainage Arrangements for Passenger Ships
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