Regulation 22 - Design criteria for systems to remain operational after a fire casualty

 Passenger ships constructed on or after 1 July 2010 having length, as defined in regulation II-1/2.5, of 120 m or more or having three or more main vertical zones shall comply with the provisions of this regulation.

 The purpose of this regulation is to provide design criteria for systems required to remain operational for supporting the orderly evacuation and abandonment of a ship, if the casualty threshold, as defined in regulation 21.3, is exceeded.

  3.1 In case any one main vertical zone is unserviceable due to fire, the following systems shall be so arranged and segregated as to remain operational:

• .1 fire main;

• .2 internal communications (in support of fire-fighting as required for passenger and crew notification and evacuation);

• .3 means of external communications;

• .4 bilge systems for removal of fire-fighting water;

• .5 lighting along escape routes, at assembly stations and at embarkation stations of life-saving appliances; and

• .6 guidance systems for evacuation shall be available.

  3.2 The above systems shall be capable of operation for at least 3 h based on the assumption of no damage outside the unserviceable main vertical zone. These systems are not required to remain operational within the unserviceable main vertical zones.

  3.3 Cabling and piping within a trunk constructed to an "A-60" standard shall be deemed to remain intact and serviceable while passing through the unserviceable main vertical zone for the purposes of paragraph 3.1. An equivalent degree of protection for cabling and piping may be approved by the Administration.