Regulation 42 - Emergency source of electrical power in passenger ships
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Regulation 42 - Emergency source of electrical power in passenger ships

  (Paragraphs 2.6.1 and 4.2 of this regulation apply to ships constructed on or after 1 February 1992)

  1.1 A self-contained emergency source of electrical power shall be provided.

  1.2 The emergency source of electrical power, associated transforming equipment, if any, transitional source of emergency power, emergency switchboard and emergency lighting switchboard shall be located above the uppermost continuous deck and shall be readily accessible from the open deck. They shall not be located forward of the collision bulkhead.

  1.3 The location of the emergency source of electrical power and associated transforming equipment, if any, the transitional source of emergency power, the emergency switchboard and the emergency electric lighting switchboards in relation to the main source of electrical power, associated transforming equipment, if any, and the main switchboard shall be such as to ensure to the satisfaction of the Administration that a fire or other casualty in spaces containing the main source of electrical power, associated transforming equipment, if any, and the main switchboard or in any machinery space of category A will not interfere with the supply, control and distribution of emergency electrical power. As far as practicable, the space containing the emergency source of electrical power, associated transforming equipment, if any, the transitional source of emergency electrical power and the emergency switchboard shall not be contiguous to the boundaries of machinery spaces of category A or those spaces containing the main source of electrical power, associated transforming equipment, if any, or the main switchboard.

  1.4 Provided that suitable measures are taken for safeguarding independent emergency operation under all circumstances, the emergency generator may be used exceptionally, and for short periods, to supply non-emergency circuits.

  2 The electrical power available shall be sufficient to supply all those services that are essential for safety in an emergency, due regard being paid to such services as may have to be operated simultaneously. The emergency source of electrical power shall be capable, having regard to starting currents and the transitory nature of certain loads, of supplying simultaneously at least the following services for the periods specified hereinafter, if they depend upon an electrical source for their operation:

  2.1 For a period of 36 h, emergency lighting:

  • .1 at every muster and embarkation station and over the sides as required by regulations III/11.4 and III/16.7;

  • .2 in alleyways, stairways and exits giving access to the muster and embarkation stations, as required by regulation III/11.5;

  • .3 in all service and accommodation alleyways, stairways and exits, personnel lift cars;

  • .4 in the machinery spaces and main generating stations including their control positions;

  • .5 in all control stations, machinery control rooms, and at each main and emergency switchboard;

  • .6 at all stowage positions for firemen's outfits;

  • .7 at the steering gear; and

  • .8 at the fire pump, the sprinkler pump and the emergency bilge pump referred to in paragraph 2.4 and at the starting position of their motors.

  2.2 For a period of 36 h:

  2.3 For a period of 36 h:

  • .1 all internal communication equipment required in an emergency;

  • .2 the shipborne navigational equipment as required by regulation V/12footnote; where such provision is unreasonable or impracticable the Administration may waive this requirement for ships of less than 5,000 gross tonnage;

  • .3 the fire detection and fire alarm system, and the fire door holding and release system; and

  • .4 for intermittent operation of the daylight signalling lamp, the ship's whistle, the manually operated call points, and all internal signals that are required in an emergency;

unless such services have an independent supply for the period of 36 h from an accumulator battery suitably located for use in an emergency.

  2.4 For a period of 36 h:

  • .1 one of the fire pumps required by regulation II-2/4.3.1 and 4.3.3;footnote

  • .2 the automatic sprinkler pump, if any; and

  • .3 the emergency bilge pump and all the equipment essential for the operation of electrically powered remote controlled bilge valves.

  2.5 For the period of time required by regulation 29.14 the steering gear if required to be so supplied by that regulation.

  2.6 For a period of half an hour:

  • .1 any watertight doors required by regulation 13footnote (now II-1/13) to be power-operated together with their indicators and warning signals;

  • .2 the emergency arrangements to bring the lift cars to deck level for the escape of persons. The passenger lift cars may be brought to deck level sequentially in an emergency.

  2.7 In a ship engaged regularly on voyages of short duration, the Administration if satisfied that an adequate standard of safety would be attained may accept a lesser period than the 36 h period specified in paragraphs 2.1 to 2.5 but not less than 12 h.

  3 The emergency source of electrical power may be either a generator or an accumulator battery, which shall comply with the following:

  3.1 Where the emergency source of electrical power is a generator, it shall be:

  • .1 driven by a suitable prime mover with an independent supply of fuel having a flashpoint (closed cup test) of not less than 43°C;

  • .2 started automatically upon failure of the electrical supply from the main source of electrical power and shall be automatically connected to the emergency switchboard; those services referred to in paragraph 4 shall then be transferred automatically to the emergency generating set. The automatic starting system and the characteristic of the prime mover shall be such as to permit the emergency generator to carry its full rated load as quickly as is safe and practicable, subject to a maximum of 45 s; unless a second independent means of starting the emergency generating set is provided, the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system; and

  • .3 provided with a transitional source of emergency electrical power according to paragraph 4.

  3.2 Where the emergency source of electrical power is an accumulator battery, it shall be capable of:

  • .1 carrying the emergency electrical load without recharging while maintaining the voltage of the battery throughout the discharge period within 12% above or below its nominal voltage;

  • .2 automatically connecting to the emergency switchboard in the event of failure of the main source of electrical power; and

  • .3 immediately supplying at least those services specified in paragraph 4.

  3.3 The following provisions in paragraph 3.1.2 shall not apply to ships constructed on or after 1 October 1994:

Unless a second independent means of starting the emergency generating set is provided, the single source of stored energy shall be protected to preclude its complete depletion by the automatic starting system.

  3.4 For ships constructed on or after 1 July 1998, where electrical power is necessary to restore propulsion, the capacity shall be sufficient to restore propulsion to the ship in conjunction with other machinery, as appropriate, from a dead ship condition within 30 min after blackout.

  4 The transitional source of emergency electrical power required by paragraph 3.1.3 shall consist of an accumulator battery suitably located for use in an emergency which shall operate without recharging while maintaining the voltage of the battery throughout the discharge period within 12% above or below its nominal voltage and be of sufficient capacity and so arranged as to supply automatically in the event of failure of either the main or emergency source of electrical power at least the following services, if they depend upon an electrical source for their operation:

  4.1 For half an hour:

  • .1 the lighting required by paragraphs 2.1 and 2.2;

  • .2 all services required by paragraphs 2.3.1, 2.3.3 and 2.3.4 unless such services have an independent supply for the period specified from an accumulator battery suitably located for use in an emergency.

  4.2 Power to operate the watertight doors, as required by regulation 13.7.3.3footnote (now II-1/13), but not necessarily all of them simultaneously, unless an independent temporary source of stored energy is provided. Power to the control, indication and alarm circuits as required by regulation 13.7.2footnote (now II-1/13) for half an hour.

  5.1 The emergency switchboard shall be installed as near as is practicable to the emergency source of electrical power.

  5.2 Where the emergency source of electrical power is a generator, the emergency switchboard shall be located in the same space unless the operation of the emergency switchboard would thereby be impaired.

  5.3 No accumulator battery fitted in accordance with this regulation shall be installed in the same space as the emergency switchboard. An indicator shall be mounted in a suitable place on the main switchboard or in the machinery control room to indicate when the batteries constituting either the emergency source of electrical power or the transitional source of emergency electrical power referred to in paragraph 3.1.3 or 3.1.4 are being discharged.

  5.4 The emergency switchboard shall be supplied during normal operation from the main switchboard by an interconnector feeder which is to be adequately protected at the main switchboard against overload and short circuit and which is to be disconnected automatically at the emergency switchboard upon failure of the main source of electrical power. Where the system is arranged for feedback operation, the interconnector feeder is also to be protected at the emergency switchboard at least against short circuit.

  5.5 In order to ensure ready availability of the emergency source of electrical power, arrangements shall be made where necessary to disconnect automatically non-emergency circuits from the emergency switchboard to ensure that power shall be available to the emergency circuits.

  6 The emergency generator and its prime mover and any emergency accumulator battery shall be so designed and arranged as to ensure that they will function at full rated power when the ship is upright and when inclined at any angle of list up to 22.5° or when inclined up to 10° either in the fore or aft direction, or is in any combination of angles within those limits.

  7 Provision shall be made for the periodic testing of the complete emergency system and shall include the testing of automatic starting arrangements.


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