C.1 General requirements
C.1.1 The emergency source of electrical power shall take over the supply of the emergency con-sumers in case of failure of the main source of electrical power. It shall be independent of the main source of electrical power.
C.1.2 The capacity of the emergency source of electrical power shall be sufficient to supply all those services which are essential for safety in an emergency.
C.1.3 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, see also B.1.10 and D.
C.1.4 For ships which need electrical power to restore propulsion, the capacity of the emergency source of power shall be sufficient to restore propulsion to the ship in conjunction with other auxiliary ma-chinery, as appropriate, within 30 min. after blackout. It is assumed that starting energy is not available after blackout. For steam ships the 30 min. admit until start up of the first boiler, see also B.1.7 and C.1.8.
C.1.5 For all equipment forming part of the emergency source of electrical power, provision shall be made for periodic functional tests, including especially the testing of automatic switching and starting de-vices. Such testing shall be possible without interfering with other aspects of the ship's operation.
Section 3 Power Supply Installations
C.1.6 For the rating and control of the emergency generators, the same principles apply as for the main generators in accordance with B.2. Unlike in B.2.4, voltage deviations of 3.5 % under steady condi-tions and of 4 % under transient condicondi-tions after 5 s are acceptable.
C.1.7 Regarding electric starting equipment see Section 7, D.6.
C.1.8 Where fins of stabilizing systems are in the area of embarking stations of life boats, these sys-tems and indicators on the navigation bridge shall be connected to the emergency source of power.
C.2 Emergency electrical power supply on passenger ships
Regarding emergency electrical power supply on passenger ships see Section 14, C.
C.3 Emergency electrical power supply on cargo ships
C.3.1 All cargo ships of 500 GRT and over are to be provided with a self-contained emergency source of electrical power.
C.3.2 With due allowance for starting currents, the emergency source of electrical power shall be capable of simultaneously supplying at least the following services for the period specified below, if their operation depends upon an electrical source:
C.3.2.1 For 3 hours, the emergency lighting at every embarkation station for survival craft and rescue boats on deck and along the ship's sides in this area.
C.3.2.2 For 18 hours, the emergency lighting
a) in all service and accommodation alleyways, on stairways, at exits and in personnel lift cars and shafts
b) in engine rooms and main generator stations, including their control positions
c) in all control stations, bridge, engine control rooms and at each main and emergency switchboard d) at all stowage positions for firemen's outfits
e) in the steering gear compartment, and the CO2 room
f) at the fire pump mentioned in C.3.2.5, at the sprinkler pump, if any, the emergency bilge pump, if any, and at the start-up position for their motors
g) in all cargo pump-rooms of tankers C.3.2.3 For 18 hours
a) the navigation lights and other lights required by the current "International Regulations for Preventing Collisions at Sea"
b) the VHF radio installation required in SOLAS IV and, where provided, the MF radio installation, as well as the ship earth station and the MF/RF radio installation
C.3.2.4 For 18 hours
a) all internal signalling and communications equipment required in an emergency b) all ship's navigational appliances stipulated by SOLAS V/19
c) the fire detection and fire alarm system
d) the intermittent operation of the daylight signalling lamp, the ship's whistle, the manually operated fire alarms and all the internal signals required in an emergency, e.g. general alarm, and CO2 alarm unless these services can be independently supplied during this 18-hour period by an emergency storage battery.
C.3.2.5 For 18 hours
a) the required emergency fire pump
b) the water-spraying systems for machinery spaces of Category A and cargo pump rooms c) the auxiliary equipment for the emergency generator set
d) at least one bilge pump for cargo spaces on open-top container ships
C.3.2.6 The steering gear for the time specified in Section 7, A.2, where an emergency supply is stipu-lated, and also the rudder angle indicator.
C.3.3 In the case of ships which regularly undertake voyages of limited duration, the national au-thorities may accept a period shorter than the 18 hours specified in C.3.2.2 – C.3.2.5, but not less than 12 hours, if they are satisfied that this ensures an adequate standard of safety being attained.
C.3.4 The emergency source of electrical power for cargo ships may be either a generator set or a storage battery.
C.3.4.1 Where the emergency source of electrical power is a generator set, it shall be driven by a suit-able prime mover with its own independent fuel supply in accordance with the GL Rules for Machinery Installations (I-1-2), Section 10 and with an independent cooling system.
The set shall start up automatically if the main source of electrical power fails, and the supply of the listed consumers shall be automatically taken over by the emergency generator set, unless a transitional emer-gency power source in accordance with C.3.4.2 is provided.
The emergency supply of electrical power shall come into operation as quickly as possible, and in any event not later than 45 seconds after the failure of the main source of electrical power.
C.3.4.2 The transitional source of emergency electrical power shall be a storage battery which, in the event of failure of the main source of electrical power, automatically and immediately supplies the sumers listed below until the emergency generator set described in C.3.4.1 is put into operation and con-nected.
Its capacity shall be sufficient to supply the consumers for a period of at least 30 minutes, during which time the battery voltage shall remain within ± 12 % of the rated voltage, without intermediate recharging.
Where called for and dependent on an electrical power source, the following consumers are to be sup-plied:
a) the lighting specified in C.3.2.1, C.3.2.2 and C.3.2.3 a). The necessary emergency lighting of the machinery space and the accommodation and service spaces can be provided by permanently fixed, self-contained, battery-powered lamps and
b) all the services specified in C.3.2.4 a), C.3.2.4 c) and C.3.2.4 d), unless such services are inde-pendently supplied for the prescribed period by an emergency storage battery
C.3.4.3 If the emergency source of electrical power is a storage battery, it shall meet the functional requirements stated in C.3.4.2.
C.4 Emergency consumers protecting the main propulsion plant
In rating the emergency source of electrical power, consideration is to be given, where applicable, to oth-er consumoth-ers required to protect the main propulsion plant in the event of a failure of the main source of electrical power. Such consumers may, for example, include the emergency lubricating oil supply and the turning gear on turbine plant. The measures to be taken are to be agreed with GL in each particular case.
C.5 Emergency electrical power supply for special purpose ships in accordance with IMO-Resolution MSC.266(84)
C.5.1 Within the meaning of this Section, "special purpose ships" are ships of 500 GRT and over in which 12 persons apart from the crew are carried for an extended period for the performance of special tasks. They include, for example, research ships, drilling vessels, etc. Consideration is given to the num-ber of additional personnel and to the size of the ship when deciding whether the ship is to be treated as a cargo ship or a passenger ship for the purpose of its emergency electrical power supply.
C.5.2 "Special purpose ships" not more than 50 m in length and carrying not more than 60 persons on board are treated as cargo ships in accordance with C.1 and C.3
Section 3 Power Supply Installations
C.5.3 If the length of the ship is greater than 50 m, the closure system for watertight doors in bulk-heads and its indicators are to be connected to the emergency electrical power supply, as on passenger ships in accordance with Section 14.
C.5.4 With regard to their emergency power supply, "special purpose ships" carrying more than 60 persons on board are to be treated in every respect as passenger ships in accordance with Section 14.