What are requirements for duration of emergency power supply as per SOLAS ?

(1) The Emergency source of electric power required shall be capable of simultaneously supplying the following services, including any starting currents and for the following periods:-

(a) For a period of 3 hours the emergency lighting required under the Merchant Shipping (Life-Saving Appliances) rules, 1990.

(b) For a period of 18 hours, emergency lighting :-

1. (i) In all service an accommodations alleyways, stairways , exits, lifts and lifts shafts.
2. In machinery spaces and main generating stations including the control positions.
3. In control stations, machinery control rooms and at each main and emergency switchboard.
4. At the stowage positions for firemen’s outfits.
5. At the steering gear, and
6. At the fire pump, sprinkler pump and emergency bilge pump and at their starting positions.

(c) For a period of 18 hours, unless they have an equivalent independent supply from a suitably located accumulator battery:-