Article 41 Requirements for vessels of 24.4 metres in length and over
In every vessel of 24.4 metres in length and over to which these Rules apply where electric power is the only power for maintaining auxiliary services essential for the propulsion or safety of the vessel there shall be provided two or more generating sets of such power that the aforesaid services can be operated when any one of the sets is out of service.
In every such vessel where the main source of electric power is situated below the uppermost continuous deck and within the machinery casings there shall be provided outside the machinery casings a self-contained emergency source of electric power so arranged as to ensure its functioning in the event of failure by reason of fire or otherwise of the main electrical installation.
In every such vessel where the main source of electric power is situated above the uppermost continuous deck and outside the machinery casings such source of power shall be capable of operating simultaneously for a period of at least 3 hours the services indicated in paragraph (5) below in addition to any other electrical load.
In any such vessel where properly installed electric navigation lights supplied from the emergency source of power are provided in addition to the normal navigation lights oil navigation lights need not be carried.
Subject to paragraph (9) below, in every such vessel the emergency source of electric power shall be capable of operating simultaneously for a period of at least three hours the following services:—
the general alarm if electrically operated;
the watertight doors if they are electrically or electro-hydraulically operated and their indicators and the warning signals if electrically operated;
emergency lights at launching stations and over-side, in all alleyways, stairways and exits, in the machinery spaces and in the place where the emergency source of electric power, if any, is situated; and in control stations for radio, navigation or other services essential to the safety of the vessel;
emergency navigation lights fitted in accordance with paragraph (4) above, communication equipment, fire detecting systems and signals which may be required in an emergency, and the daylight signaling lamp.
In every such vessel the emergency source of electric power shall be either accumulator (storage) batteries capable of supplying the services set out in paragraph (5) above without being recharged or suffering an excessive voltage drop, or a generator driven by internal combustion type machinery with an independent fuel supply and with efficient starting arrangements. The fuel provided for such machinery shall have a flash point of not less than 43°C. (Closed Test).
In every such vessel the emergency source of electric power shall be so arranged that it will operate efficiently when the vessel is listed 221/2 degrees either way and when the trim of the vessel is 10 degrees from a level keel.
In every such vessel adequate means shall be provided for the regular testing of the emergency source of electric power and its associated circuits.
In any vessel of 24.4 metres in length and over but less than 45 metres in length to which these Rules apply adequate alternative means of supply for the emergency lighting systems set out in sub-paragraph (5)(c) above may be installed.