Sec.  80.917   Reserve power supply.

   (a) The requirements of this section apply

   (1) To vessels of more than 100 gross tons; and

   (2) Beginning March 25, 2009 to

   (i)  Vessels  that  carry  more  than 150 passengers or have overnight
   accommodations for more than 49 persons; and

   (ii) Vessels that operate on the high seas or more than three miles from
   shore on Great Lakes voyages. Any such vessel the keel of which was laid
   after March 1, 1957, must have a reserve power supply located on the same
   deck as the main wheel house or at least one deck above the vessel's main
   deck, unless the main power supply is so situated.

   (b) The reserve power supply must be independent of the ship's propulsion
   and of any other electrical system, and be sufficient to simulataneously
   energize the radiotelephone transmitter at its required output power, and
   the receiver. The reserve power supply must be available for use at all
   times.

   (c)  When the reserve power supply consists of batteries, they must be
   installed as high above the bilge as practicable, secured against shifting
   with motion of the vessel, and accessible with not less than 26 cm (10 in.)
   head room.

   (d)  The  reserve  power  supply  must be located as near the required
   transmitter and receiver as practicable.

   (e) All reserve power supply circuits must be protected from overloads.

   (f) Means must be provided for charging any storage batteries used as a
   reserve power supply for the required radiotelephone installation. There
   must be a device which will give continuous indication of the rate and
   polarity of the charging current during charging.

   (g) The cooling system of each internal combustion engine used as a part of
   the reserve power supply must be adequately treated to prevent freezing or
   overheating consistent with the season and route to be travelled by the
   particular vessel involved.

   [ 51 FR 31213 , Sept. 2, 1986, as amended at  58 FR 44954 , Aug. 25, 1993;  73 FR 4488 , Jan. 25, 2008]