1. (a) Each vessel that carries bulk liquefied flammable gases or ammonia as a cargo, cargo residue, or vapor must meet the requirements of this section.

2. (b) As used in this section:

   1. (1) The terms “gas-safe” and “gas-dangerous” spaces are used as defined in § 154.7 of this chapter.
   2. (2) The term “gas-dangerous” does not include the weather deck of an ammonia carrier.
3. (c) Each submerged cargo pump motor design must receive concept approval by the Commandant (CG-ENG) and its installation must receive plan approval by the Commanding Officer, Marine Safety Center.

4. (d) Electrical equipment must not be installed in a gas-dangerous space or zone, except:

   1. (1) Intrinsically safe electrical equipment and wiring, and
   2. (2) Other equipment as allowed in this section.
5. (e) A submerged cargo pump motor, if installed in a cargo tank, must meet § 111.105-31(d).

6. (f) Electrical equipment must not be installed in a hold space that has a tank that is not required to have a secondary barrier under § 154.459 of this chapter, except:

   1. (1) Through runs of marine shipboard cable;
   2. (2) Explosionproof lighting fixtures;
   3. (3) Depth sounding devices in gastight enclosures;
   4. (4) Log devices in gastight enclosures;
   5. (5) Impressed current cathodic protection system electrodes in gastight enclosures; and
   6. (6) Armored or MI type cable for a submerged cargo pump motor.

7. (g) Electrical equipment must not be installed in a space that is separated by a gastight steel boundary from a hold space that has a tank that must have a secondary barrier under the requirements of § 154.459 of this chapter, except:

   1. (1) Through runs of marine shipboard cable;
   2. (2) Explosionproof lighting fixtures;
   3. (3) Depth sounding devices in gastight enclosures;
   4. (4) Log devices in gastight enclosures;
   5. (5) Impressed current cathodic protection system electrodes in gastight enclosures;
   6. (6) Explosionproof motors that operate cargo system valves or ballast system valves;
   7. (7) Explosionproof bells for general alarm systems; and
   8. (8) Armored or MI type cable for a submerged cargo pump motor.
8. (h) A cargo-handling room must not have any installed electrical equipment, except explosionproof lighting fixtures.

9. (i) A space for cargo hose storage or a space that has cargo piping must not have any installed electrical equipment, except:

   1. (1) Explosionproof lighting fixtures; and
   2. (2) Through runs of marine shipboard cable.

10. (j) A gas dangerous zone on the open deck must not have any installed electrical equipment, except:

    1. (1) Explosionproof equipment that is necessary for the operation of the vessel; and
    2. (2) Through runs of marine shipboard cable.
11. (k) A space, except those named in paragraphs (f) through (i) of this section, that has a direct opening to gas-dangerous spaces or zones must have no electrical equipment except as allowed in the gas-dangerous space or zone.
12. (l) Each gas-dangerous space that has lighting fixtures must have at least two branch circuits for lighting.
13. (m) Each switch and each overcurrent protective device for any lighting circuit that is in a gas-dangerous space must open all conductors of the circuit simultaneously.
14. (n) Each switch and each overcurrent protective device for lighting in a gas-dangerous space must be in a gas-safe space.

[CGD 74-125A, 47 FR 15236, Apr. 8, 1982, as amended by CGD 77-069, 52 FR 31626, Aug. 21, 1987; CGD 94-108, 61 FR 28285, June 4, 1996; 62 FR 23909, May 1, 1997; USCG-2009-0702, 74 FR 49234, Sept. 25, 2009; USCG-2012-0832, 77 FR 59781, Oct. 1, 2012]