(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.
(b) As used in this section:
(1) The terms “gas-safe” and “gas-dangerous” spaces are used as defined in § 154.7 of this chapter.
(2) The term “gas-dangerous” does not include the weather deck of an ammonia carrier.
(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.
(d) Electrical equipment must not be installed in a gas-dangerous space or zone, except:
(1) Intrinsically safe electrical equipment and wiring, and
(2) Other equipment as allowed in this section.
(e) A submerged cargo pump motor, if installed in a cargo tank, must meet § 111.105-31(d).
(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) Through runs of marine shipboard cable;
(2) Explosionproof lighting fixtures;
(3) Depth sounding devices in gastight enclosures;
(4) Log devices in gastight enclosures;
(5) Impressed current cathodic protection system electrodes in gastight enclosures; and
(6) Armored or MI type cable for a submerged cargo pump motor.
(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) Through runs of marine shipboard cable;
(2) Explosionproof lighting fixtures;
(3) Depth sounding devices in gastight enclosures;
(4) Log devices in gastight enclosures;
(5) Impressed current cathodic protection system electrodes in gastight enclosures;
(6) Explosionproof motors that operate cargo system valves or ballast system valves;
(7) Explosionproof bells for general alarm systems; and
(8) Armored or MI type cable for a submerged cargo pump motor.
(h) A cargo-handling room must not have any installed electrical equipment, except explosionproof lighting fixtures.
(i) A space for cargo hose storage or a space that has cargo piping must not have any installed electrical equipment, except:
(1) Explosionproof lighting fixtures; and
(2) Through runs of marine shipboard cable.
(j) A gas dangerous zone on the open deck must not have any installed electrical equipment, except:
(1) Explosionproof equipment that is necessary for the operation of the vessel; and
(2) Through runs of marine shipboard cable.
(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.
(l) Each gas-dangerous space that has lighting fixtures must have at least two branch circuits for lighting.
(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.
(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]