46 CFR § 111.105-31 - Flammable or combustible cargo with a flashpoint below 60 °C (140 °F), carriers of liquid-sulphur or inorganic acid.
(a) Applicability. Each vessel that carries combustible or flammable cargo with a closed-cup flashpoint lower than 60 degrees C (140 degrees F) or liquid sulphur cargo, or inorganic acid cargo must meet the requirements of this section, except -
(1) A vessel carrying bulk liquefied flammable gases as a cargo, cargo residue, or vapor which must meet the requirements of § 111.105-32; and
(2) A vessel carrying carbon disulfide must have only intrinsically safe electric equipment in the locations listed in paragraphs (e) through (l) of this section.
(b) Cable location. Electric cable must be as close as practicable to the centerline and must be away from cargo tank openings.
(c) Lighting circuits. An enclosed hazardous space that has explosionproof lighting fixtures must:
(1) Have at least two lighting branch circuits;
(2) Be arranged so that there is light for relamping any deenergized lighting circuit; and
(3) Not have the switch within the space for those spaces containing explosionproof lighting fixtures under paragraphs (g), (i) and (j) of this section.
(d) Submerged cargo pump motors. If a submerged cargo pump motor is in a cargo tank:
(1) Low liquid level, motor current, or pump discharge pressure must automatically shutdown power to the motor if the pump loses suction;
(2) An audible and visual alarm must be actuated by the shutdown of the motor; and
(3) There must be a lockable circuit breaker or lockable switch that disconnects power to the motor.
(e) Cargo Tanks. A cargo tank is a Class I, Division 1 (IEC Zone 0) location that has additional electrical equipment restrictions outlined in section 33 of IEEE 45-1998 and IEC 60092-502 (both incorporated by reference; see 46 CFR 110.10-1). Cargo tanks must not contain any electrical equipment except the following:
(1) Intrinsically safe equipment; and
(2) Submerged cargo pump motors and their associated cable.
(f) Cargo handling rooms. A cargo handling room must not have any electric cable or other electric equipment, except:
(1) Intrinsically safe equipment;
(2) Explosionproof lighting fixtures;
(3) Cables supplying intrinsically safe equipment in the cargo handling room; and
(4) Marine shipboard cables that supply explosionproof lighting fixtures that are in the cargo handling room.
(g) Lighting of cargo handling rooms. Lighting for a cargo handling room except a cargo handling room under paragraph (h) of this section, must be lighted through fixed glass lenses in the bulkhead or overhead. Each fixed glass lens must be wire-inserted glass that is at least 0.25 inches (6.35 mm) thick and arranged to maintain the watertight and gastight integrity of the structure. The fixed glass lens may form a part of a listing fixture if the following are met:
(1) There is no access to the interior of the fixture from the cargo handling room.
(2) The fixture is vented to the engineroom or a similar nonhazardous area.
(3) The fixture is wired from outside the cargo handling room.
(4) The temperature on the cargo handling room surface of the glass lens, based on an ambient temperature of 40 degrees C, is not higher than 180 degrees C.
(h) A cargo handling room which precludes the lighting arrangement of paragraph (g) of this section, or where the lighting arrangement of paragraph (g) of the section does not give the required light, must have explosionproof lighting fixtures.
(i) Enclosed spaces. An enclosed space that is immediately above, below, or next to a cargo tank must not contain any electric equipment except equipment allowed for cargo handling rooms in paragraphs (f) and (g), and:
(1) Through runs of marine shipboard cable; and
(2) Watertight enclosures with bolted and gasketed covers containing only:
(i) Depth sounding devices;
(ii) Log devices; and
(iii) Impressed-current cathodic protection system electrodes.
(j) Cargo hose stowage space. A cargo hose stowage space must not have any electrical equipment except explosionproof lighting fixtures and through runs of marine shipboard cable.
(k) Cargo piping in a space. A space that has cargo piping must not have any electrical equipment except explosionproof lighting fixtures and through runs of marine shipboard cable.
(l) Weather locations. The following locations in the weather are Class I, Division 1 (Zone 1) locations (except the open deck area on an inorganic acid carrier which is considered a non-hazardous location) and may have only approved intrinsically safe, explosionproof, or purged and pressurized electrical equipment, and through runs of marine shipboard cable if the location is -
(1) Within 10 feet (3 m) of:
(i) A cargo tank vent outlet;
(ii) A cargo tank ullage opening;
(iii) A cargo pipe flange;
(iv) A cargo valve;
(v) A cargo handling room entrance; or
(vi) A cargo handling room ventilation opening; or
(2) On a tankship and on the open deck over the cargo area and 10 feet (3 m) forward and aft of the cargo area on the open deck and up to 8 feet (2.4 m) above the deck.
(3) Within 5 meters (16 ft) of cargo pressure/vacuum valves with an unlimited height; or
(4) Within 10 meters (33 ft) of vent outlets for free flow of vapor mixtures and high velocity vent outlets for the passage of large amounts of vapor, air or inert gas mixtures during cargo loading and ballasting or during discharging.
(m) Other spaces. Except for those spaces listed in paragraphs (e) through (k), a space that has a direct opening to any space listed in paragraphs (e) through (l) must have only the electric installations that are allowed for the space to which it opens.
(n) Duct keel ventilation or lighting.
(1) The lighting and ventilation system for each pipe tunnel must meet ABS Steel Vessel Rules (incorporated by reference; see 46 CFR 110.10-1), section 5-1-7/31.17.
(2) If a fixed gas detection system is installed, it must meet the requirements of IMO SOLAS 74 (incorporated by reference; see 46 CFR 110.10-1) and Part 4, Chapter 3 of ABS Steel Vessel Rules.