(a)For the purposes of this section, a machinery space of category A is a space that contains any of the following:
(1)Internal-combustion machinery used for main propulsion.
(2)Internal-combustion machinery used for other than main propulsion, whose power output is equal to or greater than 500 HP (375 kw).
(3)Any oil-fired boiler.
(4)Any equipment used to prepare fuel oil for delivery to an oil-fired boiler, or equipment used to prepare heated oil for delivery to an internal-combustion engine, including any oil-pressure pumps, filters, and heaters dealing with oil pressures above 26 psi.
(b)As far as practicable, each fuel-oil tank must be part of the vessel's structure and be located outside a machinery space of category A.
(c)If a fuel-oil tank, other than a double-bottom tank, must be located adjacent to or within a machinery space of category A—
(1)At least one of its vertical sides must be contiguous to the boundary of the machinery space;
(2)The tank must have a common boundary with the double-bottom tanks; and
(3)The area of the tank boundary common with the machinery spaces must be kept as small as practicable.
(d)If a fuel-oil tank must be located within a machinery space of category A, it must not contain fuel oil with a flashpoint of less than 60 °C (140 °F).
(e)In general, no freestanding fuel-oil tank is permitted in any machinery space of Category A on a passenger vessel. A freestanding fuel-oil tank is permitted in other spaces only if authorized by the Commanding Officer, Marine Safety Center. If so authorized, each freestanding fuel-oil tank must—
(1)Comply with subpart 58.50; and
(2)Be placed in an oil-tight spill tray with a drain pipe leading to a spill-oil tank.
(f)No fuel-oil tank may be located where spillage or leakage from it can constitute a hazard by falling on heated surfaces. The design must also prevent any oil that may escape under pressure from any pump, filter, or heater from coming into contact with heated surfaces. [CGD 83-043, 60 FR 24776, May 10, 1995, as amended by USCG-2020-0634, 89 FR 50172, June 12, 2024]