46 CFR 181.405: Spaces required to have fire detection systems.

(a) The following spaces must be equipped with a fire detection and alarm system of an approved type installed in accordance with 46 CFR part 76, except when a fixed-gas fire extinguishing system that is capable of automatic discharge upon heat detection is installed or when the space is manned:

(1) A space containing propulsion machinery.

(2) A space containing an internal combustion engine of more than 50 hp.

(3) A space containing an oil-fired boiler.

(4) A space containing machinery powered by gasoline or any other fuels having a flash point of 43.3 °C (110 °F) or lower.

(5) A space containing a fuel tank for gasoline or any other fuel having a flash point of 43.3 °C (110 °F) or lower.

(b) [Reserved]

(c) Vessels described by 46 CFR 175.110(c) must have an interconnected fire detection system in compliance with § 181.450 installed in all enclosed areas where passengers and crew have routine access, including accommodation spaces and machinery spaces.

(d) An enclosed vehicle space must be fitted with a fire detection and alarm system of an approved type that is installed in accordance with part 76 of this chapter.