46 CFR §181.405

1. (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. (1)A space containing propulsion machinery.
   2. (2)A space containing an internal combustion engine of more than 50 hp.
   3. (3)A space containing an oil-fired boiler.
   4. (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. (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.
2. (b)[Reserved]
3. (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.
4. (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.