46 CFR §62.35-40

1. (a)Level alarms. Where high or low fuel tank level alarms are required, they must be located to allow the operator adequate time to prevent an unsafe condition.
2. (b)Coal fuels.
   1. (1)Controls and instrumentation for coal systems require special consideration by the Commandant.
   2. (2)Interlocks must be provided to ensure a safe transfer of machinery operation from one fuel to another.
3. (c)Automatic fuel heating. Automatic fuel heating must meet section 4-9-3/15.1 of the ABS Marine Vessel Rules (incorporated by reference; see § 62.05-1).
4. (d)Overflow prevention. Fuel oil day tanks, settlers, and similar fuel oil service tanks that are filled automatically or by remote control must be provided with a high-level alarm that annunciates in the machinery spaces and either an automatic safety trip control or an overflow arrangement.