🔍 Key Concepts

• 46 CFR Part 25 – Requirements for uninspected vessels (fire extinguishers) • Difference between B.H.P. (brake horsepower) and S.H.P. (shaft horsepower) for main engines • Relation between engine power and the number/size of extinguishers required in machinery spaces

💭 Think About

• Is the regulation written in terms of the power delivered to the propeller or the rated power output of the engine itself? • How does the Coast Guard usually scale portable extinguisher requirements: per smaller power increment (e.g., 500) or larger power increment (e.g., 1000)? • What UL/Coast Guard type 20-B corresponds to in the old B-I / B-II size system, and how many of those are tied to machinery-space power rating?

✅ Before You Answer

• Confirm whether the text of 46 CFR 25.30-20 refers to B.H.P. or S.H.P. • Verify the exact horsepower increment (500 vs 1000) used in the table/paragraph for machinery space extinguishers on uninspected motor vessels • Make sure you connect type 20-B with the correct USCG size class (e.g., B-II) in the regulation.