🔍 Key Concepts

• Liquefied flammable gas (LFG) tank design requirements in 46 CFR Part 38 • Purpose and location of manholes (access openings) on cargo tanks • Difference between a tank’s expansion trunk and the weather deck

💭 Think About

• Think about where it is safest to access an LFG cargo tank while still keeping vapors away from enclosed spaces and crew working areas. • Consider how LFG behaves if it leaks: is it heavier or lighter than air, and how does that influence where openings should be located? • Ask yourself which option best matches the idea of keeping cargo containment and access openings as far as practical from accommodation and machinery spaces.

✅ Before You Answer

• Check 46 CFR Part 38 for specific wording about location of manholes on LFG tank vessels. • Verify whether regulations prefer openings within a protected structure that is part of the tank system, versus simply saying "above the weather deck" in general. • Confirm whether the regulation mentions expansion trunks or tank ends specifically for manhole placement.