🔍 Key Concepts

• Gasoline vapors are heavier than air and can collect in low spaces, creating explosion hazards • Small passenger vessel ventilation and duct requirements in 46 CFR Subchapter T (verify current wording in 46 CFR Part 182 – Machinery spaces, fuel, and ventilation) • Design features that reduce the risk of fuel vapor accumulation and ensure safe venting of vapors

💭 Think About

• Which design features of ducts would best prevent gasoline vapors from leaking into unintended spaces and allow them to be safely vented? • Think about whether safety rules usually require just one protective feature, or multiple overlapping protections, when dealing with gasoline fumes on passenger vessels. • For each individual choice (A, B, and C), ask: would this requirement reasonably help prevent or control gasoline vapor hazards in machinery/fuel spaces?

✅ Before You Answer

• Verify what 46 CFR says about ducts serving spaces with gasoline-powered machinery or gasoline tanks on small passenger vessels. • Check whether ducts are required to be direct, secure, and supported, or if flexibility and indirect routes are allowed. • Confirm whether regulations emphasize preventing vapor flow/leakage through unintended openings, and whether more than one of these listed requirements is actually mandated.