Tankerman · Inert Gas — Inerted Atmosphere
A cargo tank is considered properly 'inerted' when the oxygen content is reduced to no more than:
- A8% by volume✓ Correct
- B15% by volume
- C18% by volume
- D21% by volume
Explanation
An inerted tank is held at 8% oxygen by volume or less (and at positive pressure), too lean to support combustion regardless of hydrocarbon concentration. Many operators target 5% to maintain a safe margin.
Authority: SOLAS II-2; ISGOTT
Practice the full Tankerman bank
Free spaced-repetition quizzing across 2190 USCG exam questions — it schedules your reviews so the ones you miss come back until they stick.
Related Tankerman questions
- Transfer — PIC
During a cargo transfer on a tank vessel, the Person-In-Charge (PIC) is primarily responsible for:
- Transfer — DOI
Before a transfer of oil or hazardous material begins, the PICs of the transferring and receiving facilities must complete and agree on a:
- Safety — Inert Gas
The purpose of an inert gas system on a tanker is to:
- Safety — Inert Gas
A cargo tank is generally considered properly inerted when the oxygen content is held at or below:
- Safety — Flammability
A hydrocarbon vapor/air mixture will burn only when its concentration is:
- Safety — Static
To prevent a static-electricity ignition hazard during loading of a static-accumulating cargo, the tankerman should: