Tankerman · Operations — Crude Oil Washing Conditions
Crude oil washing (COW) of cargo tanks may only be carried out when the tank atmosphere is:
- AFull of fresh air
- BInerted with oxygen below the required limit (commonly not exceeding 8% by volume)✓ Correct
- CEnriched with oxygen
- DAt atmospheric oxygen of 21%
Explanation
COW uses the cargo itself as a washing medium and generates static and mist, so it is permitted only in a properly inerted tank with oxygen verified below the limit (commonly ≤8%). Oxygen content is checked before and monitored during washing; washing stops if oxygen rises.
Authority: SOLAS; MARPOL; ISGOTT (COW)
Practice the full Tankerman bank
Free spaced-repetition quizzing across 2550 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: