Boil-Off Rate

Abbreviation: BOR

Daily fraction of cryogenic cargo lost to boil-off, expressed as % of cargo mass per day.

In practice

Charterers verify BOR against the warranted rate at every voyage. The deck cadet records cargo-tank temperature and ullage at noon; the cargo officer logs daily evaporated mass. A persistent excursion above the warranted rate triggers a charter-party performance claim.

Regulatory detail & full definition

BOR is a guarantee figure in newbuild contracts. For LNG carriers, BOR < 0.15%/day is now standard for Q-Flex and Q-Max; older steam-turbine vessels run 0.20-0.25%/day. The rate varies with sea state, ambient temperature, and cargo level (sloshing). Charterers monitor BOR closely because it directly affects voyage economics.

Boil-Off Gas
LNG carrier

Source: Industry usage; IACS UR M77

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Boil-Off Rate

In practice

Related

Boil-Off Rate

In practice

Related