The Pumping Warranty Clause That Decides Who Pays for the Delay

One Clause, a Lot of Disputed Hours

Demurrage disputes in the tanker trade often come down to one specific clause: the pumping performance warranty. The typical wording promises the ship can discharge a full cargo within 24 hours, or alternatively maintain a discharge pressure of 100 psi at the ship's manifold — provided the shore receiving facility allows it — with additional time normally allowed for stripping, draining lines, and crude oil washing.

Where the Disputes Actually Happen

Britannia's guidance is practical rather than theoretical: pumps need to be maintained in genuinely optimal condition, and crew need real familiarisation with their optimal and effective use, including the stripping system — not just knowledge that the equipment exists. Any shore-side restriction needs to be documented in pre-cargo meeting records, with a Letter of Protest issued where appropriate, and every shore-imposed stoppage or change recorded in both the cargo log and pumping logbook. For calculating actual time lost, Britannia points to tools like the ASDEM pumping calculator as a more widely accepted method than ad hoc calculation — and recommends building that method into the charter party itself, rather than arguing about methodology after the fact.

What This Means for Tanker Officers

• Treat pumping logbook entries as commercial evidence, not routine paperwork — they're exactly what gets scrutinised in a demurrage dispute
• Document shore-side restrictions the moment they occur, with a Letter of Protest where warranted — not retrospectively once a dispute has already started
• Know whether your charter party specifies a time-loss calculation method like ASDEM before the voyage, not during the dispute
• Pump maintenance and crew familiarisation with the stripping system directly affect whether the vessel can even meet the warranty in the first place

Related Reading

• HNS Convention 2027 — another liability framework tanker crews need to understand