Shore Weightometer and Cargo Quantity Disputes
Belt weighers against draft survey: how each measures, calibration drift and its direction, legitimate divergence on hygroscopic cargoes, and how the figures are reconciled.
A shore weightometer measures cargo mass on a conveyor belt as it is loaded or discharged, and it is the usual alternative to a draft survey for determining bill of lading quantity. The two methods measure different things by different routes, so they rarely agree exactly, and the size and direction of the disagreement is what disputes are made of.
The full article will cover how a belt weigher works, its calibration regime and the ways calibration drifts, the effect of belt loading and speed variation, and the accuracy that can reasonably be claimed. It will set that against draft survey accuracy on different ship sizes and in different conditions.
It will also cover the divergences that are legitimate rather than erroneous. A hygroscopic cargo gains real mass between load port and discharge port, so a load port belt figure and a discharge port survey are not measuring the same cargo. Reconciliation practice, the role of a letter of protest, and where the difference falls under the charter party and the bill of lading will be treated alongside.