Tropical Cargo Surveys Co. Ltd. provides precise and reliable Draft Surveys to determine the weight of bulk cargo loaded onto or discharged from a vessel. This method is internationally recognized and widely used for bulk commodities such as coal, grain, fertilizers, bauxite, iron ore, and similar solid cargoes.
Draft surveys play a critical role in cargo accountability, commercial reconciliation, and dispute resolution between shippers, charterers, receivers, and port authorities.
Draft surveys involve measuring the vessel’s displacement before (initial draft survey) and after (final draft survey) cargo operations. The difference in displacement, after applying standard corrections, accurately reflects the weight of cargo handled.
Tropical Cargo Surveys Co. Ltd. follows internationally accepted procedures, particularly those outlined by the International Maritime Organization (IMO), ensuring all factors that influence accuracy are accounted for, including:
Draft readings at six standard points (forward, aft, midships – port and starboard).
Corrections for trim, list, and hog/sag.
Seawater density adjustments, using accurate hydrometer readings at the time of the survey.
Ballast, fresh water, fuel oil, and other tank soundings for precise deductions.
Use of calibrated equipment and hydrostatic tables for displacement calculations.
Conducted before loading (or after discharging), the initial survey establishes the vessel’s displacement and onboard weights, including fuel, ballast, stores, and crew.
Conducted after loading (or before discharging), the final survey reflects the new displacement, from which the exact weight of cargo loaded or discharged is derived.
IMO-compliant methodology for global standard accuracy.
Independent and impartial reporting, fostering trust among all stakeholders.
Highly experienced surveyors with extensive knowledge of different vessel types and cargoes.
Quick turnaround with detailed and verifiable reports including calculations and supporting documentation.
