Bunker Quantity Survey, ROB and discrepancy investigation

When bunker figures diverge, it is necessary to understand how each quantity was obtained. TWS Maritime Service brings together measurements, documents and assumptions to support the technical reconciliation between shipowners, charterers and operators, including previously defined investigative verifications.

When to appoint

A Bunker Quantity Survey may be requested to verify fuel stocks, establish ROB — remaining on board quantity — or examine differences between measurements and operational records. The purpose of the appointment guides which tanks, periods and documents need to be considered.

If the requirement is to monitor a fuel delivery from the initial measurements through to completion, refer to BQS during bunkering. For an already identified discrepancy, the work should begin by defining the issue and the evidence available.

Survey scope

According to the appointment, access authorization and available data, the verification may include:

• Measurements in the included tanks, identification of products, and recording of temperatures and conditions relevant to determining the quantities.
• Verification of capacity tables, measurement references, stated densities and corrections relevant to calculating the quantities.
• Comparison with declared quantities, supply documents and consumption or transfer records relating to the defined period.
• In a Bunker Detective Survey, a focused examination of consistency between tank arrangement, tables, measurements and records, documenting points requiring clarification.

What the client receives

The report identifies the operation, documents used, tanks verified, calculated quantities and discrepancies found. Assumptions and limitations accompany the results, enabling an understanding of the origin of the figures presented.

Where the scope is investigative, findings are organized around the discrepancy examined. This presentation helps the appointing party direct requests for clarification, assess the need for further verifications and discuss the matter with the parties involved.

Limitations and supplementary verifications

A quantity discrepancy does not, in itself, demonstrate fraud or liability of either party. The investigation depends on the quality of records, access to measurement points and observed conditions. BQS is not equivalent to laboratory quality analysis: sampling and testing require a separate scope. There is no guarantee of recovering amounts or fully clarifying a past event.

Request this service

Provide the vessel and IMO, location, access window, products, purpose and declared quantities. To investigate discrepancies, also provide the period, disputed calculations and available documents, so that the scope of work can be defined.