The Cargo That Looks Dry and Is Not

Bauxite does not look dangerous. It loads like any other dry bulk ore, sits stable in the hold on paper, and gives no visible warning that it can turn from a solid cargo into a liquid slurry mid-voyage. That transformation, cargo liquefaction, has capsized vessels, and the entire defense against it comes down to one number: the Transportable Moisture Limit.

What TML Actually Measures

Under the IMSBC Code, bauxite fines and several other Group A cargoes can shift from a solid to a fluid state once their moisture content exceeds the TML, because vibration and ship motion cause water trapped between particles to migrate and pool. A cargo that was diggable and stable on the quay can develop free-standing water in the hold within days, and once that happens the vessel’s stability calculations, which assumed a fixed solid cargo, no longer describe reality.

The charterparty and the IMSBC Code both require that the cargo’s actual moisture content be certified below the TML before loading, using a Certificate of Moisture Content and a shipper-provided cargo declaration. The near-miss cases almost never involve a shipper lying outright; they involve a certificate that was accurate for the stockpile sampled weeks earlier, before a rain event changed the moisture profile of the pile actually loaded.

The Signals an Operator Should Never Wave Through

• A certificate dated significantly earlier than the loading date, especially if there has been rainfall at the port in the interim.
• A “can test” or flow-table result described informally rather than referenced against the IMSBC Appendix 2 procedure by name.
• Loading continuing during or immediately after heavy rain without a re-sampling of the stockpile actually being loaded.
• A shipper reluctant to allow an independent surveyor to draw samples directly from the cargo stream.

The Marcenta Protocol: Independent Sampling, Every Time

We do not accept a shipper’s moisture certificate as the final word on a Group A cargo. We commission an independent surveyor to draw and test samples from the actual stockpile being loaded, on the loading date, and we hold the vessel off berth if a rain event has occurred since the last valid test. The cost of an extra day’s sampling is trivial next to the alternative, a vessel that discovers its cargo has turned to slurry somewhere in open water.

We are actively covering:

Black Sea

Mediterranean

Continent

WAF

Cargoes and open vessels are always welcome.

chartering@marcenta.co.uk

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