Dry bulk cargoes that may liquefy


Published: 5 November 2007

During  the rainy season the risk of loading dry bulk cargoes that may liquefy increases.

Recently several vessels, which had loaded dry bulk cargoes in various ports in China, India, Indonesia and Philippines, have subsequently encountered problems. It is claimed that the cargoes due to excessive moisture content has liquefied. See latest edition (2005) of the BC Code. The cargoes that risk liquefying is listed as Group A in the BC Code (see list below). It is, however, a risk that other cargoes not listed as Group A cargo but containing fines and moisture also may risk liquefying.

It appears that these cargoes are being shipped from several ports without certificates showing the Transportable Moisture Limit (TML), and where provided, the accuracy of certificates showing the TML is, on some occasions, doubtful.

Unfortunately, we suspect that the certificates of moisture content may also in some cases be inaccurate, because the samples can be taken some time before the vessel loads, and we have seen cargo wetted by rain, which has caused an increase in moisture content.

The cargo may be mixed either on the quayside or when loaded into the vessel. In such circumstances, we advise Members to take precautions. Different colouring of the cargo and/or different shippers for different parcels of cargoes may indicate that the shipment is mixed and that one TML certificate may not be sufficient, as the cargo is unlikely to be homogeneous if different parcels/or Shippers are involved.

Shipowners and Masters were previously advised to ensure that moisture and TML certificates were provided at an early stage prior to the vessel’s arrival, and in fact, because the TML should have been established at source on a regular basis, this figure should be available long before the vessel arrives to load. Misrepresentation and reluctance to provide TML certificates are probably a good indication of problems to come.

It goes without saying that Masters should not be swayed by empty promises by ship’s agents and others as to the safety of the cargo without full knowledge of its moisture content and TML, nor of vague promises that the correct certification will be provided later, once loading has started.

In summary, we recommend:

  1. When considering the carriage of Group A cargoes and other cargoes that risk liquefying, owners should seek from charterers assurance that the certificates of moisture content and TML will be made available prior to shipment.
  2. Every cargo that contains moisture and at least some fine material should be queried prior to loading, and should be tested if in doubt. The BC Code certification requirements apply to all cargoes which may liquefy regardless of whether or not the cargo is specifically identified as posing a liquefaction risk. Never assume there is no risk of liquefaction simply because a cargo is not identified as ‘Group A’ in the BC Code.
  3. If these certificates are not available at the load port, then the Master should consider refusing the cargo, and immediately notify owners, who in turn should contact the Club for advice.
  4. Any certificates provided should be checked to ensure that they are from a reliable source.
  5. Where possible, ship’s staff should closely examine the condition of the cargo before it is loaded, and should closely monitor its condition throughout loading and whenever it is brought alongside the vessel. Even when the cargo appears to be dry, it may still contain moisture in excess of TML, but if it appears wet, or is stored in open conditions in rainy weather, then experience indicates that moisture content may well be above TML.
  6. A negative result from the can test described in section 8.3 of the BC Code (i.e. no free moisture or fluid condition is seen) does not necessarily mean that the cargo is safe for shipment. However, a positive result from such test, where moisture is seen, should leave the Master in no doubt that further testing is required.
  7. In all circumstances shipmasters and owners should closely follow the recommendations contained in the BC Code (latest edition, 2005).
  8. In the rainy season pre-loading and loading surveys should be carried out.
  9. If in doubt, please contact the Club for further assistance.

BC-code group A - cargoes that my liquefy

Cement Copper
Coal and coal slurry
Coke breeze
Copper concentrate
Fish in bulk
Ilmenite clay
Iron concentrate
Iron ore
Lead and zinc calcines/middlings
Lead concentrate
Lead ore residue/concentrate
Lead silver concentrate/ore
Lead sulphide
Magnetite and magnetite-taconite
Manganese concentrate
Metal sulphide concentrate
Nefeline syenite
Nickel concentrate
Nickel ore concentrate
Peat moss
Pentahydrate crude
Pyretic ashes
Pyretic cinders
Silver lead concentrate
Silver lead ore concentrate
Slig, iron ore
Zinc and lead calcines/middlings
Zinc concentrate
Zinc ore burnt/calamine/concentrates/crude
Zinc sinter
Zinc sludge
Zinc sulphide