Press article: Shocking liquefaction casualties must be stemmed by rigorous cargo checks
04 August 2015
The following article is reproduced with kind permission from TradeWinds. The full article, as it appeared, is available on the left, or on the TradeWinds website.
The onus is on the shipper to provide appropriate and timely information on the cargo to be transported, not least through thorough testing, and if there is any doubt masters must refuse to load it, writes Yves Vandenborn, director of loss prevention at The Standard Club.
In recent months and years, we have seen many lives lost as a result of bulk carriers sinking due to cargo liquefaction. These could have been prevented if the risks associated with transporting mineral ores and concentrates were properly appreciated and mitigated. The lack of understanding of the problem by the parties involved, and the lack of consistent implementation of the International Maritime Solid Bulk Cargoes (IMSBC) Code in load ports, has contributed to significant loss of life.
Solid bulk cargoes such as unprocessed mineral ores and refined mineral concentrates may appear to be in a relatively dry granular state when loaded. However, they can still contain enough moisture to become fluid due to the vibration that occurs during a voyage. The resulting cargo shift can be sufficient to capsize a vessel — as many have found out to their peril.
Shippers’ explicit duty
Under the IMSBC Code, the shipper has an explicit duty to provide the master with appropriate information on the cargo and sufficiently in advance of loading to enable precautions to be taken for safe stowage/carriage. Inaccurate declarations and certificates from shippers appear to be at the heart of many problems with the transport of cargoes liable to liquefy.
The IMSBC Code lists three methods of testing for the Flow Moisture Point (FMP) and moisture content: the flow table test, the penetration test and the Proctor-Fagerberg test. In addition to these, the IMSBC Code also describes the “can test” for checking whether a cargo may be suitable for shipment. This is more of a finger-in-the-air approach and involves filling a small can with the material and repeatedly banging it on a hard surface. The appearance of the material at the end of the test can be used to suggest the suitability of the material for shipment. Of course, this test should not be used as a substitute for proper laboratory testing using an appropriate methodology but if the can test indicates a propensity for liquefaction, then you know you are in trouble and that the cargo as a whole is unsafe for carriage and you need to take expert advice.
There have been cases where Group C cargoes have exhibited the liquefaction characteristics of Group A cargoes. Typically, these cargoes will have a high proportion of fine particles and will not meet the specifications listed in the IMSBC Code.
Generally speaking, the smaller the particle size of the cargo, the greater the risk of liquefaction. The critical size appears to be around seven millimetres. Anything below this size has the propensity to liquefy; and the use of an average reading is not an acceptable method, as it can overstate the safety of the cargo. Ship masters should ensure that they are fully satisfied with the condition of the cargo prior to accepting it for loading and that all conditions as per the IMSBC Code are duly met at all times.
While it is not always possible to prevent liquefaction, shipowners should ensure that due diligence is carried out to mitigate the risk. It really doesn’t take much and it could end up saving the ship and its crew.
If there are any doubts as to the safety of the cargo or the authenticity of the certificates, the members are recommended not to load the cargo and contact their local protection-and-indemnity (P&I) correspondent. Several ports have no means to discharge “wet” cargo once loaded.
Cargo liquefaction was sinking ships over a century ago and it is shocking to see this problem getting worse now. I truly believe that through a greater understanding and appreciation of the risks involved, combined with a more rigorous approach to checking mineral cargo, we can help prevent more disasters and save the ships and crews involved in the transport.