Mineral cargoes transported in bulk can liquefy if they are too wet, gravely affecting a vessel’s stability. In this circular, MS Amlin promotes further awareness of the dangers associated with the loading and carriage of bulk cargoes subject to liquefaction.
IMSBC code and a well-known danger
The dangers of liquefying cargoes are known throughout the marine industry. Nevertheless, serious incidents continue to occur, and it is essential that Masters, Owners, Charterers and Shippers are familiar with the International Maritime Solid Bulk Cargoes (IMSBC) Code. Cargoes that can potentially liquefy are listed in the IMSBC Code as “Group A” cargoes, and require special handling. The cargoes most frequently affected include iron ore, nickel ore and fluorspar. However the official list of Group A cargoes is not exhaustive and some cargoes not recorded may still pose a risk. Please be aware that all heavy bulk cargoes containing fine particles with sufficient moisture can, in fact, liquefy. Loading of bulk cargo should therefore always be conducted in strict accordance with the rules and guidelines of the IMSBC Code. For coal cargoes the IMSBC requirements were recently updated. In December 2018 MS Amlin issued a separate circular “The revised IMSBC requirements for liquefaction of coal cargoes”, which can be found here.
Examples of IMSBC Code Group A cargoes (not exhaustive):
- Aluminum fluoride
- Bauxite fines
- Cement
- Chemical gypsum
- Coal slurry
- Coke breeze
- Copper concentrate
- Copper slag
- Fish in bulk
- Fly ash
- Ilmenite (Upgraded)
- Ilmenite clay
- Ilmenite sand
- Iron and steel slag and it’s mixture
- Iron concentrate (sinter feed)
- Iron ore concentrates
- Iron ore fines
- Iron oxide technical
- Lead concentrate
- Manganese ore fines
- Mineral concentrates
- Nickel ore
- Sand
- Scale generated from the iron and steel making process
- Spodumene (upgraded)
- Synthetic calcium fluoride
- Synthetic silicon dioxide
- Titanomagnetite sand
- Zinc slag
- Zircon kyanite concentrate
Measuring Moisture
Shippers of Group A cargoes are required to provide the Master with written cargo information and particulars prior to loading. This information must include a certificate declaring the actual Average Moisture Content (AMC) of the entire cargo in all the holds at the time of loading. Little reliance must be placed on the test result of the mine laboratories and same should be inspected by an independent surveyor.
It should also include a document declaring the Transportable Moisture Limit (TML) of the cargo being loaded, together with its Flow Moisture Point (FMP). The FMP of a bulk cargo can only be officially determined by a competent independent laboratory. The TML is 90% of the FMP, and cargoes with an average moisture content level higher than 90% FMP should never be loaded.
The IMSBC Code stipulates that the test results determining a cargo’s FMP may not be older than 6 months, and that the test results determining a cargo’s average moisture content may not be older than 7 days at the time of loading. In case of heavy rains between the time of testing and loading the tests must be conducted again. The official name of the laboratory must be identified on the certificates as if in doubt, results can be verified.