Interest has increased in the possibility of liquefaction of products that were previously considered unlikely to liquefy, including bauxite and alumina. The suitability of the available test methods for individual products with wildly varying physical and chemical properties is also acutely relevant.
 
TML determination is a delicate science, which results in a report without which a ship containing bulk cargo is unable to leave port. The TML value represents a ‘safe’ moisture content, below which the cargo is unlikely to undergo liquefaction and endanger the ship and crew. It is the responsibility of the shipper to provide a moisture management plan and to prove that the cargo is being shipped with a moisture content below the TML.
 
There are currently three techniques suggested in the International Maritime Organisation’s IMSBC code – the flow table test, using impact testing to simulate plastic flow; the Proctor-Fagerberg test, based on a standard soil compaction test to determine saturation point; and the Penetration test, using vibrational testing to simulate liquefaction conditions. Each technique is uniquely suited to certain sample types, so explicit knowledge of the sample and the test specifics are paramount to an easy journey out of the port. Not everyone needs to be an expert – just employ a laboratory that is!

These changes are occurring as the Australian Maritime Shipping Authority (AMSA) are continually reviewing and improving the guidelines to improve the safety of crew and cargoes. It is important to keep track of major changes and make sure that shippers know ahead of time what will be required of them and that ports are aware of the changes affecting them. Microanalysis Australia has a long history of providing the latest information to shippers and ports and assisting with understanding regulations and guidelines to help shipments go out smoothly and without incident.