Transporting Bulk Cargoes – Testing you can Trust
Tests can be conducted to determine the maximum percentage moisture that each type of bulk cargo can hold before becoming susceptible to liquefaction. The results are subsequently compared to the moisture content of the material prior to loading, or already in the hold.
The main legislation governing safe carriage of solid bulk cargoes is the International Maritime Solid Bulk Cargoes (IMSBC) Code, which became mandatory on January 1, 2011, under the SOLAS Convention. The IMSBC lists three methods of testing for the transportable moisture limit, which are currently in use;
- Flow Table Test
- Penetration Test
- Proctor/Fagerberg Test
The Transportable Moisture Limit (TML) and the Flow Moisture Point (FMP) are tests which effectively determine the moisture content of a material, beyond which may result in the material liquefying during transit. In this case, the resulting ‘liquid’ cargo can shift or roll in the hold, and in certain circumstances remain on one side of the ship. This continued action may lead to a progressively increasing heel, which may eventually result in the capsize of the vessel.
Mandatory testing has recently been enforced as per the SOLAS convention to attempt to eradicate or at least minimize these dangers. However, these tests are largely unregulated, and quite often, if investigated, it has been found that the test equipment or procedure used has been either inadequate or incorrectly set-up, resulting in incorrect determinations, which on occasion, has led to disastrous outcomes.
The Lab (Asia) Ltd, strategically based in Hong Kong, is the first commercial laboratory in the region to have Bulk Cargoes Testing formally accredited. Assessment and subsequent accreditation was by HOKLAS (Hong Kong Laboratory Accreditation Service). HOKLAS is Hong Kong’s equivalent to A2LA in the USA, or UKAS in the UK, with whom they have a Mutual Recognition Agreement (MRA). The Lab also issue their HOKLAS accredited certificates jointly under the ILAC (International Laboratory Accreditation Cooperation) Mark, which is an international cooperation of laboratory and inspection accreditation bodies formed more than 30 years ago to help remove technical barriers to trade, and hence is a worldwide recognized certification mark.
Accreditation is the independent evaluation of conformity assessment bodies against recognised standards to carry out specific activities to ensure their impartiality and competence. Through the application of national and international standards, government, procurers and consumers can have confidence in the calibration and test results, inspection reports and certifications provided by the Test Laboratory.
The Lab (Asia) Ltd. underwent a rigorous program of training, auditing and final assessment by the HOKLAS technical assessors before finally being awarded the accreditation.
During the development of these tests and procedures, it soon became very evident to the test engineers at The Lab, that even small errors during the test would lead to wildly varying results – a variance in results, which at the outcome of the test, would make a difference between a material being classed as being within the safe limits of moisture content, and a material being classed as being outside these safe limits. The results which would have then been used to give the green light for the carrier to leave port.
The Lab (Asia) Ltd is currently HOKLAS accredited for the following tests;
- Flow Moisture Point and Transportable Moisture Limit by the flow table test (IMSBC Code and BS ISO 12742)
- Flow Moisture Point and Transportable Moisture Limit by the penetration test (IMSBC Code)
- Transportable Moisture Limit by the Proctor/ Fagerberg Test (IMSBC Code)
- Angle of Repose for Fine-Grained Materials by the pouring cone method (IMSBC Code)