TRANSPORTABLE MOISTURE LIMIT (TML)

Solid bulk cargoes such as metal concentrates may appear to be in a relatively dry granular state when loaded, however they may still contain sufficient moisture to become fluid under the stimulus of the compaction and vibration that occurs during a voyage. The resulting cargo shift can be sufficient to capsize the vessel.

Cargoes that contain a certain proportion of small particles and a certain amount of moisture may liquefy when the moisture content exceeds the Transportable Moisture Limit (TML). In the resulting viscous fluid state, cargo may flow to one side of the ship with a roll one way but not completely return with a roll the other way, causing the ship progressively to reach a dangerous heel and capsize suddenly.

It is therefore vital to know before loading if the material is safe to transport by ship, and to provide mariners transporting the cargo with an accurate TML and moisture content.

The TML is determined by sampling the cargo correctly and determining the Flow Moisture Point (FMP). Alfred H Knight (AHK) has for many years undertaken the determination of the FMP and therefore the safe TML of metal concentrates and other bulk metal bearing commodities such as iron ore. Throughout the AHK Group there is a high level of expertise in conducting this FMP test: all analysts are trained to the same high standard, with the UK Group Headquarters operating a regular monitoring programme to ensure the maintenance of rigorous quality standards.

For over 30 years, we have been at the forefront of improving this test. Throughout the AHK Group we use the flow table method following the IMSBC Code 2012 for solid bulk cargoes, including graphical validation. In addition, at our St Helens site, we now cover the scope of Flow Moisture Point / Transportable Moisture Limit testing for Solid Bulk Cargoes by all of the three tests (Flow Table, Penetration and Proctor-Fagerberg) approved in the IMSBC code. The ability to offer this service by all three of the indicated tests allows Alfred H Knight to carry out specific testing, covering a broader range of particle sizes, for such commodities as mineral sulphide concentrates, iron ore, nickel ore, manganese ore, coal and any other solid bulk commodities which may have flow properties. The ISO 12742:2007 method is available upon request.

Should you require further information about the FMP/TML test, please contact Steve Randles or our UK Group Headquarters, who will be happy to help.

To request a quotation please complete an enquiry form or contact your nearest office to discuss your requirements.

For over 30 years AHK has been at the forefront of improving this test, in the interests of safety.

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