Safe carriage of Iron ore

Safe carriage of Iron ore : 

·Iron ore is used for the production of metallic iron in steel-making.

·Iron ore can be shipped in a number of forms such as ROM, Fines, Lump & Concentrate.

·It is important to keep an eye on moisture content of Iron Ore. Moisture content -of iron ore is assumed to have a homogeneous moisture content between 0-16%. However, if kept lying in the open, the moisture content may increase due to absorption from air or rain. If the exact moisture content is unknown, a proper laboratory test may be called for. The Master must also ask the shipper to detail the cargo's moisture content and TML.

·Iron ores are heavy cargoes which occupy a small area for a large weight, i.e. they have a low stowage factor (between 0.24-0.80 m3/tonne). It is therefore important that the tank top has sufficient strength to carry certain iron ores.

·Trimming of Iron Cargoes is generally required (even though their angle of repose is mostly above 35°) to spread their weight across the entire tank top.

·It is imperative that the cargo moisture content is tested prior to and monitored during all stages of loading as, once onboard, cargo may be extremely difficult to remove. 

The shipper's TML certificate should be presented before loading, be sound and it should be no more than seven days old. A good indicator during the load is the presence of splatter marks of iron ore filings on the bulkheads. If splatter marks are evident, they should be taken very seriously as an indication that the moisture content is above the TML and the flow moisture point. If the Master is in having any doubt, he should contact the owners and the P&I Club correspondent.

·Transportable Moisture Level (TML)

TML is the maximum moisture content for a solid bulk cargo and is calculated from the Flow Moisture Point (FMP). Transportable Moisture Levels are used by port authorities and shippers to evaluate if a cargo's moisture content makes it safe for shipping. It is the limit of a cargo which may liquefy, represents the maximum moisture content of the cargo, which is considered safe for the carriage in ships not complying with the special provision. ... The transportable moisture limit (TML) = 90% of FMP.

· Liquefaction is a phenomenon in which a soil-like material is abruptly transformed from a solid dry state to an almost fluid state. Many common bulk cargoes, such as iron ore fines, nickel ore and various mineral concentrates, are examples of materials that may liquefy.

·Test Laboratory to determine a safe Transportable Moisture Limit (TML) for bulk cargoes by taking representative samples of cargo and determining the Flow Moisture Point (FMP)

·The issuance of FMP/TML certificates is one of the most important tests that test laboratory can perform, providing confidence to clients that their material is safe to transport via bulk carrier.

·The FMP is the point at which a granular bulk material becomes fluid. A Flow Table Test (FTT) is conducted to find the FMP, with the TML calculated to be 90% of this figure. This is the maximum moisture level at which it is safe to ship the material; if the cargo is found to have a higher moisture content than the TML, it is strongly recommended that the cargo not be transported (unless the vessel is specially built for this).

·  Given the significance of such testing, all analysts are rigorously monitored to ensure quality standards are met. The decision to load and transport a cargo is ultimately that of the ship’s Master and the port authorities, however highly experienced Marine Port Captain can assist based on the results of FMP testing performed in-house.

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