PREVENTING LIQUEFACTION: ENSURING SAFETY AT SEA

Liquefaction of bulk cargoes during maritime transport can have catastrophic consequences, as evidenced by recent high-profile incidents. Recognizing the gravity of this issue, Carl Durow, Loss Prevention Manager at the London P&I Club and the author of the article we found at SAFETY4SEA, emphasizes the crucial role played by P&I Clubs in providing insurance coverage against such incidents and offering advice to prevent them from occurring. By doing so, lives can be saved, and the natural environment can be safeguarded.

While the International Maritime Organization (IMO) establishes official regulations and guidance on cargo liquefaction, P&I Clubs like The London P&I Club provide supplementary advice to shipmasters, raising awareness of the issue and suggesting practical measures to mitigate the associated dangers.

The IMO has identified 75 bulk cargoes, known as Group A cargoes, that possess the potential to liquefy under specific conditions. When the Moisture Content (MC) of a Group A cargo surpasses the Transportable Moisture Limit (TML), the cargo can behave as a liquid rather than a solid due to vessel vibration and motion during transportation. In heavy seas, the liquefied cargo can shift from one side of the hold to the other, jeopardizing vessel stability and potentially leading to capsizing. Consequently, it is vital for the crew to possess a thorough understanding of this issue and to be able to identify warning signs at the earliest possible stage.

Above all, the ship's master must have confidence in the safety of the cargo to be loaded onto the vessel. Prior to loading a Group A cargo, an accredited scientific laboratory must determine the actual MC and TML in accordance with IMO regulations. The master must obtain a valid, signed certificate affirming that the MC is lower than the TML. Even with a valid certification, the master should remain aware of prevailing climatic conditions, such as prolonged periods of rain or snow after the test, which could significantly alter the MC of unprotected cargo.

As an additional precaution, the master should conduct their own inspection using the "can test." Although the results of the test cannot definitively confirm that the moisture content of the cargo is below the Transportable Moisture Limit (TML), they may indicate if the cargo has exceeded its Flow Moisture Point (FMP). Regular can tests should be performed during the loading process, and the results should be photographed and recorded.

If the master does not possess a valid certificate, if the can test results are concerning, or if they are prevented from taking a sample, loading operations should be halted.

Liquefaction / SAFETY4SEA



Throughout the loading process, the master should continue to visually inspect the cargo and take measures to prevent excessive water from entering the holds. If heavy rain occurs, an additional test should be conducted to ensure that the MC remains below the TML. In certain circumstances, it may be appropriate for the master to request the presence of an experienced, independent cargo surveyor.

If, at any point, the master suspects that the MC has exceeded the TML, they must cease loading and inform the vessel owner. Additionally, the master has the right to issue a "Letter of Protest" and seek further guidance from the P&I Club.

Vigilant monitoring of all Group A cargoes is essential throughout the voyage, even if the master was satisfied during the loading process. Holds should be regularly inspected for excess moisture, adhering to all safety guidelines for enclosed spaces. Cargo hold bilges should be regularly checked, and additional ventilation should be introduced as necessary. The crew should also remain mindful of any changes in the ship's motion, as these can indicate a shift in the cargo's state. If the master has concerns, they should attempt to minimize vessel vibrations, contact the nearest coastal state authority, and consider heading to the nearest port or place of refuge.

“The issue of liquefaction is well known, which is why the IMO has implemented regulations. If the regulations are followed, then ships and their crews should remain safe. However, circumstances can sometimes allow an unsafe cargo to be loaded onboard or cause a certified cargo to morph into something less safe. Ultimately, it is the vessel and her crew that will suffer. Therefore, it is vital that the master has the authority and training to identify a potentially concerning cargo and the capability to deal with it effectively.” If you are curious about the original article, it can be found on SAFETY4SEA.

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