Best practices and safety considerations for nickel ore shipments

Jia Hong Liu, Assistant Vice President, Technical Manager at Group Club Skuld has noted that the period from April to November marked the traditional typhoon season in the waters of the Philippines and China, coinciding with the peak season for nickel ore transportation in the Philippines.

He said that typhoons and tropical storms posed significant challenges to the safe shipment of nickel ore. The weather conditions increased the moisture content before loading and could cause severe rolling and pitching during the voyage. This in turn might result in liquefaction and shifting of the cargo.

Liu said that only recently a vessel covered by Skuld had experienced a cargo liquefaction incident while en route to the discharge port. A vessel covered by another Club also faced a similar incident.

Skuld advised members that the liquefaction of nickel ore during shipment could be attributed to two key factors:

  • the moisture content of the cargo and
  • the rolling and pitching of the vessel during the voyage.

These factors, one internal and the other external, were both necessary conditions for cargo liquefaction to occur. However, by effectively monitoring and controlling these factors, the risk of liquefaction could be significantly reduced.

Closely monitoring moisture content of the cargo during loading and carefully managing navigation during passage were the best practices for preventing liquefaction incidents in nickel ore shipments, said Skuld.

Ensuring that the moisture content (MC) did not result in exceeding the Transportable Moisture Limit (TML) as required by the International Maritime Solid Bulk Cargoes Code (IMSBC) was the critical quality control that should be implemented during the loading process.

While cargo monitoring would typically also include a pre-loading survey and guiding the crew to conduct Can Tests, Liu emphasized that it was “important to understand that the Can Tests only provide a preliminary indication of the cargo condition at the loading site, and cannot replace laboratory testing to definitively determine whether the cargo is safe for carriage”.

However, due to complicating factors hampering safe loading of nickel ore loading in the Philippines, monitoring heavy relied on Can Tests, thereby making it difficult to ensure compliance with the IMSBC Code requirements.

Vessels carrying nickel ore are usually Handy sized bulk carriers, making them more prone to liquefaction than larger vessels. Rough sea conditions intensified vessel rolling/pitching, increasing liquefaction likelihood and severity.

Investigations and analysis of previous cases have shown that liquefaction typically occurs after more than 12 hours of continuous rolling/pitching in Force 6-7 winds and waves.

Because the forward holds experience more motion, liquefaction often starts in holds 1 to 3.

Vessel pitching, rather than rolling, was more likely to induce liquefaction. However, once liquefaction occurs, rolling can cause cargo shifting, posing a greater danger to the vessel.

Crew were advised to check the condition of the cargo in each hold twice a day, when weather permitted, and also to report this to the company. If liquefaction was found, it should immediately be reported to the ship managers and Skuld. The impacted vessel should take immediate measures to reduce pitching and rolling, sail close to shore and choose the nearest port of refuge to deal with the cargo.

Skuld said that the Master should also be aware of the obligations under the relevant Code to only allow safe and compliant cargoes to be loaded and members should follow the ‘recommended precautions’ listed in the 2011 IG circular for all cargoes that contain fine particles, irrespective of the cargo group declared by the shippers.

Members are reminded to comply with the ‘notification requirements’ of the 2012 IG circular, namely that members who plan to fix or charter a ship to load nickel ore from ports in Indonesia and the Philippines, or where under an existing fixture a ship is ordered to load such cargo, the member must notify Skuld at the earliest opportunity.