Heat damage to agricultural cargoes continues to generate costly claims in marine insurance, despite being a well-recognized risk. Products like soybeans, maize, and seed cake are particularly vulnerable when stowed next to heated fuel oil tanks, especially double-bottom tanks. In many cases, poor heating practices lead to partial or total cargo loss—losses that are often preventable.
Across recent cases, heat-damaged cargoes have led to the rejection of hundreds to over a thousand tonnes of product per incident. For example, 600 tonnes of soybeans were damaged when a double-bottom tank was unnecessarily heated throughout the voyage. In another case, 1,200 tonnes of maize were lost due to fuel oil heated beyond safe limits. Such claims can exceed hundreds of thousands of dollars and may involve additional port charges and delays if damaged cargo must be discharged elsewhere.
In most situations, the cause is not mechanical failure, but operational oversight: tanks are heated unnecessarily, hot oil is transferred into tanks adjacent to sensitive cargo, or there’s a lack of coordination between departments. Damage can be visible—such as discoloration, mould, or caking—or invisible, which still leads to rejection by cargo receivers, especially if damaged product mixes with sound cargo during discharge.
To mitigate these risks, several steps are essential. Before loading, engineering and deck officers should coordinate to discuss the cargo’s heat sensitivity and agree on a suitable heating strategy. The International Maritime Solid Bulk Cargoes (IMSBC) Code should be consulted for any cargo-specific stowage or temperature guidance. Where possible, heated tanks next to cargo spaces should be avoided. If unavoidable, heating must be minimized and carefully controlled.
Special caution is needed with self-heating cargoes like seed cake. If such cargo contains excess oil or moisture, even moderate heat from an uninsulated bulkhead or nearby tank may trigger self-heating, which can escalate to spontaneous ignition.
Proper documentation is a key part of loss prevention. Ships should maintain detailed records of tank heating throughout the voyage, including temperatures and tank locations. These logs are vital when defending against claims or proving that the vessel operated within acceptable standards. In addition, fuel heating systems and sensors should be included in the ship’s planned maintenance schedule and regularly checked for accuracy
Conclusion
Heat damage to agricultural products is both costly and preventable. With proper pre-voyage planning, careful heating control, and clear communication between onboard departments, the risk of cargo loss can be significantly reduced. These simple but disciplined practices form the core of effective loss prevention—and help protect the interests of shipowners, insurers, and cargo stakeholders alike.
