The Swedish Club has highlighted how to avoid wet damaged cargo on bulk carriers in a 32 page pdf booklet, which can be downloaded below. The Club says that heavy weather in combination with leaking hatch covers is the most common cause of wet damage on cargo. However, the main concern is the incorrectly applied and poorly maintained cargo hatch covers and sealing systems.
As a result of information collected from its claims handling, many cargoes of steel and steel coils, grain, peas and solidified cement were damaged by sea and rainwater enabling the report to be produced. In fact, 34% of all insured bulk carriers suffered a cargo claim in 2017 and this has increased by 75% since 2014. For 2017, the average cargo claim on a bulk carrier was almost USD 70,000.
These incidents make wet damage the second most common claim type on a bulk carrier and the most costly, while the average cost for a bulk carrier wet damage cargo claim is almost USD 110,000 says the Swedish Club.
Leaking hatch covers are the most common cause of wet damage followed by heavy weather. These are usually closely inter-connected as seawater has entered the cargo hold through leaking cargo hatch covers during heavy weather. But there are often coinciding incidents as the cargo hatch covers may be washed over by green sea on deck when the vessel sails through heavy weather.
One of the other main concerns is not the heavy weather itself, but the incorrectly applied and poorly maintained cargo hatch covers and sealing systems. These significantly increase the risk of the cargo becoming damaged by water. The cargo hatch covers are designed to prevent water from entering the cargo hold when the vessel is sailing through heavy weather.
Overall, the most common wet cargo issues are related to the following:
– Leaking cross-joints;
– Compression bars in poor condition;
– Rubber gaskets in poor condition;
– Hatch coamings in poor condition;
– Leaking transverse packings;
– Drain channels in poor condition;
– Non-return valves in poor condition;
– Cleats in poor condition.
For these reasons, the Club has noted that weather-tightness is an essential key factor in keeping cargo dry. For a smooth, stable operation of the hatch covers on board, the panels should be stiff.
However, to maintain weather-tightness at sea, the steel structure of a hatch cover, as well as the bearing pad, cleats and sealing arrangements, must adapt to the varying shape of the coaming top while the hull is moving and flexing at sea.
The best structural stiffness of a hatch cover panel is a compromise between the above issues. The correct stiffness can be achieved by selecting the optimal proportion between the open web and box construction, with the double-skin construction being the stiffest design.
A weather-tightness test should also be carried out at least annually and always after repairing or replacing components in the cargo hatch system. When conducting water-sensitive cargo like grain, soybeans and paper it is recommended that weather-tightness is tested before each loaded voyage.
To limit the impact of the heavy weather, the possibility of excessive green sea on deck may be reduced by corrective actions such as reducing speed or altering course. The risk of green sea on deck may however not be eliminated through vessel operations and poor condition of the cargo hatch covers may lead to water ingress into cargo holds resulting in cargo claims.
Before sailing it is essential that the crew ensures that all cargo hatches and other openings are secured properly, and this is imperative if heavy weather is anticipated.
When preparing for a loaded voyage, the crew should ensure that the following is complied with:
– Before leaving port, the crew should inspect the hatch covers to ensure they are in a weathertight condition;
– It is essential that there is no cargo in the drain channels as these should lead the water away and not into the cargo hold;
– To ensure that the hatch cover is secured properly it should be secured in port as per the manufacturer’s instructions;
– If for some reason a hatch cover was secured when the vessel was at sea, there is a risk that the hatch cover might be misaligned.
Download the 32 page pdf booklet: Swedish-Club-Wet-Damage-on-Bulk-Carriers