Drifting containers pose increasing danger to other craft

Cargo insurers say that between 2,000 and 10,000 containers are lost overboard by commercial shipping vessels each year and pose an increasing hazard to other craft, reports The Log, a California boating and fishing journal.

According to the Through Transport Club, an insurer that covers 15 of the top 20 container shipping lines, TEU and FEU boxes have floating characteristics similar to those of ships. The necessary force required to sink a TEU or and FEU would have to exceed the volume of water it displaces, that is, 39 and 79 tons respectively.

Shipping containers are rarely watertight, but they still take about 57 days for an empty TEU to sink and 183 days for an FEU. Depending on size, weight, durability, density levels and volume, a container can stay afloat between a few seconds and 15 months.

Containers are more likely to go overboard today than before because larger vessels carry larger stacks - often six containers high sometimes resulting in instability in rough weather.