A recent report from The Nautical Institute International Marine Accident Reporting Scheme (MARS) described an incident in which four stevedores died.
After entering a hold, one of them slipped on a cargo of logs which had been stripped of their bark. When the other stevedores went in to try and rescue him, they too were trapped in the deep spaces between the logs. All four were later brought out unconscious and were pronounced dead on arrival at the hospital. The inherent nature of the cargo, which lead to oxygen depletion in the enclosed space, combined with the slippery surfaces of the logs, created the hazard which led to this tragic incident.
Logs are just one of several cargoes which are known to have oxygen depleting properties. This oxygen depletion can be caused by factors such as self-heating of the cargo, oxidation of metals and ores or decomposition of vegetable oils, animal fats, grain and other organic materials or their residues. The materials listed below are known to be capable of causing oxygen depletion:
Failure to observe simple procedures can lead to people being unexpectedly overcome when entering enclosed spaces. While ship's staff will no doubt be aware of such dangers and will observe sufficient precautions, it is also obligatory on the part of the ship to ensure that cargo holds are well ventilated and that the stevedoring company is warned of inherent dangers with the cargo carried on board before commencement of work.