Lessons learned from an incident in which, the lid on a waste container barrel blew off due to a build-up of excessive pressure within the waste container, caused by hot ash being deposited inside.
The build-up of pressure was observed by a member of the crew, who attempted to gradually open the compression ring on the waste container to allow for a slow and controlled release of pressure. The worker did not foresee the risk involved in this action; due to the pressure within the waste container the lid was forcefully dislodged from the locking clamp, releasing the lid from the waste container and causing it to fall 11m to the main deck below. No other personnel were present in the area during this incident.
Credit: IMCA
What went wrong
- Hot ash from the vessel incinerator was discharged into the waste container (used for offloading) and the waste container lid was closed immediately;
- Because the ashes of the incinerated waste were not yet cool, there was a build-up of hot gases. Pressure built up within the insufficiently ventilated container, causing it to inflate;
- When the crew member went to release the lid from the container, there was a loss of control and the lid was violently flung off;
What were the causes
- There was insufficient assessment in general of the risks of dealing with incinerated waste and of its disposal;
- The risks of storing hot ash in an airtight container were not foreseen;
- Lack of knowledge – the risks of manually relieving the build-up of pressure were not understood;
Actions taken
- Improvement (a goose neck vent for waste containers) quickly identified and implemented;
- Updates in waste management procedure made, including risk assessment for handling and storage of hot ash.