A high temperature alarm sounded for the freezer. The chief engineer went to investigate. On opening the main door he could smell burning and he saw flames coming from the back of the freezer. He activated the alarm nearby, called ‘fire’ on the radio, and fought the blaze with a dry powder fire extinguisher. The fire attack team soon arrived and took over extinguishing operations. There was no significant damage apart from some food and boxes.
The investigation revealed that the heating element, which is coiled around the drain pipe, had become damaged over time and was touching nearby boxed stores. When the freezer went into defrost mode, which it does automatically twice a day, the heat ignited a box or the packaging that was in contact with the coiled element. The vessel was about 10 years old and the freezer defrost had been operating in this way since new.
- It appears that there had been no regular checks of the wiring. Such checks could have helped discover the damage the coil had experienced.
- Wires carrying electrical current should be protected against physical damage. In this case, boxes and stores were placed directly against the defrost heating element. Not only could this practice damage the wire, but once the wire is damaged, as in this case, it could initiate combustion with contacted boxes.