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Mains extension melted – not fully paid out

What happened

A mains extension cable melted during use.  This occurred during cutting on deck on a vessel in dry dock; sub-contractors did not fully pay out an extension cable reel they were using to power their equipment. As a result there was induction heating and a melting of cable cord.

Additionally, it was noted that the extension cable was damaged and fixed by tape in places.

What went wrong

The sub-contractor personnel were unaware of the dangers of induction coil heating on mains extensions not fully unwound.  The extension cable and reel had not been inspected by a qualified person before use, and given the  fact that it had a taped repair, should never have been used at all.


  • Thorough inspection of mains electrical cabling before use;
  • Fully pay out coiled mains extension cables before use;
  • Consider the use of specialist 110v electrical equipment.

Please review IMCA “Are you prepared to work safely” video #14 on Electrical hazards.

Members may also wish to review:

Safety Event

Published: 12 July 2021
Download: IMCA SF 19/21

Relevant life-saving rules:
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