The incident

Seamen were grinding sea-fastening spots in the hold, when one of them complained to the Chief Officer about the quality of the grinding discs.


In fact, they were able to grind one spot away before the disc disintegrated and pieces were flying everywhere. The Chief Officer told them not to use these discs anymore, before an investigation has been conducted.

Probable cause

According to IMCA, investigation showed that the marking and appearance of the disc led to misunderstanding as to proper use. Namely:

  • The discs looked like a normal grinding disc, but also bore the text ‘cutting’, leading to the conclusion that they were cutting discs;
  • None of the officers or crew on board had ever seen a cutting disc this thick before, so that is probably why the mistake was made;
  • The discs were clearly marked ‘Not to be used for grinding’.

In addition, further investigation indicated that from this particular brand (Kronenflex) there is type A24Extra as both a grinding disc and as a cutting disc.

Moreover, there was no check of the disks on delivery, or before use, as well as inadequate attention and awareness of the crew. What is more the wrong kind of disc was not spotted before use.

Finally, the supplier asked to deliver grinding discs and instead delivered cutting discs. Nevertheless, no-one noticed.

Lessons learned

After this incident, IMCA made the following recommendations:

  • Make sure that the crew are  aware of what happened: A safety moment was planned to demonstrate that it is not a grinding disc, although it looks like one;
  • Ensure equipment and tools are carefully selected and inspected before use;
  • The purchase department should ensure the grinding wheels are of good quality and marked with an expiry date.