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Near-miss: Equipment failure: broken mast arms

A member has reported two near miss incidents in which there has been a failure of a mast arm on a CTV. Both incidents related to weld fatigue. In both cases heavy aerials have caused welds to crack and break over time until the mast arm gives way.

Photographs of mast damage following the first incident
Photographs of mast damage following the first incident
Photographs of mast damage following the first incident
Photographs of mast damage following the first incident
Photographs of mast damage following the first incident
Photographs of mast damage following the first incident
Photographs of mast damage following the second incident
Photographs of mast damage following the second incident
Photographs of mast damage following the second incident
Photographs of mast damage following the second incident
Photographs of mast damage following the second incident
Photographs of mast damage following the second incident

In both cases the CTVs were able to safely navigate back to harbour. However, this could have very easily been a different story if the conditions were different or if the mast had damaged any of the equipment.

Our member recommended the following:

  • On CTVs, mast checks should be to be added to a planned maintenance or check schedule;
  • These checks should focus on the tension of the shrouds and the strength of the welds supporting the mast arms;
  • Extra special attention should be given to those parts of the mast that are unsupported and connected to large or heavy aerials or equipment.

Members may wish to refer to the following similar incidents (key words: mast, fatigue, weld, failure):

Safety Event

Published: 29 May 2015
Download: IMCA SF 07/15

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