Near-miss: Equipment failure: Broken mast arms

  • Safety Flash
  • Published on 29 May 2015
  • Generated on 12 July 2025
  • IMCA SF 07/15
  • 1 minute read

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.

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.

Photographs of mast damage following the first incident

Mast damage following the first incident

 

Photographs of mast damage following the first incident

Mast damage following the first incident

 

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Mast damage following the first incident

 

Photographs of mast damage following the second incident

Mast damage following the second incident

 

Photographs of mast damage following the second incident

Mast damage following the second incident

 

Photographs of mast damage following the second incident

Mast damage following the second incident

 

Lessons learned

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.

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