Skip to content

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

IMCA Safety Flashes
Submit a Report

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of all. The effectiveness of the IMCA Safety Flash system depends on Members sharing information and so avoiding repeat incidents. Please consider adding safetyreports@imca-int.com to your internal distribution list for safety alerts or manually submitting information on incidents you consider may be relevant. All information is anonymised or sanitised, as appropriate.

IMCA’s store terms and conditions (https://www.imca-int.com/legal-notices/terms/) apply to all downloads from IMCA’s website, including this document.

IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall not be liable for any guidance and/or recommendation and/or statement herein contained. The information contained in this document does not fulfil or replace any individual’s or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.