Snubber failure

A member has reported the discovery of a failure to a snubber on an ROV launch and recovery system. This was discovered during maintenance and annual load test of the ROV. When the tether management system (TMS) was separated from the ROV to facilitate maintenance work, this highlighted that the snubber did not appear to be sitting level. Upon investigation, it was found that the starboard snubber guide runner had detached from the snubber. Whilst this did not prevent the snubber function from operating, it did result in the snubber not maintaining its level when operating. On closer inspection, the port side snubber guide runner was found to have cracked welds also. The failed items were not associated with the load path and therefore there was no risk of dropped objects.

The incident emphasises the need for thorough inspections during ‘routine’ maintenance tasks in order to capture any damage, fatigue or abnormalities.

Our member took the following corrective actions:

• Cleaned and prepared area for repair and welding;
• Close visual inspection of the other ROV onboard the vessel. No cracked welds were observed, but the welding was reinforced as a contingency;
• Added a six monthly visual inspection of the snubber assembly to company preventative maintenance system.

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

• Failure of welding on hyperbaric rescue chamber medical lock door assembly
• High potential near-miss: Dropped ROV/TMS leading to equipment damage