Cabling in ROV hanger inadvertently severed by the ROV launch and recovery frame

What happened?

During weekly testing of the vessel emergency firefighting pump, the engineer discovered that he could not start the pump.

What went wrong?

Initial investigations identified that the electrical cables and hydraulic hoses serving the equipment had been severed.  Further investigation established that the cables and hoses in the ROV hanger had been inadvertently severed by the ROV launch and recovery (LARS) frame which had come into contact with the bulkhead cable tray (yellow structure in second photo).

The impact between the LARS and the bulkhead cable tray was not reported immediately after it happened, possibly because it was not noticed by those involved in the operation of the launch and recovery system.

What lessons were learned?

  • When installing and/or operating powered mechanical equipment ensure that the possibility of contact between it, other equipment and fixed structures is identified and mitigated during the project planning phase and thoroughly checked during mobilisation;
  • The risk of collision was in fact documented in the task risk assessment; however, this was not translated into actual change to the operating procedures and work instructions, nor to the task itself.

What actions were taken?

  • Review of launch and recovery operations and documented risk assessments/operating procedures:
    • documents amended where necessary
    • one of the ROV crew assigned to monitor the ROV recovery process with particular reference to the proximity of the launch and recovery system frame to the vessel structure;
  • Incident and required actions discussed with those involved in the ROV operations. Employees reminded of their responsibility to speak up if they identify an unsafe act or condition, e.g. damaged equipment and/or services;
  • Installation is in progress of a permanent engineered solution to prevent contact between the LARS frame and the vessel structure.