An ROV technician received an electric shock to his left arm beneath the elbow, resulting in a burn. ROV personnel were working in the technical workshop completing a non-electrical related task, bleeding air on top of the HP filter housing from the main hydraulic circuit, when the technician received the shock. The ROV single phase power was energized, but the area of the ROV (Phase 3) that was being worked on was isolated, de-energized and locked out.
What went wrong?
Investigation established that a water drain tube had been used as a conduit for an electrical cable, both the drain and electrical cable had been cut in half, but it was unclear whether or not the cut happened during demobilization, transit, or during the skid and ROV segregation in the technical workshop. The cut cable exposed live electrical wires. Once the cut wires were isolated, personnel were able to identify that they were connected to a separate transformer, and thus the wires were found to be live even after isolating and locking out the area of work.
The system had been recently demobilized from a project. The routing of the electrical cable through the water drain was a modification to the system that had not been documented, communicated or handed over to workshop personnel after the ROV was demobilized. The electrical cable, which had been cut, exposed the bare wires rather than being disconnected and removed.
What actions were taken?
- All electrical cables should be properly disconnected and/or removed, not cut, when demobilizing equipment;
- ROV system modifications should be noted within drawings and ROV system paperwork. Major system modifications should follow a formal management of change (MoC) process, which is the responsibility of the supervisor on site;
- There should be a documented handover between the offshore supervisor and technical workshop supervisor, and this should include details of any system modifications and instructions for disconnection and removal (if not already completed).
Members may wish to refer to:
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 email@example.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.