After a transfer of 4 technicians to a wind turbine, the vessel was positioned just outside the 200-meter exclusion zone for standby. The next task was to pick up the same technicians when they had completed the work they had planned. The OOW moved the vessel from the turbine to outside exclusion zone in DP surge mode. Just outside the exclusion zone, the vessel was turned to have stern on the weather, vessel was then in a ‘drift on’ position. On completion of turn, the OOW activated auto DP by ‘double tapping’ the auto DP button, but not confirming that the vessel indeed was in full auto DP before leaving the DP desk to deal with other duties. The OOW was at the time alone on the bridge. The Vessel was still in DP surge mode and by the help of the current, the vessel drifted towards the wind turbine and made contact just 6 minutes later. The vessel had a speed of 1.1 knots at the time of contact.
The vessel hit the wind turbine with the helideck perimeter netting and the bridge wing on port side of the vessel. The incident did not result in any personal injuries, and only minor damage to turbine, and vessel. No technical issues were identified during the investigation of this incident.
Why did it happen?
- OOW failed to comply with procedures and industry guidelines.
- OOW did not confirm that full auto DP was activated after double tap of the button on joystick.
- OOW was alone on bridge.
- OOW decided to deal with some administrative task while alone on bridge.
- Vessel placed in a drift on position.
Corrective action and recommendations from the report
The incident was fully investigated, and a corrective action plan established including but not limited to:
- A review of Bridge operations procedures with emphasis on bridge routines;
- A review of Bridge operations training Module 1 and 2
Considerations of the IMCA Marine DP Committee
- The incident raises a concern regarding the robustness of the double push method of confirmation;
- After requesting an action, an operator should always confirm it by remaining situationally aware;
- Bridge manning levels should be in accordance with Guidelines for the Design and Operation of DP Vessels (IMCA M 103), section 3.8;
- Personnel in the report are referred to as Officer of the Watch (OOW) and not DP Operators (DPO). Key DP personnel should have training and experience in accordance with Guidance for the Training & Experience of Key DP Personnel (IMCA M 117).
The full MSF safety alert (20-01) can be found here.
The following case studies and observations have been compiled from information received by IMCA. All vessel, client, and operational data has been removed from the narrative to ensure anonymity.
Case studies are not intended as guidance on the safe conduct of operations, but rather to assist vessel managers, DP operators and DP technical crew in appropriately determining how to safely conduct their own operations. Any queries should be directed to IMCA at email@example.com. Members and non-members alike are welcome to contact IMCA if they have experienced DP events which can be shared anonymously with the DP industry.
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.