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MAIB: Workboat collision with wind turbine platform

The UK Marine Accident Investigation Branch has published Safety Digest 2/2023, consisting of lessons from recent Marine Accident Reports. IMCA has reviewed the report and passes on to members, as of interest, some of the incidents in the MAIB report. This is one of them.

What happened

A workboat collided with a turbine platform in an offshore wind farm, causing injuries to one of the crew and minor damage to the workboat itself. The incident happened during transfer of two teams to carry out maintenance tasks on two different wind turbines.     The master set minimum power ahead and steamed on a course between the wind turbines, intending to use the time to complete some administrative paperwork. He was working at the aft-facing chart table on the bridge, but had become engrossed in paperwork and lost track of time, when the boat, having gone off-course, collided with one of the towers.

The workboat took the brunt of the impact on its off-centre protected bow section. The crewman was thrown against a shelf and sustained two broken ribs. The master assessed the crewman’s injury and the damage to the workboat and returned to harbour to evacuate the crewman for treatment at the local hospital. There  was little damage to the workboat other than small dents and abrasions.

What went wrong

  • The workboat’s crew of master, mate and crewman were relatively new to the wind farm and still adjusting to local practices and their new contract;
  • The master was not keeping watch; he had become distracted by paperwork and had lost track of time;
  • The workboat was travelling at 5kts and, without the autopilot switched on, started turning slowly to starboard (use of the autopilot while navigating through wind farms was not permitted in the company’s standing orders);
  • The mate was on the aft deck completing some familiarisation training and the crewman was busy elsewhere;
The moment the workboat bow collided with the wind turbine tower platform


  • Crew and vessel safety remains the priority: Where paperwork must be completed, someone else should keep watch or a look out to maintain proper and effective visual navigation;
  • Watch what is going on! Use all available sensors and instruments. The slow turn to starboard may not have been evident from the bridge windows alone. Watchkeepers ought make regular checks of data from an Electronic Chart Display and Information System (ECDIS), rate of turn indicator, and directional gyro, etc. to identify hazards and take preventative action to avoid collisions;
  • Administrative burden: Paperwork sometimes needed to be done, but can a more efficient way of doing it be found?
    • How much it is absolutely vital?
    • Can the process be changed or improved?
    • Can vessel crew provide constructive feedback on the need for change to shore-based management without fear of reprisal?

Members may wish to refer to:

Safety Event

Published: 9 January 2024
Download: IMCA SF 01/24

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