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Wind (onshore)United KingdomEIR-0923

Wind turbine blade detaches at Conisholme wind farm in Lincolnshire after bolt failure

2009Published 16 Sept 2026Responsible editor: Chief Editor

SignificantMechanical
Reported damageFrom the sourceHow? Know the real figure?
Figure hidden: shown to subscribersReported figure
turbine out of service for about •• daysShown in the record →Full estimate
From the recordRoot cause hiddenFailed part hiddenThe maker is named in 7 other entries (being named is not a finding of fault)
Where
Conisholme wind farm in Lincolnshire
Operator
Ecotricity
What
A 65 ft blade detached after bolts attaching it to the hub failed
Injuries
None reported
Cause
Material fatigue in the blade or hub components

Companies named in the reporting of this entry (being named is not a finding of fault): Ecotricity, Enercon

What happened

A 65 ft blade detached from a wind turbine at the Conisholme wind farm, operated by Ecotricity, in Lincolnshire after bolts attaching it to the hub failed. The incident initially attracted public attention because local residents reported seeing glowing orange-yellow spheres in the sky on the night it occurred, prompting speculation about a collision with an unidentified flying object. Following weeks of analysis, the turbine manufacturer Enercon released an interim report identifying material fatigue as the cause, with the bolt failure described as an effect rather than the root cause.

Further tests were being carried out to determine what caused the bolts to come loose, focusing on the blade and hub components. The damaged turbine was repaired within days at the manufacturer's expense. Injuries are not reported in the source.

Contributing factors

Material fatigue in the blade or hub components is understood to have placed the attaching bolts under excessive stress, leading to their failure and the blade detaching. Bolt fatigue and design problems were reported to have been ruled out. The full manufacturer's report had not been published at the time of reporting.

Lessons learned

  1. Check blade and hub components when bolts at the rotor hub fail, as fatigue there can stress fasteners.
  2. Inspect highly loaded rotating parts on a schedule, since fatigue can lead to sudden detachment.

More lessons on structural integrity and turbines, from every incident on the register.

Not yet known

  • What caused the bolts to come loose
  • Full manufacturer's report findings
  • Turbine model and age

This entry is updated when these are reported. Get an alert for the next one like it.

Source

The Telegraph (telegraph.co.uk)

Other entries that name Lincolnshire

Published 2026-09-16. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.

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Chart to reuse with this story: Wind (onshore) incidents in the United Kingdom, by year, free with a credit (PNG).

Wind (onshore) incidents in the United Kingdom: 48 entries, with a free alert for the next one.

Wind turbine fires: the counts, the latest entries and a free alert for the next one. Also: wind turbine blade failures.

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