Orsted asked for 'no sail zones' around offshore wind farms in three countries after the rotor and blades fell off a Siemens Gamesa turbine at its Anholt project in Denmark on Wednesday.

“We are investigating the cause of the incident, and as an extraordinary precautionary measure, we are requesting the relevant authorities to establish ‘no-sail zones’ at all of our offshore wind farms that use the same turbine as at Anholt,” the company said in a statement, identifying the model affected as the Siemens Gamesa 3.6MW-4MW.

Orsted said so far its investigation has “not pointed to a systemic cause of the issue” and that the remaining units at the 111 turbine wind farm located on Denmark’s east coast continue to operate normally. “Customers in the relevant markets will not be affected,” the company said.

Siemens Gamesa said in a statement that it was working with Orsted to investigate.

“The reason for this [failure] is still unknown, but Siemens Gamesa is working together with Orsted to determine the root cause and decide on next steps,” the OEM said in a statement sent to Recharge.

Orsted’s requested ‘no-sail’ zones include areas of the sea surrounding other wind farms deploying the same Siemens Gamesa turbines, including West of Duddon Sands, Lincs, Gunfleet Sands, Burbo Bank and Walney 1 & 2, all in the UK, Borkum Riffgrund 1 in Germany, and Avedøre Holme in Denmark.

Anholt was commissioned in 2013 and uses much smaller turbines than are currently being rolled out, with Siemens Gamesa now introducing a 14MW offshore model that builds upon its 11MW machine currently being deployed.

News of the incident hit the turbine maker's shares, which closed down 5.5% in Madrid after registering a dip of up to 8.1% earlier.

Recent blade failures in the onshore wind sector include the loss of a blade at a GE 5.3MW-158 Cypress machine at a German wind farm this year, following a similar incident in Sweden last year.

Note: Orsted on Friday said requested restrictions had been lifted following initial investigations.