The ANFR explains how a wind farm located at sea was able to jam the emergency transmissions of the Regional Operational Center for Surveillance and Rescue (CROSS) of Étel in Morbihan.
The National Frequency Agency tells us this week that it received a request for a jamming instruction on September 28 from the CROSS of Étel, a coastal station in the town located in Morbihan. The center complained of interference affecting channel 16 of the marine VHF (on the 156.8 MHz frequency), yet used for safety and rescue at sea. The emission seemed to come from an offshore wind farm.
A history of frequencies
Disruption of the VHF (very high frequency) band is quite problematic, insofar as it is recognized as being essential safety equipment at sea for any navigator who finds himself in difficulty, especially when the portable telephone network is no longer accessible. A portable VHF can take the form of a kind of walkie-talkie, then used for emergency calls or distress messages, and this, on an international scale.
Given the urgency of the jamming, ANFR agents launched their investigation the next day. They first noticed from the rotating antenna of their regional center (less than 100 kilometers from the CROSS station) that the disturbing emission seemed to come from a wind farm located in the open sea, on frequency 156 .8MHz.
The agents then confirmed the source of the disturbance by taking the road towards the Saint-Nazaire bridge, where they clearly identified the wind farm.
The wind farm uses another marine VHF channel from
The ANFR quickly contacted the maritime coordination center for the wind farm, which reacted just as quickly. Luckily, personnel were present in the electrical substation installed in the middle of the wind farm. The latter was able to check the installation of the marine VHF radio, remote-controlled from the mainland to preserve the safety of the wind farm and the people who work there.
The marine VHF, which permanently transmitted on channel 16, caused the disturbance. As soon as the technicians proceeded to stop the marine VHF, Étel’s CROSS confirmed the end of the disturbances. If it wishes to be able to reuse channel 16, the wind farm will have to review, correct or even change the offending equipment. The safety of its agents is, for the time being, ensured via channel 77 of the marine VHF.
Source : ANFR
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