A demonstration of the AdBm Technologies underwater noise abatement system was conducted July 11–12, 2014 during pile driving operations for monopiles BU 32 and BU 21 in the Butendiek Offshore Wind Farm. The panel-based noise abatement system was deployed and recovered four times without incident. Acoustic testing was conducted at three locations ranging from 285 meters to 750 meters from the monopile being driven. Measurements were collected on 668 hammer strikes at a distance of 285 meters from the monopile. Attenuation of up to 36.8 dB was realized across all hammer strikes at this location. At 750 m from the monopile, 136 hammer strikes were analyzed and the noise radiated from the pile driving was attenuated to the level of ambient noise near the recording vessel, which ranged on average from 140–150 dB re 1 µPa. The results from this test strongly suggest that this system alone will be sufficient to meet the required sound exposure level of 160 dB at 750 m.
AdBm Demonstration at Butendiek Offshore Wind Farm with Ballast Nedam
(2014). AdBm Demonstration at Butendiek Offshore Wind Farm with Ballast Nedam. Report by AdBm Technologies. pp 14.