Big Bubble Curtain
The Big Bubble Curtain ( BBC ) or Big bubble curtain ( GBS ) is a compressed air system for sound attenuation in the water. The system was developed in accordance with requirements and with funding from the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) and is primarily used as noise protection during offshore pile driving and offshore munitions blasting. Harbor porpoises and seals in particular, which use ultrasound for orientation in the water , are protected by the Big Bubble Curtain. In the German waters of the North and Baltic Seas, the BMUB limit of 160 dB sound exposure level (SEL) applies, measured at a distance of 750 m from the sound source.
functionality
A flexible hose system, which is provided with special nozzle openings, is laid at a sufficient distance around the location of the sound generation on the sea bed. Depending on the nature of the sea bed and the water current, up to two rings can be used. A ship equipped with special compressors presses air into the hose system with up to 10 bar while generating the sound . The compressed air escapes through the nozzles provided. The steadily rising air bubbles change the physical nature of the water. Sound waves are broken several times and the volume is reduced.
The hose system can be recovered after each use. It is independent of other trades and does not leave any traces on the water bed.
The maximum sound attenuation that has been achieved so far is 15 dB with one hose ring and 18 dB with two hose rings. The deployment and use of the Big Bubble Curtain depend in different ways on wind strength, wave height, water depth, current and the environmental conditions of the respective construction site.
History and Development
The Big Bubble Curtain has its history with the compressed air barriers , which have been used for more than 50 years to protect against floating debris and oil spills. At the suggestion of NABU Schleswig-Holstein and various environmental associations, tests were initially carried out in 2006 to determine whether the compressed air barrier system could also be used to minimize hydro noise. Ammunition from the Second World War was to be blown up in the Kiel Fjord . A nearby harbor porpoise sanctuary was in acute danger.
In 2008 the system was used for the first time in the offshore area of the North Sea for pile-driving work for the construction of the research platform FINO 3 . The BMUB contributed significantly to the costs of scientific research and further development. The University of Hanover and the companies BioConsult, itap GmbH and Hydrotechnik Lübeck GmbH were also involved.
The Big Bubble Curtain is now used for construction work on almost all offshore wind farms and for blasting work in the North and Baltic Seas.
Individual evidence
- ↑ Big Bubble Curtain - Description of Services - Film ( Memento of the original from April 8, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Website Hydrotechnik Lübeck GmbH. Retrieved June 11, 2014.
- ↑ Ammunition in the Baltic Sea - Interview Ingo Ludwichowski ( Memento of the original from April 13, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . Hydrotechnik Lübeck GmbH. Retrieved June 11, 2014
- ↑ Blasting ammunition stopped for the time being - Article . NABU Schleswig-Holstein. Retrieved June 9, 2014
- ↑ Research and application of noise reduction measures when ramming the FINO3 monopile - website FINO3 . Retrieved June 11, 2014
- ↑ Joint project: Realization of noise protection measures during the construction of FINO3. - website . Leibniz University Hannover. Retrieved June 11, 2014.
- ↑ Project Hydroschall Borkum West II - website ( Memento of the original from December 26, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . BioConsult SH GmbH & Co.KG. Retrieved June 11, 2014.
- ↑ Hydroacoustics (underwater sound ) website ( memento of the original from October 17, 2013 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . itap GmbH. Retrieved June 8, 2014.
- ↑ It is loud off Germany's coasts - Interview Cay Grunau ( Memento of the original from April 13, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Hydrotechnik Lübeck GmbH. Retrieved June 8, 2014.
