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Protecting all Marine Life Forms. For over 50 years and countless projects across the world Hydrotechnik Luebeck is not only one of the pioneers in this field but continuously perfects and innovates their products.

Noise mitigation during offshore construction, protection of desalination plants and other industrial facilities from debris , Oil weirs and separation are areas were you can't find a more experienced and dedicated Partner.

Big Bubble Curtain – flexible used

The Big Bubble Curtain is extremely flexible and designed for pile driving in offshore areas. A hose system is installed temporarily on the sea bed. This is done before or after the pile driving platform has assumed its position.

A special vessel is part of the system. There are large hose reels on board. The stern of the ship is designed specifically for the launch and recovery of the Big Bubble Curtain. If necessary the ship combines pressure air compressors with the hose ends and forces air up to 10 bar in the tube system.
The position of the pipes on the seabed is variable and depends primarily on the local conditions and the maximum effectiveness of noise control function.

The system is also ideally suited for use in offshore blasting operations or ammunition blastings.

  • extremely flexible
  • independently of other trades
  • independent preparing the ramming position

Set-up Time
  • 60 minutes for 160 m hose-ring
  • 45 minutes for 75 m hose-ring

Offshore Compressed Air Systems

During the building of the FINO 3 research platform, a system to protect against underwater noise pollution was needed for the first time. The engineers from HYDROTECHNIK LÜBECK took on this challenge and developed the Big Bubble Curtain.

The results of the noise measurements taken during the driving of the FINO 3’s monopile were convincing. The noise-protection system, which is continually being improved, is now used primarily at the large building sites where wind farms are being installed in the North and Baltic seas. For more, please see Trianel Borkum West 2.

A further area where the Big Bubble Curtain can be used effectively is for underwater blasting operations. Using the closed bubble curtain, noise reduction of up to 95% is possible here as well. For more, please see Ammunition in the Baltic Sea.


  • Up to 95% noise reduction

  • Application
  • Pile-driving operations
  • Blasting operations

    Big Bubble Curtain – HY75

    The Big Bubble Curtain (BBC), or in German ‘Großer Blasenschleier’ (GBS), is a compressed air system for sound absorption in water. We have developed this system in line with respective conditions and with subsidies from the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear safety (BMUB). The system serves primarily to provide sound protection during offshore pile driving and offshore munitions blasting. The Big Bubble Curtain especially protects porpoises and seals which use ultrasound as orientation in water. The limit specified by the BMUB of 160 dB sound exposure level (SEL) applies in German waters of the North and Baltic Sea, measured at a distance of 750 m from the sound source.

    How does it work

    We apply a flexible tube system fitted with special nozzle openings. It is installed at sufficient distance on the seabed around the location where sound is generated. Up to two rings can be applied depending on the condition of the seabed and the water current. A ship fitted with special compressors presses up to 10 bar of air into the tube system during sound generation. The compressed air is discharged via the nozzles provided. The bubble curtain develops as a result of the continuously rising air bubbles. It changes the physical condition of the water. Acoustic waves are repeatedly broken and the noise level is reduced by up to 95 %.


    The tube system can be salvaged after each use. It is independent of all other working units and does not leave any trace in the seabed.
    The maximum sound absorption achieved up to now is 15 dB with one tube ring, and 18 dB with two tube rings. Installation and deployment of the Big Bubble Curtain are variously dependent on wind force, wave height, water depth, and the current environment conditions at the respective construction site.

    History and Development

    The Big Bubble Curtain originates from the compressed air barrier technology which we have been using for more than 50 years to protect floating debris and oil. On the initiative of the NABU Schleswig-Holstein and various environment protection associations, in 2006 we initially tested whether the system of a compressed air barrier could also be used to minimize underwater noise. Munitions from the Second World War were to be blasted in the Kiel Fjord. A nature reserve for porpoises nearby was in acute danger.
    The system was first used in 2008 in the offshore section of the Baltic Sea during pile driving to build the Research Platform FINO3. The BMUB made a considerable contribution to cover costs for scientific research and further development. The University of Hannover and the company, BioConsult, itap GmbH were also involved in the project.
    The Big Bubble Curtain is now used in almost all construction work for offshore wind farms and blasting work in the North Sea and Baltic Sea.


  • Specialized ship
  • Compressor
  • Polyethylene compressed-air pipe
  • Special nozzles
  • Air-supply, nozzle and drainage hoses
  • Control valves
  • Drainage valves
  • Entwässerungs-Ventile


  • Independent work cycles


  • FINO3
  • alpha ventus
  • Amrumbank West
  • Baltic 2
  • Borkum West II
  • Borkum Riffgrund
  • DanTysk
  • Meerwind
  • Nordsee Ost

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    Pneumatic Oil Barrier

    The pneumatic oil barrier or compressed air barrier is a plant for waters or port facilities. It creates a barrier for anything floating on the water, holding back especially floating oil and flotsam. For more than 50 years, it is used in locks, ports, rivers, canals or for the protection of industrial plants.

    In a system permanently installed hoses or pipes with special nozzle openings are anchored to the seabed. In case of alarm, compressed air generated in a compressed air system is pushed into the nozzle tube. The air exiting the nozzle produces a vertical flow, which converts to the water surface in two horizontal currents in the water. These horizontal currents keep the water surface floating oil and other substances driving back. Boats or ships can pass the barrier freely. A permanently installed compressed air system is ready for use in just a few minutes after activation. This system can operate without additional work force and can also be used in case of fire.

    The efficiency of a pneumatic oil barrier is increased by steadily rising or trailing oil flotsam advent of pressure on the barrier and exceeds the force of the current. In case of alarm is simultaneously skimming the driving materials needed to maintain the function of the barrier.


  • Rapid activation
  • No personnel required
  • Shipping traffic not disrupted
  • Turn-key delivery


  • 2 minutes for 160 m harbour entrance
  • 9 minutes for 1000 m bay


  • Compressed-air station
  • Polyethylene compressed-air pipe
  • Special nozzles
  • Air-supply, nozzle and drainage hoses
  • Control valve
  • Drainage valve


  • Croatia
  • Saudi Arabia