ScanTech Offshore support offshore wind farm construction in Europe, UK, Asia and the US with a focus on environment protection. ScanTech support big bubble curtain (BBC) operations with the supply of oil free (class 0) compressed air delivery packages.
Although ScanTech Offshore has a long history of working with the oil and gas industry, it is fast expanding into the renewables market, winning a series of major contracts to support wind farm construction through use of its specialised fleet of air compressors that create ‘bubble curtains’. The big bubble curtain was developed as a compressed air system for sound absorption in water and especially protects porpoises and seals which use ultrasound as orientation in water.
Bubble curtains are used underwater to protect marine life from loud noises during subsea operations. Ordinary construction noises travel much more easily underwater, and sound levels can be five times higher than in open air. This can be enough to harm and even kill sea life. However, air bubbles resonate in response to sound, absorbing sound energy and when formed into a curtain they reflect the sound, effectively keeping it within the curtained area.
A ship is typically fitted with a set of ScanTech air compressors to deliver compressed air to a flexible tube with special nozzle openings. The tube is installed on the seabed around the locations where the sound is generated, and the compressed class zero air creates the bubble curtain through the nozzle openings.
Partnered with HydroTechnik Lübeck
For the last two years ScanTech Offshore has partnered with HydroTechnik Lübeck (a leading German company which has been pioneering specialised bubble curtain technology for offshore farm construction) to support wind farm construction projects. Together, its stackable air compressors and SeaSentry filtration system supply the huge volumes of clean (‘class zero’) compressed air required.
“The fact that our air compressors are stackable gives us a significant advantage, because we can fit the number of compressors required on to a relatively small vessel without risk of heat build-up,’ says project manager Barry Craig. ‘Rates go up as vessels get bigger, so stackability can offer a significant saving on the overall project costs.”
A typical bubble curtain project might require 20 - 26 compressors, grouped so that five compressors feed air through one SeaSentry filtration system which cleans and conditions the compressed air to ensure only oil-free air of medical cleanliness (class zero) goes into the sea.
Protection to marine life
The team will provide a double layer of sound protection to marine life in the area, equipping a large ‘noise mitigation vessel’ with sufficient air compressors to create a double big bubble curtain around the monopile. In addition, electric air compressors will be located onboard the heavy lift / pile driving installation to provide air for a further / smaller near pile bubble curtain to give additional noise attenuation during the installation of the monopile foundations.