"Bubble curtains" around Tappan Zee Bridge’s pilings protect fish from noise [video]

During the pile driving for the construction of the new Tappan Zee Bridge over the Hudson River, keeping noise pollution at a minimum is a significant goal. Noise reduction in the air is accomplished by placing a rubber-looking covering on the hammer, while marine life is protected by the so called "Bubble curtains".  

This technique uses perforated aluminum rings that are put around the pilings near the bottom. Then, air is pumped into the rings, thus producing bubbles into the water surrounding the piles that act as a barrier. Bubbles not only drive away fish but they also absorb some of the energy from the sound waves. “The air in the bubbles creates an acoustic barrier. A lot of the sound gets reflected back (and away from the surrounding water)” said Rodney Rountree, an adjunct professor at the University of Massachusetts. "Bubble curtains" were also used successfully in the San Francisco-Oakland Bay Bridge in California.

A Draft Environmental Impact Statement (DEIS) is available, as part of the environmental review of the project.

See also: ‘First permanent piles for New Tappan Zee Bridge’

Source: The Journal News