SEATTLE, Washington – November 2, 2010 -- When the Link light rail system first began running in July 2009, Rainier Valley and Tukwilla residents in south Seattle were unprepared for the screeching, tearing and grating sounds that began filling their air space 20 hours per day, seven days a week.
Sound Transit Authority’s Justin Garrod, project manager for the Link rail system was called upon to find a solution to the high noise level that exceeded federal standards in south Seattle and dramatically interfered with the area residents’ quality of life. After doing the research and trying other methods, Gerrod and his staff discovered Acoustifence, which is comprised of a unique sound deadening material - a perfect temporary fix, Gerrod thought, until a permanent solution could be found.
After simply hanging the Acoustifence from 5,000 feet of guardrail flanking the actual rail tracks, Gerrod quickly realized he had found a permanent solution.
“We’re convinced this is it, this is the answer to the noise problem,” Garrod said. “Acoustifence met all the criteria, it’s cost effective, easy to maintain and an excellent sound deadening material.”
Additionally, installation was easy as the Acoustifence is easily cut to size for a custom fit and attached with supplied industrial strength nylon ties connecting the material to the existing guardrail.
“We combined the Acoustifence material with rail grinding (another noise reduction measure) and the combined results were exactly what we needed,” Garrod said.
When Sound Transit was originally designing the Link light rail system, noise levels were predicted by examining studies on the noise output of other similar light rail transit systems in other cities.
Based on the expected noise levels, mitigation features were designed into the original project. These features included sound-insulating some of the homes along Martin Luther King Jr. Way S. in south Seattle and constructing noise walls in Tukwila. Still, the noise deadening measures taken did not work for all areas of Tukwila, with some still exceeding federal standards. (Solid barrier walls do little to mitigate rail noise. Solid walls reflect the noise back at the rail car, which in turn reflects the noise back over the top of the wall.)
Steve Hibbens, rail noise consultant for Acoustiblok, the company that manufactures and distributes Acoustifence, said the solution worked so well, Sound Transit Authority plans to order more of the patented noise abatement material to keep in stock. Hibbens is also working with Atlanta’s rail system, MARTA, implementing Acoustiblok All Weather Sound Panels to absorb rail noise.
“Sound Transit Authority is really happy with the results,” Hibbens said. “There have been several write-ups about the project success in Seattle area papers.
“The neighbors are happy too.”
Acoustifence is a simple and economical noise abatement solution for both residential and industrial usage. A 1/8-inch (3mm) thick unique sound deadening material measuring 6-feet (1.82 meters) high by 30-feet (9.14 meters) long with black anodized brass eyelets along the top and bottom edge for easy attachment. Seventy, 125-lb. heavyduty nylon ties are included with each roll. Easily installed or removed in less than one hour, impervious to mold, mildew, and UV, Acoustifence is virtually indestructible.
The soundproofing material in Acoustifence is a proprietary formula of the Acoustiblok® Corporation, developed and refined over a 10-year period for various applications. Acoustiblok is recognized and sold worldwide, earning product awards from the British House of Commons, as well as being one of NASA’s Top 50 Spinoff companies.
Acoustifence has proven performance in highway environments, construction sites and waste-to-energy plants, and can accommodate any height fence or structure by simply overlapping the sections. To store, Acoustifence sections simply roll up like carpet into less than a 12-inch diameter.
Independent lab tests of the Acoustifence material show a sound transmission classification (STC) of 28, which represents to the human ear an approximately 85-percent reduction in sound. However, results will be less relative to surrounding soundreflective objects such as buildings or trees and the amount of Acoustifence installed.
“This very simple, economical sound abatement product will quickly become popular in new and existing landscape settings thanks to its unequalled ability to reduce unpleasant exterior noise,” Johnson said. “It boils down to providing a better quality of life for anyone living near any annoying noise source.”