Tunnel Ventilation Silencer Replacement Project

Silencers play a major role on road and rail tunnel ventilation projects throughout North America and the globe. They are instrumental in acheving the required dBA levels; specifically for emergency announcements. Vibro-Acoustics was called to replace silencers that began rusting internally. This caused metal pieces to break off during fan operation. Blade strikes were discovered by maintenance personel which promped an entire replacement task. This was a challenge in itself to remove the existing silencers and install new ones in their place as many space restrictions were present. The new silencers had to be fabricated in a way to meet the stringent acoustic requirements but also for ease of installation. They consisted of 84" inlet and 144" discharge lengths to acheive the noise requirements both at the track level and nearly street level. The silencers consisted of 3/16" plate casings and G235 18 gauge baffles as per the engineers specification. This presentation will show the steps taken to remove the old silencers, the challenges of installing the new silencers, and the testing process for ceritfiying the acoustic performance by a third party acoustical consulant located in NYC. Vibro-Acoustics was involved throughout the entire project which dates back to 2018.