Engine Co. 27

The new 2-story Washington DC Fire & EMS Deanwood Engine 27 firehouse is located within fifty feet of the freight and commuter rail line. Per the acoustical consultant’s report, 221 trains passed the site in a 24-hour measurement period, including 24 CSX freight trains and 197 metro trains. Some of the CSX trains exceeded the vibration impact criteria applied to this project of 0.0040 in/sec.

Following Federal Transit Administration (FTA) guidelines and U.S. Department of Housing and Urban Development (HUD) standards for noise and impact upon residential buildings, it was deemed necessary to isolate the building.

In collaboration with the acoustical consultant, design team, and contractor, CDM Stravitec designed a box-in-box solution with a spring-supported floor and spring-suspended ceiling for the crew quarters.

To acoustically isolate the crew quarters from noise and vibration coming from the nearby railroad, a Stravifloor Jackup concrete floating floor with reinforced steel boxes was installed. After placing the steel boxes, installing a PE-film (bond breaker), and pouring the concrete, the jack-up slab is raised to the desired level.

To further the acoustic design, the walls were supported by the isolated slab and a drop ceiling with Stravilink PHR spring isolation hangers was installed.