That’s video from WSDOT, recorded inside the Highway 99 tunnel during a first-of-its-kind test today. From WSDOT’s project spokesperson Laura Newborn:
This morning, Seattle Tunnel Partners, the contractor for the SR 99 tunnel, successfully completed the first test of the tunnel’s deluge sprinkler system. In this two-minute test, 6,400 gallons of water poured out of the overhead sprinklers along a 216 foot section of the upper road of the double-deck tunnel. The tunnel is divided into 208 fire safety zones and the fire suppression system is designed to activate sprinklers within the safety zones – or more simply, at the point of a fire. Today’s test spanned two safety zones.
Seattle Tunnel Partners has many more systems tests and safety tests ahead before the tunnel is finished. After all tests are complete and all tunnel systems are a ‘go,’ WSDOT must close the viaduct through Seattle to finish building ramps and realign SR 99 into the new tunnel. Given the amount of testing still ahead, it remains too early to give an exact date for tunnel opening, but the tunnel could open to traffic as soon as this fall.
As we reported after covering a media briefing near the tunnel’s south entrance last week, Highway 99 between the West Seattle Bridge and tunnel will be off-limits to downtown-bound traffic for up to two extra weeks beyond the viaduct-to-tunnel transition closure, to finish the main route into downtown.