PFlow VRCs Installed in Concrete Shaft Ways of Seattle Tunnel Project

On February 4, 2019, the much-anticipated State Route 99 Tunnel in Seattle opened for north/south vehicle traffic along the Seattle Harbor, connecting the south end of downtown near the Seahawks and Mariners stadiums to the north end of downtown near the Space Needle.

The tunnel is a single tube that measures 9,270 feet  long and 52 feet wide, carrying a double-decker highway that is 32 feet  wide and has two lanes in each direction. The tunnel features  maintenance and emergency egress areas on both sides of enclosed roadway decks.

One of the design challenges was to facilitate the transfer maintenance vehicles, tools, and materials between the two-level roadway decks without interrupting traffic.

The solution was provided by PFlow Industries, Inc. with two high capacity VRCs at each end of the north/south tunnel. PFlow consulted with the tunnel project engineers early in the design stage to help prevent any unforeseen obstacles.

PFlow’s engineering expertise and “Buy American” capability helped make it easy for the State of Washington to go with PFlow! Both PFlow VRCs were installed in concrete shaft ways, the south VRC was placed into the shaft way using a crane from above, while the north VRC was erected in the capped-off shaft way.

Both PFlow VRCs allow maintenance personnel to transfer their vehicles, tools, and materials between the two-level roadways inside the tunnel, ensuring that the new tunnel keeps traffic flowing beneath the Emerald City!

The tunnel spans a distance of 2 miles, and with a diameter of 57’, it is the 2nd largest tunnel in the world! Read more about the tunnel at Wikipedia.