DC's Silver Line Reaches Construction Milestone

Workers use a truss to lower the 380-tons of concrete span into place. (Photo by Armando Trull/WAMU)

(Armando Trull - Washington, DC, WAMU) The Silver Line to Dulles marked a major milestone Tuesday. Construction crews are fitting into place the final span for the bridges to carry the Silver Line trains.

"This marks the completion of the aerial structure of this project through Tyson's Corner," says Patrick Nowakowski, the executive director of the Dulles Corridor Metrorail Project. "We have over three miles of aerial structure and this is the last span being set into place."

The crews are using a truss longer than a football field to lift and move the 380-ton span, made up of 12 custom-cast concrete segments.

"Obviously when you're picking up anything this heavy and you have workers underneath it, you have to be very careful and do this in a safe manner," Nowakowski said. "We've been at this for several years now, so we've got it pretty well perfected, we take our time and we do it the right way."

When completed in late 2013, the span will carry trains over the Capital Beltway and into the heart of the largest employment center in Virginia -- Tyson's Corner. Eventually, the line will extend to Washington Dulles International Airport.