Steel Shots: Silver Bullet

Connecting Washington Dulles International Airport to the Washington Metro has been an idea before the Metro itself was built.

In the 1960s, when Dulles was connected to Washington, D.C., via Interstate 66, the median of the adjacent access road was reserved for some sort of rail transit. And even the original Metro plan from 1968 called for the system to eventually extend to Dulles.

Nearly four decades after the first Metro lines began operating in 1976, the first phase of the $6.8 billion Silver Line extension opened this past summer. The new line is nearly 30 miles long, including the portion where it runs parallel to the Orange and Blue Lines. Phase 1 adds an 11.6-mile-route from where the Silver Line splits from the Orange Line and includes five new stations. Crystal Steel in Delmar, Del. (an AISC Member and AISC Certified Fabricator) fabricated approximately 3,200 tons for this phase. Phase 2, currently under construction, is scheduled to open in 2018 and will expand the line another 11.5 miles to Dulles and add six more stations.

There are two key steel elements per station: the mezzanine, where people get on and off trains, and the canopy, which serves as a focal point. Each mezzanine uses sizeable steel elements - W36x395 - that can support over 500 kips in several locations. The steel for the canopies is a maze of difficult angles, each one unique. Due to it’s high visibility, canopy steel was fabricated to architecturally exposed structural steel (AESS) finish standards.

To learn more about the Silver Line project, read the article “Silver Bullet” in the November issue of MSC (available now!).