Reshaping Transit in Washington DC

By Luke Carothers

Opened to the public in November 2022, the Silver Line Rail Extension in Washington DC is one of the largest capital construction projects in the United States—including 11.4 miles of new track, six new Metrorail stations, and a 9-acre railyard with storage capacity for 168 railcars and maintenance facilities.  Through May 2023, six months into its existence, more than 1.1 million trips were recorded on the new extension.  At the heart of the Silver Line Rail Extension is Washington Dulles International Airport, which received all new rail connections throughout the Washington DC Capitol region.  The project was spearheaded by the Washington Metropolitan Area Transit Authority (MWATA), and called for the construction of six new stations—Reston Town Center, Herndon, Ashburn, Loudoun Gateway, Innovation Center, and Washington Dulles Airport.  

The Silver Line Extension has had a major impact on surrounding communities—with more than 420,000 people living within five miles of the new stations being afforded greater access to jobs, entertainment, shopping, and Washington Dulles International Airport.  This massive capital construction project was undertaken to provide high-capacity transit service between the Dulles corridor and Downtown Washington DC and expand the reach of the existing regional rail system.  A major goal of this ambitious infrastructure project—in addition to providing all new rail connections—was to ensure these connections were pedestrian friendly.  To make the new rail connections pedestrian friendly, project architects called for a unique design where pedestrian bridges and tunnels connected stations to parking and terminal points.  These new pedestrian spaces became a focal point during the design process, and architects set out to design “a passenger environment infused with natural light and ventilation.”  

To achieve this intended effect, the design included metal mesh for shading, which yielded a reduced HVAC load, fall protection, and visual interest.  More than 63,00 square feet of metal mesh panels were required in all to clad the project’s bridge spans, stair infill, turnstiles, and curtain wall.  For the project’s pedestrian bridge sections, mesh spans the full length and height of the pedestrian bridge, without compromising the safety and integrity of the structure.  To install these mesh sections, teams relied on using multiple framed panels with attached hardware that enabled crews to pre-install the panels.  This meant the panels could be installed under tension while also accommodating movement within the bridge sections.  

To meet the unique requirements of the project, GKD metal fabrics were used.  One of the unique aspects required for the project materials was the need for oversized mesh framed panels.  With expansive weaving looms and turnkey engineering services, GKD was an easy choice for both the metal mesh framed panels and the engineered hardware required to attach them properly.  In the process of designing the panels and attachment solutions, GKD’s Engineering team worked directly with the project’s architects.  This meant accommodating for aspects such as wind load, snow load, and live load to meet code requirements.  Another major aspect of the project was pedestrian experience, which led them to focus on adding visual interest.  To do so, the design team specified two weaves of rigid stainless steel mesh, Ellipse 2 and Ellipse 14, which both feature warp wires spaces to emphasize a horizontal pattern as a prominent visual element across all 63,327 square feet of metal mesh.

The project’s focus on the needs of passengers threads a common refrain throughout each phase of a project that was over a decade in the making.  Nearly two years after its completion, the Silver Line Extension is shaping transportation and pedestrian access in the Washington DC region with plans to further expand access to the transportation network currently under way.