How Clark packed two DC Metro station rebuilds into a 56-day shutdown

Metro closed the stations from July 6 to Sept. 6 and reopened them Sept. 7, on time and on budget, WMATA said. The agency said one long closure spared riders two years of night and weekend closures. At Bethesda, crews built a 6,000-square-foot mezzanine with two escalators and two elevators that will link to Maryland's Purple Line, due in late 2027. Grosvenor-Strathmore got its first major overhaul since it opened in 1984.

At Grosvenor-Strathmore, remote-controlled demolition robots tore up more than 18,000 square feet of tiled platform surface and the concrete topping under it, and crews rebuilt 1,200 linear feet of edge along a platform 600 feet long, Construction Dive reported. With rail power cut, every machine arrived by diesel locomotive and flatbed car. Both jobs were supplied from a single rail yard by one crane, with just-in-time deliveries. Inside Bethesda's curved vault, the team used compact spider cranes.

Record heat moved placements to 4 a.m. so the concrete stayed below 95°F. Bethesda had no straight vertical route for a pump, so the team ran a 500-foot slick line from a surface vent shaft through access tunnels to the mezzanine, using a custom mix designed not to clog over that distance. By WMATA's count, the mezzanine used roughly 220 cubic yards of concrete and 60 tons of steel, and crews placed 280 cubic yards at Grosvenor-Strathmore.

The original plans were drawn by hand in the 1970s and 1980s and often did not match the field, Clark Civil project executive Scott Betteker told Construction Dive. The team had to settle discrepancies and change structural connections within hours. Bethesda work continues behind barriers toward a 2027 finish. The Washington Post reported in 2024 that the mezzanine's cost had grown from a 2016 estimate of $2.4 million to $52 million.