DC Tunnel Project Passes Milestone as TBM Holes Through
On July 23, the cutterhead of a tunnel-boring machine, dubbed "Lady Bird," that is mining the first section of one of several tunnels being built to improve the water quality of the Anacostia River, was lifted out of a shaft near a pumping station in Washington, D.C., after completing its mission.
Manufactured in Germany by Herrenknect, the TBM removed approximately 1.2 million tons of material from the four-and-a-half-mile tunnel.
The tunnels are being built to reduce stormwater and combined-sewer overflows.
