A tunnel boring machine named “Lady Bird” was brought to the surface for a routine inspection after spending more than a year underground in Washington D.C., reports The Washington Post. The machine is 443 feet long and weighs 1,325 tons.
Crews are examining the rotating circular face of the machine, which is 26 feet in diameter and studded with cutting wheels, knives and scrapers that chew up the soil when the machine pushes forward.
The machine has tunneled nearly four miles under Washington D.C., as part of a 13-mile underground tunnel network project. Since the project began in July 2013, dump trucks have hauled more than 50,000 loads of dirt Lady Bird tunneled to a dumping ground in Maryland.
Source: DC Water