Tunnel Boring Machine Fact Sheet - Metro
Tunnel boring machines (TBMs) manufactured by Herrenknecht Company of Germany, ... tunnel boring machine Total length of each TBM and back-up 344 feet Total weight of each TBM and back-up 2,050,000 pounds drive system ... Tunnel Boring Machine Fact Sheet
Tunnel boring machine - Wikipedia
A tunnel boring machine (TBM), also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They may also be used for microtunneling. They can bore through anything from hard rock to sand. Tunnel diameters can range from one metre (3.3 ft) (done with micro-TBMs) to 17.6 ...