Tunnel boring machine

Device used to excavate tunnels

A tunnel boring machine (TBM), also known as a "mole", is a machine used to excavate tunnels. TBMs are an alternative to drilling and blasting methods and "hand mining", allowing more rapid excavation through hard rock, wet or dry soil, or sand (although each requires specialized TBM technologies). TBM-bored tunnel cross-sections extend up to 17.6 meters (58 ft) (through June 2023).

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