The shield-type TBM has a cylinder type shell structure, which allows them to be applied for various types of geology, from hard to soft rock, and it allows for stable progress in particularly inferior ground. Open-typed TBMs can efficiently excavate stable bedrock thanks to the simple structure. Propulsion is performed primarily by gripping with the main gripper, thereby allowing for timbering directly behind the face and for supplementary construction methods. The machine performs high-speed construction work in hard rock.
