Akkerman offers TBMs that range in size from 48 – 94.5" (1,200 - 2,400 mm) OD but can be customized to suit project needs. High torque hydraulic motors rotate the inner drum and cutter face to excavate spoils. The TBMs sealed steering joint allows full articulation. The operator controls the steering to maintain line and grade and monitors the spoil removal process from an interior control station. Five cutter head configurations are available for our TBMs. The dirt cutter head, carbide cutter head and sand shelves come standard with each TBM purchase and can be changed underground. A closed face attachment is available for boring in unstable ground conditions and features hydraulic closeable doors to reduce subsidence. The disc cutter head is used in rock and mixed ground conditions.