The 4812A frame is designed to operate out of a 12-foot (3.7 m) shaft and jack pipe up to 2-meters long with a maximum of 48-inch OD (1,219 mm). The 4812A features independent jacking, rotation and cutter bit operation. This frame offers 200 tons (181 mt) of jacking force, 100 tons (91 mt) of pull back force and 20,000 foot pounds (27,120 N.m) of rotational torque.
