A wrench, in terms of trenchless construction, is a high-capacity, self-adjusting handling and assembly device that allows the ability to grip and safely make up or break out drill pipe and other drill string components, thread drill string together and apply torque to appropriate levels. These wrenches can be manual or hydraulic tools used to connect or break tool joints at access points forward of the drill rig.
Also referred to as breakout wrenches or exit side wrenches.
Trenchlesspedia Explains Wrench
In a drilling rig breakout wrench system, which includes a pair of bi-directional breakout wrenches, locking cogs engage the cam and grip the pipe section. One wrench is attached to an actuator and with a rotating motion provides torque to the wrench body in order to break open the threaded joint of a drill string while the static wrench prevents movement along the string itself.
Manual wrenches are most often attached to the end of an excavator boom. Hydraulic exit side wrenches can be remotely operated which increases the safety of these drilling processes. In guided auger boring, a hydraulic wrench is utilized to turn a steel casing that has an asymmetric face at the cutting head.