Alternatively, a torque tube can be hung rigidly from four crane trolleys. In this case, the torque tube can withstand overhung loads in any direction and does not have to be hinged. A carriage supports the torque tube and usually runs along two bridges, which in turn are supported by two runways.
Torque Tubes – Hanging from Cranes
Sometimes it’s necessary to hang a nutrunner from a crane in order to achieve large travel distances. In this situation, torque tubes are used instead of a torque arm. A vertical slide floats the torque tube nutrunner, suspended from a balancer or an air cylinder.
Usually a torque tube hangs from two trolleys on a bridge or monorail. In this situation, hinge pivots have to be provided to avoid applying a moment to the trolleys.