This is a snubbing unit under a drilling rig.
The drilling rig includes the red platform you see up in the air. The snubbing unit is the next platform below.
Snubbing units can control pipe by pushing the pipe down into a hole, or pulling it out.
The advantage of a hydraulic snubbing unit is the lack of need for a rig. Even though rigs are faster, they are expensive, busy, and in short supply.
Analysis
This is a snubbing unit showing the way we are going to analyze it.
The analysis we used for this unit is specifically looking at the effect of the torque on the snubbing jack assembly. Since the jack consists of 4 cylinders on the corners, it is not very good at resisting the torque applied by a rotary table on top of the traveling plate.
A torque tube was utilized to resist this force, and this analysis was a verification of that design.