The machine handles a row of pipes that can weigh up to 30,000lbs. The pipes are supported by two fork assemblies, hence 15,000lbs load per fork. The load c.of.g. is 60inches from the acme nuts so that’s a 900,000in-lb moment. Each fork assembly has two screws 18” apart. So to resist the momentThe screws each see a 50,000lb thrust load. The screws would see minimal radial loading as the cam followers should handle the actual vertical weight. Slight radial loading would occur when the forks tip putting some vertical loading into the acme nuts through the trunnions. This is because the trunnion slots only isolate the nuts from vertical loads when the slots are purely vertical.