[Kevin Sevcik]

I think the string is being used more like a belt. You can see what's going on on the far side. The string is run through an eyelet, then tied off onto the pivot for that big cylinder. Said pivot is set up to run in a slot along the frame. So I think this is a belly climber that's using air and a PTO. That's my read on the arrangement of things anyways. I'm not entirely sure how they get onto the first rung and ratchet up, however.