Cavechat.org

When I've rigged to building structures in similar circumstances, I mostly use webbing loops in basket hitch configuration and clipped the rope in with a carabiner and figure 8 bight or whatever. Keep it simple, safe and efficient.

I'd probably use a double rope clove hitch on a bight thing or a double rope bowline of some sort... Depends on the shape of the anchor and how much I feel inclined to mess with rigging really...

Can you correctly answer these questions?
Why do you tie a tensionless hitch?
What is the required anchor object diameter for a tensionless hitch?
What is the required minimum number of wraps for a tensionless hitch?

Getting back to the original question, I've often tied a clove hitch up high on a tree due to a difficult lip. I then tensioned it and back it up to an anchor further up the sink.
I like the idea of a doubled bowline very much.
If it's angle Iron it needs a pad, and once it's padded the knot doesn't matter really.

CaverCarl