Stopper Clamp

This clamp can be used to pull on slippery poles.
Use a double overhand noose to tie a self tightening loop.
http://en.wikipedia.org/wiki/Double_overhand_noose
Due to the integration of a of rubber inlet and the loops self tightening, high axial load compoments can be held (~15kg tested). Untying is easy: You can take the loop out of the goove over the tip of the rod and pull the loop to zero to let the knot vanish.

It can be used inconjunction with
Block and Tackle - customizable: ht