Interesting... the excellent Mr Jenks said
I had totally missed that one, not being a highliner myself. So it seems that
1) It is very *likely* to be safe to have rope inside nylon tubular tape - tests with fig 8s it behaves nicely, I'm 100% confident that triple fisherman is not going to slip and behave weirdly, and I completely expect (not tested!) double to be fine also
2) It's not stronger, with single dynamic rope. On slow pull, the rope stretches and the tape fails first followed by the rope shortly after. This was not tested with static rope though and my *assumption* is that static might loadshare and be better. But worst case is if it fails the same way as dynamic it is no weaker
3) fair point made by gravy and others above that it is impossible to inspect the inner rope. You are left *assuming* that if the outer tape is good then the inner rope is good. Don't we sort of have that issue with kern rope sheath/core anyway? apart from bending it between fingers I can't actually see the core
Actually I wish I'd never asked. Before I asked I was happy in ignorance, it was surely a good idea. Now I don't know... I am tempted to do it after seeing HowNot2 tests of highline leashes... but it is no longer securely in the good-ideas box. Yes again to daWalt, when I meant forever I didn't mean forever, when it is manky tatt I will remove it, I just meant that might be quite a while it'd be left in situ
Thanks again everyone. But more confused than before