RuMR Posted September 16, 2008 Share Posted September 16, 2008 tomtom... Quote Link to comment Share on other sites More sharing options...
mkporwit Posted September 16, 2008 Share Posted September 16, 2008 ...actually, i think a girth hitch works like a knot in that some of the base material is compromised by the knot...i don't have the numbers, but a figure 8 fails a rope at something like 90% (again, i'm pulling out of my ass here)... Experiments show that a figure 8 fails at around ~70% of rope strength, which is about what I remembered. I was surprised that the bowline reduced the strenght more... Quote Link to comment Share on other sites More sharing options...
RuMR Posted September 16, 2008 Share Posted September 16, 2008 that's why i said pulling it out of my ass... it proves my point that girth hitching weakens the system, but not enough out in the middle of a route to worry about it... Quote Link to comment Share on other sites More sharing options...
sobo Posted September 17, 2008 Share Posted September 17, 2008 Good read, mk. As a reference point, the Mountain Rescue Association uses a reduction of 1/3 of rope strength in calculating the 10:1 goal for the static system safety factor (SSSF) for the addition of any knot in the system. So any knot in a 30kN climbing rope immediately throws it down to a 20kN working rope. That would mean, say, hauling a dead vertical load of 2kN (a victim, a rescuer, and a litter/other crap) is right at the 10:1 SSSF. Quote Link to comment Share on other sites More sharing options...
mike1 Posted September 17, 2008 Share Posted September 17, 2008 Personally I would stay away from building a habit of girth hitching soft to soft as you're describing. I’d do it in a heart beat if I had to, but I just think it should be considered a last resort instead of a primary method. The loose sewn or tied slings are a much safer way to go as mentioned above in pindude's post. my $0.019999999999 Quote Link to comment Share on other sites More sharing options...
Jens Posted September 17, 2008 Share Posted September 17, 2008 that's why i said pulling it out of my ass... it proves my point that girth hitching weakens the system, but not enough out in the middle of a route to worry about it... amen Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.