Friction hitch that can be tied with a bight?

[paddyvero]

It requires a prussik loop or some other piece of rope than the climbing line. I think the challenge is to use the climbing line to tie the friction hitch to the climbing line. Easy if you have the end available, a Blake's hitch or one of several other similar knots would do. But if you don't have the end available you have to take a loop out of the climbing line and use that.

 

Well you can just tie a fig 8 into the bite to create a loop, it works with a bite, but wont hold body weight on the ropes I have, maybe with a supple grippy rope?

[skinnerm1]

After not much succsess with the Farrimond, myself and a few friends got busy. I ended up with what is essentially a Knut Hitch tied on the bight with the stopper snugged up to the main knot and a small variation. No problems tying off the rope with the rope and ascending with the tail so far.

 

Was able to ascend/descend (leader tied off with the Knut variation) a 9.5 Petzl Aerial/ and some insitu, stiff as steel 10mm number with the Knut VA and a Blake's on the foot. Once dressed, it slid easily and gripped like you want it to.

 

After bopping up and down the rope on it, we hung over 200kgs of man off it without slippage. It was easy to release afterwards.

 

Care has to be taken to dress the knot properly before adding the stopper knot and snugging it up. You also have to ensure that only the top strand of the bight entering the knot is used for tying off the rope or ascending/descending. The thing can start to slip if the bottom strand of the bight entering the knot is accidentally used for this purpose instead.

 

Satisfied with it's performance so far, but I won't be taking myself off auto-belay for any high ascending quite yet.

[skinnerm1]

After further testing with the Knut Hitch variant we have found that this made-up piece of rubbish tends to allow an internal build up of slack which can cause slippage. This occurs mostly with repetitive descending and tending to the knot in this kind of situation is a pain/ could be straight up deadly if not backed up. We have gone over to a Camel's Hitch on the bight for the one in a million scenario that a friction hitch on a bight will actually be of use.

[daltontrees]

Hi I thought you were long gone, so I didn't reply to your post a week or so ago.

 

I tturns out thatthe situation you describe for what you might need a friction hotch on hte bight is not what I or I think others imagined. Tree work is frequently done frm whaty is commonly called a doubled rope system, but there is anothe popular sysem called single rope. What I suggested using the farrimond was for a doubled rope scenario. Instead you anticipate a single rope scenario. The farrimond would be inappropriate for a single rope system.

 

In effect you want to make a controllable locking device for a single rope systm using a bight of rope. That simplifies the question a lot. You can pretty much ignore all the previous suggestions.

 

The camel hitch is really just a prussik knot, but not using an 'endless' loop of rope. The ability to tie it using a free length of rope was (when I passed my climbing assessment) a mandatory requirement. As such, it's not a lot different from the old-school Blake's Hitch system.

 

But when you load a Blake's or any friction hitch that is tied on a bight the problem becomes clear, only one part of the bight 'bites' and the other does not, and this defeats the purpose of the knot.

 

I see a solution, and I will try it tomorrow and if it works I will photograph it.

[skinnerm1]

Legend! Thanks Jules. Keen to hear the outcome. We have had a good run with the Camels so far. Some of the bight assymetry problem seems to be sorted out by tying the knot with a loop instead of a bight.

[daltontrees]

Legend! Thanks Jules. Keen to hear the outcome. We have had a good run with the Camels so far. Some of the bight assymetry problem seems to be sorted out by tying the knot with a loop instead of a bight.

 

You've guessed it, making a loop is the answer, I was looking to see how neatly I coud achieve this, and very importantly using a knot that will not bind on loading. Wouldn't want to be stuck on a crag with a bound knot in the middle of my climbing rope.

[skinnerm1]

After further testing with several tied off loop variations and several bight variations no luck. I'm placing this in the too-hard basket for me at any rate. What seems promising usually turns into some bundle of deadliness either immediately or in the form of a nasty surprise.

 

Looped knots implemented with a strand of the same rope they are to be applied to (tried taughtline/blakes/knut/knut-mutant/camels variations) seem to fail quicker for some reason or bind up as in the case of the blakes variant or any of the above hitches finished off with a number half hitches - which is the only way I could get some of these to hold at all.

 

Some knots on the bight (taught line, camels, knut) work well for anchor tie off's (albeit assymetically so only one strand of the bight entering the knot can be used for tying off), however, if you attempt to ascend/descend with them, the repetitive loading/deloading will eventually cause the knot to capsize internally.

 

A Bachmann on a bight or loop of the rope & standard single-strand knot of choice tied with the tail, seems to be the least amount of gear you can get away with in a no gear situation where everything has gone to hell.

 

Did you have a crack at it Jules?