UKC

All views welcome:

When climbing as a three in series on a single rope (with all pitches less than 1/2 rope length) how do people tie the middle climber to the rope?

1) Alpine butterfly / figure 8 on bight then clip in?
1a) 1/2 locking krabs opposed on belay loop?
1b) 1/2 locking krabs thru normal tie-in points

2) I have somewhere seen a method that uses a bowline tied using a folded rope threaded directly through normal tie-in points, tied, and the free end loop secured with a locking krab to prevent walking. I cannot, however, seem to find this anywhere on the web again despite lots of searching.

3) Other...

I await the flood of wisdom and conjecture

In reply to quadmyre:

Just tend to use fig 8 on a bight with locking krab through the belay loop. (Could never get the hang of the alpine butterfly).

In reply to quadmyre:


Not quite what you describe, but you could search for bowline-on-the-bight, which is a secure middle-of-the-rope tie-in.

Or, given that the middle party is effectively being top-roped, you could use a Chris Tan death knot (forums passim).

Hmmm... so with the bowline on the bight thing you presumably have to pull through a huge loop and step through it to tie the knot off? Looks kind of funky though.

The tie-in I'd seen previously just looked like a normal bowline, other than that it was tied with two strands of rope and that the loop (where the loose end would normally be) instead of being tied off with an overhand knot or fishermans was clipped with a locking krab around the main loop of the knot (the bit going through the harness tie-in points). I just kind of liked that idea as it looked simple to do and doesn't have any potential krab-loading issues as per clipping in.

In reply to quadmyre:

3) Other...

Do a search for the Chris Tan Death Knot, it's another option. Actually pretty poorly named, it's no worse than any of the other options.

In reply to Richard:

In this situation, the CTDK is not an appropriate option. The larks foot relies on loading both strands of the rope to tighten. Loading on only 1 strand may cause the knot to slip.

You can aleviate this problem by the third man putting the second on belay too.

< Usual laugh follows>

In reply to Chris Tan Ver. XLIX:


Fair point, I know it's ideal use is for tying in the middle of a 1/2 rope which the leader has climbed on both ends of. However I've tried it once in this kind of situation (purely curiosity) and it did seem to hold. Maybe you could stick a stopper next to the larks foot on the dead end of the rope?


Ooh, that would work, leader on one end goes first, leader on other end goes second, swapping gear between ropes, third man up is belayed by both. yay two leads out of a three man group.

In reply to Chris Tan Ver. XLIX:


That's me told then...

In reply to Chris Tan Ver. XLIX:

So... another option would be for the leader to tie into the middle of the rope with the CTDK (or similar), lead, then bring up two seconds one at a time.

My question with that would be - if using a single rope doubled (effectively as a twin rope) then in the event of a leader fall wouldn't this decrease the rope stretch and thus increase the peak impact / impulse on both the leader and the top piece of protection? Unlike a real half / twin rope setup where the individual ropes have a much lower impact force rating...

Or is my grasp of rope physics letting me down here?

In reply to quadmyre:

By your description, I am assuming you are climbing with the second in the middle and the third at the end of your rope. The Alpine Butterfly is probably the best option as it allows the loading of the rope to run in a straight line.

In reply to quadmyre:

I would not use a single rope in twin mode. As you rightly pointed out, the loading on your pro will be significantly increased.

In reply to adam carless:
>However I've tried it once in this kind of situation (purely curiosity) and it did seem to hold.

< Usual laugh follows>


The stopper may be a pain to tie/untie, being in the middle.



I was thinking more along the lines of the third performing a back-belay, ie, second being belayed from top and bottom. I use this technique quite a lot on routes with big traverses, to protect the weakest member.

In reply to quadmyre:

Ive always just used an alpine butterfly and a screwgate karabiner. Not sure what the figure 8 after the butterfly would do for you?


The middle guy will always be climbing as a second, so the shock loading will be a lot less than if leading. Id never use a krab if leading.



Mat

In reply to quadmyre:

Overhand knot on a bight is fine in place of alpine butterfly. Then a quadruple figure of eight with the tail clipped back into the belay loop with a screwgate. This does use up more rope though.

The alpine butterfly/overhand knot would only be necessary if the second has a chance of receiving a two-way pull on their tie-in knot, eg if moving together.

http://www.ukclimbing.com/forums/t.php?t=192365

In reply to quadmyre:
First, I tie a blight in the middle of the rope with an overhand knot, giving myself a large loop, then thread the doubled rope through the tie in points on the harness and tie a bowline close in to the harness and clip the end in to the belay loop. Then adjust the overhand so the knot is close to the bowline (this is why I use an overhand as opposed to an alpine butterfly as it's easier to adjust) Should the second fall, then the overhand ensures that the bowline gets loaded equally on both ropes, not just one. This is also a good way to tie in for glacier travel is the middle person is not taking shoulder loops.

In reply to Chris Tan Ver. XLIX:


Yeah yeah, Mr Crash Test Dummy, that's me. I've done live testing of 3mm shock cord too, and been a dummy for hoist practice. Err, so it's probably best to ignore any safety advice I give


I can see it'd work well there, back belays can be very useful when you're in a group of 3 with a novice, but
it's not a common situation (in my experience anyway).

Anyway, on the original question, I either use a fig8 (or overhand) clipped into the belay loop, or tie a big fig8 through the tie-in loops (if my partner prefers).

If we're doing a traverse or an overhang, I'll also reclip the gear as I pass it, so the 3rd man up has some protection (and means they have to get the gear out).

In reply to adam carless:
I use the the alpine butterfly/screwgate method without any hesitation for bringing up the 2nd of 3 people on a vertical(ish) pitch. For back-belaying a traverse though, I think I'd be a little nervous because the second may be looking at a bit more of a fall.

Its almost like a leader fall, in that the shock loads are higher, and the possibility and consequences of the screwgate getting loaded across its minor axis are that much higher. I think I'd be inclined to use a maillon instead of a karabiner, or failing that go for the bowline on a bight method instead.

Sean
x

In reply to deepsoup:


If there's still only one rope loop and one belay loop attached to the krab, there shouldn't be any increase in the likelihood of cross loading whichever way the climber is moving. Or have I misunderstood the situation you're describing?

An alpine is probably the right knot to use for the middleman on a traverse purely because under the 3 way load it'll tend to stay neatly seated. A fig8 or overhand will tend to roll and may jam (it can't roll off the end because there's a krab and a climber attached).

In reply to adam carless:
By 'cross loading', I mean the krab turning sideways (like they do from time to time) and being loaded between the backbar and the gate - ie: the rope loop on one side and the harness belay loop on the other.

Most screwgates are still good for 8kN like that, I know. I don't like the idea for the middle man on a traverse because its a bit like leading, and using a karabiner for leading (as opposed to tying in directly) is definitely frowned upon.

Sean
x

Many thanks all for all your comments and advice. In the end I opted to do the bowline-on-the-bight method on the middle harness which seemed to me a simple and secure option (as an aside it's much easier to tie this before the middle person puts their harness on...) and we all set off up pinnacle butress (dewerstone) in the sun and ...

... nobody died. Everyone enjoyed the climb. Result!