/ Protecting a second on a traverse?

Please Register as a New User in order to reply to this topic.
Greasy Prusiks on 06 Aug 2017

Hope everyone had a good weekends climbing.

Has anyone here ever heard of a second being belayed from both 'above' and 'below' on traverse pitches (when in a three)? I was flicking through an old climbing book (Rock Climbing by Steve Ashton) and found a drawing of this but I can't remember ever having seen it done. I can see that it reduces the distance of a fall but surely it would put much more force on the gear? Is it no longer thought safe?

Any thoughts?
Post edited at 19:34
john arran - on 06 Aug 2017
In reply to Greasy Prusiks:

Except for theoretical situations it can only really be an advantage. If the gear behind you rips then you will fall as if you weren't being belayed from behind at all - until the next bit of gear is loaded anyway.

It's actually a very common technique for teams climbing as a three, and makes a lot of sense as the third person will typically be doing very little anyway so might as well also belay, and if there's a relatively weak climber that can be better protected by climbing in the middle of the team, why not?
keith-ratcliffe on 06 Aug 2017
In reply to Greasy Prusiks:
When I did Dream on Anglesey I was in the middle of a rope of three with 2 strong leaders who lead through. I was very glad of the two way belay on the final traverse pitch even though it proved to be technically within my range. BTW when I did it there was a small plastic white horse on a small ledge on that last pitch - does anyone else remember that?
Greasy Prusiks on 06 Aug 2017
In reply to john arran:
Thanks John.

I've never done much climbing as a three which explains why I haven't heard of it.

The thing I can't get my head around why having such a large angle between the rope and the gear doesn't cause the force to increase. For example when equalising the anchor it's better to minimise the angle between the gear and the central krab. Like this image...

http://howtoclimbharder.com/wp-content/uploads/2016/01/5040844011_e9cef43cf1_o.jpg

My question is why this doesn't cause issues in a traverse section but should be avoided on a belay.

I'm sure I've misunderstood something but I can't see what it is.
Post edited at 20:40
Mark Collins - on 06 Aug 2017
In reply to Greasy Prusiks:

Think I saw this on the BBC's Secret Britain in recent history, when the Houlding's took a presenter up Troutdale Pinnacle.
john arran - on 06 Aug 2017
In reply to Greasy Prusiks:
You're right in that the forces could increase - maybe by up to fivefold or so if both ropes are really tight - but hanging on a rope provides virtually negligible strain on a climbing rope so even a fivefold increase isn't anything at all to worry about.

Edit: the other half of your question - the difference between this and doing similar in a belay setup. Belays often need to be capable of holding leader falls of up to factor 2, which is a vastly greater force than any top-roping/seconding load. While a modern rope should comfortably be able to hold such falls, multiplying the forces to be held by up to 5 or so could potentially risk exceeding the capability of the rope.
Post edited at 20:52
Dave 88 - on 06 Aug 2017
In reply to Greasy Prusiks:
You mean vector forces? The same ones that are the reason you keep the angles in your belay to less than 60deg give or take. As John says, should be well within the limits of your rope, but I would've thought this could give your gear problems. A 100kg downward load (the climber) would put over 500kg in each direction if the angle was 180 degrees. Obviously this force is also spread along the other gear and to both belays so I don't know how much that spread the force out. Anyone shed some light on this?

Just seen John has said similar about the x5 forces
Post edited at 21:08
ads.ukclimbing.com
The Ex-Engineer - on 06 Aug 2017
In reply to Greasy Prusiks:
> The thing I can't get my head around why having such a large angle between the rope and the gear doesn't cause the force to increase.

Three reasons:
1) The ropes won't be super tight in the first place so the 'high angle' is slightly theoretical.
2) In addition to any slack, the full pitch length of dynamic rope will stretch significantly in any fall, further reducing the angle. [This is the main difference compared with a belay and you may have only been thinking about the couple of metres of rope between the closest runners and forgetting about the other 30metres or so of rope in play.]
3) Any standard belay device is intrinsically load limiting and will slip at 2-3kN anyway.

As such, any forces will certainly be no higher than those experienced in any moderate vertical lead fall.

However, although the second won't take a big swinging fall, if they do come off they're quite likely still to drop a good 2-3metres or even 4metres depending on the route and gear spacing albeit with a very soft catch.
Greasy Prusiks on 06 Aug 2017
In reply to john arran:

Thanks again.

That makes more sense now. It seems a useful method, I'll remember it.

keith-ratcliffe on 06 Aug 2017
In reply to Greasy Prusiks:
If used on a traverse on the edge of an overhang the back belay can be the difference between hanging in mid air and having some rock to hold on to - hence its use on the last pitch of Dream. Glad I didn't need it.
Michael Gordon - on 07 Aug 2017
In reply to Greasy Prusiks:

I guess not climbing much in a three I hadn't considered this before, but a really good idea. I suppose it's like giving a back rope to a second but easier and doesn't require gear to be left.
radddogg - on 07 Aug 2017
In reply to john arran:

We recently did the except thing on Assagai (HVS 5a) for the exact reasons you listed. Traversing can be harrowing for the second (and third). Another advantage is the second reclipping the gear as they pass it, retaining the protection for the third
DubyaJamesDubya - on 07 Aug 2017
In reply to Greasy Prusiks:

A technique I used recently, for a nervous second, was to get them to leave all the gear in and one of the ropes clipped in, re-clipping the trailing rope as they climbed toward me, thus protecting them from front and rear. The only tricky bit is paying out one rope as you pull one in. I just had to re-climb the traverse to retrieve the gear. A bit of a faff but, since the alternative was a retreat/lower from a very awkward position, it was worth it.
Ann S on 09 Aug 2017
In reply to Greasy Prusiks:

As per Keith ratcliffes post, three of us did Dream where two lads swapped leads on 2 half ropes and a single rope was trailed to me. On reaching the final belay before the traverse we retied the ropes so I had a half rope in front of me and a single rope behind as I was the weak and weedy middle scaredy cat. All three climbers were protected by two ropes for the final pitch.
I think this system is called triangulating.

It worked like er, dare I say, a dream.

ads.ukclimbing.com

Please Register as a New User in order to reply to this topic.