UKC

Hi There,

I'm trying to decide the best toprope anchor to use with two bolts on a sport climbing route. At the moment i'm leaning towards a sliding 'X' with two slings, but this anchor does not cater for extension in the event of a single bolt failure.

Can anyone suggest their preferences for toprope anchor? Some people I climbed with recently used two short (30cm) quickdraws with locking biners, do you think this is suitable? I think that this method does not cater for equalisation. Do you agree?

Thank you for your time.

In reply to cha1n: I wouldn't be worrying too much about equalizing bolts on a sport route....thats just me though

In reply to cha1n:
the sliding x shouldn't be too bad in this situation, assuming you're belaying from the bottom; if one bolt failed there'd be plenty of dynamic rope in the system to ensure that the sling didn't suffer too much. would give a bit of a worry to the climber though and i wouldn't use it myself. i'd just put a couple of quickdraws (or single screwgates) in and not worry too much about the equalisation myself.

In reply to cha1n:

I clip a quickdraw into each lower off bolt. If I'm feeling nervous I put a screwgate on one bolt and a quickdraw on the other. I'm not generally worried about bolt failure, and even if one bolt fails the force exerted by whats basically a short low-factor dynamic fall onto the other isn't likely to cause the other to fail - I'd happily take those on a single bolt on the route itself without worry.

It exposes me to a minute risk, which is that the first bolt fails under about bodyweight whilst being used for toproping and the second then fails after a short dynamic fall, but frankly I think the chances of that are so remote as to not really concern me.

AJM

You're right that using two longish quickdraws doesn't cater for equalisation. The normal solution to this problem is simply to tie an overhand knot in the "sliding X" at the point where you'd be clipping the crab. This effectively isolates each part of the sling. You then clip the crab(s) though both "independent" loops as for a normal Y-hang.

http://www.chetwynd.info/images/other/equal_1.gif

Yes, it does mean you've got a bulky knot just at the point you want to clip your crab, but you normally can "dress" the setup to have it sit out of the way enough to be useful.

Hope that helps!

Will

In reply to Dom Whillans:

I'v never seen the sliding x before, just read up on it at it looks quite scary if one of the anchors went! Instead of twisting one side of the sling, why not tie an over hand knot (or figure of eight, even better) in it and attach 1 or 2 crabs onto that, making sure the sing is equalized first.

In reply to Will Sheaff:
beat me too it...

In reply to The Green Giant:
that's why i wouldn't use it... i've seen people use it at belays before, but never on a sport climb. i think it can be useful if the attachment krab needs to move around, as the system does equalise itself (unlike an overhand knot); but i've never wanted to use it.

In reply to Dom Whillans:
it will if your top roping because the carabiner will take any of the movement from left to right by the climber. My of tying the over hand knot was slightly different to the guy above me, I didn't look at his link before i commented. If you put the sling through the to carabiners on the bolts then pull the sling down in the middle, get the mid point and tie an over hand knot on the bite there. this s easier and less likely to have adjust method of doing it, obviously you then put a carabiner in the loop created.

In reply to The Green Giant:
sorry GG, my "it" referred to the sliding x, not the overhand solution, which i agree would be far preferable!

In reply to cha1n:

I would suggest reading John Longs thoughts on this.

The Sliding X - for a long time maligned seems to have been shown to be quite a good system.Tests showed that even if on anchor failed the system was not "shock loaded" everyones big fear.

Forget about one of the bolts failing it is very unlikely - what is more likely is that you get sling damage from movement - my current beef with the sliding X is its lack of redundancy if the sling gets cut.

The good solution seemed to be:
1. having a sling with two isolating knots and 2 krabs on each of the 2 isolated middle strands
2. A sliding X and a back up sling per Will Gadd's thoughts
http://gravsports.blogspot.com/2007/01/equalizing-belays.html

http://splitterclimbinggear.com/Anchors.html

In reply to cha1n:

If you tie knots in the 'legs' of the sliding X it's possible to retain the auto equalisation to a large extent while limiting the dynamic loading in the event that one anchor fails. The closer to the anchor the knot is the more equalisation you get, but the greater the dynamic loading.

In reply to cha1n: It depends what I'm doing but the bolts will be close enough that equalisation is pretty irrelevant.

If it is just me and my partner(s) working a route then I'll just use two of my standard quickdraws, preferably ones with DMM Revolvers on them.

If I'm rigging for a group I'll use a 120cm sling and 3 screwgates (a steel one for the rope if I've got one). Normally the bolts are close enough to clip the ends of the sling to them then tie a fig-8 in the middle to equalise.

In reply to cha1n:

Sliding X is actually a pretty good way of equalising gear with a short sling and a good amount of rope out* especially where the applied force direction can change significantly (pieces catching a pendulum). My main concern is if one piece rips and the X arrangement extends, it pull flick the gate of the sliding crab open. A sturdy screwgate sorts that.

*Like the top of a sport route or equalising a pair of mid route RPs, each individually poor but together ok (can also be done putting one rope on each).

OP: I'd just put a quickdraw or screwgate in each bolt and don't worry about it not being 'perfect'.

jk

In reply to Mark Stevenson:

why a steel one for the rope? Are they better in high wear situations as involved in group work?

In reply to cha1n:

Come on guys, you're really overplaying this. Two bolts. I assume they're not little old american quarter inch things... Do you really think one is going to fail? Do you really think in the event of a failure the shock is going to break the other - especially with the dynamic qualities of a climbing rope? It's your body weight plus that of your belayer, that's all. You have a HUGE safety margin. The extra load if the second falls off while climbing is minimal. Clip a screw gate (or two - to orient the krab correctly, ie at 90° to the rock and not flat against it) into one bolt and a qd into the other.

In reply to jon: Ah but he may be tied in with a bowline in which case I can say that he will die with absolute certainty.

In reply to mike kann:

Yeah, didn't think of that. It'd snap the rope before any load came on either bolt...