/ Top rope anchors using slings

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Mark Duncan - on 22 Sep 2016
Hi, quick question. I'm climbing at a place that has big spires at the top of each climb (bit like climbing a tower). I want to set up anchor for a bottom rope. Is it safe to stick one sling around the top and attach a carabiner for the climbing rope to go through. The spires widen as they go down so the sling won't slide down and I will make sure that when the sling is sat around the spire that the angle where the carabiner sits is within 30-90.

I see the pros of this is that the masterpoint can move with where the climb goes. The obvious con is that it's only one anchor. I can back this up with another piece of gear, but that means equalising and I'm looking for a quick fix! Unless, would I be able to use two slings that were looped over two separate spires/spikes, tied together at the equalising point with an overhand knot, with the carabiner threaded through the loop for the climbing rope?

thanks all, you are a great source of knowledge! hope it makes sense.
john arran - on 22 Sep 2016
In reply to Mark Duncan:

If an anchor is bombproof enough (e.g. a large, well-rooted tree) it doesn't need backing up. You'll need to use your learned judgement to assess whether your single anchor falls into this category.
SenzuBean - on 22 Sep 2016
In reply to Mark Duncan:

> Unless, would I be able to use two slings that were looped over two separate spires/spikes, tied together at the equalising point with an overhand knot, with the carabiner threaded through the loop for the climbing rope?

That sounds like a quick option (as long as you're threading the carabiner through both slings so they're independent).

If you have a length of static rope, you could use that relatively easily as well. Tie a bowline with one end of the rope around one spike, bring a bight of rope to where the carabiner will sit, then wrap over the second spike, and back - tie an alpine butterfly with the loop around the second spike, then tie an isolating knot where you left the bight and clip it.

Or tie a bowline around one spike with one end, then a bowline around the second spike with the other end, and with the too-long loop between them - take a bight where the carabiner needs to go, and tie an alpine butterfly on the bight and clip it.
AlanLittle - on 22 Sep 2016
In reply to Mark Duncan:

I would be asking myself how strong the mortar is on these spires if they're masonry
Aztec Bar on 22 Sep 2016
In reply to AlanLittle:

When I was in the Police we decided to Abseil out the third floor widow of the Police station while on night duty (don't ask, we were bored!).

Preparations went well, a central pillar was used as anchor, bit of carpet around to stop plaster getting damaged. First person was about to go when someone thought they would check a hatch in the bottom of the pillar. It turned out the 'pillar' was four bits of plasterboard holding 3 cables! We called off the attempt.
CurlyStevo - on 22 Sep 2016
In reply to Mark Duncan:
You need to make sure the rope is over the rock edge and not rubbing on the rock. Also the abrasion resistance of the slings, sharp edges and number of ascents should be considered. One random punter ascent on a 12mm dyneema sling with no sharp edges and where the climber is directly under the 100 % bombproof anchor so not swinging side to side should be ok. 1 person under the responsibility of your duty of care, hmmm might want to use a super chunky sling or static rope. Many people or any doubts of abrasion or cutting then multiple anchors needed imo. You can use rope protectors or carpet to help against abrasion and minor sharp edge doubts.
Post edited at 16:21
GrahamD - on 22 Sep 2016
In reply to Mark Duncan:

It depends on what your spires are - if they are solid rock then the fact that there is only one anchor isn't really a problem. Even if you backed it up and one spire failed all that would happen would be you have a spire landing on you !

At some points you have to trust single points(your harness, for instance)

Things you really need to look out for are any abrasive edges on the sling; I tend to use wide nylon tape knotted as a sling for this sort of thing as a) it spreads the load across a wider width of sling so less likely to be abraded b) its cheap as chips and that the screw gate gate cannot rub on the rock (which can unscrew the gate). If in doubt use back to back screwgates.
Mark Duncan - on 22 Sep 2016
In reply to Aztec Bar:
Sorry dude, didn't make myself clear. It is rock, dolamatic limestone. It was my poor attempt to describe the tower like spires.
CurlyStevo - on 22 Sep 2016
In reply to Mark Duncan:

goes without saying that in my previous reply the spires that are slung must be 100% bombproof if you ever intend to use only one.

Limestone can be quite sharp in places so there could a risk of cutting / abrasion IMO. The rock would have to be very smooth to trust just one anchor IMO even with chunky rope / slings.
Ian Parsons - on 22 Sep 2016
In reply to Mark Duncan:

>It is rock, dolomitic limestone.>

Brassington/Harborough?
GrahamD - on 23 Sep 2016
In reply to CurlyStevo:

> goes without saying that in my previous reply the spires that are slung must be 100% bombproof if you ever intend to use only one.

They need to be bombproof if using two. The consequences of pulling 100kg of rock down on top of yourself and your partner if one fails don't reall bear thinking about.
Mark Duncan - on 23 Sep 2016
In reply to Ian Parsons:
Good guess, but the delights of Beacon Hill, Loughborough
Post edited at 10:28
Mark Duncan - on 23 Sep 2016
In reply to CurlyStevo:

Thanks man, think what I'm getting from this, as it will be for lots of my mates, is to set up anchors how I normally set them up, with a couple anchor points with static rope all equalised witha overhand knot (with protectors etc.)

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