The video showing "Belaying on several removable anchors: Load distribution" (3rd video) has an interesting method of bringing together the sling to the master-point (larks foot but with about 6 strands). looks like it could be useful in some scenarios. I might have a play with it in a safe place and see what its like, try out some modes of failure etc
has anyone here ever used this method? any obvious limitations/benefits?
Is there not a possibility that it one piece to fail the girth hitch could slip and cause the whole system to fail. I use a similar method but with an overhand knot to prevent this from happening.
I was wondering exactly the same thing - the girth hitch looks extremely elegant and fast and was immediately appealing, but if for example a stand was cut would it not just pull through the girth hitch, making everything unravel? An overhand knot isn't much more tricky to tie, and is more robust against failure in my mind. BUT, requires a great big knot, which has been playing on my mind recently (having found the DMM videos) when tied in Dyneema.
I'm more and more inclined to carry a long 7 mm cordelette for such uses these days, rather than knotting long slings, especially when cams are in the belay.
This was my first thought, along with what happens if a single piece fails. with an overhand all should be fine but a girth hitch...well I'll have a play with it one evening and see what happens.
I can see the advantages of it but it certainly isn't anything I've ever seen before so I have a gut feeling that there is a reason its not a commonly documented method of anchor building.
I echo the concerns of the others who have posted. This seems very unconventional from both UK and North American norms. The terminology does not translate well. I do not understand why cord is being passed directly through the eye of a piton which is not cord or tape compatible. pitons tend to be in situ fixed gear and not assessable for strength and security unless placed oneself. The large larks foot on crab approach as well as being potentially extendable can capsize over the gate and produce a pinch opening pressure on the krab. The 2 point anchors shown have a very high inner anchor angle which greatly increases the load on each point. (look up wikipedia on anchors for basic physics-120° max!) If one reads definitive texts such as John Longs book on anchors or similar UK texts (Rockfax Trad) the techniques shown are not seen. If one watches the excellent and free BMC, Glenmore Lodge, American Alpine Club and SIET You Tube videos no such language or techniques are used. This is not what is taught nor done usually and I dont see how it is quicker. If the aim here is to initiate the inexperienced then it is highly unconventional, loses meaning in translation and a few established standard simple techniques are better for introductory skill teaching.
I fail to see the need to larks foot around a tree. It's outdated practice. All knots weaken slings and although the practice is preferable on a wide tree, which may cause the carabiner to take a wide load this case is the exception rather than the norm, wrapping the sling round normally will be stronger in most circumstances.
I find the odd larksfoot overhand cross onto the krab in the same vein, simpler to use a clove hitch, which also uses less sling therefore lowers the angle of loading between the anchors.
Personally for equalising I go for the centrally clipped overhand in most circumstances as it doesn't weaken the sling as much, and again uses less sling than an overhand on bight, again decreasing loading angle while also being easier to untie after loading.
Saying that all the methods shown are valid and useful but I wouldn't say they are the simplest, efficient, bombproof solution.
I am slightly skeptical about the readiness of European climbers to knot slings. I generally think that UK climbers are slightly more conscious of best practice as the clip and go attitude that bolts breed isn't really an option if you're trad climbing.
I too immediately questioned the use of larks foots. They are very weak and could possibly slip if an anchor fails unlike an overhand or clove hitch. Also if you are leading through then why bother with a long equalised sling at all, you can quickly tie in to several pieces and equalise them using the two ropes tied to your waist. That's pretty much what most UK trad climbers do all the time. The ropes are dynamic and can also absorb some energy to reduce shock on the anchors.
It works well - I use a 5m length of dyneema cord with a DMM Boa but normal 7mm cord is more than strong enough. What's interesting is that if you remove one of the three pieces there's no slippage at all on the larks foot. In addition it uses far less rope than trying to tie an overhand knot and is much easier to orient correctly and undo.
> I too immediately questioned the use of larks foots. They are very weak and could possibly slip if an anchor fails unlike an overhand or clove hitch.
And the evidence for these claims?
Ok perhaps "very weak" for a larks foot is a slight exaggeration but its generally considered to reduce the strength of the rope/sling to about 50% whereas overhands and clove hitches only reduce the strength to about 65%.
Yes, in reality a larks foot will still be strong enough in most situations but if the stronger alternative is quick and easy to tie then why not use it?
Re slippage, I've never seen any testing of a larks foot only loaded on one side of the knot but I've never seen it referenced to be used that way whereas a clove hitch is intended to be loaded on one side of the knot only. Perhaps a larks foot would just tighten up and hold when pulled on one side but I'd rather not be the one to test it when my life depended on it.
Well I was wondering if you knew someting they didn't, after all the video is produced by Petzl and the presenter was for many years DAV Safety Officer and is an instructor for the German guide school so you'd guess they did actually test it first before putting it out .
The advantages are clear over an overhand, less material, easy to untie after loading ( put 6kN through an overhand and you won't untie it in a hurry if ever) and better load sharing. When you tie an overhand the path of the knot disturbs the equalisation of the strands and the larks foot is far better.
I've pull-tested to 6kN on each of the three loops formed (the other two completely free) with a 12mm Dyneema sling and see no slippage at all apart from the normal knot take-up and no indication it will ever occur. The strength I haven't yet tested as 6kN is normally sufficient.
What is the opinion on video 3, "Guide to belaying: Series connection with 2 bolts"?
I have never seen this method for building an anchor with bolts. I usually try to equalised both anchors then make the points redundant.
It's bolts, just clip into them. The method shown is normal practice.
It's a method endorsed by ENSA. See 5:38 in this thought provoking video "Should you change the way you belay".
Re the abseiling one. Clipping the end of the tether to the guide hole on the plate seems neat, but it the so formed loop were to catch on the rock control might be an issue
Like many who have posted here I initially watched the girth-hitch anchor video thinking 'that's dangerous'. However, your response has left me very interested in starting to use this technique. It seems significantly faster to set up and dismantle than the traditional overhand. I'm guessing the reduced, stronger anchor angle (oh slightly widens anchor angle by taking up more sling/cord) probably negates any extra % loss in sling strength of using a hitch instead of a knot. Couple of questions though:
Is the breaking point of a girth hitch affected by the size of the crab it is attached to? For example, lets assume three points of pro (and thus a large/wide girth hitch). Would the hitch break at a lower Kn pull when attached to a DMM Phantom (narrow seat for hitch and narrow I beam bar) compared with a HMS crab with round bar (no I beam)?
Also, in the traditional method widely used in the UK the loops formed by the overhand knot in the sling are the powerpoint. But in the video they use the girth-hitched crab as the powerpoint of the anchor (clipping other crabs to this). Bearing in mind the question above, would a rap ring be a stronger, safer and lighter option for the girth-hitch powerpoint?
Hope this all makes sense! thanks
Probably but until someone tests it we don't know.
You could use a ring or anything really, I wouldn't personally as they aren't versatile enough. You would be carrying something that has no other purpose.
Okay thanks Jim, real eye opener for me
That's a cool video with some interesting techniques. Like others, I'm a little wary, but I think the girth hitch/lark's foot for the master point is a great idea...I don't think it would slip, and it would be fast and easy to set up and untie, certainly easier than an overhand of 8, which is often used as the master point for similar anchors. I think it would be great for ice climbing, too, where knots can get so tight/frozen that they are nearly impossible to untie. The whole south tyrolean technique also seems fast and elegant. I might experiment with it.
The think that really freaks me out though is the girth hitch/lark's foot of webbing directly through the old piton...that gives me shivers. It seems like the sling could easily break. I'd use a carabiner there.
But in general nice to see different ways of doing things.
Further to Maxsmith's question about using a Rap ring, would there be any risk in using another sling to create the powerpoint in order to save karabiners? for example a short 30cm open runner in place of the krab, maybe using a strop bend.
Hi Dell, whilst the strop bend is the safest way to connect two slings without metalwork, it's still way, way less safe than using a carabiner. I also think girth hitching three loops to a single 30cm sling could have unpredictable effects. In my opinion what you are suggesting is dangerous so please don't try it! The weight saving between a 30cm sling and rap ring would be tiny in any event.
For those concerned about slipage inside a girth hitch in the event of a failure.
I use this method a fair bit, where I have to. Safety considerations when guiding often mean multiple point anchors due to the number of participants and the potential for multi directional loading, which in turn can mean it's quite awkward to create a master point.
This is by no means definitive.