Monday, 25 April 2011

Secretaries Super Direct & Precious Cargo

On Thursday myself and G headed up Glen Nevis after work. I had my eye on a route called Secretaries Super Direct HVS 4c,5a*** This was my first HVS lead of the year, and only my second HVS lead at all. G jumped on the 1st pitch (4c) and cruised up it without even thinking. This psyched me up nicely for getting on the lead on the crux pitch. This is a beautiful slab with some very delicate climbing and some rather spaced out gear. The difficulties start as soon as you leave the belay, with a high step over a ledge to get off the ground. From here it was delicate footwork and small hand holds for some way to reach the next ledge. From here it eased off, with the holds getting bigger and the gear more closely spaced. A lovely route which deserves over one of its 3 stars.
Me on the Crux (photo by G)

After this we headed down to Scimitar Buttress where G has been working a route called Precious Cargo (E5 6a*). We slung a toprope down it and G jumped on to see how it was feeling. After a few practices, working the harder moves and scoping out the gear (1 size 0 cam 9m up!) he decided he'd better get on the lead before it got too dark. He made smooth work out of the route, making it look easy! There was 1 heart in the mouth moment when a foot popped just before he clipped the gear at 9m but he quickly composed himself, clipped the gear and got it done! Good work fella!
I had a wee play on the route and got most of the moves sussed before by fingers finally gave out halfway through the final crux. Nice route but don't think i'll be leading it for a while yet!

Monday, 18 April 2011

Sunshine on Phantom

Today myself, Kev and Hue headed back up the Glen for a quick few hours climbing as the weather was so nice.
Kev was wanting to get on the lead on something a little trickier and i was hoping to get another VS tick in so the best option seemed to be combining Pandora (Severe) and Phantom Slab (VS).
These were both new routes to us all which was nice for a change! Kev lead up the 1st two pitches of Pandora which involved an easy slab climb on the 1st pitch and a slightly trickier, very exposed 2nd pitch to gain a good belay ledge.
Kev leaving the 1st belay

From here i took the lead, heading up Phantom Slab. This gave beautiful, delicate slab climbing in a nicely exposed setting, with enough gear on it to stop it being overly worrying.
Phantom Slab

To finish the day off Hue lead us up Pinnacle Ridge (Severe)
Hue on Pinnacle Ridge

Saturday, 16 April 2011

Back to basics

On Saturday myself and Nick headed up the Glen after work to have a play about. Nick is a pretty experienced climber but hasn't done much outdoors so the evening was largely spent going over the basics of placing anchors, rigging different belay setups and such like. To get things going i lead up Pinnacle Ridge (Severe), explaining the principles behind the different belay setups used as we climbed before heading back down to ground level to let Nick have a go at setting things up himself.

He picked it all up surprisingly quickly and was soon looking pretty slick with a lot of the setups. Hopefully most of it sticks!

Thursday, 14 April 2011

All Things Equal? Musings on Equalising Anchor Systems...

Last night i managed to get myself into a discussion about the usefulness of a piece of climbing equipment know as an Alpine Equalizer which is made by the American company Trango (demo video from Trango here). Simply put the Alpine Equalizer (AE) allows a climber to quickly equalise a 3 point anchor system at a belay stance. Its potential advantage over conventional belay set ups is that it allows for dynamic equalisation between anchors, meaning that if a climber should fall in a direction the belay is not rigged for then the AE automatically readjusts the lengths of each leg to equalise the belay and distribute the forces between each anchor as evenly as possible.

 All very nice but the major flaw i see in this design is that the only way to make each anchor point independent, and thus remove the possibility of shock loading the whole system should 1 anchor fail is to clove hitch the sling to each anchor, which means it can no longer readjust the equalisation and acts in the same way as the set up would if rigged with a standard sling.

At first I dismissed the AE as a useful piece of equipment for these reasons but some of the points brought up in the discussion made me begin to question this, so i did a little research of my own. From the day i started climbing i was taught, as i'm sure most people were that anchors for a belay should be Independent, Equalised and at the right angle (i.e under 90degrees) but some of the reading i've done is making me question this.

Its particularly the Equalised part which i'm questioning. Not so much the need for all your anchors to be equalised but the best way to do this. For equalising 3 anchors using a sling my first reaction would be to link all three anchors with a long sling, bring all the arms together and tie an overhand (Fig. 1). This gives independent anchors and i always assumed fairly evenly equalised ones.
Fig. 1
A lot of the reading i've done however suggests that this system doesn't distribute the load to the 3 anchors nearly as evenly as you might think. Indeed a report entitled 'Multi-Point Pre-Equalised Anchor Systems' (available here) shows that the forces on the center arm of this set up will be almost double that of either of the side anchors. Unfortunately the copy of this article i have is read only so i cannot copy their results into here but they're easy enough to find in the article.

Their findings also suggest that the length of each arm of the sling is inversely proportional to the forces exerted on it. E.g. if the middle leg in Fig. 1 was shortened to half its length, the forces exerted on it compared to the side anchors would double. I've attempted to demonstrate this in Fig. 2 but i'm not sure how clear i've made it. Imagen the side anchors are in solid rock set back from the belay and the yellow sling represents another piece of rock protruding between them, thus the middle leg is considerably shorted... Make sense?

Fig. 2

So if the usual systems used by climbers don't actually equalise the anchors nearly as well as we though then is it time to consider a new approach? Perhaps.

A report titled 'A Look at Load-Distributing and Load-Sharing Anchor Systems' published in 2007 looked at this (available here), studying the load distribution between different Load Distributing (Alpine Equaliser style setups) and Load Sharing (normal setups as shown above) setups and the forces experienced when one leg of the system should fail. Their results are interesting to say the least. They experimented with 7 different load distributing setups, using different materials and rigs and one standard load sharing setup.

Their results show that the different materials used to rig the load distributing anchors have a great impact on how evenly the forces are distributed between the anchors.For load testing onto all three anchors, seemingly the less friction there is in the system the more evenly a load distributing anchor will spread the forces. The systems which used higher friction materials such as 1" nylon tubular webbing result in significantly higher forces being exerted on the center anchor than either of the side anchors. Slicker materials seem to be able to very nearly evenly distribute the force, although a slightly higher force is always exerted on the center anchor.
The Load Sharing anchor on the other hand, experiences higher forces on the center anchor than all but the highest friction Load Distributing systems. Fig.3 is, as far as i can tell, the Load Distributing setup used in this report, although the diagrams a a little hard to decipher so it may not be an exact replica. Mine in made using 5mm dynamic chord.

The conclusions which can be drawn form this are that if rigging a belay with 3 or more questionable anchors then, while it seems impossible to truly equalise them in the real world, a Load Distributing setup as shown above could almost certainly distribute the load most evenly, thus reducing the chances of any one anchor failing.

Fig.4 & 5 show another 2 options for Load Distributing belay setups.
Fig. 4


Fig.4 is my attempt at creating a Load Distributing setup which would minimise the shock load on the other anchors should one fail. In practice if the center anchor fails then a very small shock load results but if either of the side anchors fail you are still left with a large shock load as the system readjusts.
Fig.5 is essentially a home made Alpine Equaliser. 2 crabs could also be used (one for either strand of the sling in the center) which might reduce friction in the system. Using a DMM Revolver style crab would also help.

Coming back to the original point however, none of these systems manage to create a belay which is both equalised and independent, meaning while they reduce the chances of any of the anchors failing if one does, the rest of the system is shock loaded.
'A Look at Load-Distributing and Load-Sharing Anchor Systems' explores what exactly happens should this situation arise.

Obviously the Load Sharing system comes out of this study best as no shock load occurs when one anchor fail and the force is shared fairly evenly between the other 2 anchors. The results for the Load Distributing systems is more interesting however.

When one of the side anchors failed all of the Load Distributing anchors experienced high Maximum Arrest Forces and poor equalisation, i.e larger forces are transfered onto one of the two remaining anchors. Interestingly it seems to be the higher friction systems which equalise worst under normal circumstances which equalise best when a side anchor rips.
When the center anchors rips the forces are shared far more evenly between the remaining 2 anchors but the Load Distributing anchors still experience much higher forces than the Load Sharing system.

My Conclusions?
It seems to me that you have three options.
1) use a Load Sharing anchor system, knowing that it will most probably exert disproportionate loads through some of your anchors but also that should one anchor fail it will exert the least force on the remaining anchors. It is however, worth remembering that when setting up a Load Sharing system that keeping the length of each leg of the system equal will help to minimise the differences in force being exerted on the anchors.

2) use a low friction Load Distributing system to truly distribute the forces as evenly as possible and thus minimise the possibility of any one anchor failing but accept that if one does your other anchors will be subjected to greater forces than if any other system were used.

3) use a high friction Load Distributing system. This will share the loads between anchors better than a  Load Sharing system but not as well as a low friction Load Distributing system. Its will also exert more even forces on the remaining anchors should one anchor fail than a low friction Load Distributing system but still subject them to a much greater force than if a Load Sharing system was used.

So which system should be used where? As with so many things in climbing i think there are too many variables to really come up with a defiant answer for this. It each system has its pros and cons and argument could be made for and against each on a number of situation.

Thoughts on setting up low and high friction Load Distributing systems:

DISLAIMER: This part is largely based on my own experiences and a healthy chunk of guess work.

It seems to me that the most important factors influencing the total friction of a Load Distributing systems will be the material used to join the anchors and the crabs used. This of course excludes the idea of adding additional equipment such as fig8s for simplicity of setup.
From the results it appears that thiner, slicker materials create less friction. As such i would imagen that narrow dyneema slings or webbing would be best for reducing friction and wider, stiffer sling (nylon tubing for example) would create a higher friction system.
As for the crabs i would assume that large diamiter, round topped crabs would cause less friction, or even better a DMM Revolver with integrated pully. While conversly smaller crabs which would result in sharper angles being crated in the webbing should produce a higher friction system.

For some more reading Will Gadd has a few thoughts on it as well which are worth reading. These can be found herehere and here.

These are my personal opinions on the matter based on what i have found through a little research. If anyone has any comments on anything i have said please feel free to say. Also if anyone has come across anything along related lines please let me know! Every days a school day after all!

Monday, 11 April 2011

'Sunshine on a rainy day!'

The forecast for yesterday was for the weather to start off ok but quickly turning to low cloud and showers. Despite this Nick, Lou and myself optimistically headed up Glen Nevis to see what we could get done before the rain hit. Luckily for us the forecast turned out to be a little pessimistic and we had perfect blue skies, sunshine and a light breeze all day!

For a nice start to the day Lou lead up Three Pines (severe), a lovely route with some rather interesting moves under a roof to gain a ledge. Fun climbing on good gear!
Lou on the awkward start of Three Pines

 Myself and Nick then followed her up before moving up to South West Crag. Here i lead up Tear (HS) which is a lovely line but somewhat spoilt by being extremely polished by the number of Outward Bound groups which use it

Nick Loving it on Tear!

After this Lou lead up Resurrection (VS), one of the finest routes in the glen, before i lead up Damnation (VS)

Just before the delicate, balancey crux of Resurrection 

Another great day out with lovely weather, rounded off by a nice walk round Cow Hill before the rain finally hit about 9pm!

Friday, 8 April 2011

'All by myself...'

This evening i was expecting to be working in the Lime Tree but got a text just before i was due to start saying it was dead so not to bother coming in. This suddenly left me with an entire evening free and nothing to do! Seeing as i'd been stuck in work all day already, staring green eyed at everyone strolling along the High Street, enjoying the sunshine i decided i was going out to do something. I fancied heading up the glen for a climb but a few quick calls and texts confirmed that everyone else was either busy or too tired after a long day on the sun baked rock already! No matter, i headed up the glen anyway, hoping to spot someone i knew's car and join them, sadly the only people who's car i recognised was Isi who was just packing up as i pulled up, having been out since about half 10.
Well i hadn't come this far to just go home again so i dumped the rope and rack in the car and headed up with the intention of soloing something easy then heading home. 6 or 7 routes later i decided that the daylight was running out so i'd better call it a day!
I managed to climb:
Three Pines Variation (VDiff)
Tykes Climb (VDiff)
The Gutter (Diff)
Quartz Wall (Diff)
Styx Right Wall (VDiff)
Pinnacle Ridge (Severe) &
Upper Pinnacle (Diff/VDiff)

Just before the roof on Three Pines

2 climbers packing up after Pine Wall. Taken from P1 of the Gutter

Scimitar Ridge, from the top of Styx Right Wall

I've climbed all of these before but only done a few as solos so it was an interesting experience. Now its time to relax with a glass of wine and let my arms recover! Hopefully i'll be back out climbing on Sunday if the weather holds.