UKC

As part of a local climbing club I received an email warning of a recent bolt failure due to misuse, so for the sake of public awareness I'm posting the email in entirety below. The failure relates to Harrison's Rocks, but the principles apply to all fixed anchors in southern sandstone crags;  Stone Farm,  High Rocks,  Harrison's Rocks,  Bowles Rocks,  Eridge Green Rocks and any others with fixed anchors in the area. Information is as follows:

Last week a visiting climber apparently setup a slack line from the back retaining bolt on the Isolated Buttress at Harrison’s rocks to the tree on the mainland to assist his group to negotiate the gap from the buttress. Because this loaded the bolt the wrong way the bolt failed and smashed the surrounding rock.  Therefore the bolt above Wailing Wall should not be used until this is rectified.

The rocks at Sandstone Crags are very soft and the bolts are put in as a pair tensioned by a wire and should only be front loaded by a vertical rope. [There is a request for] the BMC/HRMG immediately put up signage on the tree that explains the code of practice for the buttress so this does not happen again.

The only way for a leader to gain access to the Buttress to setup ropes is to solo up to the top.  I have seen Birchden Wall 5b and Crowborough Corner 5c being used but the easiest way is the Boulder Bridge Route 2b. You can protect yourself by attaching two ropes and a belayer at the top by the tree and another belayer at the bottom to stop your swing if you fall off on the traverse.

The only way you can get off the buttress when you have finished your climb is to climb down your climb or reversing the Boulder Bridge Route 3a as LOWERING OFF IS STRICTLY FORBIDDEN because of the erosion it can cause.

Leaders often put up a SAFETY ROPE to protect the traverse off. This safety rope should not go through any bolts for the same reason of side loading them. The rope is put around the large boulder at the top and then three turns around the tree and back to the bolt on the mainland (front loaded). Climber should attach a small sling to their belay loop with a karabiner called a Cats-tail and then clip it to the safety rope. The safety rope should not be touched or used in doing the reverse Boulder Bridge Route. The reverse traverse should be climbed!

Can't they just put a bridge in? 

Putting in a bridge is controversial. The rock is soft and erodes quickly; Isolated Buttress is relatively intact because the difficult access puts some people off, as such it will tend to remain in better condition than surrounding rock, for enjoyment by future generations.

They have recently decided to do just that: put a bridge across.

https://www.thebmc.co.uk/harrisons-isolated-buttress-the-bridge-decision

I've heard this. As a long-time climber at the crag and as a bridge engineer with a geotechnical hazard specialist as a sibling, I think it will increase erosion of the rock with increased footfall and consequent long term damage. But I accept my voice is only one among many and the decision has been made, so I will grumble on and accept it.

Do they mean slackline or a slack rope. If the latter I'm surprised it blew. 

Surely most of the bolts are pulled sideways when toproping, the sling goes along and then over the edge. Is the issue to do with loading it in line with the backup-tensioned bolt?

Odd email. Hope noone got hurt

The report was of a slackline, but it is hearsay and may have been either. It's incidental really.

The issue is with the direction of load and the bolt anchored to.

In normal use the anchor bolts are loaded sideways, yes, so the mode of failure is shear through the bolt itself or failure of surrounding material in compression (the standstone 'crust' is pretty stiff so is usually adequate). However, in the scenario above the sling or chord wasn't resting against the rock, so the direction of load has a tension component, hence it blowing and damaging the rock.

The bolt they anchored to wasn't the primary front bolt, nearest the edge of the rock face. They tied into the secondary back-up bolt. I don't know the embedment depths of the bolts but I do know this is not how the system is designed for use. It has failed as a consequence and now the anchor can't be used, the rock is damaged, and the climb is unprotected.

I haven't heard any reports of being hurt, I certainly hope nobody was.

I understood that the decision had already been made by the BMC to put in a bridge! 

So why yet more meetings on the subject!? I know it's controversial, but it was before the last vote, and always will be.

This is starting to sound like Brexit. Have a vote and if it doesn't go the way some want it, have another one, and if that doesn't please everyone have another one, and so on until everyone has died off or forgotten what the issue is, or the Isolated Boulder has been pulled so hard by horizontal ropes and slack lines that it falls over........

Completely disagree. Understanding exactly why and how a bolt failed is fairly important.

The bolt in question has not failed due to a slackline, If I’m correct, then this is the same bolt that was pulled out at the end of last year and is awaiting repair work. The bolt is often used incorrectly for a 'slack rope' on the bolder bridge access route and as such has been pulled it in the wrong direction (again) causing it to come out.

Clearly the bolt was insufficient. Loaded the wrong way? Laughable.

If bolts on sandstone are loaded the wrong way then they can twist and loosen. A little movement is ok as the modern bolts are very deep, but some are not as long and are 30+ years old (many are on a list for replacing but still tested and passed checks last year). Although the bolts are tested to be safe (as much as possible on sandstone) they are only tested for direct pull as used for top roping only. Not for any other use, like some of the bolts are seeing on the buttress. The back bolt failed anyway which shows you that someone has not been using it correctly.  

Paul, do you know just how weak, internally, the S/E Sandstone is? Almost all the strength is in the iron in the surface; about 4 or 5 mm in, it becomes virtually uncemented sand. I remember once seeing the remains of some overhanging boulder that had fallen off the crag not far from Isolated Buttress (I can't remember exactly where now). It was some quite familiar feature and all that was left on the ground, at the bottom, was a pile of fresh sand.

So why on earth did anyone think bolts in southern sandstone are trustworthy?

Because they look trustworthy and generally are? It's not intuitive that using one without tension in a straight line from the other will be enough to break it, I always thought it was more about redundancy like with 2 bolt lower-offs 

Maybe only using the front one and in direction of tensioned wire from the back bolt is worth adding to the sandstone code?

Trustworthy?  Does that mean 1 in 100, 1 in 500 is allowed to fail, or what? 

Are these bolts are being installed according to any manufacturer's instructions? because they would probably say don't install them in soft weak rock types.

I don't think you'd be allowed to use bolts in southern sandstone for window cleaning, let alone roped access.

It's all very well criticising, how about you offer a solution?

let's imagine the same belay and same rock in Germany.Now try to imagine the bolt failing.

Do you think that might be because climbing <i>isn't</i> commercial or roped access?

The rock anchoring industry would sell you a solution to fix a six-lane suspension bridge or a dam to Harrisons Rocks, getting one to take the minimal requirements for roped access or the more stringent ones for rock climbing is easy. Presumably the solution chosen decades ago has proved satisfactory since we don´t hear of failures but is open to misuse by less experienced/careful climbers.

I´ve been approached about various bolt-testing and design studies for a number of the southern sandstone venues but nothing ever seems to actually be done (though there´s a student out there doing something but that will take years probably knowing how they work). Technically it´s easy to make something better but if the existing bolts keep passing their testing regime I guess there´s no reason to do something.

Failure of the traditional 15cm long ring bolts happens rarely but regularly in the Elbe sandstone, usually after the sandstone around the bolt erodes away (many of the bolts have been placed decades ago). More typically the problem is spotted in time, and the bolt replaced after community discussion. 

CB

Okay, I've done that, my imaginary bolt pulled out of my imaginary rock when some imaginary person pulled on it the wrong way.

I think that more down to common sense. Some people use both but we set them up for the front one to be loaded only.

We got a supply of bolts form you last year Jim and they look like they will work nicely for the current standard we are working to.

Belay on something else, or solo and don't belay.  Next question?

That sounds very convincing, but "Decades ago" invites images of such structures as Stone Henge, and the Severn bridge.  But "Decades Ago" can technically also apply to 2008, when the Killers released their 3rd album.

Good to know the bolts are being tested, it's just weird such fixed top roping anchors are only safe in certain loading configurations, and are installed on a BMC owned crag.  Do the signs at Harrisons (I didn't read them when I went 'decades ago' ) say Warning!  Specific Bolt Clipping Setup is Needed to Ensure Safety?!

Isn't the project the student's working on, just a function of drilling in a much stronger anchor much deeper?

Well since you asked so nicely I've taken the trouble to come up with another one just for you:

Can you help out those who don't onsight E5 and maybe aren't keen on soloing by describing what exactly they can find to rig their top ropes off at Harrison's Rocks?

It's Kent, not the outer Hebrides.  How far back do you have to go before you find a fence post or a tree, or a nice sturdy "Get Off My Land" sign?

And if someone can't rig a top rope safely, well they shouldn't be bloody top roping should they?

Whether or not it's common sense that a bolt here is not like a bolt everywhere else, maybe it's worth putting it in the posters and leaflets so 'some' people learn 

Personally I think don't chip, don't wire brush, don't draw chalk all over everything, don't blow torch, don't litter are all common sense. In which case sandstone code of practice can be just: don't use pof and do use a bouldering mat for bouldering

Incidentally the Sandstone Code still says to fix a tight rope from the bolt above Edwards’s Effort to the tree in line with the step across. Clip the rope to your harness and use it as a handrail to protect the step

https://www.thebmc.co.uk/bmcNews/media/u_content/File/access_conservation/a...

You have to remember why the bolts were placed in the first place.  People couldn't be bothered to rig the ropes to the "Get Off My Land" sign properly so deep slots were being cut in the crag. by moving/stretching ropes.

The, apparently erroneous, assumption was that  making the rigging much easier by placing bolts close to the edge would stop this.

Yes on the old code, we updated it last year.

http://www.southernsandstoneclimbs.co.uk/p/code-of-practice.html

The leaflet is only a basic guide. I do see your point, but if we put in every step it would become a book which is what we needed to avoid.

The new Rockfax sandstone guide has a page on bolts and notes that item so hopefully that ticks that box.

Just to note that there are no bolts at Eridge Rocks (nor is there to be any)

Cheers