UKC

I've clipped my share of them, but never seen one before it was set. Just curious.

M

In reply to Max_01:

depends on the rock and the type of bolt.

In reply to Paul at work:

If M10 they usualy about 65mm

In reply to Paul at work:

OK- what about glued in staples, eg Portland.

In reply to Max_01:

55-60 mm for Portland

Some of the big belay staples can be up to 100 mm or more

In reply to Max_01:

Go and climb on the chalk cliffs near Rouen - and hope they're very long.

They are btw.

In reply to steve taylor:

Thanks for the replies.

I checked out the fixe website too.

Their M10 expansion bolts come in 70mm and 100mm versions, and their glue in bolts are 80mm long.

Ta

Max

In reply to Max_01: I put up my first new route on Kalymnos last year, and it's funny how normally I never think about the bolts I'm clipping and whether they are safe, but the first time I came off the ab-rope and weighted a bolt that I'd placed myself... eek!

In reply to Nick Smith - UKC:

which raises the question: how much force can your average bolt take, and how frequently, lets say in limestone and granite, have they been known to fail ?

In reply to Max_01:

If it was a hard rock eg Granite 75mm

Most of the 10mm expansion bolts we use (Fixe etc) are 90mm

Longer and fatter if softer rock

In reply to stonewall: No idea, but I've only heard about bolts failing when they had suffered a lot of corrosion over the years. eg, on sea cliffs, or if they were glue-type bolts where the glue hadn't been mixed properly or something.

... just looked it up. A Fixe 10mm 25kN Expansion Bolt has a shear strength of 25kN = 2500kg ?

In reply to stonewall:A bolt failed on Berzins, either last year or the year before, on Frankie (the irony).
There's still some hand-drilled bolts in Yorkshire that are only about 1" deep.

In reply to Serpico: i hate bolts, dont they weaken the rock and so instead the the bolt breaking the rock does.

In reply to mac_climb:No.

In reply to Serpico: yet another lie ive been told,

In reply to mac_climb:

Not quite the whole story. Some old bolts only went in a short distance and were designed for aid so only went in a short distance. They may weaken flakey rock but bolts placed for free climbing by experienced people are as solid as the rock, and placed in solid rock for the most part.

only those experienced should place bolts, that way you know the route is safe.

In reply to sutty:

We have a lot of hand drilled (self drilling) Terriers still in use. They are about 25mm long and a bolt is screwed into the threaded interior of the sleeve. With a 10mm bolt the hole you ended up with a 14mm hole and great surface area.

They are really solid (surprisingly) and I have replaced ones that I thought would need replacing, that frequently have often held huge falls and they were fine.

In reply to nz Cragrat:

We used them a lot in the past but they are now rusting away and are being replaced by resin sealed bolts in yorkshire to optimise their life.

There needs to be some control of bolts used by lots of people as a faulty placed bolt could hurt someone in a fall.

There is to to be a best practice group formed to place good bolts it seems, those interested should email the BMC yorkshire area for details.

Personally I have used everything from Biven type curtain rings, golos from the 60s which were split sleeved aluminium with bolts hammered into them and the type you describe, all ok for aid but suspect after a few years. the ones on the Brandler Hasse in 61 were wrapped in cigarette packets to hold them in, I replaced one wrapper for added security before using it for aid.

In reply to sutty:

I replaced some terriers that were near the sea. Not sea cliffs but... there was nothing wrong with them. The 8mm ones that cavers use... scary. And those split rivet button heads that were used by the Yanks (damn that bolting on lead for bad gear) ...well

In reply to Nick Smith - UKC:
A Fixe 10mm 25kN Expansion Bolt has a shear strength of 25kN = 2500kg ?
A Newton is a unit of FORCE rather than what we commonly know as weight. It is specifically the force that is required to make a mass of 1 kg accelerate at 1 metre per second per second. So it depends entirely on the force applied: a 2500kg climber (no, I don't know any either - though a few come close) resting on a bolt with zero force would not quite snap a bolt rated at 25KN, but the same climber shoving himself off downwards with some force would. You have to take the force applied to the unit into account. In normal circumstances (i.e. if you're not falling because you've just pulled off a huge boulder and have been falling and accelerating for a few seconds) the energy absorption of a dynamic rope (and the quite huge safety margins used by gear manufacturers) will ensure that any correctly placed bolt will hold about 16 elephants (one unit of elephant being the equivalent of 1 fat climber. Place your bolts carefully and you won't hit the ground.
At least, this is what I understand it to be. If anyone dies as a result of trusting this posting, please don't sue me; I'm not a physicist.

In reply to Steve Parker:


Weight is a force.

In reply to Steve Parker:

the human body can only handle, for a brief instant , a shock force of 12 kN without risking serious injury,

In reply to Skyhook:

Good references

http://home.echo-on.net/~toadhall/outside/climbing/shock.html

In reply to nz Cragrat:
http://home.echo-on.net/~toadhall/outside/climbing/shock.html

Being a bit pedantic here, but from that site:

"But every fall creates an enormous amount of energy.

That's wrong. And yes, weight is a force.

??? to Nick Smith - UKC:

the reason I asked is that last year on a multi-abseil descent in the ecrins some congestion ahead of us caused about two or three people to come to rest on the belay we were hanging on (the usual two bolts and a chain). Them clipping into the hangers and also the chain links made me wonder how much it could all take.
Seems it was all safe enough ?

In reply to nz Cragrat:

That's why we use dynamic ropes. If you fell three metre onto a steel hawser your spine might just snap.

In reply to Skyhook:

Yes but I was referring to the general perception of it, which is probably more similar to mass, unless most people are more educated about physics than I find them to be. Fair enough to point it out though.

In reply to stonewall:

Yes, the bolts should handle 20 or more climbers each weighing (sorry, massing 100kg just resting on the belay - and there aren't many climbers that heavy.

I found it was a similar situation on some of the popular multi-pitch routes in Mexico - despite the warnings in the guidebook, many American climbers seemed quite happy to set off up the routes when there were already multiple parties climbing the route, which gave rise to traffic jams ("cluster f*cks") at the belays. Sometimes there were 10 climers at a belay, some going up, some going down and all gettings their ropes tangled, etc

In reply to Max_01:

A subject that has also intrigued me since I got into Sport climbing. The other aspect that concerns me, having climbed a lot at Portland and Swanage, is how stong is the glue / resin ? I can appreciate that the staple itself can hold a fair amount of downwards force, since the force is effectively trying to bend the staple. But how about "outwards" force, i.e. if you were to try and pull the staple straight out of the rock. I understand that for this very reason the belayer must stand close to the base of the crag, so that the force is, as far as possible, downwards rather than outwards. But when faffing around at the top, unthreading, rethreading, etc., it's very difficult sometimes to just hang on the staple. I sometimes find myself tied into the staples, feet braced against the rock, leaning outwards. At this point the force on the top staples is more outwards than downwards. I know resin is pretty strong, but it's only as good as it's adhesion to the rock.

I always try and avoid putting an outwards force on the staples, but sometimes it's very awkward, and I do get worried. Am I just being paranoid ?

In reply to Nick Smith - UKC:
10 climbers at the belay ! quite a get together.
what about clipping into the chain links - OK ?