This topic contains 24 replies, has 2 voices, and was last updated by Glenn 13 years, 2 months ago.
June 13, 2005 at 12:00 am #3089
Given the increasing number of people dabbling in this area, It would benefit the climbing community if we had an open (and detailed) technical discussion on bolting systems, and how they are used.
2. Bolt type
3. Bolt length
4. Bolt preparation
5. Bolt diameter
6. Thread length
7. Glue type
8. Hole preparation
9. Rock scaling and sounding
10. Hints and tricks: experience with certain rock types around Perth.
Please refrain from running-down other peoples bolting systems on this thread, I would recommend anonymous posting.
If we get enough replies of sufficient quality I will write an article for western climber giving an overview of the systems discussed.
In particular I would be interested in a description of the bash-in carrot system presently in use in WA. I have used this system myself quite a bit over east and note that there are subtle differences in the way this kind of bolting is undertaken.June 13, 2005 at 12:00 am #3090
No problem sharing my beta.
I use Fixe stainless steel double expansion bolts with the corresponding Fixe hanger. They’re about 12cm long, 10mm dia. They are good for any type of WA rock apart from MR limestone. Placing them is easy….
1) Drill a 10mm dia hole to a depth deeper than the bolt legnth (so you can hammer the shaft in if you want to get rid of the bolt)
2) With a blow tube, blow out the dust.
3) Hammer the bolt into the hole, lining the hanger up as it gets close and backing the nut off a little as you hammer.
4) Once the bolt’s in, tighten the nut and climb on!
No glue, no fuss, bomber bolts. Approx 15$ each retail or cheaper if you have the right contacts…
Rock prep – hake sure there is no loose flakes or dodgy rock surrounding the area and make sure you have a good flat area that youre placing into.
Personally i find glue in bolts a pain in the butt to place so if im not bolting limetone ill use the above.
Cheers EJune 13, 2005 at 12:00 am #3091
I use 10×70 or 10x90mm stainless steel expansion bolts with a UIAA P-hanger for all route styles.
There are various proprietary expansion bolts specific to climbing eg petzl / fixe etc but I have found that stainless “dyna bolts” are cheap and bomber when placed in granite or sandstone – dont use for WA limestone (chalk).
I’ve not used glue-in anchors but I can say that I have seen one fall out under the weight of a quickdraw – why bother with messy glue when you can place expansion bolts and be climbing on them the second they are tight.
Glue is probably fine if you follow all the manufacturers specs to the letter but try doing this while hanging in a harness for an hour putting 10 or 15 bolts in a 30 degree overhang. Human nature says there is potential for taking shortcuts…
Expansion bolts are easy, drill, blow, tap in, tighten, climb.
My personal opinion of carrots (bash or glue-in) is that these were the world standard of fixed pro of 50 years ago. Since WA climbing is about 50 years behind the rest of the world, carrots still fit right in…
Seriously though why waste time grinding down a bashie to the right “carrot” shape when there is an inexpensive off-the-shelf item which is reliable. I reckon if it was put to a vote the majority of climbers (except WA dinosaurs) would prefer a solid expansion bolt and hanger to a carrot when fixed protection is required.
One further thing to note about bolting – Using the right type of bolt is one thing but even the best hardware is next to useless if placed poorly. Much attention should be paid to the rope path to ensure the rope runs freely and not over sharp edges. Bolts should be placed within reach of good or reasonable holds, before cruxes and above ledges. Bolts should be placed in flat areas of solid rock – I have seen plenty placed in detached flakes within 50cm of bomber rock! Bolt spacing should be dictated by the availabilty of good placements, potential for ground legde fall, etc not an abitrary 1.5m spacing.
Thats my two cents.June 13, 2005 at 12:00 am #3092
Sorry, that should be 12x70mm dynabolt.
Manufacturers safe working loads for this anchor are 11.6 kN (~1160kg) tensile and 7.9 kN (~790kg) shear. Failure loads would be significantly higher – so they are bomber enough..June 13, 2005 at 12:00 am #3093
A further thought on bolting:
Cost is a big factor in deciding how to bolt a route. Folks are more apt to cut corners when it hurts in the hip pocket.
I have talked to active climbers who would contribute to a bolting fund to see decent , hangered bolts placed in a responsible fashion. Places i have lived in the USA have a system like this that works well. I know this has been a thread topic already, but it could work. A contribution box at each gym? Or a CAWA managed thing?June 13, 2005 at 12:00 am #3094
Hell, I know I’d cough up when it comes to a donation box at a gym.June 13, 2005 at 12:00 am #3095
Does glue add value in coastal environs?June 14, 2005 at 12:00 am #3096
Many thanks for the comments thus far. Is there anyone else willing to describe your bolting system of choice?June 15, 2005 at 12:00 am #3097
I use 10 x 70mm glued machine bolts or 12x80mm Dynabolts or 10mm Fixe P bolts. The argument against Dynabolts is obvious: you cannot abseil off the hangers. So rad sport climbs are best served by P bolts, gluing and all. You asked.June 16, 2005 at 12:00 am #3098
For top anchors / rap stations / belays glue is not necessary either, use two dynabolts with hangers off-set 150-200mm horizontally and vertically. Add a steel biner or screw-link (maillon or similar) to the hangers to allow threading of the rope.June 18, 2005 at 12:00 am #3099
I’ve found the two articles available via this link quite useful. Not WA specific but give a nice rundown on many of the variable factors.June 18, 2005 at 12:00 am #3100June 18, 2005 at 12:00 am #3101
I did not mean for anchors; I meant when you work a route and want to pack up at the end of day then being able to lower off from ANY bolt is a real bonus. Also fixed hangers get stolen, I’ve seen this 3 times and supergluing the nut does jack to stop that. Expansion bolts don’t work in places like Kalbarri + limestone down south. So plenty of scope and place for glue-ins.June 18, 2005 at 12:00 am #3102
Oh yeah, another place where Ben shows depths of ignorance is re: carrots. carrots were not “world standard of fixed pro 50 years ago”. The only pro used 50 years ago were pitons and chockstones. Carrots started off as aid climbing protection in USA in the 70s, this was the 1/4″ variety, ofen accompanied by home made hangers so thin they looked like they were cut from a Coke can with a pair of tin snips. For free climbing pro they have never ever been used anywhere else in the world but Australia. NOBODY ELSE HAS EVER USED CARROTS FOR FREE CLIMBING. Go overseas, see and ponder. So depending on your point of view: carrots are either a bonza dinkum superb Ozi invention, or a cheapskate dangerous shortsited piece of crap.June 19, 2005 at 12:00 am #3103
Dear Dead bolt,
You bashed the carrot right on the head, they are indeed a cheapskate dangerous short sighted piece of crap.June 19, 2005 at 12:00 am #3104
Although I agree about carrots, Dead Bolt, please don’t make personal attacks on anyone, just stick to the subject. We don’t need that kind of twaddle on this forum, and certainly not in our community.June 21, 2005 at 12:00 am #3105
I thought you might like a few quick thoughts from perspective of a rock mechanics engineer: my experience is in bolting systems for underground mines, and I have also placed a fair number of bolts for rock climbing including carrots, mechanical expansion bolts and glue-ins.
1. To my knowledge there is no database of pull tests across all bolting types, on which to base our assertions.
2. Recent tests have shown that cement grouted bolts rely mainly on friction, NOT COHESION i.e. glue forms a rough interface between the bolt and the rock which is fricional, with very little or no cohesion.
3. Bolts for rock climbing are very short compared to mining applications. Mining application bolts are 2.4m long. Bolting for hanging services (similar loads to a factor 2 fall) are 1.2m long. Perhaps an engineering study would show that ALL OF THE BOLTING SYSTEMS WE USE IN CLIMBING HAVE A LOW (and similar) FACTOR OF SAFETY since they are overwhelmingly influenced by the surface quality of the rock into which they are installed.
4. I no longer use carrots because of the installation and long term reliability issues mentioned in previous emails.June 21, 2005 at 12:00 am #3106
I hope life’s treating you well. I’m in Oman and it is 45C outside, again. Anyway, there was an article in Rock Mag about 10 years ago where all sorts of bolts were failure tested. This article was copied in the New Routes book at Mt Designs Perth, not sure if it’s still there. I have copies. The main point I remember from it is that shear strength is basically function of the thickness of the bolt and not really related to how it is installed i.e. glued, expansion or carrot. But pullout strength is completely different matter this is where carrots were found to be several times weaker. So obvious deduction is that carrots should not be used where pullout forces are large, like overhangs. Another point I would like to make is that to my knowledge climbing gear has no safety factors in it at all i.e. carabiner rated to 20kN (2 tonnes static weight) is actually supposed to break at 20kN, i.e. this is the ultimate failure load. On the other hand industrial-rated equipment does have safety factors, safety factor of 3 is quite common in engineering material strength, i.e. something rated to 20kN would actually fail at 60kN. So this is why if you walk into the Hilti shop in Belmont and say that you want an expansion bolt to anchor from for high access work you will walk out with a 1″ diameter bolt! Good for a laugh, eh?June 22, 2005 at 12:00 am #3107
Of West Oz origins, I don’t climb “equipped” routes there because I find much of the bolted routes a bit sketchy (as a consequence I’m restricting myself to bouldering and trad on the occasional visit back home). I am based in Europe and have a tendence for sport routes where I know the equippers. We’re spoilt for choice but I lower off a fair few and walk away where I think they’re suspect: my life, my decision.
My interest in the subject increased somewhat following a couple of problems encountered here:
1. An October04 lead on a Callanques climb of relatively recent instal, clearly corrosion affected bolts on the 2nd pitch. Anyone relying on the bolts and falling on that pitch is likely to die.
2. A big block fell out of a highly frequented local crag recently and killed 2 walkers passing by underneath. Authorities have demolished the crag and are assessing others in the area. Good installation originally but repeated falls over the years might have weakened the rock.
I retobolt occasionally and I’ve tried to get more data rich as a consequence of these recent close encounters. Tried finding a techie database and couldn’t. At the risk of being repetitive, the nearest thing I found was embedded in literature on the site below. Some of which is dated but relevant bits on rock type, glue, shear types are interesting (hence my earlier post which countered ben’s in a slightly less confrontive way to Dead Bolt…though definitely less entertaining).
Apart from that site there’s the sandstone bolt testing piece on chockstone’s website. More experienced route equipper’s around here have been great info sources and tend to discuss requirements directly with the likes of Petzl/Hilti when in doubt(not the local hardware store).
None of the climbing gear I’ve come across in Oz, UK and Europe has matched safety standards required for human protection employed in mine, industrial or building installations. When retrobolting I try to move them from worthless to bomber from a climbers perspective…the more I read the more I become aware of a disconnect.June 22, 2005 at 12:00 am #3108
Hey folks. Ive just scored access to a large number of glue-in P bolts, so i may become a gluer after all.
Can anyone share their beta on no-fuss glue tubes? What type, where do you get it and how much is it?
Cheers EJune 23, 2005 at 12:00 am #3109
Hi Ross and Rod:
Thanks for the comments and notes. I have drafted a quick response to the notes you sent. I find this topic quite interesting and I hope we never adopt industrial standards. This would reduce all the fun in climbing. I find it really interesting that there is a general perception by some climber that bolted routes are safe (and low risk)….
# Ross’s notes:
I would really appreciate a copy of that article you mentioned. If you are willing please send me an email to the below address and I will send you a fax number.
Based on your notes, the findings of the rock article seem to reflect basic findings in rock mechanics:
– pull out strength depends on axial load transfer along the bolt. Longer bolts have higher pull-out strength
– shear strength is a function of bolt strength, unless the rock fails first.
In the systems I study, bolts are not the weak point in a system – rather the rock. Rock strength changes with time. Rock is much more sensitive to thermal fracture and dynamic loading than steel.
What interests me is the behaviour of the bolt-rock system. Rock is about 10 times weaker in tension than compression. Add in discontinuities (joint sets etc) and the strength drops considerably. Also small failures of the rock could lead to mechanical failure of the bolt: i.e. a small chip or breakage at the base of the hole collar allowing for a moment rather than pure shear – resulting in possible bolt breakage. You see this a bit in the bluies.
When we design bolting systems underground we don’t use factors of safety on the support elements, we consider the reliability of the bolt-rock system over a particular period of time (our bolts are often stretched by deformations in the ground), and the factor of safety of the bolt-rock system. We test these systems to destruction on a regular basis to check our assumptions. This is fun.
It would be interesting to test 100 or so field installed rock-climbing bolts to destruction to build a statistical database of behaviours. Perhaps such data is in the article you mentioned?
I am truly amazed that so few bolting systems are reported to fail. Perhaps we simply don’t fall frequently enough on most of the bolts we place?
# Rods notes:
Thanks for the link. This was an interesting article – I intend to track down the citations when I get a chance. If you are interested I will send you and Ross a copy.
I agree with your opinions regarding the safety of bolted routes, although in total contradiction to all reason I still climb them (providing they don’t appear “rusted out” or over bashed carrots, or reliance on only one bolt to prevent ground fall…). Even so, I make a big effort never to fall…ever. I have seen too many rock falls in seemingly perfect rock….
Most people don’t realise that rock can contain micro-fractures that grow and coalesce over time. This is particular true in rock that has been blasted (i.e. quarries) but thermal effects in natural rock faces probably behaviour in a similar way (consider the extreme: fire). There is evidence that thermally induced fractures grow can occur at relatively modest temperature gradients, not to mention “locked in stresses”. Rock slopes and cliffs are constantly moving.
What rock type was the crag in which the block fell-off.June 23, 2005 at 12:00 am #3110
Good quality limestone (as opposed the sugar enjoyed in West Oz).
As opposed to fire we regularly see rock breaking down due to freeze cycles, these cliffs aren’t high enough to experience much of that which is why it seemed odd. A block at the base of one of these small cliffs which fell out last year has a bolt surrounded by an m3 of rock (that block fall being the first sign of instability). As far as I can tell the block that fell on the walkers came out of another cliff.
Likewise I try not to fall (my total count is 3 times)…but they’re a hoot when they happen!July 13, 2005 at 12:00 am #3111
in regards to the glue in systems. Powers KF2 and ramset 101 are used extensively throughout the east coast of australia. they are quick setting and fairly fuss free. they are polyester based adhesives. Ramset 801 is used to a lesser extent. its an epoxy resin and is a lot stronger than the KF2 or 101 but a lot messier and take 24hrs to cure. you can get the KF2 or 101 fairly cheaply (ie $25 per tube) and they useually do about 20 bolts per tube depending on how efficiently you use them.
Trubolts are fantastic bolts for solid rock. they offer the best strength to hole diameter ratio as the shaft of the bolt is the same as the hole size (where dynabolts the shaft is 2mm smaller than the hole size due to the sleave).
the Fixe double wedge bolts are great bolts. i can get them a fair bit cheaper than $15 if anyone wants any.
stephen_hawkshaw (@) yahoo.co.ukJuly 16, 2005 at 12:00 am #3112
Glenn – your email does not work; I scanned that article for you but your mail box must be full….I will send a copy to Jon Gregg so you can source it from there.July 18, 2005 at 12:00 am #3113
Our sys-admin rebooted the server over the weekend. Should all be fine now.