Bolting Bible??? Request for peer review

[Franz]

My good friend Mo found this extensive doc (see link) about bolting and anchors. This is the closest I have yet seen to a comprehensive bolting manual. I am impressed with the comprehensiveness and scientific approach of the author.

My request:
i. Peer review. For those in the know, do you agree with the statements in the doc?
ii. Request for more docs - do you know of similar documentation of official nature that can be looked at when researching bolting practices?

Humble request: Lets keep to the point on this post

http://www.bolt-products.com/Glue-inBoltDesign.htm

PS: be careful, this is a lengthy doc. Please read the thing before commenting.

[BAbycoat]

do you want a scientific comparison of bolting methods, or an instruction manual on how-to-bolt?

[Franz]

I'm trying to take the guesswork out of bolting while trying to avoid the word-of mouth approach.
The doc in the link has a scientific approach, which I like. It gives me a tool to use for selection of method and materials, based on the location (rock type & quality).

To answer your question, I think I am looking for both.

As per my original request: I am hoping some of our tech gurus can read the doc in the link and give an opinion on the content.

[danglingdingle]

Jeez that link is detailed,

I was very interested to see that the brushing and blowing of the holes makes such a big differance.

Doesn't really seem like you need any more than that web site.

seriously though, it's probably a good idea to get hold of the ARF.

http://www.climb.co.za/anchor-replacement-fund/

they'll tell you every thing you need to know.

[Andy Davies]

Franz I suggest you keep it simple as follows:

1] Use proven existing technology - ie 10x90mm Fischer FBN or Hilti HSA-R anchors with commercially available hangers. (These are good quality stainless steel anchors)
2] Place bolts in solid rock
3] Place bolts to alow for easy clipping, no ankle breaking and to reduce rope drag. Top rope the route and chalk dot the best bolt positions.

PS word of mouth is good - a book can only teach you so much.

Good luck

[Franz]

Big thanks to danglingdingle & Andy!

I'm not dissing word of mouth, there is a lot of value in learning from the experience of others (and in so doing not repeating mistakes). As an engineer I am however very interested in the science behind what makes an anchor stick, etc.

[Franz]

I also found this valuable local info
http://www.saclimb.co.za/bolting.html

Thanks J

[paddy]

My two cents worth

Invest in quality lower offs
Invest in a torque wrench
Chase quality
Respect existing routes (will your wonder line compromise an existing route)
Ignore those f***ers who backseat drive your efforts and have never tried to open a route

[Franz]

Thanks Paddy. Valuable advice.
I would also like to add three words:
i. permission
ii. Permission
iii. PERMISSION

I still welcome technically minded responses to the post from anyone.

[BAbycoat]

IMHO bolting is similar to trad - best learnt through apprenticeship.

[Franz]

Thank you BAbycoat. There is a lot of value and merit in apprenticeship.

However, I started the post with the objective of gaining responses on the theory of bolting, and to hopefully get a peer review on the accuracy / validity of the original link I posted.

Maybe later I will create a new thread on the merits and practicality of apprenticeship and how it relates to / interacts with theory.

Without taking away from your post I would appreciate responses aimed at the original request.

[Marshall1]

I read most of it & found it spot-on.

[Franz]

Thanks! I appreciate the effort

[Justin]

Here is a link to a bolting document that Derek Marshall created sometime ago.

Permanent Protection – Bolting Basic Overview

Big up to Derek for creating this document

[Franz]

@Derek Marshall

Thanks for spending the effort on creating the presentation. WOW and RESPECT are two words that come to mind.

1 humble question:
i. Why is it a myth that a 90mm expansion anchor is stronger than a 68mm? I would think that longer and thicker would be equal to stronger?

and one comment (from your doc, and also the others):
U-bolts / staples scare the $h!t out of me after reading the test reports, and the science that goes on in the background.

[Marshall1]

90mm & 68mm are both 10mm thick & are rated exacly the same strenght. Its a question of how strong the rock is.

U Bolts in solid rock are ok, but rather use expansion bolts or glue-in P bolts.

[Franz]

Its a question of how strong the rock is.

Thanks! The basic theory being longer bolts for softer rock..

[WarthogARJ]

Not trying to hijack the thread, but this sort of discussion is EXACTLY the reason why what both Derek and Frans have done is good.
And others.
Put a bit of science into things.

It's a good thing to publish the test data as well as the results of testing.
As well as the interpretations.
That way it can be used buy other people in THEIR work.

As far as the effect of longer bolts is concerned, then sure, all else being equal they obviously tend to be stronger, but perhaps not greatly so.
As you increase the bolt length, the axial strength increases, but then starts to level out.
In soft rock you'd do probably better by using a different "glue": on that permeates the rock.
Or perhaps a different type of bolt.

The way I'd look at it is that SHORT bolts could be good in very hard rock (to reduce drilling effort), and STANDARD length bolts used in general.
In SOFT rock you should probably look at other measures, I doubt that a small increase from 68mm to 90mm would be enough.

Alan

[Franz]

@WarthogARJ
Thanks for the contribution. No hijack.
One small correction, I did not publish my own work, only some stuff I found on the net. Would be wrong for me to take the credit.

[Marshall1]

Hi Alan, no tests were done, no science intended... just a basic guide line to entertain the folks at MCSA on a Thursday night. They were mighty bored when I was finished.

doing it = >0
doing nothing = 0
theoretical = 0
Thus theoretical = nothing

[Franz]

just to aviod misunderstanding, the first link in the thread is not my own work, but the work of someone at bolt-products in Germany.