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anchor testing rig

mikllaw

2-Sep-2010
12:28:36 PM

I’ve put together a hydraulic testing kit for bolts to test the strength of existing anchors, target which types of anchors are weak or unreliable, or maybe show that some of the old anchors are ok.

The unit is pretty beefy and will pull 50 kN (5 Tonne), I selected this capacity as I worked with Ric Weber (the owner of the Muir Valley climbing area in the Red River Gorge, Kentucky) who often tested bolts to his rig’s limit of 20kN. When they didn’t fail he was faced with the issue of removing them rather than leaving potentially damaged anchors in the rock. The higher capacity of this unit should avoid this problem.

I’ll also get together some information for testers on using the rig, including safety and avoiding damaging rock on climbs. A solid glue-in should pull out a big come of rock, I don’t want to leave craters on cliffs so any serious testing will be away from climbs.

I’m funding some of this myself, and hope to raise the rest from a few climbing clubs, gyms, and outdoor stores. The SRC and VCC clubs, Mainpeak stores, and SICG gyms have promised money. The system is relatively portable (~20 kg) and I hope that it will be used around Australia so that various geeks can test anchors in the local rock. Anyone will be able to use it, but sponsors will get first bite.

Rick Weber testing in Muir Valley

I should be getting it in a week or two and need to machine some fittings to take shackles, does anyone have access to strong chains and shackles?


nmonteith

2-Sep-2010
12:38:25 PM

I have a handful of overly beefy shakles at home that someone donated to me years ago. They are too big for normal rap points so i'm happy to give them to you. I look forward to some bolt destruction!


IdratherbeclimbingM9

2-Sep-2010
12:39:11 PM

On 2/09/2010 mikllaw wrote:
>I should be getting it in a week or two and need to machine some fittings
>to take shackles, does anyone have access to strong chains and shackles?
>
When I did some homework a little while back, I found the strongest chains and shackles (lots of varieties/strengths to choose from), were available much more cheaply from a heavy lifting company rather than a bunnings type store or a locksmith. All of it rated due the oh&s applications it's normally used for, and they sold chain by the weight/link, so custom lengths were easy to get and shackles matched the same specs.

widewetandslippery

2-Sep-2010
3:27:57 PM

My 2cents. Wouldn't wire rope be easier and lighter to move about and work with?

mikllaw

2-Sep-2010
9:26:34 PM

much better, but fixed in length, chains are a bit more adjustable

widewetandslippery

3-Sep-2010
10:33:42 AM

NB. not a rigger.

You can get wire rope clamps a bit like a gibbs ascender. Since the wieght of wire is less than chain you then have the problem of do you take a greater length of wire or a lighter pack. I'd think the rope would be easier to work with. (just giving food for thought)

I have tested anchors against each other going with:

anchor + shackle + wire rope + rope clamp + load cell + shackle + anchor

Sorry I'm not good doing the squiggly picture thing.

Applaude you eforts.

mikllaw

3-Sep-2010
12:04:58 PM

I'll look at using these, particularly if they fall off the back of a truck, cheap is good!
I'll proabaly place 2 bolts as an anchor for any concerted testing, and equalise them with a wire sling so that I can test a lot of bolts at slightly different angles.

Any other cheap ideas gladly considered

widewetandslippery

3-Sep-2010
12:50:57 PM

What about that gal wire rope the RTA uses for those road barricades designed to slice motor bike riders in half? Someone must have some bolt cutters?


cruze

3-Sep-2010
1:06:42 PM

I am not following this. You have chosen a high capacity rig to test anchors to failure? Once they have failed you have a dysfunctional anchor in situ (or attached to a piece of rock at the base of the cliff) that will need replacing.

Why not just replace the anchor or not replace the anchor?

If it is to get a general feel for anchor strength (how glue binds to rock in that location and under those conditions, etc) it seems that there are many other variables that can't be determined - how clean a hole was before the first anchor was placed, type of glue used, variations in rock quality from placement to placement, etc. I realise I may have misunderstood your intentions, and overestimated the variability in these variables, but could someone inform me?

I could have been thrown by your initial comments about existing anchors, and perhaps you are just looking to place new bolts under different conditions in random bits of rock to see if their strength can be maximised when actually applied to routes??!!

widewetandslippery

3-Sep-2010
1:14:14 PM

Testing is good. To quote the great man Dirty Harry a mans got to know his limitations. Destructive testing is required to gain credible and reasonable statistics so safe non destructive testing can be carried out. Its like making a person. You destroy them and then see what they can cope with.

mikllaw

3-Sep-2010
1:50:07 PM

On 3/09/2010 cruze wrote:
>I am not following this. You have chosen a high capacity rig to test anchors
>to failure? Once they have failed you have a dysfunctional anchor in situ

Indeed, obviously there is a lot more to this than the simple message I started with. Firstly, anchors that are tested will be removed. The three main things I'd like to test are:-
-"Some" existing anchors. I'd only do this where they are likely to be low strength (carrots, cracked glue-ins etc) and there little chance of damage to the rock. I don't intend testing strong anchors on climbs and leave big craters, if they need replacing you should do it the normal way.
- Representative testing on real rock, preferably away from climbs, there will be some rock scarring. I'd like to find a boulder in the scrub, put in 30 Ubolts and test (rough sketch in a previous post). This will probabaly be the bulk of the testing. Safety and manipulating a 20kg rig will be a lot easier on the ground too.
- Testing of trad gear in number of placements. Once again not on climbs.

By taking "copious" notes during testing, a nd sharing all results, we should be able to get a lot of quality data, most testing is very limited- typically on one rock type, one or two (poor) anchor types, and maybe 20 tests.


cruze

3-Sep-2010
2:54:26 PM

Thanks.

One Day Hero

3-Sep-2010
3:40:04 PM

Data will be improved if you test bolts placed across a range of stupidity. I suggest taking a bunch of different drugs along and adding them to your system one by one, continue bolting till you pass out.

grangrump

3-Sep-2010
5:00:27 PM

Thanks MikL
Will look forward to the results, especially if you can be persuaded to do different rock types (different sandstones, limestone, granite?)
I would be interested to see if close holes (e.g. adjacent replacement bolting) lead to practically higher rock failure (coning).
thanks again for all the trouble


ajfclark

3-Sep-2010
5:05:03 PM

Didn't that kind of thing get a little bit of a look in section 2.2.6 of Hawkshaw's thesis? The extra hole would just be considered lost volume wouldn't it?

grangrump

3-Sep-2010
5:13:52 PM

Thanks, good reference.
But on mangled routes you may find quite a few replacement holes within a few inches of each other (the ideal bolt location at a stance is typically quite a small area?).


IdratherbeclimbingM9

3-Sep-2010
7:00:54 PM

On 3/09/2010 grangrump wrote:
>But on mangled routes you may find quite a few replacement holes within a few inches of each other (the ideal bolt location at a stance is typically quite a small area?).

Blerrie heck. What is 'sport climbing' coming too?

Trad has forever been limited to available placements. Guess what? ... sometimes they are even inconvenient!
Forgive my mirth, but I find the fact that the sporties now complaining about their convenience compromised quite funny!!
☺


rodw

3-Sep-2010
8:21:46 PM

To be fair m2 if your going to bother placing an artificial bolt it may as well be in the optimal position...trying to compare it to how protection is forced to be placed in trad is a bit silly IMHO. hehehehehe x -12


IdratherbeclimbingM9

3-Sep-2010
9:13:16 PM

On 3/09/2010 rodw wrote:
>To be fair m2 if your going to bother placing an artificial bolt it may as well be in the optimal position...trying to compare it to how protection is forced to be placed in trad is a bit silly IMHO. hehehehehe x -12

I am glad that you also see some humour in it rodw, albeit the other side of the coin.
I chuckle when I think how engaging a climb must be, when the only thing one need worry about is convenience! ~> Yes, it is a silly game we play!!

mik

6-Sep-2010
5:55:39 PM

Hilti already make one of these. I used the "tester 4" on high access anchors high rise/industrial etc. It tests to 20kn and they make one that goes to 40kn, weighs about 4kg including frame and tester.

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