Is there a good way to test bolts?

[GypsumWolf]

If I go to a cave and I don't know if the bolts are good or bad, what is a good sure way to tell? Or do I just need to put a waighted line on it to test it?

[adleedy]

Swing on it?

[fuzzy-hair-man]

If I go to a cave and I don't know if the bolts are good or bad, what is a good sure way to tell? Or do I just need to put a waighted line on it to test it?

As I understand the only way to see how much an anchor will hold is to pull until it breaks, off course the anchor is not much use after that

So I'd say there is no sure way to tell.

I'd just look around at the rock it's placed in, is it rock? or crystal? crystal can be dodgy, are there any fractures or cracks near by? are there any cracks that look like they may have been caused by the anchor being loaded (bad news don't trust it)? what sort of rock is it? (hard, soft, mud-rock matrix).

The anchor it'self: Is it loose? (bad news don't trust it) does it look like it's pulling out? it should sit flush or 1 - 2mm below the surronding rock. If it has a removable hanger are the threads OK? rusted? what does the placement look like? if it was put in a bad place maybe the person who placed it didn't know what they were doing? or it was placed as a tempory anchor. Is there any chipping around the bolt? What is the pull direction? a pull at right angles to the bolt, paralell to the rock offers the most strength.

Lastly how desperate are you to get down there? can you back up the bolt? are there any natural anchors to use, or to use as backups?

If you do use it watch how it behaves as you put your weight on to it. Can you use that bolt to get to a better anchor?

My 2 cents

[Stridergdm]

Swing on it?

No no no.. that's silly and dangerous.

You should always cave with someone heaver than you are.

And make them go first.


(next in my useful tips will be advice on outrunning bears.)

[adleedy]

Swing on it?

No no no.. that's silly and dangerous.

You should always cave with someone heaver than you are.

And make them go first.


(next in my useful tips will be advice on outrunning bears.)

ahh, but you see you not need outrun the bear, only the other man lol

[Stridergdm]

Swing on it?

No no no.. that's silly and dangerous.

You should always cave with someone heaver than you are.

And make them go first.


(next in my useful tips will be advice on outrunning bears.)

ahh, but you see you not need outrun the bear, only the other man lol

Ah, Grasshopper, you already know my advice then.

[BenC]

If you have the room and can do it without killing someone, rig your rope then have everyone in the party pull on it as hard as they can, if it stays...
then it's a judgement call. If it doesn't start looking for another anchor.
And do everything Fuzzy said!

[hunter]

WildWolf,
I think fuzzy's beta is dead on but I'll go ahead and add my list of checks...

-As has been said, back up whenever possible and there should never be less than two anchor points. Also think about what will happen if a bolt fails and try to minimize shock loading.

-Know a bit about bolt types, these guys have some good info on bad bolt types:

http://www.safeclimbing.org/education/bomberbolts.htm

Also of particular concern in caves is corrosion, if the bolt head (not the hanger) is looking really rusty I would worry. Note that the many people place non-stainless bolts but use stainless hangers, so the hanger often looks fine even though the bolt could be bad.

-If it's 1/4 inch diameter, worry. This is for two reasons, first they aren't that strong to start with, and second they are mostly quite old (most people use 3/8in now). I try to replace 1/4 inch bolts and so far I've been able to get out about a half of them with a small crowbar. The rest I couldn't budge.

-Check the hanger closely, most new hangers are bomber but aluminum can crack and the old leaper hangers (thin, angular, and rusty) have been known to fail.

-Check if the bolt is tight. The nut should not turn with hand strength and the bolt should not wiggle side to side under load. Carrying a small adjustable wrench is a good idea since bolts can loosen over time and with extensive use. If you start to tighten a bolt and it either spins or starts coming out after more than a few turns it is bad. I also once busted the top off a nut/bolt assembly while checking if it was tight (with a short wrench and very little force), quite obviously bad and more than a bit scary.

-Ask around and see if you can find out who placed the bolts and when, maybe someone should replace them. Don't blindly trust.

-Check as frequently as possible. I've placed two bolts and cranked them all the way down only to find two days later that they needed tightening. It's really a good idea to check an anchor each time you pass it.

-For some bolt types (rawl 5 piece, fixe removable) you can remove the entire bolt and check it. This is time consuming and takes care in a muddy cave but is worthwhile if you are worried.

-In the end remember that you don't know how long the bolt is, when it was placed and even the guy that placed it isn't sure about the rock so back it up! I'm emphasizing this point because a backup recently saved me from a 15ft fall when a brand new 3.5x3/8in bolt popped out of good looking rock.

James

[Scott McCrea]

Good post, Hunter.

I'm emphasizing this point because a backup recently saved me from a 15ft fall when a brand new 3.5x3/8in bolt popped out of good looking rock.

Yikes! Why do you think it failed? I haven't heard of too many bolts failing.

I have seen a lot of loose bolts. I keep saying that I'm going put a wrench in my pack, but, I still haven't done it.

[hunter]

Yikes! Why do you think it failed? I haven't heard of too many bolts failing.

I'm still not certain but I think it was some combination of mud in the hole and harder rock combined with a direct outward pull (the bolt was in a roof). The bolt just popped straight out with no deformation and no damage to the hole. I normally tighten bolts hard but not as hard as I possibly can (since they are supposed to be set at a specific torque this is a
compromise which still puts me above the recommended torque). I should also note I cleaned the hole and the bolt was pretty darn clean looking after it popped out as well.
After the bolt popped we hammered it back in and two of us cranked as hard as we could. It didn't budge after that.

Overall this shook my faith in bolts. I try to avoid roof placements but the bolts are made for a straight out pull in concrete so limestone really shouldn't be an issue. I blew/brushed out the hole pretty well and tightened the bolt hard so I really thought it was good. The natural I backed up to ran over a series of sharp edges (hence the bolt) but it certainly saved me.

I have seen a lot of loose bolts. I keep saying that I'm going put a wrench in my pack, but, I still haven't done it.

It comes from climbing but I think this is actually more of a danger. I've seen one rawl bolt pop out just because it had unscrewed from it's nose cone and I've seen a number of wedge bolts where the nut had come almost all the way off due to vibrations from the rope...

James

[Ralph E. Powers]

ahh, but you see you not need outrun the bear, only the other man lol

Actually make the other guy RUN for help while you stand still... bears tend to go after moving prey.

==========
Seriously on dodgy bolts like someone said... don't trust them. Find a back up or something better to be the primary anchor then use the questionable bolt as secondary with as little slack between as possible. At least if it does blow out (hope it'll never do) then you won't shock your rope and primary anchor too much or not at all.
If you can't find a better primary anchor... re-consider your options... if you know how to place a bolt then come back and do it yourself (and inbetween ask around)... the pit will ALWAYS wait.

[Stridergdm]

Last spring, was doing a local pit. Decided to exit.

To speed things up since a number of us were getting hypothermic, I recommend to the guy going before me to put a figure 8 in the rope and clip to a bolt over a particular chokepoint. I had seen the bolt on the way down and realized this was really ideal for a little rebelay. (given the shape of the pit, I don't think most people bothered, and probably most NE cavers aren't up on their rebelay techniques.)

Anyway... he climbs up, wedges himself in, ties the knot, clips it off and then releases himself so he can climb up the main drop.

I start up. As I'm getting closer to the bolt confusion set in. The rope was on the rockface BEHIND me, not in front of me where the bolt was.

Get up and realize there there were multiple bolts, at least the one I had seen, and at least one behind me. The one he had clipped into.

This one of course the one that looked far sketchier and probably is ripe for removal (rusted, etc.)

Now fortunately, again given the dynamic of the pit, if it had blown out, I probably would have suffered a few nasty bruises, but nothing life-threatening.

Still a bit disconcerting.