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Chockstone Photography
Australian Landscape Photography by Michael Boniwell
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Chockstone Forum - Accidents & Injuries

Report Accidents and Injuries

 Page 7 of 10. Messages 1 to 20 | 21 to 40 | 41 to 60 | 61 to 80 | 81 to 100 | 101 to 120 | 121 to 140 | 141 to 160 | 161 to 180 | 181 to 196
Author
BOLT WARNING - Pierces Pass, Blue Mountains

nmonteith
8-Feb-2009
10:26:44 PM
crap - that middle caption should say Bucket Bunny Buttress.
hotgemini
8-Feb-2009
10:35:24 PM
80mm? Damnit, I must have misread that line.

One Day Hero
9-Feb-2009
12:13:43 AM
On 8/02/2009 nmonteith wrote:
It's also interesting to see that the carrots
>we have been clipping for all these years on popular routes are the smallest
>of the lot. Discuss!

And yet the failure rate for carrots is quite low?! I personally trust the wisdom of the blueys bolters from the eighties who were almost all pretty experienced and pretty cluey dudes.
In canberra, during the same period, hundreds of hardware galv expansion bolts were placed. To my knowlege none of them has failed in the super-hard canberra granite, even though the load limit (if given at all) is 200kg. The point being that the bluies guys would have known about, and experimented with expansions and chose not to go with them.

I reckon the carrots can be looked at as custom fit lost arrow size pitons (once considered the most bombproof gear going) If they're pounded in well, they should be pretty super, plus I suspect the rust packs around the shaft and sticks even harder (up to a point).....Anyway, look how many are out there and how few have failed. I'm not down with the anti-carrot propaganda, especially when the discussion has been kicked off by stainless expansions going wrong.

Oh yeah, I speak the croatian lingo pretty fluently. If anyone wants stuff translated, cut and paste it and I'll give it a go.

Also........pull your head in Macca, there's a time and a place and this is neither!

nmonteith
9-Feb-2009
9:26:32 AM
On 9/02/2009 One Day Hero wrote:
>I reckon the carrots can be looked at as custom fit lost arrow size pitons
>(once considered the most bombproof gear going) If they're pounded in well,
>they should be pretty super, plus I suspect the rust packs around the shaft
>and sticks even harder (up to a point).....


Has this reached that point yet? Old belay bolt on Dueling Biceps on the Sydney Sea Cliffs...

anthonyk
9-Feb-2009
9:29:33 AM
On 8/02/2009 nmonteith wrote:
>It's also interesting to see that the carrots
>we have been clipping for all these years on popular routes are the smallest
>of the lot. Discuss!

well, even though the raumer bolts are longer they have a smaller contact area, just the small (<2cm) expansion sections. the body has to pull so you can't have that much grip just from the bash-in strength, actually i don't think bash-in strength should be considered at all, it has to pull while being tightened and manufacturer recommendations just say fit the bolt the exact size as the hole, ie don't expect any tension. so really you've got 2cm of contact length on ~8mm diameter, not 78mm of it, even if it is ift properly and done up tight.

in comparison the carrots are shorter but (potentially) have tension on a larger surface, depending on the amount of threading and tapering, and how the hole size compares to the size of the bolt. but its likely a fair bit more than the expansions, and hopefully in quite tight.

but.. from visual inspection when you're climbing you can't tell a great deal about a bash-in carrot, unless its actually wobbly you're still working on the assumption that whoever put them in did it right.

nmonteith
9-Feb-2009
9:38:49 AM
On 9/02/2009 anthonyk wrote:
>in comparison the carrots are shorter but (potentially) have tension on
>a larger surface, depending on the amount of threading and tapering, and
>how the hole size compares to the size of the bolt. but its likely a fair
>bit more than the expansions, and hopefully in quite tight.

Wouldn't any sort of taper mean that the part which is actually gripping is actually the 1mm section of the taper that 'fits' - unless the rock compresses when the bolt is driven in? (which is highly likely in the Bluies!). If you showed a carrot bolt to an engineer from Hilti or Ramset (I've done this!) they would freak out when you said we hang our lives on one of these and expect it to hold 2 tonnes.
AndyRicho
9-Feb-2009
11:00:47 AM
Neil, i don't think we should be making comparison's in the safety of carrots to that of the bolts used on the Croatian route, but thanks for your diagram as it will make what i'm about to write a little easier to understand.
As most would of seen on you tube by now these bolts came out very easily. While Simon and Mike were doing this footage i made my way down to the base of the cliff and removed a large number of bolts. What i found with ALL of them was they had little or no expansion, even after being tugged out with my hammer. I took some measurements off a bolt that had NO movement on 1 sleeve and the other had moved 1.8mm. The sleeve that hadn't moved measured 8.7mm at it's outer side and 8.3mm at the side that slides up the cone. These sleeves will compress slightly when the bolt is tapped into the correct sized hole in solid rock and have good contact with the rock when tightening to create good holding power. However the sleeve that had moved still measured 8.7mm at it's outer and 8.4mm at the side that slides up the cone. Almost NO expansion has happened at all. At this point clearly the force needed to hold the sleeve for expansion was less than that to crumble the rock in front of it and the bolts come straight out.
Sorry if my explination is a bit hard to understand but basically this style of expansion bolt just does NOT work in soft rock

nmonteith
9-Feb-2009
11:24:23 AM
Your explanation makes sense to me Andy! Thanks for filling us in on your theories. Has anyone tried drilling and placing one of these from scratch? I was thinking about trying it this arvo on some choss rock in Sydney. Someone suggested using a 7mm bit. I did notice that the bolt I was given was all gunked up with the typical 'mud' that you get in Blue Mountains rock - which would certainly stop much in the way of any expansion happening. My diagram was merely to demonstrate a size comparison with a standard Bluies carrot. Hopefully all these removed 8mm bolts can have a new life on a Buffalo slab somewhere. They look perfect for that job.

nmonteith
9-Feb-2009
11:30:03 AM
p.s. - i would have thought at worst the Raemer bolts should act like a carrot if hammered into a small hole. Certainly they work like that when hammered into good rock with the correct diameter hole. I'd happily whip onto one that hadn't been tightened, just hammered in to solid Grampians rock.
AndyRicho
9-Feb-2009
11:36:32 AM
I haven't tried it from scratch, but the bolts i removed ranged from 1 tug to quite a few good tugs to come out and they were all the same. i also tried tightening some first, after pulling the shaft through with no noticeable difference in the force required to move my spanner i pulled the bolt with the same result at the sleeve.

nmonteith
9-Feb-2009
12:06:06 PM
I still think that the initial drilled hole was oversized. They may have used an 8mm drill-bit, but in soft rock a shaky hand or blunt bit can easily make a hole larger. I know this from drilling carrot bolt holes - which rely on a very specific size. Hole sizes varies substantially depending on how you hold the drill (over head in awkward position you are much more likely to drill a larger hole). That's why I think the only real way of knowing for sure is to drill from scratch with 8mm bits and 7mm bits.
Onsight
9-Feb-2009
12:06:56 PM
Following on from what Andy has just said....

Another thing we noticed is that the very last (top) bolt on the route had a LOT more thread sticking out than any others that I saw. About 2cm sticking out.

This last pitch climbs up at an angle, so they either repositioned their rap rope several times or bolted on the way down (I think more likely) which would maybe make this the first bolt they placed on rap. All the other bolts had little thread sticking out (they looked good) but we could also loosen at least 90% of the nuts by fingers. This is just my theory, but it's almost as if knowing they were having problems tightening the bolts, their solution was simply to not tighten them much at all.

This is a translation of Cujics statement on a Croatian forum in relation to this:
"As the rock is soft 2-3 of them started rotating, and others were tight (at least then). What atmosphere conditions did later, it's the question. "

Onsight
9-Feb-2009
12:10:42 PM
>I still think that the initial drilled hole was oversized. They may have used an 8mm drill-bit,

Cujic says he used an 8mm bit.

These details make no diff Neil. Wrong bolts, shitfull job. End of story.

nmonteith
9-Feb-2009
12:12:10 PM
Did it look they they had rapped on any of their own bolts Simon? (ie was there mallions or rings on any of the hangers?). If they were rap bolting you would presume they would have had to unless they tied numerous ropes together.
mikl law
9-Feb-2009
12:12:21 PM
On 9/02/2009 nmonteith wrote:
>I still think that the initial drilled hole was oversized. They may have
>used an 8mm drill-bit, but in soft rock a shaky hand or blunt bit can easily
>make a hole larger.

I think that the sleeve on the Raumer bolts is larger than 8mm, they are compressed when banged into hard rock and can then be expanded by the cones cut into the shaft.
As you hit them into soft rock they ream the hole to their expanded size. Bashing them into an 8mm hole would probably end up with an 8.7mm hole, which they don't work in.

nmonteith
9-Feb-2009
12:16:47 PM
I'm just interested to know if you COULD make these bolts work ok in soft rock. If you can make them grip with a bit more thought, then it makes the Croatians even more negligent. I would think that after bolt 1 didn't tighten up properly then you'd start thinking of plan B. It seems crazy they they just continued placing more than 40 of these bodgy placements and then committed their OWN lives to this mess.
mikl law
9-Feb-2009
12:17:55 PM
On 9/02/2009 One Day Hero wrote:
>And yet the failure rate for carrots is quite low?!
True, but they don't get fallen on as often as rings (though there was a lot of airtime on BBB till all the loose holds were tested by gym bunnies).
They are ok in black rock (solid and dry inside) and quite poor on some orange steeper rock (where it may be wet inside). Either way their outwards strength is very poor (don't lean out on them)


>the wisdom of the blueys bolters from the eighties who were almost all
>pretty experienced and pretty cluey dudes.
But this is empirical experience (better than none), and we haven't done any modern testing of these.



nmonteith
9-Feb-2009
12:21:51 PM
On 9/02/2009 mikl law wrote:
>True, but they don't get fallen on as often as rings

Yes indeed - as seen yesterday Mike. I was unwilling to fall on your old carrots on the sea-cliffs but then whipped on the rings no probs.
AndyRicho
9-Feb-2009
12:22:00 PM
I think that's spot on Mike, along with Neil's piece about a blunt bit or shakey hand. The combination of the hole being slightly oversized from drilling, then getting reemed out more when the bolt gets bashed in, net result, nothing happens! Simon sums it up perfectly, wrong bolts, shit job!!!!!!!!
Onsight
9-Feb-2009
12:35:32 PM
On 9/02/2009 nmonteith wrote:
>Did it look they they had rapped on any of their own bolts Simon?

They have said that they did.

They have also said they tested the bolts for downwards pull but not outwards.

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There are 196 messages in this topic.

 

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