Fires in Cape Town and Bolts

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XMod
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Re: Fires in Cape Town and Bolts

Post by XMod » Fri Mar 13, 2015 5:34 pm

Hi ok got a reply from Fischer. This is the table the guys doing the test produced for them. Hmm Im not a scientist type (shouldn't the loads be ten times that??? :? - no details were given about the test - sorry) but it seems that 1 hour of exposure would probably not weaken it to a level that need concern us (green) 1.5hrs is getting dodgey (yellow) and at 2hrs we are down to 0.6KN which is borderline or below (red). Im gonna forward this to ARF and MCSA types, it would be nice to have more details about the nature of test but as they were performed in 2004 and 2006 it may not be possible to get that info.
fire test.png
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Ive tried going through some videos from the fire but cant get any idea how long the fire raged at the crags - and there are a few crags that are affected.

So Nic (or someone) maybe you need get the pull rig organised although if you stick to non-destructive levels of force you may not be able to draw any conclusions from testing(?)

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Re: Fires in Cape Town and Bolts

Post by Katherine » Sat Mar 14, 2015 2:17 pm

Hi guys, I know nothing about anything on the topic, but I just wanted to say thank you to all of you for taking the time to investigate on something which affects all of us climbers.

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Re: Fires in Cape Town and Bolts

Post by Guardian » Sat Mar 14, 2015 3:16 pm

I do not know anything about bolts, or engineering, so delete this post if it doesn't help, but I like graphs.
Just want to say that I don't agree with you, XMod, that 1 hour is not a problem based on what I see in that table.

The graph shows that the major damage is done by 60 minutes. And from there it levels out.
If you extrapolate the trends of these graphs then the most significant reduction in kN would be in the first 30 minutes of fire exposure.
Since bolts should have a pull out resistance of 15 kN, I would guess that is where these started, and then the first 30 minutes have around the same damage as the next 30 minutes.
Also, I don't like the < signs in front of the values. If it fails at anything lower I would like to know that, these should be minimum strength.
My thoughts, not sure I understand the table and the experiment correctly.

I also do not understand the table caption as it mention sizes (M8-M16) which are not present in the table as well as three different Bolt types also not present in the table.
I would guess the table only shows relevant results to your query ?
More info on the fire conditions for this test, as well as the crags would be useful. The tests are probably done with constant direct fire which I would not expect in a veldfire for such time spans.
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Re: Fires in Cape Town and Bolts

Post by XMod » Sat Mar 14, 2015 5:19 pm

Yes, graph is interesting. Im not sure about the test table either. The test (as stated) is for threaded bar set into reinforced concrete. The bolts we use have knurling along the shaft not threads and of course we are going into rock. I assume the different types of anchors pulled at similar values.

As far as I can see, the values are; the maximum force which the fixing will still withstand after that length of exposure to fire, which would explain the less than or equal to signs, in other words they will hold forces less than or equal to the value.

Yes the fire exposure in a lab is a constant temp - wildfire is not likely to be anywhere near that intensity and duration.

The values also appear very low - if correct they are actually way below spec for climbing anchors - so my assessment of safety is not correct. So please ignore that comment and pretty colours on the table.

There is obviously more to the report which I have not duplicated here - if interested PM me and I can mail you a copy of the complete report. Also Fischer are more than willing to help us with any further queries, I agree the report (even the complete version) is brief and does not give any details about the methods or circumstance of the test (concrete failure or glue failure for example), it would be nice to know more from Fischer, so, if anyone has specific questions please post up so we can forward it on.

How relevant this fire test is to our own situation is highly debatable - I was just trying to determine what exactly a rating of F120 was.
As I said above; pull testing is the reliable way to check the anchors and U-Pat SA recommended we pull test them.

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Re: Fires in Cape Town and Bolts

Post by Wes » Mon Mar 16, 2015 10:33 am

Firstly, thanks guys for all the effort researching this.

I see a problem with the table and the graph, that there is no indication of temperature, this is a pretty important variable as some fires burn fast and hot and others slow and cooler.

I'm all for non-destructive pull testing a few lower bolts at the affected crags.

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Re: Fires in Cape Town and Bolts

Post by XMod » Mon Mar 16, 2015 5:34 pm

Wes the table is from a laboratory fire test where the temp is constant for that period. I don't know what temps were used nor the nature of failure etc.

Pull testing needs to be done.

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Re: Fires in Cape Town and Bolts

Post by Nic Le Maitre » Thu Mar 19, 2015 10:14 am

Right, so Dion Tromp of High Angle has said he will do some non-destructive pull testing for us with the proviso that someone will have to go to Peer's Cave, Lakeside and Silvermine to have a look at the bolts, see which ones are "high risk" (close to vegetation/low down/epoxy looks damaged) and come back with a list of bolts that should be checked. So volunteers please? I know that there is a large sport climbing community in CT and this is wholly in your interest, so if you would please step forward.
Happy climbing
Nic

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Re: Fires in Cape Town and Bolts

Post by Thermophage » Thu Mar 19, 2015 1:19 pm

Nic Le Maitre wrote:Right, so Dion Tromp of High Angle has said he will do some non-destructive pull testing for us with the proviso that someone will have to go to Peer's Cave, Lakeside and Silvermine to have a look at the bolts, see which ones are "high risk" (close to vegetation/low down/epoxy looks damaged) and come back with a list of bolts that should be checked. So volunteers please? I know that there is a large sport climbing community in CT and this is wholly in your interest, so if you would please step forward.
There is a large sport climbing community in CT...They also are very actively involved in ARF... :lol:
I can go check em out sometime. going to Kalk Bay tomorrow after work so will check if anything burn there while we're up there so long.

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Re: Fires in Cape Town and Bolts

Post by Nic Le Maitre » Thu Mar 19, 2015 1:41 pm

Thanks Cuan.
Happy climbing
Nic

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Re: Fires in Cape Town and Bolts

Post by XMod » Sat Mar 21, 2015 3:20 pm

Thanks Cuan - but are we allowed back in there yet? Notices on TMNP website say not. Amping to get on my proj and also to renovate a bunch of rusty top anchors with nice shiny stainless steel clip-in anchors (gear's just sitting here waiting....)

I would also be willing to do an inspection but only when allowed by the park. Im glad someone has undertaken to pull test - U-pat said we must do it - makes sense.

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Re: Fires in Cape Town and Bolts

Post by Thermophage » Sat Mar 21, 2015 5:35 pm

I'm going to Kalk bay...the crag didn't look too burnt from the road.
But we had to cancel as partner was stuck in traffic ;(

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Re: Fires in Cape Town and Bolts

Post by Nic Le Maitre » Sun Mar 22, 2015 2:48 pm

Anyone feel like contacting SANParks to see if we can arrange access to check? I've heard a tentative timeframe of 4-6 months for Silvermine and up to 2 years for Tokai
Happy climbing
Nic

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Re: Fires in Cape Town and Bolts

Post by XMod » Mon Mar 23, 2015 1:17 am

Could possibly be arranged, contacting Leighan Mossop directly would be the best approach. Im not prepared to give her a call lest I get accused of falsely claiming to represent MCSA by a certain member again (falsely accused I might add - do wish ppl would find out the facts before throwing their weight around, tut tut!). Probably Cormac or Cuan should do it as they are the ARF peeps.

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Re: Fires in Cape Town and Bolts

Post by Thermophage » Mon Mar 23, 2015 8:53 am

Yo peeps,

I'll bring it up at our MCSA Rock Sub Committee meeting on Wednesday evening.
Bunch of the people have contact with TMNP and we'll chat about getting in touch.

Cheers,
Cuan

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Re: Fires in Cape Town and Bolts

Post by Wes » Mon Mar 23, 2015 9:15 am

Nic Le Maitre wrote:Anyone feel like contacting SANParks to see if we can arrange access to check? I've heard a tentative timeframe of 4-6 months for Silvermine and up to 2 years for Tokai
If history is anything to go by. The ban will be lifted long before you are able to secure permission.

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Re: Fires in Cape Town and Bolts

Post by ShaolinWood » Mon Mar 23, 2015 3:49 pm

Thanks for all the research and info!

Don't know if it's worth a thought but I'm actually more worried about the rock than the anchors.
I looked around at some of the destruction around where I stay and one thing I picked up was the amount of shattered rock.

The heat caused many of the rocks and boulders to crack and literally pop. Mostly flakes from the top layers of rock but there was quite a few large chunks that came off...

So maybe a good idea to just go out with helmets for a while?
Also give some of those familiar holds a good knock to see if they're still solid...
Cheers
Gerhard

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Re: Fires in Cape Town and Bolts

Post by Thermophage » Mon Mar 23, 2015 3:54 pm

It is HIGHLY unlikely any of the crags were affected in any significant way above even the first bolt.
Most crags were not heavily vegetated at their base either.
But lets go pull a few for piece of mind...or just take some trad gear, place that and skip bolt no.1 :)

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Re: Fires in Cape Town and Bolts

Post by XMod » Tue Mar 24, 2015 1:12 am

Yes Shaolin you are right, I too am more concerned about the rock than the bolts - but we must pull test them anyway for peace of mind. Helmets are always a good idea but very much more so after fire. As you say it is normally fine exfoliation flakes that come off (these are however very sharp, come off without warning and can cut you badly if they land on you). Once the crags do open everyone should exercise caution for a good while afterwards.

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Re: Fires in Cape Town and Bolts

Post by Justin » Tue Mar 24, 2015 7:53 am

My 2 cents.

Find some boulders or piece of rock and install a variety of bolts.
Apply a flame thrower (varying heat and durations).

Test pull the bolts and assess from there on.

I'm concerned (I'm also not an engineer) that testing the bolts could put unnecessary strain on the bolts and weaken them.
One of the first bolts to fail at Silvermine main was a mechanical anchor that withstood a HUGE (intentional) fall.
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Re: Fires in Cape Town and Bolts

Post by Thermophage » Tue Mar 24, 2015 8:18 am

Justin wrote:My 2 cents.

Find some boulders or piece of rock and install a variety of bolts.
Apply a flame thrower (varying heat and durations).

Test pull the bolts and assess from there on.

I'm concerned (I'm also not an engineer) that testing the bolts could put unnecessary strain on the bolts and weaken them.
One of the first bolts to fail at Silvermine main was a mechanical anchor that withstood a HUGE (intentional) fall.
Good idea Justin...I know of some good boulders up Echo Valley which we could put some bolts in and test :thumleft: hehehe

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Re: Fires in Cape Town and Bolts

Post by Nic Le Maitre » Tue Mar 24, 2015 8:58 am

FWIW: The guy who has volunteered to do the pull testing is Dion Tromp of High Angle who has loads of experience in this area. Installing and pull testing of anchors is something he does routinely. The aim is not to pull to failure but to see if it can still handle a load, say 10kN, that it should be able to handle without trouble if the glue is undamaged.
Happy climbing
Nic

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