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The big trad gear destructo challenge


Superstu

5-Nov-2010
12:03:47 AM

Oh dear. The website was a little more popular than I expected, and now its exceeded the monthly bandwidth (and its only the 5th!) and gone in a sulk. I can't even access it to move it somewhere else. Jumba sucks.

mikllaw

5-Nov-2010
7:26:09 AM

can we throw some $ at you to aim at the problem?


Superstu

5-Nov-2010
8:32:50 AM

As you probably guessed from the domain name, the destructo site was just piggy backed onto something else (which isn't ready to face the world yet). I'm still pretty surprised I exceeded the bandwidth limit so quickly (10Gb/month). I think I'll have to move it elsewhere, I don't like this current provider's method of shutting the site down if you exceed your plan; other hosting services use throttling (your site just gets slower) but at least you can continue to operate. Give me a few days to sort it out.

Anybody out there in chockersland do this stuff all the time and can recommend a better provider?


Superstu

5-Nov-2010
12:23:19 PM

Back on line ~ for the moment.

A little OT, but is this normal for a little webernet page? What does chockers click over in a month?

Visits Pages Hits Bandwidth
01 Nov 2010 148 3912 8746 1.68 GB
02 Nov 2010 256 4015 9508 2.35 GB
03 Nov 2010 281 3930 10277 2.87 GB
04 Nov 2010 367 4288 11458 3.25 GB

I got a 25Gb limit now for the month. Already up to 10Gb. Will have to move it to a transfer-limit free web host. Ambyeok I will be speaking to your Bangladeshi friends...

The list of countries is even weirder. I didn't even know they had climbing in Costa Rica. All I remember was bull fights, babes and beaches.
.


ajfclark

5-Nov-2010
12:33:15 PM

Your PM box is full


Superstu

5-Nov-2010
12:51:04 PM

Emptied

patto

5-Nov-2010
1:00:36 PM

On 5/11/2010 superstu wrote:
>Back on line ~ for the moment.
>
>A little OT, but is this normal for a little webernet page? What does
>chockers click over in a month?
>
> Visits Pages Hits Bandwidth
>01 Nov 2010 148 3912 8746 1.68 GB
>02 Nov 2010 256 4015 9508 2.35 GB
>03 Nov 2010 281 3930 10277 2.87 GB
>04 Nov 2010 367 4288 11458 3.25 GB
>
>I got a 25Gb limit now for the month. Already up to 10Gb. Will have to
>move it to a transfer-limit free web host. Ambyeok I will be speaking to
>your Bangladeshi friends...
>
>The list of countries is even weirder. I didn't even know they had climbing
>in Costa Rica. All I remember was bull fights, babes and beaches.
>.

Nothing surprising there. The ratio of visits to bandwidth seems to make sense. It seems like there is 10Mb per visit. Not surprising since you have 7mb of pdf files!

Take those pdfs down right now and shrink them to 1mb or so.

kieranl

5-Nov-2010
10:04:44 PM

On 5/11/2010 superstu wrote:
>Back on line ~ for the moment.

>The list of countries is even weirder. I didn't even know they had climbing
>in Costa Rica. All I remember was bull fights, babes and beaches.
>.
Meg has a cousin who owns a bar in costa Rica but I don't think she'd be looking at a climbing site.

Rolsen1

6-Nov-2010
7:59:46 AM

On 5/11/2010 superstu wrote:
>Back on line ~ for the moment.
>
>I got a 25Gb limit now for the month. Already up to 10Gb. Will have to
>move it to a transfer-limit free web host. Ambyeok I will be speaking to
>your Bangladeshi
>

You can also consider moving your static files over to amazon S3 it's cheap and fast - I think new users get 15GB free per month for a year

davereeve

6-Nov-2010
10:16:58 PM

Very nice work guys....real world results rock!


pmonks

7-Nov-2010
5:25:41 AM

On 3/11/2010 superstu wrote:
>A haul bag with rocks will behave a little differently to a human. Perhaps
>we borrow pmonk's blow up sex doll and fill it with water?

I'm not sure a blow up sheep full of water will be a better approximation of a human body...


Zane Priebbenow

8-Nov-2010
1:57:10 AM

Great work on all the testing and publishing of results!

On a related topic of sorts, came across this destruction testing video from DMM on slings. It demonstrates the catastrophic scenario of falling onto a sling attached to your anchor, with interesting results for Nylon over Dyneema. Most climbers would be conscious of the dangers in even a small fall on a static line/sling etc. but this video certainly drives home the concept...

http://www.dmmclimbing.com/video.asp?id=5

True that the solid test load used doesn’t replicate the shock absorbing characteristics of a human body, but still an interesting demo.
Apologies if already posted somewhere here before.


ajfclark

8-Nov-2010
7:23:19 AM

Previous discussion on this including this video:

http://www.chockstone.org/Forum/Forum.asp?Action=DisplayTopic&ForumID=6&MessageID=13258&Replies=42&MsgPagePos=-1
http://www.chockstone.org/Forum/Forum.asp?Action=DisplayTopic&ForumID=1&MessageID=90489&Replies=32&MsgPagePos=-1

mikllaw

8-Nov-2010
8:53:08 AM

On 8/11/2010 Zane Priebbenow wrote:
> It demonstrates the catastrophic scenario of falling onto a sling attached to your anchor.
And that's why they invented climbing ropes....
I still don't understand why anyone would do this, will they also release videos on the dangers of ramming nut tools into your eyeball, supergluing your willy into a finger crack, or getting a dull job?
-Rant over-
There was a nasty double fatality at The Needles some years back where a belay failed, i wonder if this could be the cause? Not only are possioble forces higher, but they can pull in much crazier directions.
If you are 1m right of a belay and you fall on a rope the load will still be pretty much straight down (stretch and the fact that the anchor rope is running back to the belay all conspire to reduce the effective angle of loading).
If you fall on a sling you could develop forces that have a large horizontal component, gear doesn't always like this.

One Day hero

8-Nov-2010
6:05:05 PM

I love the guy who thinks that a bunch of old wires breaking at 120% of their rated load is a good demonstration of why old gear is so unreliable!?!

What's the point of doing scientifical testing? Should give out all safety info in pamphlets with large, colourful font and no words more than 4 letters!

One Day hero

8-Nov-2010
6:24:08 PM

I have a mate who sets every wire to somewhere around bodyweight with a cool whipping action of the whole arm.....you can hear the thudding through the rock from 50m away! His grumbling seconds (including me) usually have something to say about this process but......I've never seen a single one of his wires get lifted out by the rope or fail in a fall. That horizontal choss placement which pulled at 30kgs would have been filtered out by the Valdivia nut-setting method.

One Day hero

8-Nov-2010
6:33:49 PM

On 1/11/2010 Wendy wrote:
>Does that pull cylinder shock load them or gradually increase the force?
>
Cool, I want a shock-loading cylinder.......bet wendy is thinking of the 'testing rig' in No Country for Old Men.....maybe having a little mixed up fantasy about doing some rebolting work with Javier Bardem? ;)


jam

9-Nov-2010
11:27:51 AM

Just a note but a potentially important one... On the breaking forces explained page you state:

"One Newton is the amount of net force required to accelerate a mass of one kilogram at a rate of one meter per second per second. A kilonewton is 1000 of these units. This is equivalent to the force a mass of ~ 1000kg is subject to under gravity."

Actually a kN is equivalent to the force of a static load of 100kg under gravity, because 1kg exerts a 10N force under gravity. So just divide any newton rating by 10 to get the equivalent kilogram loading.

It's also important to note though that kN ratings mean much more useful than "kilogram ratings", since the kg rating assumes that the mass is static (not moving). So you could theoretically hang 1000kg off a bomber placement without it failing, but what's more relevant is that you'd be able to stop a 100kg mass (a person) falling at 10m/s (a 1 metre fall under gravity) through a perfectly static rope (obviously not that relevant to climbing since our rope is all dynamic, but calculating dynamic rope loading is much harder, and this gives you a ballpark figure).

mikllaw

9-Nov-2010
12:13:47 PM

On 9/11/2010 jam wrote:
> but what's more relevant is that you'd be able to stop
>a 100kg mass (a person) falling at 10m/s (a 1 metre fall under gravity)
>through a perfectly static rope

No, the force would be infinite
You are confusing F=ma (definition of a newton) with Momentum (mv) or kinetic energy (1/2 mv^2). To absorb the kinetic energy you need to do work =Fd , force (rope tension) x distance (rope stretch) over which that acts.


jam

10-Nov-2010
3:33:56 PM

you're right of course - it's been a while since my high school physics days and i got speed and acceleration switched up!

so i guess what you really need is the deceleration of the falling climber to calculate the force exerted on the equipment.. which i imagine is really hard to calculate since we don't know how long it takes for the climber to stop?

also i can see that the kinetic energy absorption is relevant to the rope, since there is obviously a limit to how much KE a rope can absorb but is it possible to relate it to the force exerted on the equipment?

please understand i'm not trying to question you or have a go - i'm just interested in figuring out what the correct maths is, because once i can understand that, i can apply the maths to various situations and i'll have a much better idea of how good my equipment and placements are (especially with the data you've collected - thanks for that by the way :) )

oh, and force in newtons is still 10 x mass in kg (roughly) since acceleration due to gravity is 9.8m/s/s - so 100kg exerts ~ 1kN

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