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Chockstone Forum - Gear Lust / Lost & Found

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 Page 1 of 2. Messages 1 to 20 | 21 to 26
Author
Petzl Pro Traxion Good all round Pulley Choice?
Adc
16/10/2011
9:49:49 AM
Hi people

Some advice Please

Need a pulley system for big wall
Is the Petzl Pro Traxion Pulley the best all round choice?

Thoughts, value, alternatives?

Have Jumars but yet to purchase a stand along pulley

Thanks
Lee C
16/10/2011
11:59:15 AM
I've found it to be way better than a mini traxion for heavy hauling and worth the weight but would go for the mini if only doing one to one hauling. Also the mini traxion is great for self belay on a fixed (must be static) line.
Adc
16/10/2011
12:13:05 PM
Thanks
So the mini would do for basic hauling and all round big wall device?

Lee C
16/10/2011
12:22:19 PM
it's ok until your load gets heavy. You really notice the difference between the two pulley sizes once you're hauling more than about 40kg. If you only wanted one and you were doing a multi-day wall the pro would be the way to go.
Mr Poopypants
16/10/2011
1:01:30 PM
Hey, Lee, pardon my ignorance but why do you have to use a static for self-belay with the mini-traxion. I've used it a fair bit with dynamics, as well. Am I on a path to self-destruction??? (Apart from my usual one???)

G.
Lee C
16/10/2011
1:44:31 PM
yeah likewise and i wouldn't not use it on a dynamic but just gotta be careful not to fall to far on to it as they're not rated for dynamic load (maybe 2.5KN from memory).

sliamese
16/10/2011
4:03:32 PM
A big pulley rigged with an ascender both on the same screwgate works quite well too! Pro is nicer than mini when u dont have to unclip it to open the side panel too! So go the pro/big pulley if your doing any long routes!

IdratherbeclimbingM9
16/10/2011
5:03:35 PM
On 16/10/2011 Lee C wrote:
>Also the mini traxion is great for self belay on a fixed (must be static) line.
&
>yeah likewise and i wouldn't not use it on a dynamic but just gotta be
>careful not to fall to far on to it as they're not rated for dynamic load
>(maybe 2.5KN from memory).

?
I would have thought that a dynamic rope would be a HUGE advantage in that situation in reducing the loading on both the gear and the climber.
~> You might want to rethink that strategy; ... though the obvious answer is not to fall in the first place!

gnaguts
16/10/2011
5:31:51 PM
Yeah spot on M9, dynamic loading occurs when an object falls onto a static point.
Whereas a static loading is where an object is hanging from a static or fixed point.
Nothing to do with what rope you use just the way that you fall or rest on said ropes.
the use of Kn in a rating refers to the ability of the item to withstand dynamic loading.
the use of Kg indicates that the load is static and is not Kinetic

gnaguts
16/10/2011
5:50:08 PM
In reply to the OP I would save my $$ and just go with an auto block of some kind on a nice wide pulley as this is easier to haul than a small pulley, an ascender clipped to the pulley biner has been suggested, but a prussic would work just as well but would be lighter !
Ive done a lot of hauling in the past, and found that by rigging high anchors it was possible to avoid using 3:1 systems and just use my body weight as a Stomper 1:1.

I would hang off the other side of the pulley on a jumar from my harness held upright with a chest harness/sling and then pull up on the other rope going down to the pig with another jumar facing down, just be sure to put a lanyard on the downward facing jug so it doesn't go down the rope and get out of reach.

IdratherbeclimbingM9
16/10/2011
5:56:38 PM
On 16/10/2011 jammin wrote:
>dynamic loads occur when an object falls onto a static point.
>Whereas a static load is where an object is hanging from a static point.
>Nothing to do with what rope you use just the way that you fall or rest
>on said ropes.

Hmm.
The homework I have done would indicate that it is not a 'static point', (we might be interpreting things differently here), but the ability of the fall point to dynamically absorb the loading applied to it, hence a dynamic rope is ideal in this situation.

Think, fall verses rest. If one falls and same is statically arrested then huge loads on all components involved, but if one (even very softly) loads a point statically regardless of rope type, then the load is held statically.


I agree with the above suggestions of using wider pulleys for heavier loads.

Regarding prussik vs ascender holding the load between hauls, one can obtain 'prussik minding' pulleys that serve this purpose very well, as they have a flat edge that causes the prussik to bunch up under haul which tends to loosen it and alllow the process, but doesn't stop the prussik grabbing the load when under tension.

gnaguts
16/10/2011
6:03:33 PM
On 16/10/2011 IdratherbeclimbingM9 wrote:
>On 16/10/2011 jammin wrote:
>>dynamic loads occur when an object falls onto a static point.
>>Whereas a static load is where an object is hanging from a static point.
>>Nothing to do with what rope you use just the way that you fall or rest
>>on said ropes.
>
>Hmm.
>The homework I have done would indicate that it is not a 'static point',
>(we might be interpreting things differently here), but the ability of
>the fall point to dynamically absorb the loading applied to it, hence a
>dynamic rope is ideal in this situation.
>
>Think, fall verses rest. If one falls and same is statically arrested
>then huge loads on all components involved, but if one (even very softly)
>loads a point statically regardless of rope type, then the load is held

post edit:
I think re reading this that the word "load" and "loading" are at fault in the confusion.
>statically.
>☺

If an object falls onto a static point (Anchor) then this is dynamic/kinetic loading.
if using a static device to catch said load (low stretch rope or static slings or worst case scenario chain or cable then the dynamic/kinetic force/energy is absorbed without any stretch or absorption, this is called a shock loading, and is usually fatal.

I think the word dynamic is sometimes an easy one to confuse with the types of loadings and the types of equipment we have at our disposal these days.
I hope this clears up any confusion.

IdratherbeclimbingM9
16/10/2011
6:10:18 PM
Fair enough.
We were using different interpretations.

gnaguts
16/10/2011
6:28:27 PM
Cool, we're just caught up in the vernacular, but I also agree with what you have posted
in regards to the science of fall arrest it is something that I see as being the most difficult for climbers to comprehend in terms of the forces involved.
I saw a lead fall where the leader ripped four pieces on a big whipper, and the gear was thrown off the rope through biner rattle or chatter.
The final biner that held the fall was stretched open because as it was chattering the nuts wire got caught in the gate notch of the biner , forcing it to stretch to near failure.
the lucky binder was rated to 2.5 ton, the climber was a lightweight.
Lee C
16/10/2011
6:58:10 PM
On 16/10/2011 jammin wrote:
>Yeah spot on M9, dynamic loading occurs when an object falls onto a static
>point.
>Whereas a static loading is where an object is hanging from a static or
>fixed point.
>Nothing to do with what rope you use just the way that you fall or rest
>on said ropes.

I agree with the theory here and it probably rings true for most situations in climbing...but having used both dynamic and static there is obviously a vast difference in how far you fall before you stop resulting lots more acceleration and subsequent force and sure this extra force is distributed over a longer period of time with the dynamic but it definitely seems to outweigh the force when using a static rope.

Additionally probably the biggest problem with toothed devices is that when they "fail' it is in fact the rope sheath that fails (first) and a static sheath is vastly better in that regard.
Adc
16/10/2011
7:25:06 PM
Thanks Might go with the Pro then
patto
16/10/2011
7:50:30 PM
On 16/10/2011 Lee C wrote:
>I agree with the theory here and it probably rings true for most situations
>in climbing...but having used both dynamic and static there is obviously
>a vast difference in how far you fall before you stop resulting lots more
>acceleration and subsequent force and sure this extra force is distributed
>over a longer period of time with the dynamic but it definitely seems to
>outweigh the force when using a static rope.

A quick calculation shows that your assumption is incorrect

If you assume ZERO SLACK in the rope then the subsequent peak force is 2x body weight regardless of the elasticity of the rope. Thus the force on static and dynamic ropes is the same.

As soon as there is slack in the system then the dynamic rope being more elastic will give lower peak forces. For the large amount of slack in lead falls obviously a dynamic is required to keep peak forces at survivable levels.
Lee C
16/10/2011
8:41:26 PM
Yeah like I said I agree in theory but I suspect there's more to it...

Rocker
16/10/2011
9:17:32 PM
Patto, could you please clarify?

On 16/10/2011 patto wrote:
>
>A quick calculation shows that your assumption is incorrect

F=MxA

>If you assume ZERO SLACK in the rope then the subsequent peak force is
>2x body weight regardless of the elasticity of the rope. Thus the force
>on static and dynamic ropes is the same.

F= 80kg (800nm) climber x 0 Acceleration
Therefore the force (or weight) on the rope is 80kg, how can it be 2x?
Yes, in this instance there would be no difference between ropes.

>As soon as there is slack in the system then the dynamic rope being more
>elastic will give lower peak forces. For the large amount of slack in
>lead falls obviously a dynamic is required to keep peak forces at survivable
>levels.

F= MxA
F= 80kg climber x decceleration from a fall
Therefore a static rope has a higher decceleration resulting in a higherforce produced in a fall.

It would be logical that a dynamic rope would therefore be best used in a self belay... But ive been wrong before!


skink
16/10/2011
9:35:33 PM
On 16/10/2011 jammin wrote:
>the lucky binder was rated to 2.5 ton, the climber was a lightweight.

shouldn't that be 'rated to 25kN' ;-) or was this biner specifically designed for 'static' loads?

 Page 1 of 2. Messages 1 to 20 | 21 to 26
There are 26 messages in this topic.

 

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