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Burning Ropes on Lead Fall

Jakob

15-Jun-2013
6:17:22 AM

So I have been trying to break into new grounds in my climbing lately which has involved a lot of lead falls in an indoor gym (don't judge me, I've just moved from NSW to Florida which is an 8 hour drive from the nearest climbable rock). One route in particular has a crux that I am constantly falling on with my feet above the last draw, so I am maybe coming down 5 - 6 metres after pulling my belayer off their feet. I'll then climb right back up, then fall again.

After a recent session, I noticed that my brand spanking new, Mammut infinity 9.5m dry treated rope has some pretty significant friction burning over the sheeth. Its rough enough to have gone from buttery smooth clips to giving me rope burn as I pull up to clip. I bought myself a 9.8mm short gym rope, dry treated as well. After one session with maybe 8 lead falls on this new rope I noticed the beginnings of the same burning on the sheath. The sheath is becoming rough to touch, sort of like if you ironed it and it has slightly melted.

I have worked routes outdoors with my own draws, taking the same number of lead falls working a crux and have never experienced this type of damage to my rope. I'm wondering if this is due to using the aluminium draws as opposed to steel. Maybe steel has higher friction / lower heat dissipation?

Has anyone ever experienced this? A google search revealed nothing!

trog

15-Jun-2013
6:36:52 AM

Not sure about relative heat dissipations & it seems pretty quick, but it's quite easy to glaze (and flatten) ropes like this on long abseils &/or multiple people in quick succession using racks with aluminium bars + static ropes...

I've often seen some people clip into the gear and to let the rope rest, to recover some elasticity after a fall. Although I think it takes a while to recover properly and the real reason they clip in is probably closer to stopping their belayer from lowering them that crucial 20cm..., can't find the link I'm thinking of.
Would also give time for the heat in the biner to dissipate a bit too.

http://www.rockandice.com/lates-news/using-steel-carabiners-for-fixed-quickdraws

Maybe lower off and start again on the other end? good for you anyway :)

latch

15-Jun-2013
7:08:46 AM

I had a rope pretty badly burnt once in a gym. A heavier friend took a large fall and managed to scorch about 1.5m of the sheath. At the time I thought it was due to the lack of friction in the system (all draws were in a straight line on an over hanging wall) meaning that the load was only on the draw he fell on and not spread across the system like it would be in most cases on a real route. Might be wrong though.

IdratherbeclimbingM9

15-Jun-2013
9:08:13 AM

On 15/06/2013 latch wrote:
>I had a rope pretty badly burnt once in a gym. A heavier friend took a
>large fall and managed to scorch about 1.5m of the sheath. At the time
>I thought it was due to the lack of friction in the system (all draws
>were in a straight line on an over hanging wall) meaning that the load
>was only on the draw he fell on and not spread across the system like it
>would be in most cases on a real route. Might be wrong though.

It is the nature of the ropes used these days. Never used to happen when we climbed on manilla...
;-)

Seriously, I reckon latch is on the money. That combined with a hard catch (grigri anyone?), means the rope is getting a pretty good workout, and when in a concentrated portion of the rope, would easily give that kind of glazing as a result.

On 15/06/2013 Jakob wrote:
>I have worked routes outdoors with my own draws, taking the same number
>of lead falls working a crux and have never experienced this type of damage
>to my rope. I'm wondering if this is due to using the aluminium draws as
>opposed to steel. Maybe steel has higher friction / lower heat dissipation?

I doubt the heat retention in the top krab would be significant, given that you are working the route and climbing back up to it. I am not a physics guru but understand enough of it to know that if you add time to the equation of forces involved (slippage/softer catch), then this helps dissipate the force and the default heat-byproduct in all parts of the system (including the rope), involved.

I would also expect that if repeated falls are taken on a select portion of rope that doesn't have time to recover then that portion of rope would start behaving more statically, (read plastic vs rubber-band behaviour), and any missing stretch (default force absorbtion), would translate into higher heat byproduct.

Jakob

15-Jun-2013
9:16:32 AM

Yeah, come to think of it it was a dead straight climb on a vertical wall. I still feel it might have something to do with the steel biner. As far as the catch goes, it was super soft. ATC and I was moving the belayer about 2m. Very comfortable falls. I guess thats the reason I have 2m of rope that is now burnt!!!

IdratherbeclimbingM9

15-Jun-2013
9:29:04 AM

On 15/06/2013 Jakob wrote:
(snip)
>I still feel it might have something to do with the steel biner. (snip)

I think material the krab is made of is less significant in your scenario than the radius's involved.
You are using a thinnish lead rope, made thinner by repeated falls on it with minimal recovery time, and if those falls are caught by a small radius then you are making the rope work pretty hard.
A slightly larger radius catch would be kinder to the rope, but having said that, even a bigger radius catching-krab is easily exceeded in it's ability to contribute any significant force/heat dissipation, given the work-out you are subjecting it too.

I won't be buying your used ropes when you have finished with them!
Heh, heh, heh.

Miguel75

15-Jun-2013
1:25:54 PM

Was your belayer using a grigri? The only time I've glazed a rope was using my grigri as part of my ascending/descending rig. I was cutting laps on an ~20m climb and after the session noticed I'd glazed a fairly lengthy length of it:)

Who else has glazed a rope? How'd you do it?

White Trash

15-Jun-2013
1:32:00 PM

On 15/06/2013 Miguel75 wrote:
>Was your belayer using a grigri?
jacob wrote;
"As far as the catch goes, it was super soft. ATC and I was moving the belayer about 2m. Very comfortable falls".

sounds to me like the belayer had the rope locked off instead of allowing slippage?

>Who else has glazed a rope? How'd you do it?

abseiling.

Miguel75

15-Jun-2013
1:49:13 PM

On 15/06/2013 White Trash wrote:
>On 15/06/2013 Miguel75 wrote:
>>Was your belayer using a grigri?
>jacob wrote;
>"As far as the catch goes, it was super soft. ATC and I was moving the
>belayer about 2m. Very comfortable falls".

I don't read so good;)

E. Wells

15-Jun-2013
7:13:22 PM

So heres what to do. Chop your rope if your not comfortable with it, then climb some more and trash it melt it rough it up blow it out, then chop it again....repeat process.

There are 10 messages in this topic.