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damaged 9mm rope analysis

Superstu

2-Feb-2015
7:56:49 AM

I climb on 9mm double ropes a lot. The 50m rappability is nice, also the safer clipping. The downside is that when you get a slightly damaged section along the rope you get super paranoid with such a thin rope. I found one such fuzz the other weekend and running two pinched fingers along the rope confirmed a narrowing "flat" spot which spooked me no-end. Being only 1.5m from one end, the rest of the weekend was spent jostling with my climbing partner for who gets to tie into the "dodgy end", antics with tie-ing in short and so on.

Back home it was time to chop the end and make a less practical but more re-assuring 45m rope. I thought I should open up the rope after the chopping to see what was actually going on under the sheath. From the photos the fuzz on the sheath does not look that serious but you'll just have to run with me here as it definitely "felt" very flat (or at least permanently compressed) at the point of concern, which is the normal way I determine whether rope damage is superficial or serious.

The result seems to show no actual damage to the core. Interesting to look at the inside cores anyway which look a lot more compressed and flaky then I was expecting. In hindsight I should have asked mikl if he's up for dropping a beginner off an edge with this rope and see if we can break it under the appropriate strains. I'll have to wait until I get another scarey fuzzy compressed section in the rope again.

The good Dr

2-Feb-2015
9:41:00 AM

A flat spot on the rope can ocur from either, or a combination of sheat and core damage. It is not possible to know if the core is damaged unless you cut the rope apart, so it is always better to be safe than sorry.

Snacks

2-Feb-2015
10:49:44 AM

On 2/02/2015 Superstu wrote:
>Being only 1.5m>from one end, the rest of the weekend was spent jostling with my climbing
>partner for who gets to tie into the "dodgy end", antics with tie-ing in
>short and so on.
>
>Back home it was time to chop the end and make a less practical but more
>re-assuring 45m rope.

Why'd you chop the extra 3.5m? :P

I think you're still right in chopping it irrespective of what any tests show. You'd need to do drop tests rather than a gradually increasing load test anyway which means you'd need plenty of "similar" samples...

If in doubt, chop it out! (Same maxim as the debolting guys)

jprockbelly

2-Feb-2015
11:36:15 AM

Slightly off topic, but I'm curious to know if anyone has heard of a climbing rope actually breaking. I know there are several instances where they have severed over sharp edges, but has there ever been a confirmed case of a rope snapping simply from load?

ajfclark

2-Feb-2015
11:37:47 AM

Pipeline climbing gym accident was chemical damage. Does that count?

http://caves.org/section/vertical/nh/52/RopeBreakagefinal.pdf

The good Dr

2-Feb-2015
11:45:26 AM

Have seen a friends rope where the core mostly parted whilst being used for abseiling. The sheath remained intact. It was a rope that did have a flat spot (where the core failure occured).

Wendy

2-Feb-2015
12:38:51 PM

On 2/02/2015 jprockbelly wrote:
>Slightly off topic, but I'm curious to know if anyone has heard of a climbing
>rope actually breaking. I know there are several instances where they have
>severed over sharp edges, but has there ever been a confirmed case of a
>rope snapping simply from load?

Not actually breaking in practice, but still:

http://eu.blackdiamondequipment.com/en/qc-lab-retiring-old-ropes.html

jprockbelly

3-Feb-2015
10:01:20 AM

Interesting reading there, thanks all.

I was recently told that there has never been a confirmed case of a rope breaking simply from the force of a fall. Although the evidence offered was this 15 year old article from the UIAA.

http://theuiaa.org/upload_area/files/1/About_Ageing_of_Climbing_Ropes.pdf
(must be read in a german accent)

On 2/02/2015 The good Dr wrote:
>Have seen a friends rope where the core mostly parted whilst being used
>for abseiling.

Yikes! That is scary. Was there any explanation as to why this happened?

Jayford4321

3-Feb-2015
10:39:39 AM

On 2/02/2015 jprockbelly wrote:
>Slightly off topic, but I'm curious to know if anyone has heard of a climbing
>rope actually breaking. I know there are several instances where they have
>severed over sharp edges, but has there ever been a confirmed case of a
>rope snapping simply from load?

Original Matterhorn ascent fatal fall?

jprockbelly

3-Feb-2015
11:38:02 AM

On 3/02/2015 gnaguts wrote:
>Original Matterhorn ascent fatal fall?

Ha, ok fair enough. Although I'm not too worried about the tensile strength of ropes that predate nylon.

The good Dr

3-Feb-2015
3:10:40 PM

On 3/02/2015 jprockbelly wrote:
>Interesting reading there, thanks all.
>
>I was recently told that there has never been a confirmed case of a rope
>breaking simply from the force of a fall. Although the evidence offered
>was this 15 year old article from the UIAA.
>
>http://theuiaa.org/upload_area/files/1/About_Ageing_of_Climbing_Ropes.pdf
>(must be read in a german accent)
>
>
>On 2/02/2015 The good Dr wrote:
>>Have seen a friends rope where the core mostly parted whilst being used
>>for abseiling.
>
>Yikes! That is scary. Was there any explanation as to why this happened?

Not sure. The rope had a flat spot, though what had caused this was unknown. The rope was also about 5 yrs old I believe and had seen plenty of action. It is likely that there was core damage. The rope was immediately retired and thrown away so I did not get a chance to grab it and inspect it thoroughly.

phillipivan

4-Feb-2015
8:46:35 AM

On 3/02/2015 jprockbelly wrote:

>I was recently told that there has never been a confirmed case of a rope
>breaking simply from the force of a fall. Although the evidence offered
>was this 15 year old article from the UIAA.

Perhaps because by the time a fall is big enough to potentially snap a rope out right other things have likely gone wrong, and other the forces involved are likely to cause failure in other weaker parts of the the system.

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