UKC

Mate says he saw someone fall at the Roaches the other day and their rope snapped, apparently the climber was OK. Anyone know why the rope snapped?
sjc

In reply to sjc:

Peregrine falcon bite?

In reply to nniff:

My money is on a wallaby.

In reply to sjc: it'll end up a chalkstorm in a teacup.

In reply to sjc: I heard it was on the mincer, not shore how it snapped tho?

In reply to sjc:
Glib answer - 'because it got damaged'?

In reply to Alroy:

I doubt the boundary between the land and sea had much to do with it at all.

In reply to sjc:

My guess is that the force on the rope exceeded its breaking point.

You're welcome.

In reply to Alroy:

I've always said that route was a bastard.

In reply to Andy Say:
Sorry - I seem to have started a stream of facile answers. What I meant was that in all likelihood the rope was damaged by being cut/abraded on the rock as part of the fall or previously leading to its failure. The old BMC video 'Fall Back' analyses an incident on Hen Cloud where a leader took several falls and didn't pull the rope through between attempts. The rope was severely damaged by rope abrasion caused by a poorly extended runner (as I recall) and eventually the rope failed during the final (!) lead fall.

In reply to sjc: It's almost certainly been exposed to some chemical or has run over a sharp edge. My mate used to climb on 30 year old ropes, they felt like steel hawsers. He took a huge whipper and the ropes held, his number 5/6 nut snapped.

In reply to GridNorth:
rope failure can also occur from being dragged accross a rough but not particularly sharp edge.

In reply to CurlyStevo: That's a worry, I'm constantly dragging my rope across rough surfaces and I would have thought most climbers did exactly this all the time. There must come a point when a rough surfaces is in fact a series of sharp edges.

In reply to GridNorth: It does not need to be sharp.

To clarify a rope can snap from being dragged under tension across a rough edge. The abrasive force involved in a fall can damage the sheath and coupled with a high impact this can cause the rope to snap.

This is another reason to extend those top ropes over the top of the crag, and why abseiling is better than lowering a second over an overlap... as any time you are dragging a weighted rope over any edge you are abrading the rope to some degree, and all that damage can add up.

In reply to mal_meech: I take it then that there are recorded instances of ropes breaking in this way. I'm afraid I'm one of those people who has gone around for years saying "ropes don't break". If this is indeed true then I'm wrong and they do.

In reply to GridNorth:
there was an article recently showing a rope snapping getting dragged accross a not paricularly sharp (but rough edge). Not sure if I can find it or not,

this was a horizontal edge and the rope being weighted from the side

In reply to GridNorth:
'Ropes don't break' = sort of true.
'Damaged ropes can break' = undoubtedly true.

There ARE recorded instances of abrasion under load (normally repeated on one area of the rope) leading to rope failure.

In reply to GridNorth:

It is by no means common, but it does happen. Most often it is just the sheath which is severed, but occasionally the core strands can be cut through as well. This is more likely with a sharp edge, but sideways motion across a rough edge seems to be pretty bad too.

Your tale about your mates old rope is interesting. If he broke a no.5 nut then either he exceeded 12kN force on his top runner or that nut was already damaged in some way. One thing that happens to ropes as they age is that they start to lose their elasticity. So, an old rope itself may not break, but it may cause other components to fail because the impact force ends up being higher than it should be. Food for thought eh?

In reply to Dan Middleton, BMC:

I've had this happen with the rope running across a not particularly rough, rounded gritstone edge. The rope slid down just under body weight (no big whipper) and badly abraded the sheath.

I can imagine a couple of ways this might happen on the Mincer.

In reply to GridNorth:

Many years ago (1986, I think) I cut through a fairly new 9 mm rope whilst top-roping Diet of Worms at Curbar. The rope was running over a rough (but not especially sharp) edge but slid sideways over the edge for a couple of feet and caught on a quartz pebble. The mantle snapped completely and 2/3 of the threads in the kern were gone too. This was from top-roping with the weight of a climber merely sagging onto it.

It's a dangerous world out there: be careful!

In reply to Andy Say:
Exactly.

Dragging a loaded rope across any form of edge casues some form of damage, and "damaged ropes can break"

I fell in northumberland where the new rope dragged along a (rounded but rough)edge and you could see the blue of the rope left as a streak along the edge of the rock... Thankfully only cosmetic damage that time but makes you think.

In reply to Dan Middleton, BMC: Indeed. I have to admit that I had not thought of that last point that you made.

I had the sheath of a rope abrade through on Sauls Crack (when it was a VS) when I took a whipper.
This was only noticed when my mate took over the lead and I couldn't feed the rope through my Stitch plate

In reply to sjc et all:
as a side note: this was only recently pointed out to me, but it’s kind of obvious really.
De-sheathing a rope is easily done. Because the bobbins all wrap circumferentially round the core, you only need a longitudinal cut of about 1cm to go through the entire sheath.
mmmmm,

In reply to sjc:
So no one knows. Are incidents like this supposed to be reported to the BMC or something. See if it is a faulty batch of rope or something.

In reply to sjc:

I have an example of what I can only imagine was the core fibres breaking. I took a long leader fall (under ff 1) from near the top of high rock in the Cheddar gorge, 50' fall but lots of rope out. When I (finally) managed to pull myself back onto the rock the 8mm rope that took the fall kinked and twisted into very tight twists, so much so that I had to make safe on the other rope and re tie into the damaged one, the rope went in the bin.

Jb.