/ Climbing Ropes - Fall Factor
It means that when you've had 6 falls, you need to send your rope to me for safe disposal.
Try reading this:
It's basically the number of drops it takes to make it fail at 1.77 fall factor with a 80kg mass attached to it.
Lol, no it isn't.
Op: It's of almost no practical use. It has some minor value as something by which you can compare ropes before you buy, but ultimately will likely not influence your decision process about throwing one away.
Also, just reading the thread title, the number of falls rating, is not the same as a 'fall factor', just in case you were mixed up. A fall factor is a measure of the severity of an individual fall.
I think the best description of the practical significance of the numbers is at http://www.highinfatuation.com/blog/straight-from-the-mammoths-mouth-things-you-want-to-know-about-r... . Here are two quotes:
"One of the big differences between ropes will be how climbers wear it out—if they wear it out from falling a lot, or if they wear it out from abrasion on rough rock. Although there are other elements in play that we can use to affect these properties, one of the differences in construction we use that reflects these design priorities is the relative thicknesses of the core vs the sheath—we can make two 10mm ropes, one having a thin core and thick sheath, and the other having a thick core and thin sheath. All other things being equal, the rope with the thick core and thin sheath will hold more falls before going flat, but wear faster from abrasion; and vice versa..."
"...People who are comparing two ropes of similar diameters can usually see this in the test results—Mammut publishes the % of each ropes weight that is sheath so that people can judge for themselves what rope they will be happiest with. If you fall a lot, choose a rope with a high fall rating; if you don’t fall that much then choose a ropes with a thicker sheath (and if the manufacturer doesn’t publish that info call them and ask for it!). If you climb both abrasive rock and you fall alot, then think about how you wore out your last rope—if it went flat 10 or 15 feet from the ends, then get the rope with the high fall rating for the size and if the rope just fuzzed up to the point it felt sketchy or fat or lost its dry treatment, then concentrate on a rope with a thick sheath and a compact weave."
So if I pig out to 80Kg and take N number factor 1.77 falls on my brand new N fall rated rope, it will break on the Nth fall?
That's the bit I'm disagreeing with, but I'm happy to be corrected if someone can find a definition which says exactly that.
If you used the same lab using the same setup as they test, yes. though there might be anomalies such as those not failing on the 6th time, say, when you expect it.
> So if I pig out to 80Kg and take N number factor 1.77 falls on my brand new N fall rated rope, it will break on the Nth fall?
Another confounding factor is that the test is done with a steel weight, the conventional engineering wisdom being that an 80kg steel weight produces loads you'd expect from (I think) a 103 kg squishy person, so you're gonna have to keep pumpin' the beer and chips for a bit longer than originally anticipated.
I think the comments I posted earlier from the Mammut rep give a useful way to think about the relevance of rope statistics to the purpose the rope is intended for.
So what exactly happens then ??? I take it the rope won't just snap/break - I would imagine that it loses all of it's stretch
In general use i.e. not misuse, ropes won't break. There are a number caveats to that statement but if you are using your rope indoors for fall practice, you are never going to snap the rope (unless you keep using the same section of rope etc.).
I like to see the UIAA fall thing as a comparison between ropes though all ropes have to pass the same test, some will exceed the minimum tests, most will pass, some will fail but these won't be able to be sold.
It might snap, but that is not the definition. The definition (for a single rope) is that the test mass is subjected to less than 12kN in the fall factor 1.77 test. If the rope does this N-times in a row it is an N fall rated rope.
PS. FF=1.77 is a super hard fall. You are unlikely to experience even one during your climbing life. So don't worry about it. Think about how fast the rope will wear for the type of climbing you do.
The OP used "fall factor" in the title when she was talking about "fall rating" in the text. To be clear:
- The fall factor is a measure of the severity of a single fall - specifically the distance fell before the rope went tight divided by the rope length between the climber and anchor (before stretch).
- The fall rating is the number of FF1.77 falls with an 80Kg mass the rope can take before failure as measured in a UIAA test.
To answer the OP's original question- the UIAA test involves very severe falls - much worse than most real climbing falls* and much worse than any fall at an indoor wall. People largely ignore most routine falls and, in practice, replace ropes when they show signs of damage or severe wear or become stiff and hard to handle or just get old. If you take a big fall (say FF->1) you should count these up and replace the rope before you get to the fall rating (bearing in mind the other aging and wear factors).
*FF 1.77 as mentioned above is a super hard fall - but - short falls with high fall factors count - eg a 2m fall 1m above a hanging belay is a FF=2 and will eat the reserve in the rope (but you can cut off this section instead of retiring the rope). In practice short falls like this are best avoided for this and other reasons (place gear early).
I must admit I'd always assumed it meant that the rope would RESIST N number falls, not that it would break on the Nth. It might of course break on the N+1 fall but equally it might break on the N+10 or N+100 fall.
Thanks David. Where is this written down? I have searched the UIAA website.
a gentle slump
A bit of a nerve Jangling plummet
Oh Shit im going to die
©® choss 1986
Nice post, but I disagree with that bit. Pit Schubert's advice seems to be: consider throwing the rope away once the core is exposed. The rope will tell you when it's buggered, they don't damage internally without visible external signs.
Agreed. Know your rope, its Pretty Obvious when its done.
A slight Side, but relevant Issue.
Has there ever been an instance in modern Times, Since 1980, of a Climbing rope ever snapping?
I dont think so. And im not including over a Sharp Edge etc, just plain out snapping?
I believe it was the Technical director or someone from the UIAA that said that modern climbing ropes just don't break in general (proper) usage.
Pit Schubert, head of the safety committee.
Apparently not. Pit Schubert wrote a nice article about it all:
Are you sure? I was under the impression the 12kN criteria applied *only* to the first drop,
Opps. Sorry. I stand corrected.
I think I should have said that the UIAA standard, as in the EN 8292, demands for a single rope that the first drop gives <=12kN and that it must then survive without breaking a further 4 such FF=1.77 drops with the test mass.
Although Jim Titt might be along in a minute to correct me further.
These two documents are worth looking at:
Yeah, thanks. I've seen those before though, and neither seems to explicitly define that the number of falls criteria is tied to what you and others are saying. Perhaps its just implicit.
Looking at the Beal web site for their 9.1mm Joker rope it says:
"Number of falls UIAA Laboratory" and then gives the number of falls for this rope as
single: 5 - 6
double: 24 - 26
twin: > 25
So, I'm guessing (just like you suspect) they mean the number of UIAA test falls at a FF or 1.77 before the rope snapped. And that at least 3 ropes were tested in each configuration (single, double, twin) and the numbers are for the worst performing rope.
Whatever, ropes that have taken lots of big fall factor falls shock load the climber more and are at risk of breaking, neither of which I would want to face on my lead rope on a poorly protected mulitipitch. Such ropes could be safely used for tr practice or easy safe leads. Equally, lots of biggish falls without letting the rope relax can increase shock load. Its all part of dumb things climbers do.
One of the key points to note here is that the UIAA falls are using a static belay where no slippage or movement can occur and accross the same section of rope. AFAIK it nearly always breaks on that section. If differing sections were loaded and/or the belay was more dynamic you'd expect many more falls to be held before the rope snaps.
Good question :)
I suppose it means you would be likely to survive 6 horrible spine jarring factor 1.8something falls down a test tower but would likely be put out of your misery by the 7th.
In the real world it means little. A high rated rope may be a little tougher than a low rated one but it's generally the mistakes that ruin a rope not a series of monster falls... rigging over edges, swinging falls dragging tight ropes over grit bulges, that sort of thing.
I come in at over 100kg when geared up and if I take a FF2, its a risk I don't want. I think it does mean something in the real world... you just get a bigger safety margin than the tests. Other things are just usually more important: for instance I've seen quite small FF trash a rope and other trash long extenders when rubbed loaded on a not especially sharp (but rough) grit edge.
What does it mean to you? (I assume you mean the UIAA falls value here).
I take it you read the BMC article that ropes don't break?
I don't think the UIAA falls rating of a rope can be correlated to its sharp edge performance.
It is indeed the very worst-case scenario.
Possibly they don't break because people are not dumb enough or robust enough to take repeated long FF2 falls on them. The much lower risk in practical circumstances doesn't mean its not there at all. My concern would be more about the shock reduction capacity of old/heavily used ropes having taken many FF0.5+ falls.
There aren't any UIAA stats that convey how dynamic a rope remains after many factor 0.5 falls so trying to interpret that from the existing stats seems rather futile. I doubt you actually take many 0.5 factor falls anyway.
I agree with jkarran in the real world the number of UIAA falls means little.
Me too. I do also agree that it has some (pretty minor) value for comparing ropes. Pit makes he point in his article that rope wear from falls is very different to rope wear from abrasion, sport climbers vs winter warriors if you like. So stats like this might help inform some buying decision process if you want a rope that will take more of a certain kind of abuse.
I've never paid any attention to it though, when the rope is fooked, it will tell me.
So how do you use that information while buying a rope? Where does it rank in relative importance?
I must confess I never even read the specs when buying rope, they're all more than good enough. I just go for the right length, diameter and price. Perhaps I'm more blase than I thought.
I think when experts argue the ordinary less well informed climber can get bad ideas and that's my concern here. For instance I never would have said 'ropes don't break' like that article Stevo listed did: they even say in the article that they do but only when noticeable damage has occurred. They rightly recommend inspecting ropes before use but many climbers don't do this.
One plus from this new approach is that the daft logging of Fall Factors in University clubs can stop, backed by evidence from the BMC as required. Rope logging, as the article points out, will likely continue for other reasons but the safety issues can be dealt with less bureaucratically. I looked after many Uni club ropes for years that were used winter and summer and despite all the advice I gave (that i got from the BMC) some people were still climbing on ropes that had noticable damage such that I had to take the rope off them and retire. Some climbers ARE dumb.
Do you take many 0.5+ factor falls? The only realistic scenario I can think of for that would be working a sport route with the crux at the start, in which case I think I'd rather choose a different project with the crux a bit higher.
The phrase 'ropes don't break' was qualified by the caveat 'if you want to break a rope you have to cut it over a sharp edge, corrode it in acid or use a weight drop machine'. you'd have to be pretty dumb to think that ropes don't break, ever!
I don't do that, but I've seen it happen indoors with multiple falls in a row and the weight never fully removed from the rope in between falls. Not just working a lead (where the crux is lowish) but also in 'fall practice' sometimes where the highest bolt wasn't clipped on purpose to increase the length of the fall.
An even dumber thing I saw once was someone who should know better testing a micro-crab in a busy wall by shock loading it in a fall (from more than a bolt length above)... came real close to decking when it snapped.
Ah, yes, that would do it.
I generally do one or two falls per bolt on my way up a route, so I'm hitting a different bit of the rope each time. And change ends after each route.
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