safe working load – rope question

[MARK D]

I am totally new to mountaineering, despite years of ski patrolling, etc.. I'm looking for some guidance on safe working load limits on rope.

Regarding safe working load (SWL) I've seen different numbers used, like 10% of a rope rated at 5000 lbs is correct, or is it 20%, or is it 1/15th (about 7% – this is confusing. Any guidance is welcome. Obviously, the less strain you put on a rope the better, but how far can you push it, and what is a good standard to apply?

My main interest in this subject is to not die while rappelling and getting info for safe rappelling from a chairlift or short cliff. thanks.

[Bob Gross]

The answer is: it depends.

Part of it depends on the type of rope and its intended use. For example, there are dynamic ropes that stretch and are used for lead climbing. There are static ropes that do not stretch very much and are often used for rappelling. There are kernmantle ropes and laid (twisted) ropes. Some ropes are intended to protect a leader fall for only some small number of tries, and then it should be retired. Some are good for only a few years after manufacture.

Often, when you buy a new rope, it will have a tag on it that spells out some or all of its specs.
–B.G.–

[nanook ofthenorth]

from what you posted I'm a little confused – what are you doing with it?
Chairlift evac is different then glacier travel – you use the rope differently. Could you elaborate?
btw safe working load is a measure of the ropes strength in a static situation – a dynamic rope in a fall is quite diffrent

[W I S N E R !]

If you're talking about a single person rappelling (and you're not taking falls on it), just get a good approved static rope. I have one of these for canyoneering/rappelling:

http://www.rei.com/product/793079?preferredSku=7930790014&cm_mmc=cse_froogle-_-datafeed-_-product-_-7930790014&mr:trackingCode=6D847AF1-E390-DE11-B4D4-0019B9C043EB&mr:referralID=NA

Under typical circumstances you'd be pretty hard pressed to make a 32Kn rope fail while rappelling unless you were trying to lower livestock over sharp edge.

Your question is a little vague though…do you know what you're doing?
Rappelling is a pretty straightforward task…I wouldn't be worried about the strength of a UIAA approved rope- I'd be more concerned with knowing knots, anchors, and climbing safety.

[Dean F.]

This being BPL and all, are there lightweight ropes that would be appropriate for light scrambling, the occasional rappel while canyoneering, etc.? (I'm NOT interested in real mountaineering, just roping-in on the occasional scramble.)

For a static rope, what about this:

http://www.rei.com/product/751495

Or is 9.2KN simply not enough?

(What I know about ropes I could write on my palm…)

[W I S N E R !]

That rope would be fine.
Many people use even lighter 8mm ropes for alpine climbing- running a twin/double rope while leading (two 8mm simultaneously/one doubled 8mm)and then rappelling on a single.

A single person rappelling really doesn't put much force on a rope if you're not trying to pendulum, bounce around, make sudden stops, etc.

As for a 9KN, 10.2mm rope, that's pretty much standard for rock climbing: taking a limited number of lead falls that place an enormous amount of stress on a system (a rope is rated for a certain number of falls of a certain force). I can't see what you'd be doing while simply "scrambling", rappelling, or canyoneering (activities that typically involve going down, not shock loading a rope after falling while going up) that would take one of these ropes to it's limit- they're made for far worse.

This article will explain a lot about ropes to non-climbers:
http://www.alpineexposures.com/pages/faq-climbing-ropes-explained-test-uiaa

There's a small link in it explaining fall factors: that will answer many questions and is essential knowledge for climbing safety.

[nanook ofthenorth]

I think your looking for a glacier rope, 30-40m of 8mm double rope sold for glacier travel. If you are climbing with it and placing protection for the leader you NEED a dynamic rope. Even for simple glacier travel a dynamic rope is highly recommended. If the leader is just scrambling up, finding a good stance, and belaying the second you could go with as small a static rope as you could handle, I might sugest wearing gloves too.
I have heard of people using 5.5mm tech cord as a retrieval line for their dynamic rope.

[nanook ofthenorth]

Dean,http://www.rei.com/product/751495, is not a staic rope – it is a dynamic one. 9.2kn is the impact force of the rope. Rather then repeat what others have written better, could I suggest that you try any of the excellent books in the Mountaineers Outdoors Expert Series? Their one on alpine climbing is really excellent and should answer many of your questions.

[W I S N E R !]

This gets hard to explain on the internet…

If a rope is being solely used for hauling or lowering STATIC loads, a STATIC (non-stretching) rope is preferable- less stretch/bounce usually means more control.

If there is any chance a DYNAMIC load (sudden force) will be placed on a rope, a DYNAMIC (stretching) rope is needed- stretch means a softer catch and SAFER fall.

Imagine freefalling 10 feet on a static rope: jerking to a stop. You could break your back- thus the need for dynamic climbing ropes.

But where this becomes hard to give advice (and probably a bad idea to do so):
I don't know what a rope for "scrambling" is. What is "scrambling"? What does your style of "canyoneering" entail? Is there a chance for a fall? What sort of anchors are being used in the belay? Is there a belay anchor?

*****It's all too vague (and therefor probably dangerous) to give climbing/hardware advice over the internet. Nobody knows the experience level of those giving advice, nor the experience level of the audience.

Edit: And Dean, as Robert pointed out, the rope you posted is dynamic. I didn't notice you referred to it as a static. Crucial difference.

[MARK D]

Wow – thanks for the replies so far. My primary interest is a static rope which is light & easy to carry, will support me and fit my Kong Robot or black diamond rappelling plate (it's gold…), and have a safe working load. If I bring this gear with me skiing, I will probably bring a 6 or 7mm rope and 1" webbing to make a sling with.

I currently have 8mm static rope – about 45 ft worth. I looked at Technora 5mm line, some 6 and 7 mm static line as well – I don't need (or want to carry) 10mm line or similar heavier rope. For a chairlift evac or rappelling down a 15 ft cliff in dry weather, I don't need 60 meters of 10mm line.

I do not expect to drag this line over sharp rocks, fall with it or anything else, just looking for some guidance on good rope that is safe for a 175lb guy with skis & boots on. So – what protocol do YOU use when determining safe working load? hmmm?

[nanook ofthenorth]

Hi Mark – sounds like you just want a line to rap off of when skiing gnarly terrain. Look at the accessory lines – 6,7mm? If you go for 8mm a dynamic 1/2 rope is more versatile. Bear in mind that knots in the rope decrease strength by 20-60% depending on the knot, so take that into account when planning your safe working load.
I use a 8mm dynamic for what your talking about, but I also use it on the way up and on glaiers. You could with practice leave the plate behind and just use a munter or a dufaldortz rappel (as in fixed lines into chutes).
Hope that points you in the right direction, not sure how comfortabule I feel giving spicific pointers online, a guide would be able to set you straight and might have some other better susgetions.
Cheers

[W I S N E R !]

I'm not sure if a Kong or the BD device you have can safely use rope thinner than 8mm anyway- if that's what you carry, I'd stick with your 8mm.

[nanook ofthenorth]

munter is lighter and cheaper and work on smaller ropes — bring your gloves!

[Roger Caffin]

First of all, you need to distinguish between industrial use in a commercial environment and personal use in the mountains.
* For commercial use you need to have a generous safety margin for two reasons: litigation, and careless workers. This is where safety margins are used.
* For personal use: you need to be sure the rope can take the load. This is hugely different. (And remember that dynamic loads are greater than static loads while abseiling.)

The next thing to consider is how and where you deploy the rope. I use 40 m of 6 (six) mm kernmantle for scrambling and abseiling (BD ATC descender) while WALKING in the mountains. The strength is perfectly adequate even as a single rope for how I use it (pack hauling, top roping). But this does NOT including lead climbing and dynamic falls! Nor does it include full-on canyoning (for which I use 10.5 mm static ropes).
And when I get home the rope gets spread out on the floor and I check every foot of it between my fingers, while cleaning and drying it. Then it is carefully stored in the dry/dark.

This rope will not die from the loads we put on it. It will probably die from abrasion over rock edges and embedded dirt. When it shows damage it will be replaced.

Would I recommend this weight rope to you? No. Nor would I recommend any weight rope to anyone. My wife and I are both experienced rock climbers and we know what we are doing. I strongly recommend you start by getting some training in rope-use and abseiling from a rock climber (not from an industrial rope-use teacher). And that training should happen in the mountains. Then, you make your own mind up.

Cheers

[David Olsen]

You need to check with the ski patrol organizations. They
do this stuff all the time and most ski areas provide the
rope anyway. Last one I had was 6 mil. and was used doubled
over the chair so it could be retrieved and wouldn't be
left to tangle in the works. This was 20 years ago and may
not be considered safe anymore, so I would
check protocol with your ski area. Your device may not be
the right one for this purpose.

Do you expect to lower a dog too?

[Douglas Ray]

I think this topic has been well covered in the posts above, but I'll throw in my two cents as someone who is bot a climber and used to rappel for a living.

Technically a rappel system only needs to hold your body weight, although I've read that someone did some tests and figured out that by bouncing and swinging around while hanging on the rope one can effectively double the force on it. So generally, I figure that I don't end up weighing more than 220lb,or 1kn, so rappel system only needs to cope with a 2kn load at most.

Knots and such can weaken a system by as much as 50% (actually more, but I just don't use weaker knots than that when my life is on the line). So that means in theory one could safely rappel on a single strand of 4mm line.

In reality you want to have margin for things to wear some in use, and looking at something the size of a boot lace that you are hanging from is scary, and trying to get enough friction to safely rappel on such a tiny cord would be very difficult. I've used webbing of that strength to build rappel anchors in the mountains, but that is a one-time use application. Rappelling on any cord smaller than 8mm tends to be troublesome with any sort of standard device.

I would say check with the makers of your rappel device and see what the minimum size they recommend is. I don't think I've ever talked to someone who has used anything smaller than 5mm cord to actually rappel on, and I think with something that small the only way to get enough friction would be with a supermunter knot, and the cord would need to be retired very often.

I'd worry more about creating friction and controlling your descent than the cord breaking. 6mm would be comfortable for me in the situation mentioned if I had a good way to make friction. Double strands can help a lot in this regard.

[Dean F.]

Interesting. That rope came up when I searched for "static rope" on rei.com. That'll teach me to trust them…

Well, I'm not the OP, but I think MY question was answered.

By "scrambling" I mean hitting the occasional terrain somewhere between hiking and mountaineering, as in the "75 Scrambles in Washington" guidebook. Class 3 or maybe low class 4. In other words, situations in which a timid hiking partner might appreciate a top belay. I want nothing to do with a climb that would require real protection or have a real risk of a significant, long fall. Also, I'm not really interested in truly technical canyoneering, but I have noticed that there are a LOT of canyon routes that only require a short rappel or two, and I'd like to access them. (I guess being able to use an ascender would be nice, too.) Despite my ignorance, I have rappelled quite a bit, both single- and double-strand. But I have always used military rappelling ropes, even when rappelling on my own. I've only ever used carabiners and figure-8 descenders as a rappelling device, and I'm quite comfortable with them. And I prefer a Swiss seat to a real rappelling harness. (Because I can easily make one on demand, and a short bit of rope is more multi-use than a harness.)

So, it sounds like an 8mm (or perhaps even smaller) static rope would be adequate, and still generate enough friction for rappelling?

I'll read more. Oddly, I do have a mountaineering book someone gave me as a gift once, as well as the Army mountaineering manual.

Thanks, All.

[Bob Gross]

Almost forty years ago, I was an assistant instructor in an Army rappelling class, and all we had back then was a short equipment list. 150' lengths of (green) half-inch laid nylon rope. Swiss seat instead of a harness. Two carabiners per person. Leather gloves. Period. No modern rappelling devices. No kernmantle ropes.

–B.G.–

[Dean F.]

@Bob-

We are truly dinosaurs, Brother. That green twisted (whatever that is called, not kernmantle) nylon rope is exactly what I'm talking about! But you should SEE the new update of the Army mountaineering manual that just came out a couple of years ago: magic slippers, plastic mountaineering boots, all manner of exotic protection, etc.- all kinds of whiz-bang stuff.

[Bob Gross]

Say it isn't so!

Back in the day, all of our rappelling friction was on two carabiners, so by the time we had zipped down 100 feet or so, there was a very hot carabiner almost lined up with the forearm. I still have faint burn scars from that.

Dinosaur, indeed. This was near the DMZ in a faraway land.

–B.G.–

[Dean F.]

I perused that mountaineering book, and I guess what I'm looking for is a rope for tying in on a running belay on class 4 scrambles, and then top belaying once the leader is in place. Maybe for moving together over a snow or ice field, too. And, as I mentioned, occasional rappels in nontechnical canyons. (But not real class 5 rock climbing.)

As such, I guess I should take a class, and get a few basic pieces of protection. Most scrambles almost by definition have a lot of natural protection so I think I'd be well served simply with a bunch of webbing runners and a few carabiners, but a handful of chocks couldn't hurt either. Anyone have any recommendations for lightweight chocks? I kinda like the multi-purpose capabilities of the Black Diamond Hexcentric or Lowe Tri-Cam. Are they relatively light as protection goes? Or should I just get a selection of wired nuts? (Spring-loaded cams look heavy.)

I guess I'm curious about the UL view on protection. (With an emphasis that I'm not talking about technical rock climbing, and not even anything very close to vertical. In THOSE situations, since you're life is on the line in such an immediate and dramatic fashion, I'd personally say "Damn the weight!")

Well, this is all a bit premature, anyway. I have to take a class or something, first. But I like to take a while to think about such things, so I'm interested in opinions.

I'm also beginning to suspect that I'm not going to escape buying two ropes. Rappelling, I understand, is best with a static rope whereas any kind of belay or moving together requires a dynamic rope.

[nanook ofthenorth]

Well in that case you defiantly NEED a dynamic rope – I personal use a single 60m 8.1 double rope for that kind of terrain, if I was to buy specifically for that I might go with a single 40-30m 8mm dynamic rope.
For pro I would go with 5-6 nuts (skip the smallest and largest, pick every other size), maybe pink, red, brown tri-cam (to .75in) and then hexs in the 1in and up sizes. For anything smaller then the gold or silver small DMM Walnut I would bring pins (both partners need hammers). Or I might bring two Bugaboos and a 1/2in angle in case I needed gear for rapping.
5-6 trad-draws and 1-2 120cm (double length) slings. One cordolet that you could use as bail cord, more if you are on glaciers.
Hard to say not climbing where you are – buy a bit, try something moderate, adjust, repeate. No way to shortcircut this stuff – you need to learn it yourself and the best way is by climbing.
Hope that helps.

p.s. I personly might be tempted to do away with the belay device and just use Munter hitches for belaying/rappeling too.

pps I would HIGHLY recomend hiring a guide to show you guys the ropes, it will make you a much safer climber. I would take any advice online as advice and would evaluate it for saftey/relavance myself — as you should with my posts.

[Anonymous]

"Well, this is all a bit premature, anyway. I have to take a class or something, first."

A very good idea. There are a lot of things to learn, even for basic scrambling, which are best learned hands on.

As for gear, wait until you take that class. You will have a much better idea of what you need initially and what can wait until you gain experience. Climbing gear can be pricey, and it is easy to blow a grand or so on shiny trinkets that you may well never use. Class 4 should not require much of a rack, which is the priciest category of gear. Anyhow, let a professional instructor guide you in these matters. It will save you a lot of money and quite possibly your life. Climbing, which, in my book, includes class 4 scrambling, is a very unforgiving pursuit and an unprepared neophyte's first mistake is likely to be their last.

[W I S N E R !]

Definitely look into tricams- simple, lightweight, and very versatile.

And another vote for getting a guide if you don't have an experienced friend. Books can't explain the nuances and there's all kinds of bogus climbing advice floating around out there…you never know your sources.

Personally, I've rappelled at least half a dozen 5.15s to-date. You can trust me.

:)

Total tangent, but…Robert:
With all due respect, I don't really get your fondness for the munter…I know everyone has their preferences but I think there's also a reason I've never met a climber that doesn't carry a belay device when on the rope.

While every climber should know it for emergencies, I don't necessarily think it's the best go-to for rappelling and belaying, especially not on a regular basis.

On longer rappels they'll horribly kink your rope if the end isn't free to relieve potential twisting. I used one in a canyon on a ~80' rappel and spent the next 15 minutes trying to untangle my rope before moving on. Maybe this was somehow my doing- yet I've NEVER experienced this while using a device. I know it's a common criticism of the munter. Now I've never used one enough to personally prove this, but it's also my understanding that if they're used regularly you'll waste your rope's sheath faster. More fuzz = more dirt and grit in your rope = less potential rope life.

I understand it's usefulness in emergencies and its role in climbing history…but if you're intentionally going out to climb or "scramble" or rappel and you're already carrying a harness, rope, and protection, why not also just carry an ATC? What's one small piece of very safe and reliable gear if we're already going to the trouble of carrying the all the rest?

[Anonymous]

"With all due respect, I don't really get your fondness for the munter"

+ 1

"I understand it's usefulness in emergencies and its role in climbing history…but if you're intentionally going out to climb or "scramble" or rappel and you're already carrying a harness, rope, and protection, why not also just carry an ATC? What's one small piece of very safe and reliable gear if we're already going to the trouble of carrying the all the rest?"

+ 1

Aw, heck, + 1 your entire post, Craig.

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