Discussion Topic |
|
This thread has been locked |
tradmanclimbs
Ice climber
Pomfert VT
|
|
|
Apr 12, 2009 - 11:16pm PT
|
They use a lighter weight because if they used the heavier weight the rope would break too easily. I do a lot of logging with old climbing rope and skinny rope works but it breaks a LOT easier than fat rope.
|
|
Pakdong
climber
|
|
|
Apr 13, 2009 - 12:21am PT
|
not that I have any design to go try it....what would be the problem, other than edge resistence etc..., of climbing on a single half rope?...say a 8.2mm. Since doubles are set up to hold falls on a single stand at a time, why not just climb on a single stand? If the fall factor isn't high, is there much issue? I guess that leads to the question..what exactly is a "Single Rope"
WBraun.... what circumstances did you climb a single 8.8mm for all that time?
|
|
WBraun
climber
|
|
|
Apr 13, 2009 - 12:22am PT
|
Light
Don't fall though ....
|
|
blahblah
Gym climber
Boulder
|
|
|
Apr 13, 2009 - 02:27am PT
|
I believe a lower weight is used to test a double rope because you will never take a factor 2 fall on one double--if you're in a factor 2 fall situation, you will fall on both doubles. So singles need to be able to withstand a more severe fall, even though many falls in a double system will be caught on just one rope. Hopefully no one is taking many > factor 1 falls on any rope system.
|
|
tradmanclimbs
Ice climber
Pomfert VT
|
|
|
Apr 13, 2009 - 10:27am PT
|
Useing a 1/2 rope as a single has its benefits and risks. Lots of folks do it for alpine climbing where falls are rare and weight is a huge issue. Skinny ropes are NOT as durrable as fat ropes. If you use your 1/2 rope as a single you could toast the thing pretty quickly. Once the skinny rope breaks down the impact forces will be even higher than they allready are which is higher than a single rope anyways. Ropes do break and cut easier when they are broken down. Definatly NOT recomended in any situation where you would be doing a lot of falling and ANY lowering. lowering toasts your rope way fast .
Even the skinny expensive single ropes wear out quickly from lowering and projecting. For sport cragging where weight is not an issue its silly to use super light expensive skinny singles. A nice inexpensive 10.2 will last longer and work just fine. If you can't carry an extra 16 oz of rope up to Wiamea with your 12 draws then I suppose you will have to cough up the dough for that expensive skinny single.
Stuff yer pack with with 14 ice screws, 3 ice tools, crampons, medium rock rack, bunch of pins, 8 screamers and a bunch of slings, water,food , 3 pairs of gloves etc.etc,etc, and that expensive skinny single starts to make a lot of sense..
Its got to be kind of nuty to use super skinny rope on walls. fatter ropes are stronger, last longer and offer more cut resistance.
|
|
August West
Trad climber
Where the wind blows strange
|
|
|
Apr 13, 2009 - 11:53am PT
|
I'm not as concerned with the high impact forces as I am with the extra stretch you seem to get with skinnier ropes. Sierra granite is pretty bomber and when it isn't, you always have the option of addng a screamer. But a rope with extra stretch just gives you that more chance of hitting a ledge and wiping out an ankle.
The Beal Joker is rated for twin, half, or single. I've been pretty happy using it as single for light weight multiple pitch. When my partner and I simul-climb easy routes, we usually use a single 8.8mm.
|
|
tradmanclimbs
Ice climber
Pomfert VT
|
|
|
Apr 13, 2009 - 12:13pm PT
|
When we climb ice as a threesom we often bring up the 2nd and 3rd simo on a single strand each of 8.1 ice floss. Amazing how far a Top rope fall is on a single 60 or 70m strand of 8.1!! Its pretty effin exciteing to be climbing way the heck off the deck WI5+ and have the guy just above you pop off and go wizzing by spinning out into space with all those sharp points windmilling arround!!! It also makes you concentrate your swings when you see that skinny little rope just inches away from your razor sharp ice tool!! My partner managed to allmost slice one of my 8.6mm ropes in half with a single swing. She was following on both ropes at the time so in no danger.
|
|
rgold
Trad climber
Poughkeepsie, NY
|
|
|
Apr 13, 2009 - 12:33pm PT
|
Basically, it centers on why an 8ish rope is acceptable for half ropes. If and when you fall, are you still not falling on one rope, over a single edge? Does the physics of a fall change when you are using the Double rope technique? On your first piece, I am assuming it would be exactly the same as with a single rope as you have only one rope through one piece. If this is the case, then why would you be ok with having less of a fall rating?
I'll repeat a comment here: half ropes are strong enough to catch any fall. But they don't recover as well and so won't catch as many, not enough in general to get a single-rope rating.
Skinny double ropes make total sense for multi pitch ice climbing. they make no sense at all for single pitch climbing
I've done various single pitches with double ropes for many years---just did one yesterday, in fact. Marginal pro opportunities with chances to place trinkets more or less at the same level but spaced horizontally provides a scenario in which double ropes are a significant improvement over a single.
But I'm biased, because at this point I only own double ropes. Except for splitters, I think they are almost always a better bet. Their biggest drawback is weight, which is noticeable at the end of long pitches.
Its nice in theory to speculate that you can provide a better belay by keeping red short while the leader clips blue but in real life it dosen't work that way. A Real fall in that situation would most likly resuly in a fair ammount of rope slippage while the belayer juggles fingers trying to brake the right rope. In real life practice the belayer is more likly to feed the wrong rope and short you on the one you are trying to clip. then once you do get clipped you stand a decent chance of getting short roped on the other strand when you start climbing again.
I don't think one ought to include incompetent belaying as a drawback of double ropes. It is true that the belayer needs a few rudimentary skills not needed by the single-rope belayer. Here is a hint to those considering the use of doubles: the belayer needs to watch the ropes as much as the climber, and has to develop the very minor skill of sometimes taking in a rope with the non-braking hand.
if I have a line of bolts I will inform my belayer and treat the half ropes as twins and just clip em both to each draw. This is the easiest way to enshuer that you will get a decent belay and not get short roped or dropped.
Personally, I never do this, but again I climb with belayers who know their job. I simply never clip both ropes to the same piece. If there is a really mission-critical placement, I consider it worth two pieces, and one rope goes into each. As for bolts, I've found quite a few bolted pitches that are handled better with doubles, for example
'practice' using two single ropes as doubles could lead to death as the impact force would most likely exceed what your body/pro could withstand. You might as well fall onto a static rope.
Right,and since the impact force is higher,and the protection experiences twice the impact force,it's not adviseable to clip them both
The theoretical increase in load from double-clipping is 40% (more precisely, the square root of two times the load, not two times the load.) On some big falls, this 40% or so increase might exceed the 12 kn UIAA maximum, which is why not all double ropes are rated as twins.
All 1/2 ropes are rated as twins.
This is false, if by rating one means the UIAA rating (and there is no other meaning as far as I know).
One of the biggest myths is that single strand of 1/2 rope has a lower impact force than a normal single rope. According to Sterling ropes this is NOT TRUE. A single rope has a lower impact force than a 1/2 rope because there is more material in the single rope to absorb energy. The skinny 1/2 rope can not dissapate as much energy and therfore transfers that energy to the pro. belay device and falling climber.
My memory of Jim's comments is that the loads are essentially the same. However, if properly clipped doubles reduce the various angles at intermediate biners, then the cumulative effect of carabiner friction will be less and so more of the rope will be available for stopping the fall, possibly leading to lower peak loads at the top piece. In reality, I'd guess there is no significant difference.
I must have a thick scull because I still cannot figure out why they would drop a lighter weight for the half ropes.
Welcome to a large and thriving community of numbskulls. I've never heard a good explanation for the use of a 55 kg weight rather than an 80 kg weight.
|
|
Sherri
climber
WA
|
|
|
Apr 13, 2009 - 12:42pm PT
|
I got a pair of the PMI Verglass twin/double(rated as both) ropes last year and I love 'em, especially for multipitches where I don't want to drag a tag line.
Still working out the finer points of using them as doubles, so I appreciate the diaglogue here.
Last time I climbed with them, I clipped both ropes to one piece using separate biners(attached to one sling) and for some reason they turned into an auto-brake. As I moved up, the two biners would seat into each other and the rope would get pinched between them. Arrrgh. Thankfully, I was near the end of the pitch and the misery was short-lived.
I'd hate to have this braking action happen at a crux or something. Should I be using TWO slings, one for each biner to keep them from joining up?
|
|
Ghost
climber
A long way from where I started
|
|
|
Apr 13, 2009 - 12:45pm PT
|
I've never heard a good explanation for the use of a 55 kg weight rather than an 80 kg weight.
Cuz it's easier to hoist the lighter weight back up to the top of the tower?
That always struck me as odd, as well. There's one reasonable explanation upthread (from blahblah), but still...
|
|
rgold
Trad climber
Poughkeepsie, NY
|
|
|
Apr 13, 2009 - 12:51pm PT
|
Last time I climbed with them, I clipped both ropes to one piece using separate biners(attached to one sling) and for some reason they turned into an auto-brake. As I moved up, the two biners would seat into each other and the rope would get pinched between them. Arrrgh. Thankfully, I was near the end of the pitch and the misery was short-lived.
I'd hate to have this braking action happen at a crux or something. Should I be using TWO slings, one for each biner to keep them from joining up?
As I said before, there is almost never any reason to clip both strands of a double rope to the same piece. If you don't trust a single strand, you probably shouldn't be using doubles to begin with. The only time I ever do this is if I have two seconds following, one one each rope, and they both need the ropes to run through some piece for directional reasons.
Clipping both ropes to the same piece is best done slings of different lengths, so the two rope-end biners can't interfere with each other.
|
|
Sherri
climber
WA
|
|
|
Apr 13, 2009 - 12:55pm PT
|
Thanks, rgold. I'll try the different length slings next time. (Yes, I had clipped both to the same piece for directional because I had two climbers following. How'd you know?!)
|
|
tradmanclimbs
Ice climber
Pomfert VT
|
|
|
Apr 13, 2009 - 01:09pm PT
|
Rgold, I have bought 4 sets of 1/2 ropes in the last decade, all diferent brands and diamaters and every single one of them had a little child proof pictuer guide on the furnished reading material that showed both ropes clipped throuigh the same biner as being safe.
Sorry but unless you are climbing very poorly protected and tricky gear placements it is darn silly to bring 400ft of rope to a 60ft crag..
So you don't own a single rope and you are so used to the doubble rope system that you think it is dead easy. That is totally fine, I didn't know how clunky my old purple Kolflachs were untill I strapped on my new Nepal Extreems either. A few years ago I did a Seneca, Gunks, Cannon, cathedral loop with Alex. We climed the doubbles for about 10 days straight except for the driveing rest days. When we got back to VT and hit up Deer Leap we broke out the single rope for some trad cragging. WOW! what a pleasuer to suddenly have such a simple light system... I am so used to doubbles that normaly I don't notice the extra work either but on this day due to how imersed we were in climbing evey day I really noticed the difference.
So you are so used to it you feel the belaying and rope management with doubbles is really easy. So do I. Thing is though, many of the rope slaves that I tourture don't seem to get it as smoothly. Been short roped with doubbles more times that I can remember! Also seen some pretty interesing rope salad ( cluster tangles) over the years.
Big fat straight line of bomber modern bolts, damn straight I will treat my doubbles as twins. faster, easier and the ropes will run better.
I can give you a damn good belay with doubbles but I can do it better in most cases with a single. Think of all those times when the leader is out of sight and you are guessing which rope he is clipping and which one to feed out while you are trying the reel the other one in... Think most sport pitches where clips are super fast and the game of feeding out and reeling in is so precise.
All that being said you won't catch me on a multi pitch climb without my doubbles ;)
|
|
blahblah
Gym climber
Boulder
|
|
|
Apr 13, 2009 - 01:21pm PT
|
rgold: I love reading your stuff and know that, as a general matter, your knowledge of physics applied to climbing is much greater than mine.
But I challenge your below statement:
"I'll repeat a comment here: half ropes are strong enough to catch any fall."
Why do you think that a single half rope is strong enough to catch even a single factor 2 fall? A single half rope would never have to do that when used as intended, and they are not tested with a weight that is heavy as (most) climbers. To spell it completely, I think a single rope will catch a factor 2 fall because of the testing that is done on a single rope; the testing on a half rope is not equivalent and is done with a weight that is significantly less than an average adult male climber and very much less than the weight of a heavy climber loaded with gear.
This concept is related to my above post explaining that a single half rope is never subjected to factor 2 falls when used as intended--I don't think most of you are getting it, and if you think a single half rope is strong enough to replace a single rope re: factor 2 falls, maybe you're right, but unless you've done your own testing you're just guessing.
Edit: I saw the response from rgold that (one) double rope can withstand several UIAA single rope drop tests. If so, that does address my concern.
|
|
rgold
Trad climber
Poughkeepsie, NY
|
|
|
Apr 13, 2009 - 01:24pm PT
|
Rgold, I have bought 4 sets of 1/2 ropes in the last decade, all diferent brands and diamaters and every single one of them had a little child proof pictuer guide on the furnished reading material that showed both ropes clipped throuigh the same biner as being safe.
And most, if not all, of those ropes were not rated as singles because, when both clipped, the load in a UIAA test fall with an 80 kg weight exceeds 12 kn.
Sorry but unless you are climbing very poorly protected and tricky gear placements it is darn silly to bring 400ft of rope to a 60ft crag..
This will be news the the Brits, who will have to be notified that they have been darn silly for many years now. As for me, especially in my dotage, "darn silly" is probably on the gentle side of the possible criticisms and I thank you for your restraint.
Think of all those times when the leader is out of sight and you are guessing which rope he is clipping and which one to feed out while you are trying the reel the other one in...
As I suggested, (and as I'm sure you know) the trick is to look at the ropes in front of you, not at the leader, whether or not the leader is in or out of sight. This makes it simple to handle the ropes properly and with appropriate speed. Sounds to me like you need to upgrade to a better brand of belay slave.
Oh yeah, pedant that I am, I tried to ignore this for a while but my character defect has finally won out..."double" and "doubles" only have one "b."
|
|
tradmanclimbs
Ice climber
Pomfert VT
|
|
|
Apr 13, 2009 - 01:25pm PT
|
I have NO real scientific data as well but from a logging standpoint 1/2 rope breaks a whole crapload easier than single rope. You can still pull a pretty darn bik log out of the woods with 8.6mm rope but if it snaggs on something it breaks quick. Same situation with 10.6mm and you have to really mosh the truck to break the rope.
|
|
rgold
Trad climber
Poughkeepsie, NY
|
|
|
Apr 13, 2009 - 01:29pm PT
|
The UIAA rating for half-rope logging is only for non-snagging applications.
|
|
ionlyski
Trad climber
Kalispell, Montana
|
|
|
Apr 13, 2009 - 01:34pm PT
|
I don't think the advantage of double length rappels when using doubles or twins should be stated, when making the comparison between single vs double because most of the time what we're really comparing is "single with tagline" vs "double" techniques. The text books always highlight this advantage for doubles, as if you weren't planning to haul or pack a second skinny line with your single system.
RGold, I've paid attention to your contributions on this subject before and am trying hard to become better at belaying with doubles but I still can't look you in the eye and tell you that you won't fall farther. If I'm honest I know there are times too, as I'm paying out with one, whilst taking in with the other, that I wouldn't want you to fall at that exact moment. In general, if you're leading on doubles while I'm belaying you, you're going to have a bit more slack in the system than with singles. I realize you wouldn't climb with me anyway but I'm just being honest.
Arne
|
|
rwedgee
Ice climber
canyon country,CA
|
|
|
Apr 13, 2009 - 01:35pm PT
|
In the photo you should have used slings, not draws to route the rope. I'd rather carry more slings than another rope any day.
Used the Mammut 7.7mm clipped as one, as designed, for a while for long ice routes for the advantage of long raps. They were just too skinny to handle(mainly tying/untying in at the anchor) with gloves on. Even a clove hitch was hard to get out. They were super stretchy with low impact as you would want for ice, horrible to rap on. It was like a bungee cord. No good in the Sierras as with that much rope you will get them stuck or pull rocks down rapping.
Even clipped as on one they were never equally tight in a fall due to whatever, if not simply the way they're positioned in the belayers glove.
|
|
ionlyski
Trad climber
Kalispell, Montana
|
|
|
Apr 13, 2009 - 01:40pm PT
|
Hi there Tradman,
Say, where are you logging with ropes?
Arne
|
|
|
SuperTopo on the Web
|
Let us know!