Half Ropes...

[tomtom]

Half

[scrambled_legs]

But I think you may be reading this too literally. By left and right, I believe they are just designating the individual ropes, not describing where on the route to use them. The salient point is if you fall, it will be onto one rope. whether you have clipped that rope in an alternating fashion or consecutively along one side of the route is completely dependant on the route, and (in a vacuum) not going to determine whether the rope fails or not. hopefully someone will correct me if I'm way off.

 

No that's not what I meant at all. I was referring to the comments about clipping alternately. I took this to mean that you clip the left rope then the right rope then the left, regardless of where your protection is. Unless the route is straight up I don't believe this is right. I always took it as you clip whatever rope you have to to make them run the straightest line possible. The left rope to the left gear and right to the right. If you have 3 pieces in to the left of the belay and then wander right you should have 3 pieces clipped to the left rope only. This is where I'm confused. If you fall at that point you are essentially using the 8mm rope as a single and you never see a 8mm single rope being used. Why would having another rope attatched to the belay make this any safer than one single, besides the fact that you might be stopped with a factor two fall 30m below the belay? If its safe to climb like this, why isn't it safe to use an 8mm single? If on a wandering climb you alternate left and right rope, you end up with a mess of crossing "Z"s. Is that they way they're intended to be used so that if you pop a piece or break a rope, you only fall to the next piece on the other rope.

 

My theory is that these ropes are strong enough to catch a big whipper. The problem is that they are so tiny a crampon, ice axe or rock fall can easily cut one of the ropes. If that happens, you just have to clip the other rope and you're still on belay. Thats why I think half ropes aren't rated as singles yet are practically used as one. Do you think is right?

[catbirdseat]

Come on, now. You are just making this way too difficult. You have to use common sense.

 

If you don't have a good reason to do otherwise, clip alternately. If the route wanders, do what you have to do to mitigate rope drag and/or protect your second on traverses.

 

Usually you can manage to clip alternately for your first few placements until the fall factor decreases. After that, the skinnyness of the rope becomes less of an issue. As I see it, edge cut resistance becomes the biggest source of risk.

 

In my experience, even on wandering routes, it is seldom necessary to make more than two or three consecutive clips on one rope. You still get SOME redundancy from having the other rope. It depends on where the ground and/or ledges are.

[jmace]

This is where I'm confused. If you fall at that point you are essentially using the 8mm rope as a single and you never see a 8mm single rope being used.

 

Try alpine climbing.

 

THe rope is fine its rated for a fall it can hold a fall thats what its meant for. Twins are the ropes you cannot do this, why buy twins, specialty item you hardly see them around because they have few uses.

[David Trippett]

sorta related....I heard (Beal I think) is coming out with a 80m 8.2mm rope with bi-pattern and thicker sheath for alpine use. You can use it single for easier stuff and double it for harder leads up tp 40m, the bi-pattern is supposed to help keep the sides sorted. 40m raps as well...

 

I'm not sure why you wouldn't just take 2 half ropes....but I guess not having the knot whilst descending might help mitigate getting the knot stuck and pulling loose rock off. 80m leads would be cool....but I'd be a bit nervous falling with 70m of rope out in the alpine with a single 8mm....and you better hope that "hard" pitch isn't longer than 40m.

[catbirdseat]

sorta related....I heard (Beal I think) is coming out with a 80m 8.2mm rope with bi-pattern and thicker sheath for alpine use. You can use it single for easier stuff and double it for harder leads up tp 40m, the bi-pattern is supposed to help keep the sides sorted. 40m raps as well...

 

I'm not sure why you wouldn't just take 2 half ropes....but I guess not having the knot whilst descending might help mitigate getting the knot stuck and pulling loose rock off. 80m leads would be cool....but I'd be a bit nervous falling with 70m of rope out in the alpine with a single 8mm....and you better hope that "hard" pitch isn't longer than 40m.

Anyone care to guess what the elongation would be on said 70 meters of 8 mm rope?

[robert]

Anyone care to guess what the elongation would be on said 70 meters of 8 mm rope?

Given that Beal's 8.1mm rope is 37% elongation I would say about 25 meters for a 70 meter and almost 30 for an 80 meter. That assumes ideal conditions and all of the rope out, but still, 100 feet is a lot of stretch.

[scrambled_legs]

This is where I'm confused. If you fall at that point you are essentially using the 8mm rope as a single and you never see a 8mm single rope being used.

 

Try alpine climbing.

 

THe rope is fine its rated for a fall it can hold a fall thats what its meant for. Twins are the ropes you cannot do this, why buy twins, specialty item you hardly see them around because they have few uses.

 

Really? What kind of Alpine do you do on an 8mm. I hope you are just referring to crossing glaciers or running snow ridges. You don't mean on fifth class alpine routes do you? I've never seen someone on 5.8 or harder with an 8mm, but that's what I'd compare climbing grade 4+ ice to. Why is the Beal Joker advertised so much if a half rope can hold the same fall as a single? Sorry just not understanding this yet.

[jmace]

Sorry just not understanding this yet.

 

I see that, I just dont get why you cant understand that a single strand of a half rope can hold a fall. I think if you grasp that then you could move on to why half ropes are used in climbing as an entire package from getting up to getting down.

[Dru]

scrambled legs has never been the sharpest pencil in the box so its no wonder homey has to hear it several times before he understands it.

[scrambled_legs]

Okay well everyone seems to be in agreement that a half rope takes just as much of a force load as a single rope in a fall.

 

THE FACT IS THAT HALF ROPES WITH THE EXCEPTION OF THE BEAL JOKER, HAVE NOT PASSED THE SINGLE ROPE RATING!!!!

 

Dru, please explain to me then why a rope that is taking the same force as a single cannot be rated as a single???

 

 

Please answer the above question oh brilliant one, as no-one has yet!!! As great as your smart ass comment is why don't you try and dumb it down a bit and write a little more with those pencils that you are so fond of so us common folk can understand it.

 

I just dont get why you cant understand that a single strand of a half rope can hold a fall.

 

I don't get why you don't understand my question? A half rope can't pass a single test but it can still hold a fall on a single strand? please explain!!!

[Dru]

single rope test is not for a single fall, dumb ass!

[scrambled_legs]

And a half rope test is???

[jmace]

THE FACT IS THAT HALF ROPES WITH THE EXCEPTION OF THE BEAL JOKER, HAVE NOT PASSED THE SINGLE ROPE RATING!!!!

 

Fair enough, sounds like a good rope

 

I don't get why you don't understand my question? A half rope can't pass a single test but it can still hold a fall on a single strand? please explain!!! single???

 

As Dru says different test, Single ropes are tested with a 80 kg weight and Halfs are tested with a 55 kg weight.

 

 

hope that helps

 

PS id buy the joker if thats what all this is about

[TrogdortheBurninator]

go on a diet until you weigh 55 kg. Start using your 8.? rope as a single. Take only factor 1.78 falls. When you reach n-1 falls, retire the rope (where n is the rated number of falls).

 

Or....

 

Just use common sense like everybody else that uses half ropes.

[scrambled_legs]

I know that there are different weights used for the different tests, that's what I had put in one of my first posts and that's why I'm asking these questions. Is the single rope test with 80kg supposed to simulate the worst case scenario fall? That's what I took it as and so when I buy a rope that's rated for 12 falls, I usually retire it before 8 good ones. That way I know that I'm under the safety margin. A half rope takes the same force in a fall but they test it with a tiny 55kg weight?

 

I always thought a half rope was tested under the same system until I started looking into it. When I found out that it is tested with a 55kg weight despite the same fall forces, it got me thinking. 55kg is what 121 lb's and I weigh around 170lbs with my gear? So when I buy a half rope with an 8 fall rating I shouldn't retire this at 6 falls but more like 2 or even 1. If the rope doesn't even pass the single test for 1 fall then maybe I should use a different system when I have the possiblity of a fall.

 

If twin technique doesn't create too much of a shock load then I may start using it with a screamer whenever I'm in a dicy section. Or I might start using the trick with different length draws for each rope on one piece as someone suggested. Thanks for that by the way!

 

My whole thing is that I'd like to know how many falls a half rope can take with the single test as that is what is happening when you fall on it. There is no difference in the force load when falling on a single or a half and who weighs 120lb's ice climbing? If I knew that it'd pass with a 3 fall rating then I'd use half rope technique always without worry but will it even hold one fall? I don't know cause they dont test it? When they tested the Beal Joker it went from 5 falls on the single test to 20 on the Half rope test. So my Phoenix rope which is 8-9.5 as a half, should be around 2 when tested as a single.

 

Apparently my questioning this makes me a dumbass even though several other people on here clip twin technique or clip both ropes through different draws on the same piece when they're concerned about a fall because they don't trust half rope technique.

[TrogdortheBurninator]

I have BW excellence 8.6s. These are one of the few edge rated half ropes. Supposedly they are good for one sharp edge fall, but not two. I am not sure if this is the single rope sharp edge test, or an additional double rope test.

 

The important consideration is the fall factor. A factor 1.78 fall is a hard fall (factor two is max). I dont think most folks make a habit of taking falls anywhere near this hard on a regular basis. A 20 footer 40 ft up a route is only a factor 0.5 fall by comparison. Unlike the test, real ropes will likely have significant time between falls where the polymer molecules can relax to a less elongated state. In practice ropes should take considerably more falls (even decent whippers) than the test suggests. I would imagine the test is pretty conservative by design.

[catbirdseat]

Scrambled_legs, the thing you have to understand is that UIAA tests are far harsher than anything your rope will see in most situations. I had a rope that was rated to 12 falls and I must have taken a several dozen falls on it before I retired it and that was only on account of sheath damage.

 

First of all the 12 falls in the test are on EXACTLY the same segment of rope. The edge is in the same place each time. The chances of getting 12 falls in precisely the same place while climbing are infinitesimal.

 

I think there are others here who could comment better than I on the differences between test falls and reality.

[John Frieh]

SL: still got your retired ropes laying around? I'd be happy to give them a good home since they aren't safe anymore

 

Does this help at all? UIAA

[Geek_the_Greek]

I dunno if this has been said yet, but you're never going to subject a single strand of a double rope to factor 2 forces. If you climb above the belay and fall with no pro, both strands catch you. If you place pro on one strand and then fall, the fall force is reduced (because you have placed intermediate pro), but yes, it is absorbed by a single strand. Is this the answer you were looking for?

 

Max fall factor with double ropes (on a single strand) < max fall factor with single rope.

 

Yes, that's the "smaller than" sign.

Edited January 30, 2006 by Geek_the_Greek

[TrogdortheBurninator]

Yes, that's the "smaller than" sign.

 

I was sure it was an alligator

[Dru]

It's a consummate V.

[TrogdortheBurninator]

[Geek_the_Greek]

Correct, no alligator.

 

 

People were getting confused here, so you know, I'm trying to help.

[TrogdortheBurninator]

Dru wouldn't know majesty if it bit him in the face.