Double rope advice

[assmonkey]

Fuggit, assmonkey is buying himself an early Christmas present. I'm going to get double ropes for the express purpose of climbing ice. So, being a total ice newbie, can some of you hotshots help with purchasing advice? I think I want 60m doubles, but all the offerings make my head spin (8.1, 8.6, etc.). Help assmonkey.

 

On that note, anyone want to take this ice newbie ice climbing this winter?

[IceIceBaby]

Well for pure lead, approaches, and mobility on double the skinnier the better (the 8.1)

A good compromise bt lead and TR will be the 8.5-/+

For durability and allot of practice the 9 will do well (u can do one strand for TR without worrying too much)

[specialed]

I guess they make 8.1 doubles. But as we all know, double ropes, unlike twins, must be rated for catching a fall by themselves. I personally wouldn't want to whip on an 8.1. The standard is 8.6 I believe. I've had edelweis and beal 8.6 doubles. The Beals were lighter and more compact, but the edelweis's are proving to be more durable.

[Lambone]

If you'd like to use them for siummer alpine climbing at all, go with edellwise sratos...I often climb on a single strat in the mountains.

 

If it is strickly ice, go with skinnier ones. I baught a good pare of Rocas at Pro Mountain Sports. 8.1s I think. Don't fall.

 

Whatever you do make sure it has a good dry treatment and is at least 60m....70m isn't a bad idea.

[Rodchester]

Make sure that the ropes are "double" ropes as opposed to "twin" ropes...unless you want to use a twin ropes system. Just know the difference.

[glassgowkiss]

thinner ropes, more mess. i use 8.5 for that reasonspecially if you climb 3 people.

[Doctorb]

Beal Ice Line, 60m, dry, 8.1mm. A bit of a tangle on rap sometimes, make sure you're not the heavy guy.

[assmonkey]

You guys rock, thanks for the information. It does help.

 

One more question for you: I can clip doubles together into a single piece of pro, like an ice screw, correct? I understand that twins MUST be clipped together, but I can do something like this with doubles, right?

 

Clip 1: center blue, orange

Clip 2: left blue

Clip 3: right orange

Clip 4: center blue, orange

 

If I fell on the 1st or 4th piece, the ropes will hold a fall correct? And on the 2nd and 3rd as well?

 

To date, all my climbing experience has been on a single rope. And yes, I am actively seeking proper mentoring.

[abalch]

Clip 1: center blue, orange

Clip 2: left blue

Clip 3: right orange

Clip 4: center blue, orange

 

Not a good idea. If you start twin clipping, stay twin clipping. You can use doubles as twins, but if you do as you decribe, and fall after clip two, you have two different lengths of rope out possibly, and even if it is close to the same amount, you can cause rope damage, because the ropes will quickly slide against each other when you fall in the one piece where they are clipped together. the different lengths of rope means one rope doesn't stretch, while the other does through the carabiner. You can minimize this problem, if you don't have the extra ice screw, by putting one short, and one long runner on the first clip, so the rope are independently clipped. It is advisable to use lockers on the end of those runners where the rope goes through, to avoid problems in the unlikely scenario of the long runner opening the gate of the short runner.

[Stephen_Ramsey]

Assmonkey,

 

I'm just a beginner, so I'm probably misinformed. But I was taught that you do not want to twin-clip with a "double rope". I was told the reason is because twin-clipping increases (in the event of a leader fall) the force on the piece of protection, as compared to using a single-clip with a rope of the same diameter. With official twin ropes, twin-clipping is OK because the ropes are designed for this (i.e., they have the diameter and elasticity such that even with a twin-clip, the combined force on the piece of pro is less than some threshold).

 

The following explanation assumes a serious leader fall in which the belay is at least somewhat dynamic (some rope slips through the belay device). The maximum force that the belayer (with the belay device) can exert on the rope to slow it down (as it slides through the device) is dependent upon the thickness of the rope. With an 8.5 or 9mm double rope, this force is larger than with a 8.1mm twin rope. Twin ropes are designed to be thin enough that even when this force is doubled (two strands of rope going through the belay device), the net force on the anchor is less than some magic number that is considered "safe". But no such guarantee is made if you twin-clip a double rope, and both strands of the double-rope go taught at the same time.

 

The foregoing analysis neglects the kinetic friction of the rope passing around the carabiner at the "last" piece of pro. This friction force depends on the diameter of the rope relative to the cross-sectional radius of the carabiner. I believe this friction force is increased if the diameter of the rope increases. This has the effect of very slighly reducing the force on the anchor, relative to the twin-rope scenario. But I don't think it compensates for the increased force from the belayer.

 

Bottom line-- if you twin-clip with double ropes and take a leader fall, your last piece will see a net force that is (possibly significantly) greater than what you would have with a twin-rope system.

 

Again, just repeating what I was told. Take with the appropriate grain of salt.

 

In any event, I make it a point to never twin-clip with my 8.5mm double ropes, even if I'm clipping a bolt.

In ice or alpine climbing, I personally am much more frightened of a piece ripping, than I am of the rope breaking. Just a personal choice.

 

Cheers,

Steve

Edited December 17, 2003 by Stephen_Ramsey

[Rodchester]

Twin ropes you are supposed to clip both into each piece of protection, screw, rock gear, whatever. With double ropes I have always been taught, and always do, clip only one rope into each piece of protection.

 

It has always been my understanding (don't quote me though, ask the rope manufacturer) that double ropes are basically thin single ropes, meaning that they are made/tested/rated individually to take a certain amount of leader falls (not as many as an actual single rope though). While twin ropes are made/tested/rated to sustain a fall only with the two ropes working together.

 

One might assume that clipping both double ropes into the same protection doubles the rope strength, thus making you safer. Now, I'm no physics guy, but my understanding is that a fall on two double ropes clipped into a single piece of protection will increase the force created on the protection. Not necessarliy by 2 times, but something like 1.5 times. The net effect is that you are putting more force on the protection than required and that the additional force created cause a piece of protection to fail.

 

I'm sure that I have not explained it very well. And maybe may ass is just plain wrong. But this is what I have always understood. Anyone know better?

 

Jim Nelson says....

Edited December 17, 2003 by Rodchester

[Rodchester]

Rope systems

 

As all the ropes are designed and manufactured for different Rope Systems, it is of crucial importance (!) that climbing ropes are only used for the purpose they are designed for. So for example, never use a twin rope in a Single Rope System nor using a twin rope in a Double Rope system.

 

I'm just here for the beer....

[Stephen_Ramsey]

Rope systems

 

As all the ropes are designed and manufactured for different Rope Systems, it is of crucial importance (!) that climbing ropes are only used for the purpose they are designed for. So for example, never use a twin rope in a Single Rope System nor using a twin rope in a Double Rope system.

 

I'm just here for the beer....

 

This is a good point, although it is common practice to use double ("half") ropes in "single" rope mode, for roped simul-climbing on moderate alpine terrain, where fall forces are unlikely to approach the forces of 80-kg UIAA test drops.

 

Cheers,

Steve

[Rodchester]

Thought this was interesting:

 

Ropes

 

Single, Half, and Twin Ropes

 

A single rope must sustain on one strand a minimum of 5 test falls with a drop weight of 80 kg without breaking. Single ropes are recommended whenever a fall on a single strand can occur. They are safe in the event of a fall and are used in situations with potentially high fall factors.

 

Half ropes must also sustain 5 test falls on a single strand with a drop weight of 55 kg. They can be used as a single rope when the fall factor is less than 1. In the event of a serious fall, the necessary safety factors can only be achieved when the rope is used double. The double-rope technique is where each strand is clipped separately through different runners, giving two distinct very light single ropes. The greatest advantage of this technique is it provides less risk of total rope system failure.

 

Twin ropes are tested with a drop weight of 80 kg on two strands together and must survive 12 test falls. The twin-rope technique, when used correctly, provides the highest safety margin in event of a fall. In this technique both ropes are clipped together through the same karabiners where they act as a stronger, safe single rope.

 

 

So half ropes(Doubles) are only tested to 55.

 

Best explanation I've found so far...

Edited December 18, 2003 by Rodchester

[David_Parker]

So essentially when using double (aka 1/2) ropes, you really have two independent systems going on and in the event of a fall, one rope is doing ALL the work and the other is merely a backup system. In the event of the top pro failing, there will be quite the shock on the next lower piece with the other rope. Even more if your last 2 clips are on the same rope. So you can argue that one 1/2 rope needs to not only hold a fall all by itself, but a fall where there could be a lot of rope run out. I question the amount of force on the second or subsequent piece in the scenario of the failed first piece as compared to just having two ropes clipped through one piece. This being said, I'm not so sure I wouldn't be tempted to double clip anyway for center pro pieces.

 

Also, since a double rope is designed to act like a thin single, it does give me comfort to know in an alpine situ, I can just use one 1/2 and keep the other in my pack unless the climbing gets really hard.

 

The whole thing makes me wonder about using double ropes where you're on ground where you might be running it out a lot (alpine, WI II to IV-, class IV, etc).

 

Man I'm even more now!

Edited December 18, 2003 by David_Parker

[Stephen_Ramsey]

So essentially when using double (aka 1/2) ropes, you really have two independent systems going on and in the event of a fall, one rope is doing ALL the work and the other is merely a backup system. In the event of the top pro failing, there will be quite the shock on the next lower piece with the other rope. Even more if your last 2 clips are on the same rope.

Hi David,

 

I'm not sure I agree (or I'm confused, which is perhaps more likely). It seems like it would only be "even more if your last 2 clips are on the same rope" if the rope broke.

 

Let's suppose your last two pieces were on the blue rope, and the piece before that was on the orange rope. In this scenario, if just the top piece pulled, you'll just fall to the next-to-last piece as if on a single blue rope. The second piece would have to pop as well, before the orange rope comes into the picture. Now, if the blue rope broke, then I agree, you're going for the big ride (all the way to your third piece).

 

The other thing about twin ropes is that the two ropes are right next to one another and are thinner, which increases the chance (albeit unlikely) that a single rockfall or errant adze chop can cleave both ropes, as compared to a double rope system. With a double rope system, the ropes are usually a bit more separated. This is one reason that I tend to favor double ropes over twin ropes (although rope drag is still a more important factor for me).

 

It seems like occasionally twin-clipping with a 1/2 rope might decrease the distance of a fall in the event a rope breaks, but at the cost of (in the event neither rope breaks) increasing the potential force on the piece that was twin-clipped. I guess it's a case of "pick your poison"...

 

But as I said, I maybe misunderstood your post, or I could be just totally confused....

 

Cheers,

Steve

Edited December 18, 2003 by Stephen_Ramsey

[IceIceBaby]

You guys rock, thanks for the information. It does help.

 

One more question for you: I can clip doubles together into a single piece of pro, like an ice screw, correct? I understand that twins MUST be clipped together, but I can do something like this with doubles, right?

 

Clip 1: center blue, orange

Clip 2: left blue

Clip 3: right orange

Clip 4: center blue, orange

 

If I fell on the 1st or 4th piece, the ropes will hold a fall correct? And on the 2nd and 3rd as well?

 

To date, all my climbing experience has been on a single rope. And yes, I am actively seeking proper mentoring.

 

Yeah man, u want to keep to the bare minimum the clip of the 2 strands together in double system b/c it will increase the impact on the piece(ice screw) so definitely try NOT to clip them together on the first few clips unless u get bomber bolt or something but still it is not a good practice

[kurthicks]

Half ropes must also sustain 5 test falls on a single strand with a drop weight of 55 kg.

 

so if you weigh less than 55kg (121 lbs), can you use a half rope as a single rope all the time? Not that I would (or fit that criteria), but it seems like it could be safe...

[gnibmilc]

You guys rock, thanks for the information. It does help.

 

One more question for you: I can clip doubles together into a single piece of pro, like an ice screw, correct? I understand that twins MUST be clipped together, but I can do something like this with doubles, right?

 

Clip 1: center blue, orange

Clip 2: left blue

Clip 3: right orange

Clip 4: center blue, orange

 

If I fell on the 1st or 4th piece, the ropes will hold a fall correct? And on the 2nd and 3rd as well?

 

To date, all my climbing experience has been on a single rope. And yes, I am actively seeking proper mentoring.

 

The PMI and/or Beal 8.1mm. Get my vote.

 

 

PMI rates and tests them as both twin and double use....but really we are talking about using these things for rappeling, not falling...but even then, the very low impact force of the 8.1mm in the double mode negates the need for "screamers" or any of that stuff. Even as a twin, the impact force is pretty low, better than most single ropes. you can simu-rap with them even if you are fat. They get a little flat but come back. I've rap'd a bunch on them and I just can't throw them out...the sheaths are still good, they've got bounce to them, although I've still never fallen on them on ice or rock or dirt. i trimmed them to 50 meters from sixty and just keep using them (maybe 5 years??).

 

look at the weight of a pair of them compared to any single (plus a second rap line of any sort) or other doubles.

 

Consider the impact force of these in double mode (when the protection/belay is poor) and the impact force in the twin mode (bolts, good cracked granite) and do the math.

 

If you need two ropes to rappel, no question.

 

If want to minimize impact force, no question (double).

 

If you want minimize elongation to avoid a ground/ledge fall due to stretch, no question (twin).

 

If you want to reduce drag on the wandering route - double mode.

 

The only thing they suck for is single pitch sport climbing and they aren't too neat for the seconds when climbing as three because if they fall, they are going to stretch the fall into a good distance and could cut the rope if sharp corners, etc are around.

 

http://www.pmirope.com/sport/pmiropes/dynamic/halftwin-8_1verglas.html

[David_Parker]

Sorry for the confusion Steve. I added that bit at the last moment without rereading it. You have set the record straight. With 2 subsequent clips on one rope, either the second piece would have to fail or the rope break before impacting the "other" rope.

 

I'm thinking ice climbing mostly as that's what I do most and am most inclined to use a 2 rope system. I tend to run it out more than many so this stuff got me thinking. So taking Ice baby's advise, best to for sure clip alternate ropes for your first two screws no matter what. But in a scenario say with a situ where you go around a big corner and you want to direct both ropes, you might be ok to clip both as long as you go back alternate clipping again for the next few screw. Obviously there are a bazillion scenarios and best to not clip both as a rule, but to do so isn't neccessarily gonna cause both ropes to fail or anything.

 

So if you are climbing with TWINS, and you are basically clipping both ropes and get to a place where you could significanly reduce rope drag by making a few placements with alternating clips, Is that terrible?

[Stephen_Ramsey]

Those 8.1mm ropes are indeed nice.

 

The only thing they suck for is single pitch sport climbing and they aren't too neat for the seconds when climbing as three because if they fall, they are going to stretch the fall into a good distance and could cut the rope if sharp corners, etc are...

You make a good point about rope elongation. I've actually decked when top-rope ice climbing on a single 8.1mm strand, due to the belayer misjudging the rope stretch. Fortunately it was a soft landing in deep powder.

[Stephen_Ramsey]

David,

 

I'm thinking ice climbing mostly as that's what I do most and am most inclined to use a 2 rope system. I tend to run it out more than many so this stuff got me thinking. So taking Ice baby's advise, best to for sure clip alternate ropes for your first two screws no matter what. But in a scenario say with a situ where you go around a big corner and you want to direct both ropes, you might be ok to clip both as long as you go back alternate clipping again for the next few screw. Obviously there are a bazillion scenarios and best to not clip both as a rule, but to do so isn't neccessarily gonna cause both ropes to fail or anything.

Good point. I hadn't thought about the redirection scenario.

 

Cheers

Steve

[rbw1966]

To avoid friction when going from alternating clips to clipping both strands to the same piece you can add an extra biner and clip each strand into a seperate biner.

[IceIceBaby]

but to do so isn't necessarily gonna cause both ropes to fail or anything.

 

true to that the stand point is not rope failure it is more of Pro failure due to high impact...that is why we use the double rope in the first place each strand transmit LOWER impact to the pro increasing the chance of it holding in marginal placement (=ice placement)

 

So if you are climbing with TWINS, and you are basically clipping both ropes and get to a place where you could significantly reduce rope drag by making a few placements with alternating clips, Is that terrible?

 

not recommended the impact per strand on twin is the lowest of the rope systems (that is why they tell u to clip them together...it is worse then rubber band by itself) if u fall on one strand the elongation might land u on a ledge/deck or/end due to this property the rope is more susceptible to cut over sharp edge which will lead to landing on ledge/deck

so in short use a longer sling and like they said 2 biners will help too

almost forgot.....

[Bug]

I have been using twin 9's for twenty years now. I will go to 8.7's next purchase due to the increased rope strength. I prefer 50m or 165'. I use the two together as one lead rope and use lots of slings to decrease rope drag. Two ropes get me off the mountain quick in a storm and are way stronger over edges and other adverse situations. 60m is overkill. More weight, more pieces, more rope handling, and further away from your belayer.

I know the question is about alternating clipping ropes and I am not a serious ice climber like David_Parker. But this is the system that I have come to like best for alpine rock after trying every other alternative that comes along.