Jump to content
  • Announcements

    • olyclimber

      WELCOME TO THE CASCADECLIMBERS.COM FORUMS   12/08/21

      Thanks for visiting Cascadeclimbers.com.   Yep, we are still going!    Just put a new coat of paint on the site. Still the same old community of climbers, skiers, and people who love to get outdoors. Hope you had a great 2021, and wish you the best for 2022 and beyond.  Thanks again for stopping by.
Sign in to follow this  
assmonkey

Double rope advice

Recommended Posts

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? cool.gif

Share this post


Link to post
Share on other sites

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)

Share this post


Link to post
Share on other sites

I use 8.4mm Sterling Marathon, 60m, dry for ice. Nice rope.

 

8Falls, 6.27kn Impact force, 30.1% Dynamic Elong, 44g/m

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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.

ooo.gif

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

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. wave.gif

 

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 by Stephen_Ramsey

Share this post


Link to post
Share on other sites

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 by Rodchester

Share this post


Link to post
Share on other sites

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.... bigdrink.gif

Share this post


Link to post
Share on other sites
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.... bigdrink.gif

 

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

Share this post


Link to post
Share on other sites

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 by Rodchester

Share this post


Link to post
Share on other sites

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 cantfocus.gif now!

Edited by David_Parker

Share this post


Link to post
Share on other sites
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.... wave.gif

 

Cheers,

Steve

Edited by Stephen_Ramsey

Share this post


Link to post
Share on other sites
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.

ooo.gif

 

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 Geek_em8.gif

Share this post


Link to post
Share on other sites
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... hellno3d.gif

Share this post


Link to post
Share on other sites
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.

ooo.gif

 

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

 

8-1mmVerglas.jpg

 

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

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites

Those 8.1mm ropes are indeed nice. thumbs_up.gif

 

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.

Share this post


Link to post
Share on other sites

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

Share this post


Link to post
Share on other sites

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.

Share this post


Link to post
Share on other sites

I was having this conversation with an engineer I know who works for a rope company just the other day. When inquiring about “twin clipping” with a half rope, he had the following to contribute:

 

“If you're planning on some sort of gnarly trad climb where you're definitely putting yourself in a spot where there's a good chance of taking [a whipper], my suggestion is to clip both double ropes into individual biners to your last piece of gear before heading into the crux.”

 

And, FWIW, taken from the UIAA tech manual:

 

UIAA 101 testing requirements:

 

Construction: Kernmantle with core having a greater mass than the sheath Sheath Slippage: Must be less than 20mm over a 200mm sample or no more than 10% Static Elongation: Tested using an 80kg weight for single and twin ropes and a 55kg weight for half ropes:

 

Single and Twin Ropes (using both strands): Must be less than 8%.

Half Ropes: Must be less than 10%

 

Impact Force: Tested during the first factor 1.739 fall (4meter fall on 2.3meters of rope).

 

Single Ropes: Impact must be less 12 kilonewtons (kN) using an 80kilogram mass.

 

Twin Ropes: Same as Single ropes, but using both strands during the test.

 

Half Ropes: Impact must be less than 8kN, tested using a 55 kilogram

mass.

 

Falls Held: Number of falls rope holds before breaking.

Single Ropes: Must hold 5 falls of an 80kg mass.

Twin: Must hold 12 falls of an 80kg mass.

Half: Must hold 5 falls of a 55kg mass.

 

bigdrink.gif

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×