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By Orphaned
Dec 6, 2011

Just bought a set of sterling photon fusions and was wondering because they r rated both for half and twin use if I can clip them in half or twin alternating on the same pitch? If not then why?


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By Gregger Man
Dec 6, 2011
gg

Not wise.
Once you've clipped as per a double rope, a fall can make one strand go tight while the other stays slack. If both strands are held side-by-side in a single carabiner basket (as per twin rope technique) you could melt the sheath where they run against each other.


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By bearbreeder
Dec 6, 2011

from mammut ...

Hello (named removed),

you had a question on your Mammut rope Phoenix 8mm and whether it can be used in twin and half rope technique in one single pitch. This is the case, you can always clip the two rope strands as twins, then split them as doubles, join again etc. This is exactly the advantage of half ropes compared to twin ropes where you always need to clip both ropes.

Hope this helps you,
best regards from Switzerland,


(named removed)
Productmanager Climbing Equipment


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By Crag Dweller
From New York, NY
Dec 6, 2011
My navigator keeps me from getting lost

you're going to get different answers from different people. but, regardless of the answer, why would you want to use double/half ropes as twins? i can't picture a scenario where there would be any reason to do so.


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By David Appelhans
From Lafayette
Dec 6, 2011
Imaginate

I'm with Gregger Man on this one even though mammut said otherwise. It is not a good idea because the ropes can move at different speeds when they are clipped as doubles, so if they are going through the same biner the one catching the fall can potentially melt through the other one.

I was taught the ropes by a friend who learned a lot from swiss guides and he taught me it was fine to alternate double and twin technique (he had the phoenix btw). I have since changed my mind and I stick to either twin or double for a pitch.


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By David Appelhans
From Lafayette
Dec 6, 2011
Imaginate

Crag Dweller wrote:
you're going to get different answers from different people. but, regardless of the answer, why would you want to use double/half ropes as twins? i can't picture a scenario where there would be any reason to do so.


There are a couple reasons; mostly convenience and rope stretch.

First belaying with twin technique is just alot easier than feeding out slack on one rope and taking in slack on the other. Sure double technique is not that hard, but maybe you are just teaching someone or just don't want to deal with it on a straightforward pitch.

The rope stretch is the biggest one though. Getting caught by one of the doubles has alot of stretch and lets you fall alot further, possibly hitting a ledge or loosing some ground you'd rather not reclimb. So if these are issues you expect on a pitch switching to twin technique makes alot of sense.

I was on a pumpy climb recently using double technique where every time I fell the skinny little double stretched a long ways and made me climb the same pumpy crux again. In hindsight I wish I would have done that pitch with twin technique.


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By Crag Dweller
From New York, NY
Dec 6, 2011
My navigator keeps me from getting lost

David Appelhans wrote:
There are a couple reasons; mostly convenience and rope stretch. First belaying with twin technique is just alot easier than feeding out slack on one rope and taking in slack on the other. Sure double technique is not that hard, but maybe you are just teaching someone or just don't want to deal with it on a straightforward pitch. The rope stretch is the biggest one though. Getting caught by one of the doubles has alot of stretch and lets you fall alot further, possibly hitting a ledge or loosing some ground you'd rather not reclimb. So if these are issues you expect on a pitch switching to twin technique makes alot of sense. I was on a pumpy climb recently using double technique where every time I fell the skinny little double stretched a long ways and made me climb the same pumpy crux again. In hindsight I wish I would have done that pitch with twin technique.


The second scenario, to prevent decking as a result of rope stretch, seems to me like one that might justify using doubles as twins.

As for the difficulty of double rope technique, it's not really. It takes about 2 minutes max to get it down. And, IMO, using twin technique to compensate for bad double rope technique is just a bad idea. Kind of like using a gri gri to compensate for bad belay technique.


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By Cory
From Boise, ID
Dec 6, 2011
Relaxing in the Tuttle Creek Campground after a fun day in the Hills

Gregger Man wrote:
Not wise. Once you've clipped as per a double rope, a fall can make one strand go tight while the other stays slack. If both strands are held side-by-side in a single carabiner basket (as per twin rope technique) you could melt the sheath where they run against each other.


Interesting, I've never heard this before. Has this actually happened before in real life or in a test? Sounds a little far-fetched, but I could be mistaken. Even when belaying the whole pitch as twins both strands aren't going to engage at exactly the same time. Where did you get this idea from?


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By Gregger Man
Dec 6, 2011
gg

Cory wrote:
...Where did you get this idea from?

I've heard it repeated here and on the Taco, but the only place in print I can find the idea is in Extreme alpinism: climbing light, fast, & high By Mark Twight p.162
It makes intuitive sense, but I've never done any tests to verify it. Whether on not one strand would damage the other would depend on the shape of the carabiner and the direction of the fall, etc. Eh, It might be fine.
But I still don't think it's wise if you want to take care of your ropes.


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By Rich Farnham
Dec 6, 2011

The only risky situation I see is when one rope is moving (under load) and the other isn't. That would concentrate all of the wear on one spot and create a problem. In twin rope lead falls, both ropes are moving, so this isn't a problem.

The only situation I can come up with where this could happen is a fall while using the double rope technique (i.e. only one rope clipped through the highest piece -- the one holding the fall), if you had clipped twin lower on the pitch. The rope catching the fall will pull tight, and run through the biners as the belayer stops the fall. The other strand will not be pulled upward, making it possible for it to be rubbed by the loaded strand down where the ropes were clipped as twins.

I think it would still take a pretty specific scenario to actually damage the untensioned line. There would need to be some direction change through the piece, and the untensioned line would probably need to be pinched against the side of the biner in some way.

So, I guess it's possible, but it seems unlikely. I'd love to hear from someone that actually uses the system as this is all just internet speculation...


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By NickMartel
From Tucson, Arizona
Dec 6, 2011

Its fine just clip them each through their own biner. For example, pitch starts with 2 cracks 3 feet apart. Clip one rope into gear in right crack and one into gear in left crack. After 35' one crack ends and so you start clipping both ropes into each piece (since there is no longer a right and left) but you do clip each on its own biner. Then after another 25 feet you have a traverse right for 15' then back left to above the original line so you clip the right rope into the pro on the traverse(s) then when you are back above the original line you resume clipping both ropes through each piece (although for rope drag issues you may want to skip clipping the right rope into the 1st piece after the traverses). It also makes it much safer for your 2ed during the traverse....


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By Buff Johnson
Dec 7, 2011
smiley face

Rich, I've done one or the other. At directional changes or traversing, if I'm using half-technique with 2 Seconds, then I'll use two slings of different lengths into one pro point (it's easier with alpine draws). I've not heard any manufacturer say it's alright to combine techniques in the same pitch. The same overall climb using either one technique or the other as you switch pitches depending on terrain, yes.


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By Rich Farnham
Dec 7, 2011

Buff Johnson wrote:
I've not heard any manufacturer say it's alright to combine techniques in the same pitch.

I hadn't either until I read the comment above (third post) that was supposedly from Mammut.


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By Buff Johnson
Dec 7, 2011
smiley face

Aside from nylon movement differences when combining techniques on the same pitch, I'm concerned about potential loading behaviors on biner gates, twisting out slings, and unintended loading directions on pro.

As well, the half-technique is 'supposed' to load distribute and lessen force between pro, so I would like to keep that technique as-intended and not combine into twin on the same pitch. But, I guess that's disputed and I can see why; Sterling, I think offered that one in some backyard testing.

Really, the biggest rule I think is these systems are meant as a possible last-chance in tenuous terrain if you blow it when falling isn't an option while leading. Twight does have a point, this is meant for light and fast in a technical alpine setting. If falling is expected, I'll just use a single rope, bring a tag if needed, or lessen my level of acceptable terrain risk in some way.


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By bearbreeder
Dec 7, 2011

as mentioned by someone above ... i have used it on the first few bomber pieces or bolts to prevent a ledge fall/deck where the half rope stretch is not a good thing ... afterwards the pitch breaks off and wanders abit ... so a switch to double rope is helpful

its also useful when you eff up a bit, intending to do the pitch as twins all the way, but find out mid pitch its better as doubles ... im sure some people here never screw up ... but hey thats the internet

to put it simply if mammut tells me its fine, and they have liability ... im not worried about it ... perhaps their ropes are "special"

i dont commonly use it ... but its useful to know it can be done


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By Copperhead
Dec 7, 2011

Gregger Man wrote:
I've heard it repeated here and on the Taco, but the only place in print I can find the idea is in Extreme alpinism: climbing light, fast, & high By Mark Twight p.162 It makes intuitive sense, but I've never done any tests to verify it. Whether on not one strand would damage the other would depend on the shape of the carabiner and the direction of the fall, etc. Eh, It might be fine. But I still don't think it's wise if you want to take care of your ropes.


This is how urban legends start.


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By Gregger Man
Dec 7, 2011
gg

Copperhead wrote:
This is how urban legends start.


I'm also skeptical of armchair speculations about gear failure, but I don't think this particular point rises to the level of urban legend.

International Handbook of Technical Mountaineering By Pete Hill, p.215
Can friction damage the sheath when you combine double rope and twin rope technique on a pitch?
Can friction damage the sheath when you combine double rope and twin rope technique on a pitch?


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By germsauce
Dec 7, 2011
Hippos kill people

i agree with whoever said that if you fall on twin ropes clipped into the same gear then they are both moving, one will not get stuck and rip through the other, plus they are typically both skinny 8.5m or so, so there should be plenty of room in a 'biner basket for both. Used half/twin for the first time this summer on the diamond and found them to be awesome, super light, you can split the rope-load while carrying gear in, you can split ropes if you want on wandering pitches and you've got two rap lines for the end of your climb. Thinking of purchasing half/twins for next year's alpine adventures.


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By bearbreeder
Dec 7, 2011

Gregger Man wrote:
I'm also skeptical of armchair speculations about gear failure, but I don't think this particular point rises to the level of urban legend. International Handbook of Technical Mountaineering By Pete Hill, p.215



while i appreciate the quote ... i still take mammut's word over the internet or some book

they make and test their ropes, should they give inappropriate advice in its use, they suffer the consequences ... climbing companies are pretty careful about such things

perhaps there are actual tests out that show otherwise? .. if so we can can send those to mammut ...


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By Copperhead
Dec 7, 2011

Gregger Man wrote:
I'm also skeptical of armchair speculations about gear failure, but I don't think this particular point rises to the level of urban legend. International Handbook of Technical Mountaineering By Pete Hill, p.215

Perhaps, but it is being overblown at the least. Trust the manufacturer.


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By Gregger Man
Dec 7, 2011
gg

I'm curious, too.
I just emailed PMI and Bluewater to see if they can shed some light.
Stay tuned.

edit to add the wording of my question to PMI & Bluewater:

Hi.
I'm wondering if someone on the technical side would care to comment on this discussion:

www.mountainproject.com/v/half-vs-twin/107396265

The crux of the matter is whether or not it is possible/likely that the sheath of a half/twin rope pair would be damaged if a climber used half rope technique for part of a pitch, then twin clipping technique before a hard fall. It seems reasonable to me that one strand would be weighted first and run faster than the other, and that the friction between the two clipped into a single carabiner at the high point could damage the sheath.

Fact or opinion?
Have you done any tests that would prove or disprove this hypothesis?

Cheers,
-gg


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By Buff Johnson
Dec 7, 2011
smiley face

They may also be misunderstanding the context of the inquiry and looking only at how the rope strand(s) performs to the specification. So, while you have a rope that can essentially combine techniques and perform within either certification testing at any given point along the way, is combining a good thing to do overall for a climbing team? I don't think it is. Most of this applies outside of the purvue of a rope manufacturer and the assumption of risk is still on the climbing team as to the situation at hand.


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By bearbreeder
Dec 7, 2011

Buff Johnson wrote:
They may also be misunderstanding the context of the inquiry and looking only at how the rope strand(s) performs to the specification. So, while you have a rope that can essentially combine techniques and perform within the certification testing at any given point along the way, is that a good thing to do overall for a climbing team? I don't think it is. Most of what we do is outside of the purvue of a rope manufacturer. The assumption of risk is still on the climbing team as to the situation at hand.



i disagree ... i think a lot of what "normal" climbers do is what a rope is meant to do ... now im sure there are people who dont replace ropes for over a decade or people who use it to walk their dogs ... those are likely outside what a rope should be used for

but the majority of climbers IMO ... use climbing ropes for what they were intended for ... to climb

one thing to note is that manufacturers can "rate" ropes differently ... for example while mammuts ropes are not "rated" (you wont see the ratings) as twins ... all their doubles can be used and are tested as twins, its also in their documentation ... the reasoning given is on steph davis blog below (ive copied the text from the mammut rep)

i suspect that dead elephant ropes arent any more "special" than other ropes ... so its likely other manufacturers are being more "conservative" with their ratings

www.highinfatuation.com/blog/straight-from-the-mammoths-mout>>>

In continental Europe, outside of a few areas, fewer people use half-rope technique--most people use their half ropes with Twin technique clipping both strands together—consequently most of the half ropes on the market will pass the test for both half and twin ropes, and this is common enough that it is assumed. All of Mammuts half ropes will also pass the twin rope test--here's what Mammut has to say about the subject in our rope booklet: "...here you have the choice between twin rope technique, where both ropes run parallel through the protection and half rope technique, where the «left» and «right» ropes run separately through different protection points...". (incidentally that is available here, there's some good info buried within... www.mammut.ch/images/Ma... ) Speaking only for Mammut, we generally don't certify our ropes to more than one standard because there is a very real concern that people make assumptions about a rope based on the fact that it is marketed differently, that often don’t really hold true. As an example, our Serenity 8.9mm single rope was initially introduced with both single and half rope specs and many people assumed that it was “more durable” than a thinner half rope, when the reality is that it was far less durable than our thinner Genesis 8.5mm rope—this was the subject of Steph's blog post here: www.highinfatuation.com... . In general we would rather steer people into using their ropes in the manner that will result in the greatest degree of utility for most people, which is why we have shied away from dual certifications like this. It isn't right or wrong, but my sincere belief is that more people wind up with a rope that better suits their needs as a result. Hopefully that adds a bit of perspective, but please fire away if it raises still other questions.


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By Buff Johnson
Dec 7, 2011
smiley face

The blog statement is dancing around the question at hand on whether combining techniques is actually a good idea or not. I can draw from their comment that, yes, during the overall climb you can employ a better method given the situation for each pitch. But, ease of utility is not the same as looking at the system behavior that you get if you mix techniques within the same pitch.

So I guess I respectfully disagree with what Mammut is saying if it goes to that initial comment stating mixing in the same pitch is fine.


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By bearbreeder
Dec 7, 2011

Buff Johnson wrote:
The blog statement is dancing around the question at hand on whether combining techniques is actually a good idea or not. I can draw from their comment that, yes, during the overall climb you can employ a better method given the situation for each pitch. But, that's not the same system behavior you get if you mix techniques within the same pitch. So I guess I respectfully disagree with what Mammut is saying if it goes to that initial comment stating mixing in the same pitch is fine.



buff ... see the response i posted on the third post

i emailed mammut specifically asking about using both techniques in a single pitch ... the product manager in switzerland replied that its fine (not some call centre rep or other such)

im not set on using em that way .... if mammut can be shown to be "wrong" by actual real world data ... not just the "opinion" of other people or manufacturers

id be very interested if mammut is giving "bad advice"


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By funkyicemonkey
From Colorado
Dec 7, 2011

Having almost allways climbed on doubles I find this very interesting. I will often clip both ropes through a single runner for directional reasons. However lately ive been doing this less and less as my new biners are so much smaller than they used to be. I would think that the larger area of stress on a smaller biner might infact allow the ropes to run over each other in a fall. Ive noticed that even with impeccable belaying one rope will allways have different tension - so other than friction i dont see a problem.


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