Single, Double, Twin


Original Post
Ken Carrara · Jul 25, 2016 · Holtsville, NY · Joined Mar 2015 · Points: 235
I recently made the crossover from TR tough guy to trad climber. I am interested in buying thinner ropes for trad to stop dragging my large diameter TR ropes around with me anymore.

Double and twin rope techniques are very appealing but I'm not sure what rating should be prioritized. Double and twin rating are a must, but would a rope that is also rated for single use be better? Is the extra diameter gained by the single rating not worth the added mass, bulk and friction?

I climb in groups of two and three equally as often. The main goal is to speed up climbs in groups of three, reduce rope drag, and reduce the number of raps.
worth

Andy Hansen · Jul 25, 2016 · Longmont, Colorado · Joined Sep 2009 · Points: 2,068
Just buy two Sterling Nano IX's and that will solve all your problems. Rated single, half and twin. I personally wouldn't want to be on the following end of a sole twin or half rope especially in locations with sharp edges, long traverses or the potential for repeated falls (too much rope stretch).

RangerJ · Jul 25, 2016 · Denver, CO · Joined Jan 2012 · Points: 0
You definitely do not need single rate ropes if climbing as a party of three. With a part of two double and twin ropes add safety against sharp edges. If you want to slim down your rope diameters go with doubles. The Sterling Nano IX is a great rope, but you can cut more weight and bulk with ~8mm doubles.

Brian Abram · Jul 25, 2016 · Celo, NC · Joined Oct 2007 · Points: 208
stephdavis.co/blog/straight...

Don't assume that thicker single ropes are more durable than thinner half ropes. Mammut says the Genesis is more durable than the Serenity when it comes to abrasion due to its sheath construction.

Also beware folks telling you that half ropes have lower fall impact forces than single ropes. The reason you'll see that is that half ropes are tested with a severe fall with a 55kg weight, but single ropes are tested with the same severe fall with 80kg. So of course you'll see lower kN impact force specs listed for half ropes. In real life your weight isn't going to change whether you climb on singles or half ropes, and you will still usually only be falling onto one strand of the half. The truth is that half ropes have about the same range of impact forces as singles when halfs are tested with an 80kg mass:

http://willgadd.com/single-and-half-rope-impact-forces-data/

Unless you climb around sharp edges, one half rope is perfectly fine to follow or toprope on. The Genesis would maybe be better for toproping than a Serenity, apparently.

Edit: just to troll some yer-gonna-die folks, half ropes are probably also perfectly fine for leading on when used as singles on terrain where falls aren't really expected. They can handle typical low impact falls just fine. Probably a few severe falls as well. Though arresting those falls as a belayer might suck. I'm not saying you should do this. Just saying that I might do this.

Also, your weight might be relevant. For example, I weigh about 80kg with gear, and my wife weighs about 55kg with gear. The Mammut Serenity 8.7 specs at 5-6 UIAA 80kg falls at 8.1kN (the single rope test), and the Beal Gully 7.3 specs at 6-7 UIAA 55kg falls at 5.2kN (the half rope test). In that regard, is my wife "more safe" leading on a single Beal Gully or a more durable Genesis than I am leading on a single Mammut Serenity?

Kyle Tarry · Jul 25, 2016 · Portland, OR · Joined Mar 2015 · Points: 64
turd furgeson wrote: +1 If you climb in a party of three you need single rated ropes.
No, you don't.

It is perfectly acceptable to follow on a single half or twin rope. As size and properties of half and twin ropes vary significantly, the climber(s) need to make a judgement about how comfortable they are on any particular rope in any particular season. I'd understand hesitance to follow a traversing pitch with sharp rock on a 7.3 mm Beal Gully, but I don't hesitate to do it all the time on my 8.6 mm Beal Cobras.

Ken Carrara · Jul 25, 2016 · Holtsville, NY · Joined Mar 2015 · Points: 235
Thanks for the info. My main concern is when I'll have two followers. I want them to climb simultaneously and wasn't sure of the single rating was necessary for that application. The diameter range in consideration is 8.5 - 9.2. Any thinner and I'd be the one sketched out.

Nick Drake · Jul 25, 2016 · Newcastle, WA · Joined Jan 2015 · Points: 413
I went to a sport crag one day and grabbed the wrong rope. Took a lead fall on one strand of my 8mm Mammut with the third bolt (not clipped) at my waist. Solid whip, ripped my belayer off the ground. A half rope will certainly hold a lead fall, just throw two biners on your belay device or be prepared to get a burn.....

Also I do own the 9mm nano as my alpine rope and there is significantly more stretch on that than the 8mm Mammut.

To the OP, consider a triple rated rope for your main rope and pair it with a smaller half/twin rated rope for your party of 3 or really wandering pitch days. Half rope management at belays is a pita, if you don't NEED to use them on a multi pitch it's not worth the hassle.

Kyle Tarry · Jul 25, 2016 · Portland, OR · Joined Mar 2015 · Points: 64
Ken Carrara wrote:Thanks for the info. My main concern is when I'll have two followers. I want them to climb simultaneously and wasn't sure of the single rating was necessary for that application.
Definitely not necessary. You can follow or top-rope on a half or twin completely safely (although top-roping on one may reduce it's life-cycle, especially the lowering part). The forces involved in a top rope or following fall are much less than a lead fall.

The greater concerns are increased stretch (need to manage the possible fall distance of a follower) and possible reduced durability (sharp edges, rockfall). These are both, however, manageable.

Bill M · Jul 25, 2016 · Fort Collins, CO · Joined Jun 2010 · Points: 101
Thinner ropes wear out much faster than thicker ropes and for me at least doubles are harder to manage. My normal rope is a 9.8 single. I have a 8.9 rope that is rated single, double. I can partner that with a 8mm double as well. If I am TRing or cragging I tend to bring an old 10.2 I have.

bearbreeder · Jul 25, 2016 · Unknown Hometown · Joined Mar 2009 · Points: 25
Ken Carrara wrote:I recently made the crossover from TR tough guy to trad climber. I am interested in buying thinner ropes for trad to stop dragging my large diameter TR ropes around with me anymore. Double and twin rope techniques are very appealing but I'm not sure what rating should be prioritized. Double and twin rating are a must, but would a rope that is also rated for single use be better? Is the extra diameter gained by the single rating not worth the added mass, bulk and friction? I climb in groups of two and three equally as often. The main goal is to speed up climbs in groups of three, reduce rope drag, and reduce the number of raps. worth
mammut genisis 8.5mm ... with a 49% sheath percentage ... rated as doubles and twins

mammut actually says they are MORE durable than their skinny single (tri rated) ropes ...

http://stephdavis.co/blog/straight-from-the-mammoths-mouth-things-you-want-to-know-about-ropes/

For instance, our Genesis 8.5mm half ropes are designed for ice and alpine climbing. Climbers rarely fall in these situations but they do subject their ropes to incredible abrasion and they need them to be very cut-resistant. With these ropes we consider a high number of test falls held to be of relatively less importance, so we sacrifice the falls-held rating—which reflects to a large degree how long a rope will last under repeated hard falls—in order to build a rope that will be ultra-durable under very harsh abrasion conditions and will be more difficult to scrape through to the core. We do this in part by altering the tension the rope is braided under, the pattern of the braid, chemical treatments that are thermally applied during the heat-treating process, etc—but we also use a relatively thin core and a very thick sheath, because that helps the rope to be as durable as possible under these types of situations.

Some of our ultra-thin single ropes like the Serenity 8.9mm have a relatively thin sheath because even with all the tricks we can muster we still need a certain amount of core in order to pass the UIAA test for a single rope—in this case we use a thinner sheath to achieve a very low weight and thin diameter, but we do thins knowing that this is a very specialized rope that is only appropriate under very specific circumstances. In these cases they are used by very experienced climbers for hard sport climbs or alpine routes where they are willing to sacrifice a level of abrasion resistance in exchange for lighter weight—this is why we recommend that people do not use any of these very thin single ropes for workout climbing or toproping. People also need to recognize that even though these are single ropes, and even though the diameter is larger than our Genesis half ropes, under conditions where the main danger is cutting or abrasion the thicker rope might actually be LESS durable and have a lower safety margin.

People who are comparing two ropes of similar diameters can usually see this in the test results—Mammut publishes the % of each ropes weight that is sheath so that people can judge for themselves what rope they will be happiest with. If you fall a lot, choose a rope with a high fall rating; if you don’t fall that much then choose a ropes with a thicker sheath (and if the manufacturer doesn’t publish that info call them and ask for it!). If you climb both abrasive rock and you fall alot, then think about how you wore out your last rope—if it went flat 10 or 15 feet from the ends, then get the rope with the high fall rating for the size and if the rope just fuzzed up to the point it felt sketchy or fat or lost its dry treatment, then concentrate on a rope with a thick sheath and a compact weave.


;)

Brian Abram · Jul 26, 2016 · Celo, NC · Joined Oct 2007 · Points: 208
Bear breeder. Seriously. Sorry I didn't paste the entire article, but my link was there for hours before you chimed in. ;)

CTdave · Jul 26, 2016 · Victor, Id. · Joined Apr 2013 · Points: 190
Stering Nano IX 9.0 rated as a single, half, and double. Plus the Sterling Fusion Photon 7.8 rated as a half and double. Perfect. I heard you shouldnt use these as doubles b/c thier diameter differance causes differant elongation lengths and could cause too much friction when stretching. But ya got one when all you need is one and ya got two for those wandering pitches and double raps. All while saving weight in the alpine, neither are meant for TR.

Ken Carrara · Jul 26, 2016 · Holtsville, NY · Joined Mar 2015 · Points: 235
The 8.9 - 9.2 diameters seem the most versatile they have all three ratings but is it necessary? The rope would be for trad only, the only single use they will get is for a follower. If not I could drop down to 8.5

For sport or TR, I use my beater ropes.

Kyle Tarry · Jul 26, 2016 · Portland, OR · Joined Mar 2015 · Points: 64
CTdave wrote:I heard you shouldnt use these as doubles b/c thier diameter differance causes differant elongation lengths and could cause too much friction when stretching.
Do you have a link to a source for this? I question the validity of this, but it would be good to know if it was the case.

Generally, if you're employing standard half technique, when you fall you're only falling on one rope anyway, so I don't see what the relative stretch would be that relevant.

Ken Carrara wrote:The 8.9 - 9.2 diameters seem the most versatile they have all three ratings but is it necessary?
I think it depends on what you want and how you plan to use the rope, but for what you've described I don't think it's necessary. The single rating is specifically for leading on it, so if you're not going to do that, there's no reason to pay the money and carry the weight.

I could see using a single/half rated rope for alpine/mountaineering where it's mostly low angle but occasionally you need to lead a steep section on it. That being said, I do this on a half rope and don't feel bad about it.

Tony T. · Jul 26, 2016 · Denver, CO · Joined Jul 2009 · Points: 10
Well, this is a timely discussion since I was just wondering about this subject. Is it safe to presume that rapping on one skinny rope out of a twin/half rope setup is safe as well? I know that it can certainly depend on terrain (sharp edges), weight, etc., but generally speaking?

I'm also happy to hear about the Mammut sheath strength since they make the set of half/twins that I have (Phoenix I think?). I was thinking of making a tag-line so I could do raps longer than 30-ish meters, and I've learned the hard way that you want at least a 6mm tag-line (or to have a lot of the heavier rope on the tag-line side of your blocker knot).

One related question...don't flame too hard, I'm just spitballing ideas here. Would there be any benefit or added safety to climbing/belaying using a single one of the half/twin ropes but have it going through both sides of the belay device almost mimicking having two ropes? It's hard to explain, but basically think of making a U with one rope, and the leader would be tied in to both ends.

I understand that the fall forces would be contained within the single rope still, but I'm just trying to think if there would be any sort of added safety or advantage. Yes, it would be considerably shorter anyway, and the belayer would have to be able to communicate up to the climber when the rope was running out since it would get caught on the belay device divider. Yes, the second would either need to tie an 8 on a bight and clip in, or have the leader toss one end down.

However, if the climber fell and one side of the rope got cut, that would still leave them tied in on the other side and the belayer would still be able to hold the brake, right? I know that's a pretty edge-case scenario, but again...spitballing.

chills · Jul 26, 2016 · Boulder, Colorado · Joined Apr 2012 · Points: 0
Ken Carrara wrote:Thanks for the info. My main concern is when I'll have two followers. I want them to climb simultaneously and wasn't sure of the single rating was necessary for that application. The diameter range in consideration is 8.5 - 9.2. Any thinner and I'd be the one sketched out.


there are many ropes in that diameter that fall under the triple rating

id say aside from your second possibly feeling more comfortable with sharp edges ect.

having the ability to lead on a single in the event of a core shot whilst using as doubles is very atractive to me from a versatility standpoint.

i prefer the swift 8.9 by edilrid
but i belive mammute just came out with an even skinnier triple rated rope i wanna say 8.5 to 8.7

good luck with your purchase

Brian Abram · Jul 26, 2016 · Celo, NC · Joined Oct 2007 · Points: 208
Tony T. wrote:Well, this is a timely discussion since I was just wondering about this subject. Is it safe to presume that rapping on one skinny rope out of a twin/half rope setup is safe as well? I know that it can certainly depend on terrain (sharp edges), weight, etc., but generally speaking? I'm also happy to hear about the Mammut sheath strength since they make the set of half/twins that I have (Phoenix I think?). I was thinking of making a tag-line so I could do raps longer than 30-ish meters, and I've learned the hard way that you want at least a 6mm tag-line (or to have a lot of the heavier rope on the tag-line side of your blocker knot). One related question...don't flame too hard, I'm just spitballing ideas here. Would there be any benefit or added safety to climbing/belaying using a single one of the half/twin ropes but have it going through both sides of the belay device almost mimicking having two ropes? It's hard to explain, but basically think of making a U with one rope, and the leader would be tied in to both ends. I understand that the fall forces would be contained within the single rope still, but I'm just trying to think if there would be any sort of added safety or advantage. Yes, it would be considerably shorter anyway, and the belayer would have to be able to communicate up to the climber when the rope was running out since it would get caught on the belay device divider. Yes, the second would either need to tie an 8 on a bight and clip in, or have the leader toss one end down. However, if the climber fell and one side of the rope got cut, that would still leave them tied in on the other side and the belayer would still be able to hold the brake, right? I know that's a pretty edge-case scenario, but again...spitballing.
Rapping is fine. Using both ends of one half rope as basically 2 ropes is not unheard of. Go for it. On big link ups when I've taken a single half rope or a 30m half rope, I've doubled it over for short cruxes.

rgold · Jul 26, 2016 · Poughkeepsie, NY · Joined Feb 2008 · Points: 40
Ken Carrara wrote:Thanks for the info. My main concern is when I'll have two followers. I want them to climb simultaneously and wasn't sure of the single rating was necessary for that application. The diameter range in consideration is 8.5 - 9.2. Any thinner and I'd be the one sketched out.
A single strand half rope---not rated as a single---will still hold one or two UIAA FF 1.78 falls with the 80kg weight. What it won't do is hold enough successive UIAA falls to get the single rating. A single-strand twin rope not rated as a half may not hold a single UIAA FF 1.78 fall with 80kg, but nowadays many double ropes seem to be half/twin rated anyway.

What you want is half ropes in the 8.5 range. Considering durability, it is hard to do better than Mammut Genesis. I would not sign up for extra weight and diameter just to get the triple rating unless you really plan to use (one of) the ropes as a single rope.

Make sure to test out your rappelling and belaying systems to be sure you have enough friction for the ropes you choose.

John Wilder · Jul 26, 2016 · Las Vegas, NV · Joined Feb 2004 · Points: 1,495
rgold wrote: What you want is half ropes in the 8.5 range. Considering durability, it is hard to do better than Mammut Genesis. I would not sign up for extra weight and diameter just to get the triple rating unless you really plan to use (one of) the ropes as a single rope. Make sure to test out your rappelling and belaying systems to be sure you have enough friction for the ropes you choose.
This.

I climbed on the Bluewater Excellence lines for years and would also recommend those if you're in the market.

I definitely would not invest in any kind of rope with a single rating if I was only using them as a pair- too much weight/bulk with no compelling reason for it.

Kyle Tarry · Jul 26, 2016 · Portland, OR · Joined Mar 2015 · Points: 64
Tony T. wrote:Would there be any benefit or added safety to climbing/belaying using a single one of the half/twin ropes but have it going through both sides of the belay device almost mimicking having two ropes? It's hard to explain, but basically think of making a U with one rope, and the leader would be tied in to both ends.
Yes. This is not uncommon.

It makes much more sense with a twin rope than a half. Half ropes arguably can take a lead fall, whereas twin ropes may not be able to (see rgold's comments). Therefore, if you only have a half rope and you need to protect a leader on steep terrain, this is really your only (safety-approved) choice.

The only downsides to this are you can only climb half as far (obviously) and it's not as easy to manage the rope (tying in the second, etc).

John Wilder · Jul 26, 2016 · Las Vegas, NV · Joined Feb 2004 · Points: 1,495
Tony T. wrote:Would there be any benefit or added safety to climbing/belaying using a single one of the half/twin ropes but have it going through both sides of the belay device almost mimicking having two ropes? It's hard to explain, but basically think of making a U with one rope, and the leader would be tied in to both ends. I understand that the fall forces would be contained within the single rope still, but I'm just trying to think if there would be any sort of added safety or advantage. Yes, it would be considerably shorter anyway, and the belayer would have to be able to communicate up to the climber when the rope was running out since it would get caught on the belay device divider. Yes, the second would either need to tie an 8 on a bight and clip in, or have the leader toss one end down. However, if the climber fell and one side of the rope got cut, that would still leave them tied in on the other side and the belayer would still be able to hold the brake, right? I know that's a pretty edge-case scenario, but again...spitballing.
Couple of things regarding this idea.

1) What you're describing is done all the time when simul-climbing or climbing terrain where a long rope is a PITA.

2) There is no added safety benefit for most technical rock climbing scenarios- in fact, losing 30-35m of rope would be a huge disadvantage, imho.

In general, you really shouldn't worry about your rope getting cut. You should be aware of sharp edges and such, but ropes are pretty sturdy and general abrasion and most technical rock really isnt going to slice your rope in a fall. There are always exceptions to the rule, but I don't go out climbing with the mindset of carrying a second rope because my first rope is going to get cut in half if i fall.

Guideline #1: Don't be a jerk.

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