Doubles vs Singles

[Fred]

Well, Fred may have been telling Stevo something he already knew, but I learned from both post and response, so thanks guys.

Teth

FYI Teth

single ropes (clip and go)
double ropes (alternate clips)
twin ropes (always used as a pair)

You hardley ever hear of twin ropes. They are used in the alpine world. I think the only advantage is longer rappels. duno

[The Mitt]

Since I have been learning doubles and the advantages while climbing at the Whites. I am sold and will start climbing with 60m doubles, once I can afford them.

Positive:
1. Feel Safer - put one piece in. clip it with one line, get the belayer to watch you climb a few feet. Put another piece in over your head and clip with the other rope. If you fall while clipping you only fall as high as you are above the first piece and not the length of rope you have out for the one above your head (sounds confusing but is very comforting)

2. Raps are longer - Do one 60m rap vice 2 30m raps. Less setting up equals less chance of screwing up and quicker escape. Sharp rock 2 ropes are better than one.

3. Helps reduce rope drag with long meandering routes.

4. Climbing on really sharp rock that may cut your rope = half as likely to cut both of them

Negative:

1. Takes some practice - Don't cross your ropes. Crossing = mega drag

2. Heavier - 2 people one rope each.


My 2 cents
Mitt

[Fred]

1. Feel Safer - put one piece in. clip it with one line, get the belayer to watch you climb a few feet. Put another piece in over your head and clip with the other rope. If you fall while clipping you only fall as high as you are above the first piece and not the length of rope you have out for the one above your head (sounds confusing but is very comforting)

Fall will still be longer than a regular rope because of stretch.

2. Raps are longer - Do one 60m rap vice 2 30m raps. Less setting up equals less chance of screwing up and quicker escape. Sharp rock 2 ropes are better than one.

There is only one effective strand on rappel (closed loop tension). One goes it all goes. Thus sharp rock = more likely to cut through on an edge rappelling. Greater risk while rappelling but longer rap.

3. Helps reduce rope drag with long meandering routes.

I've seen so many people mess this up... it is true but one must know what they are doing.

4. Climbing on really sharp rock that may cut your rope = half as likely to cut both of them

Way more likely to cut any of the two thus resulting in overal greater risk for bigger fall and injuries.

[Fred]

I own doubles and have used them both on rock and ice.

The only two advantages I can agree with are:

1. reduced impact force (always good for ice climbing and also good for pour trad placements)

2. reduced drag on GREATLY (keyword) wandering routes (there are few routes that actualy meet this criteria where runners can't fix your drag problem)


I use mine for ice only.

[The Mitt]

Fall will still be longer than a regular rope because of stretch.

Don't think so. There is not that much more streatch in a double to make the fall longer than a single with a clip above the head. Of course I am comparing short falls like 5-10 feet.

There is only one effective strand on rappel (closed loop tension). One goes it all goes. Thus sharp rock = more likely to cut through on an edge rappelling. Greater risk while rappelling but longer rap.

Yeah that was silly for me to write that. Closed loop + sharp rocks = bad for any rap. I would still rather rap one long than 2 short.

Way more likely to cut any of the two thus resulting in overal greater risk for bigger fall and injuries.

Disagree here, although it is easrier to cut a smaller diameter rope when you compare a 8mm to a 10mm there is not a huge difference, even if the double gets cut and you go for a long ride its better than having a 10mm single get cut; the ride will last the rest of your short life.

Really I think its a matter of preference. For me 2 feel safer, whether truely safer or imagined.

Mitt

[The Teth]

Interesting discussion.

I calculate that if one rope were tight on the Mitt’s harness, that the additional length of the other rope (or the additional length required on a single rope) for the Mitt to clip a piece at the extent of his reach above his head (double the length from his harness to his hand) would be about 7.5 feet. Would the addition rope stretch of a double rope be enough to discount the advantage of removing up to 7.5 feet of slack from the system?

I get wig out on repel anyway, so repelling a continuos loop with a smaller diameter rope would probably not help inspire my confidence. It would be faster and easier than two separate raps though. I have heard that ascending an 8mm rope scares the crap out of even seasoned big wall climbers.

It seems like it requires a bit of skill and experience to use double ropes properly. How hard is it to belay double ropes? Seems like you would be wishing for a third hand when playing out slack on one while locking off the other, at least until you got the knack of it.

Teth

[Fred]

I think you'll find that 8 times out of 10 you probably won't stretch out that much because there isn't that much rope out. But if you are 90ft off the deck, your fall on the doubles would probably resemble the fall on the single with slack pulled out. 7.5ft is generous. That is the point I was trying to make.

Belaying on doubles can be easy as long as you learn the right way. If not... it can be scarry as hell for the leader.

[Fred]

Disagree here, although it is easrier to cut a smaller diameter rope when you compare a 8mm to a 10mm there is not a huge difference,

I think there is probably a significant difference. Cutting the 8mm strand with the same tension force will go much quicker. See manufacturer test falls over sharp edge.

even if the double gets cut and you go for a long ride its better than having a 10mm single get cut; the ride will last the rest of your short life.

good point. It's all or nothing. hehe

[The Teth]

Maybe Fred, but hitting, say a ledge, after 7.5 feet of rope stretch is a little softer than hitting after falling 7.5 feet due to slack. It likely exserts considerably less force on your piece as well, in the event that you don’t hit anything.

Just picking at the point. I agree on the rest though.

Teth

[Fred]

Maybe Fred, but hitting, say a ledge, after 7.5 feet of rope stretch is a little softer than hitting after falling 7.5 feet due to slack. It likely exserts considerably less force on your piece as well, in the event that you don’t hit anything.

this is true

also, refer to my previous post about impact on gear where I stated that is the major benefit of doubles

cheers

[mathieu]

I just got 2 70 metre doubles, I figure on ice they will be great since you can now stretch pitches a bit longer. On the down side I now have to carry one or two more screws since I now have 10m extra per pitch.

Interesting discussion. I use my doubles for almost every thing except sport. I have only ever bought one single rope and this last set is my fourth and fifth double rope.

I don't know where this conversation started but as Fred mentionned at first, only twins should be clipped together. I used to clip both ropes on some pieces but one day I went sport climbing with my doubles (I didn't own a single back then) and I was clipping both ropes in at every bolt and someone pointed out that this would bring the forces on each bolt up very high if I fell. Reason:

one single impact force = 7.5 to 9kN
one double impact force=5 to 6kN
two doubles impact force = 10 to 12kN
Twin ropes impact force (two strands) = 10kn

Well the persons reasoning was that you had too high of impact force with clipping doubles, I guess it depends how much impact force and strecth you want.

Twins are just too small, rapelling with them is scary, hell I had cordellete that was thicker than 7.5mm. But their advantage is lighter than doubles, can reppel the full rope lenght and still have a back up if something cuts your rope (while climbing). They are big in Europe/UK

[The Teth]

Another thread on another forum on the same topic:

http://www.supertopo.com/climbing/threa ... #msg260913

[Fred]

the bottom line is

33% more force/impact on your gear and body

[The Mitt]

No matter what the system there is a trade off. I guess it depends on the type of climbing and the climber. Mine is as physiological as fact. There are those times when the demons start playing with your head about how safe is your gear, looking down at 2 ropes just helps me justify moving on. The new ropes for sport climbing are getting down to 9mm and less.

Belaying with 2 ropes is very different than one and should not be done without practice and someone to show you. As a matter of fact belaying is something that is very much taken for granted.

There is a good discussion re belaying on RC.com (Too drunk/tired to find it). We were at Whitehorse and saw a very famous climber/ guide for the region belaying a girl who was on a fairly run out route with little gear and she was sketched out at 20 feet, 8 feet above her piece. The "guide" was 15 feet away from the base of the cliff with a good 6 feet of slack in his system. We could not believe our eyes. I think it is very important to every now and then reevaluate how you belay, how you anchor and how safely you climb. Everyone develops bad habits, its important to recognize them and make adjustments.

Stepping down from soapbox.

Mitt

[waterat]

singles - good fer top roping and short ice climbs

doubles (or half ropes) - better for longer, multi pitch or wandery routes, also 3 on a rope, for the reasons The Mitt states - he has obviously been listening to his brit buddies then...

Eg.. 3 of us climbed 'the old man of hoy' a 450' sea stack a few weeks back.....with the fairly limited number of belay points on a climb like that, then you do need the two ropes to get off again....also, leader goes up on two, brings second up on one rope and third guy on the other rope...that's just an example, but it would be a really useful and handy skill for a climber to be able to use the two rope system as required.

my 2 pence worth

[The Mitt]

You can't be THE Waterat? I thought he forsaked us for the motherland.

Mitt

[waterat]

You can't be THE Waterat? I thought he forsaked us for the motherland.

Mitt

Indeed it is I....

I like to keep tabs on my colonial friends now and then....glad to see you are still 'active'.....I'll drop you a line soon...cheers...