Can I use Half/double rope with the twin rope technique?

Hi I know that half/double rope needs to be clipped alternatively on each side to the pro. And the twin rope are clipped together. However, when I am reading Mammut's site
mammut.ch/en/ropes_dynamic_…;jsessionid=EB5874E72644179F6C2EFB88C0C7EB95

that the half rope can use as twin rope as well. But someone told me that if you do that, when you fall ,the impact force will be doubled and that can damage the pro.

What is your opinion?

Thanks

Another reason is that you might get friction melting of the sheath during a fall.

It depends on the rope. There are a few ropes out there that are certified as both, but not all half ropes are certified for use as twins. It is my understanding that if you use some half ropes in twin configuration, you will increase the impact force beyond acceptable levels.

So did I misunderstand mammut's website, or I jsut don't know what I am talking about, lol?

If your rope is rated for both techniques, then yes.
Otherwise no it is not recommended as falling on ropes used as twins not designed as such will increase the force on protection.
Basically you will decrease the elasticity of the rope system and will encounter a harder fall.

An important point is that if you start a pitch using one technique, continue to use that technique til the end. Don't start alternating ropes and then clip as twins or vice versa.

Kevin Friesen wrote:Another reason is that you might get friction melting of the sheath during a fall.

This is a reason not to mix and match twin/double technique but has no bearing on using doubles as twins.

Use doubles as twins (or doubles) but don't switch back and forth during a single pitch. Said another way, clip both ropes through each piece (twins) the whole pitch or alternate every other piece (doubles) the whole pitch. That is according to Mammut and perfectly safe.

Bang wrote:Hi I know that half/double rope needs to be clipped alternatively on each side to the pro. And the twin rope are clipped together. However, when I am reading Mammut's site mammut.ch/en/ropes_dynamic_…;jsessionid=EB5874E72644179F6C2EFB88C0C7EB95 that the half rope can use as twin rope as well. But someone told me that if you do that, when you fall ,the impact force will be doubled and that can damage the pro. What is your opinion? Thanks

Why do you want to? Just use double technique. You get lower impact forces and better redundancy that way. Might be a little harder for the belayer to manage the two ropes, but who cares, you're the one leading.

If you were the Honey Badger, you wouldn't give a S#!+ - you'd just do whatever you wanted to do.

Scott Bower wrote: Why do you want to? Just use double technique. You get lower impact forces and better redundancy that way. Might be a little harder for the belayer to manage the two ropes, but who cares, you're the one leading.

Hi Scott, no I was not gonna to do the twins way. But I am confused by the website when I was reading it. So just want to check if I have got things straight up!

Thanks for the input folks!

You can with the new mammuts ... They are tested as twins and doubles

bearbreeder wrote:You can with the new mammuts ... They are tested as twins and doubles

You can use any set of doubles as twins. When doubles are clipped into the same piece, the impact force will be on the order of that of an ordinary single rope.

What's questionable, as others have stated, is whether you should mix double and twin rope technique on the same pitch. Some climbers advise never to do this; some say it's ok to start out with twin technique, but once you split the ropes, don't revert to clipping them together; some advise to always clip the first piece with both ropes; and some think you can freely go back and forth—that there is no practical risk that the ropes will burn through.

Jay

Beagle wrote:If you were the Honey Badger, you wouldn't give a S#!+ - you'd just do whatever you wanted to do.

just remember, in this country, when you screw your own self up, just drama queen the shit out of it and your screwed up equipment. you'll be an instant hero.

Thanks folks for the inputs! So far they are very helpful.

Jay Tanzman wrote: You can use any set of doubles as twins. When doubles are clipped into the same piece, the impact force will be on the order of that of an ordinary single rope.

I've only climbed on doubles a couple of times so I am by no means an expert but I've read in about a billion different places that doubles should not be used as twins exactly because of the increase in the impact force and the consequences this can have on your pro. Not trying to argue with you here Jay because it would be awesome in my opinion if someone has done some actual testing using doubles as twins, but the usual "I know lots of people doing it this way" doesn't cut it in my book. Where did you get this information as I would very much like to investigate it myself.

Hey Yarp if you have read the original Mammut website, you may see what they mean.

when I was reading up on double rope technique, if you haft to clip both ropes into same piece of pro, make sure they are on separate biners, and that one is extended away from the other one. Other wise it make horrendous rope drag, and you put alot of force on that piece at that point. Personally I'm a big fan of doubles, but you and your belayer haft to have your shit together, and alot people don't. so practice practice practice.

Yarp wrote: I've only climbed on doubles a couple of times so I am by no means an expert but I've read in about a billion different places that doubles should not be used as twins exactly because of the increase in the impact force and the consequences this can have on your pro. Not trying to argue with you here Jay because it would be awesome in my opinion if someone has done some actual testing using doubles as twins, but the usual "I know lots of people doing it this way" doesn't cut it in my book. Where did you get this information as I would very much like to investigate it myself.

Rgold made the calculation on rec.climbing some time ago. Using assumptions that will tend to overestimate the force, a pair of doubles clipped into the same piece will increases the force by 40% compared with one double rope. You can compare impact force ratings between double and single ropes for a manufacturer and see that 140% of the double rope impact force is in the ballpark of the single rope impact force.

That said, a 40% increase is probably too high. As rgold showed, the increase in impact force rating for a Beal Joker used as a pair of twins vs. a single is only about 18%. Either of these calculations shows that fear of the increase in impact force when a pair of double ropes are used as twins is unwarranted. Furthermore, rope manufacturers like Mammut clearly state that their doubles can be used as twins.

Jay

Beagle wrote:If you were the Honey Badger, you wouldn't give a S#!+ - you'd just do whatever you wanted to do.

Honey Badger doesn't care...Honey Badger doesn't give a Sh#t!

Your friend bought into a popular misconception regarding double ropes used as twins. Yes you can use doubles as twins, it increases you impact force but not by double. Jay is spot on and rgold is truthworthy. Here is an old thread that went into some of the math about it: mountainproject.com/v/half-…

My 8.2 mm doubles are not officially rated as twins, but I'll occasionally use them that way when I don't want to fall as far because of ledges and pinnacles and when I want a simpler system for my belayer to manage. I won't mix and match styles on a pitch because I don't want one rope moving more quickly through a biner and burning the other rope. This can't happen if you clip each piece of protection in the twin style.

Jay Tanzman wrote: a pair of doubles clipped into the same piece will increases the force by 40% compared with one double rope. You can compare impact force ratings between double and single ropes for a manufacturer and see that 140% of the double rope impact force is in the ballpark of the single rope impact force. That said, a 40% increase is probably too high. As rgold showed, the increase in impact force rating for a Beal Joker used as a pair of twins vs. a single is only about 18%.

and

mountainproject.com/v/half-…

Great info. Thanks!