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builttospill
Mar 31, 2010, 10:33 PM
Post #26 of 31
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Registered: Jan 8, 2004
Posts: 814
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Yes, pack volume is another consideration that I had forgotten about. Even a thin single takes up a fair amount of space. One of my Mammut twins is TINY. Still, it's all individual preference and risk tolerance.
As for using two different ropes in a set: I would feel 100% comfortable using two different half/double ropes as a set. They are used independently of one another in terms of protection and falling, so it should be fine. I would hesitate significantly to use two different twins, because different elongation amounts and what not would mean that they would not be sharing force equally during a fall. There is also the potential for the ropes to rub during a fall if they stretch at different times and in different amounts maybe.
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takanhase
Mar 31, 2010, 11:50 PM
Post #27 of 31
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Registered: Mar 8, 2004
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Another thought....What about taking a single rope and taking a thin tag line as a back up in case you need two ropes to rappel with. this has been an option I was looking at as you can spare the weight and still have the extra safety margin(if that's how you roll ) and save weight and pack space, it seems like a win-win situation to me.
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harpo_the_climber
Apr 1, 2010, 3:58 PM
Post #28 of 31
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Registered: Feb 26, 2005
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takanhase wrote: Another thought....What about taking a single rope and taking a thin tag line as a back up in case you need two ropes to rappel with. this has been an option I was looking at as you can spare the weight and still have the extra safety margin(if that's how you roll ) and save weight and pack space, it seems like a win-win situation to me.
This has been discussed, and it is less than ideal, although it can work if nothing goes wrong. Using the method I remember, the tag line isn't strong enough to rappel on, so you feed the full strengh rope through rappel anchors, tie it to the tag line, tie a butterfly or or inline figure 8 in the full strength rope just short of where it is tied to the tag line, and then clip a locker through the butterly/figure 8 and aroung the free side of the full strengh rope (on the other side of the rappel anchor) you will single rope rappel. Using this method, the knot with the locker comes tight against the rappel anchor when you single rope rappel the full strengh rope. When you are off rappel, you pull the tag line and the locker run downs the free end of the full strength rope.
With this method you can get by with a very thin tag line (5mm?) because it never holds body weight, it just has to pull the full strength rope down. The problem with this method is that if the ropes get stuck after the free end of the full strength rope is pulled above the bottom rappel anchor, you are left with the option of leading or ascending the 5mm tag line to retireve you ropes.
I guess you could carry a static rope that would strong enough to use as part of a double rope rappel, and arrange the knot so you could pull the dynamic rope, but I am not sure how much weight you would save if your static rope was strong enough to rappel on.
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adnix
Apr 5, 2010, 6:34 PM
Post #29 of 31
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Registered: May 20, 2003
Posts: 584
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takanhase wrote: Another thought....What about taking a single rope and taking a thin tag line as a back up in case you need two ropes to rappel with.
I've tried that system for few routes but it doesn't feel right. Abseiling is not easy and you carry extra weight. In theory the system sounds great but in real life it's too complicated.
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graniteboy
Apr 9, 2010, 10:37 PM
Post #30 of 31
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Registered: Dec 1, 2001
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I routinely carry a thin alpine line (8 or 9mm, depending on route) and a 5mm tag line to extend the raps to a full rope length. When using this system, however, I use a single chain link on the rap anchor, small enough that the fisherman's knot can't be pulled thru it, and weight the system on the 8 or 9 mm rope only, as I run the fisherman's knot up against the chain link. Then, just pull the 5mm for retrieval. So, in essence, you're rapping on a single 8mm, with the 5mm as a retrieval cord.
I've been playing this game for a couple decades now, and I think it works pretty well in circumstances where a 30mm rappel just won't cut it.
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creemore
Apr 12, 2010, 8:00 AM
Post #31 of 31
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Registered: Jan 22, 2003
Posts: 61
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I've used this "split" set-up a few times but it was always out of immediate need. New doubles are the way to go...when you can.
On a long road trip, short on cash, a rope or 2 cut, local store doesn't have what you need...stuff like that.
Most of my climbing is on trad, ice and/or alpine routes. I use other peoples ropes for cragging. For easy ridges and glacier travel just the half rope. On harder ridges just a thin single.
As doubles, it works alright. I've had a 9.2-4 single with a 8.1-4 half. I've used fatter ropes as doubles but it's just not worth it for the drag/friction.
I would mainly use the single rope then the half worked well as a directional. If it was a straight up pitch, then no belay was required on the half. Other times it was just taged up. Sometimes used to haul a pack. Don't expgect a long life if jugging it.
You're double rope techniques should be above par. No big deal if there different lengths. Sometimes that even helps to get the knot past potential rope eating spots on rapel.
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