alpine rope systems

[Colin]

I am considering three different options of what rope system to use on alpine climbs that require full-length rappels. I cannot yet decide whether I should buy two twin ropes, two half ropes, or a 60m length of 7mm static line to compliment my 60m 9.4mm single rope. I would appreciate anyone posting why they like or dislike any particular rope system.

[forrest_m]

I tried for a long time to make the 10mm/7mm system work and finally abandoned it after a number of narrowly averted epics. I think it might work in big-wall rappelling, but the problem is most alpine rappels pass over ledges, through piles of loose rocks, over/behind flakes, through treees, etc, and I found that it's *very* hard to pull on the super-thin cord, esp. for 60 meters of length. It's hard to pull on the cord hard enough to move the full length of the lead line. Even though it's a "static" line, the stretch makes it even harder. Anytime the other half of the rope going up snags on anything, you have to wrap the 7 mil around your hands and reef, which is particularly hard (read painful) when it's cold out. The lightweight rope is also even more likely to get whipped around by the wind and get stuck. I badly wanted to like this rope system, so I kept trying, but IMHO the disadvantages outweigh the advantages.

I've never used twins (though, again, I've found it's hard to pull on ropes that are TOO thin), but have done a lot of climbing with doubles. It's great to be able to use them to reduce rope drag on wandering pitches by clipping alternate pieces. I especially like them for climbing with 3. You lead on both ropes, then belay both followers (who climb simultaneously) with a GiGi. It's no slower than with 2 and you can split the group gear 3 ways on multi-day routes. Plus, you can always lead on just one rope if the other gets damaged. I know, its not recommended by the mfr., but it's safer than soloing. ;-)

[This message has been edited by forrest_m (edited 12-07-2000).]

[Alex]

Colin, I'm thinking 180 degrees from Forrest, and suggest you get the 7mm.

I've been working with two different systems lately, both have their uses.

I got in the habit of climbing on two strands of 8.5 mm ice climbing (both as twin or as double), and I really like this system. I also use this same rope system sometimes for trad routes in the summer. The upside is reduced rope drag, the psychological comfort of having *something* still on you if you chop a line leading or following ice climbing, and the very smooth and handy 3-person party system where the leader leads the belays the followers up simultaneously with a GiGi. The downside is some serious rope management is need to make this work at hanging belays or small ledges. If you were starting clean slate, I'd say go for this rope system. The rope management aspect is serious, but you'll be able to cope if you are very careful.

The other system I've been using is a 70m 9.4 single PMI lead line for alpine rock. This is similar to the thing you have going now. I either take just it (allowing 35m raps) or I take 45m of 6mm. Upside is rope management is much improved over dual strands, and *man* you can lead really really long pitches with 70m or rope! Downside is that there is no weight savings with this system over twin/double system. The psychological safety net for ice climbing is gone, too, so I am still reluctant to climb ice on single strands. Forrest raises a real and legitimate issue that if you plan to really beat on your ropes, a 6mm or 7mm zip line has no place in the mountains, and I would tend to agree with him, but I have never actually had to use this thin strand line in a retreat yet, so I have not had any bad experiences with it. I guess for routes where the decent is known to be rap'ing off, I would bring beefier lines.

But, you already have the 9.4 line, so why buy more ropes? the 7mm zip line will be a cheap (and light) addition for your trip, compared to two new strands of 8-9mm that you will only use half the time. I would go 7mm, use it until its time to retire your lead line, then assess again and decide whether its time to replace with dual strands.

[This message has been edited by Alex (edited 12-07-2000).]

[forrest_m]

Alex, it sounds like you actually agree with me, then... The following is slightly off-thread, but I want to pick on something that you mention very casually in your post.

I'd be careful with using the same ropes for both twin and double technique. They really are designed to work differently, even though they may appear very similar. The composition of stretchy vs. static fibers is often different. The double ropes are designed to each function more or less independently, each strand has to pass the same tests as your thicker single line (same setup, just fewer falls). The twins are only designed to work together, thus a single twin rope will often fail in a *single* UIAA std. test fall. So there is increased risk clipping alternate pro with twins because you could easily fall on a single strand.

Likewise, if you clip both ropes of a double system into one piece of gear (especially early in the pitch where you likely have nearly the same amount of rope out on both strands) then the impact force on your pro is actually significantly greater than the design impact force (which is intended to keep the force on your body and your pro within certain limits). Esentially you're falling on one 16mm rope! I used to clip both strands into the double for the first couple of pieces (it felt safer), but I finally figured out that this is actually where the situation is the worst! This super-fat line will essentially function as a static line. Do you really want to increase the impact force on your tied-off ice screws?

The twins have a differnt configuration of nylon strands and differnt elongation characteristics designed to overcome this, but this is what makes them dangerous to clip singly. Obviously, in the real world, you do what you gotta do. Just about any kind of cord is safer than nothing. It makes sense to me to start clipping every other piece with your twin when you top out the 50 feet of 5.10 and are running out 100 feet of blocky, wandering 5.4 to the anchors.

I'm not trying to impose rules on anyone, but it does make me cringe when people use "twin" and "double" interchangeably - Colin and everybody else needs to have accurate information in order to make informed choices about how they are going to climb.

[Lowell_Skoog]

For long rappels with a 50m lead rope, I carry 55+ meters of 6 mm static line stuffed into a bag. I make sure that there is a rappel ring or a small loop on the anchor sling. The lead rope passes through this, so if the thin line fails, there's a reasonable chance that the knot joining the two ropes will jam, preventing the big ride. I throw down the lead rope, but not the thin line. Instead, I clip the stuff bag to my harness and let the thin line pay out from the bag into my brake hand. There is never any tangling of the thin line with this system. I've never had too much trouble pulling down the rope (pull the thin line and re-stuff it as you go), but certainly this could be a problem at times. If I anticipate bad rope drag I shorten the rappel. The only place I've seen much wear on the thin line is near the end tied to the lead rope. I buy a little more rope than I need so I can cut away the worn section once or twice before retiring the line.

I made up this system, and I'm open to criticism about it. If you can convince me that it's unsafe, I'm all ears.

Lowell Skoog

lowell.skoog@alpenglow.org

[dbb]

Along those lines that Lowell mentioned, there is an excellent technique for rapelling with chopped ropes. This may be a little off topic, but then again, as long as were talking about ropes...

The idea is to use a small loop tied in the rappell sling that is smaller than the knott joining the two ropes (or knott in middle of a single rope). You thread the rope through the hole regularly, and rapell on the single strand that is held up by the knott jammed against the small loop. When you're down, you simply pull on the other line that has impeding knotts in it from being chopped and tied together.

The advantage of this system is that you can do full length rappells, 25 meter or 50 depending on what ropes you have, without "passing" a knott on rappell. This would have worked beautifully for some friends of mine who were a party of 3 with one 50m rope that was cut *twice* on one side. They did 18 rappels down the SE ridge of Fisher, each passing a knott on every rappell. Needless to say, it took a while.

Also, I would recoment double ropes for colin. They are much more versatile than twins because you can use them seperately for not so technical climbs and leave all the extra weight of a single at home.

[forrest_m]

You're right, Alex, it does all come down to personal preference. My point wasn't to say that it's an automatic death sentence to use doubles and twins interchangeably, but to point out that though many people use them as if they were the same, there are real differences between them. It may not make much difference when you fall from way off the deck, or with bomber pro, but think about it... you say that one is unlikely to have equal lengths of each rope out. This is generally true, except for the first 30 or 40 feet (where you haven't placed much pro and the ropes are often still pretty even). This is exactly where you *also* have a greater chance of high-impact-force falls (ie, you develop more force on you and your anchors in a 10 foot fall with 10 feet of rope out than in a 30 footer with 100 feet of rope out). The two load-increasing elements would compound each other. I use screamers to limit the load on pro in dicey situations, so I don't think it's unreasonable to think about the effect of your rope(s).

Again, every situation is different, and there are no "rules" - for example, I might be more concerned about hitting the ground or a ledge due to rope stretch than about wrenching a bolt out of the wall with high impact force. In that case I might go ahead and clip both doubles. (I've also clipped both cords in 'cause I was sketched and only one 8.2 mm strand just *felt* way too thin... logical reasoning be damned)

Lowell, I've never had any doubts about the safety of the 10mm/7mm system, only the convenience. I admit, the small rope we used for a long time was pretty thin (it might have been 6mm? 5.5?) because, like you, we always jammed the knot against a narrow loop in the anchor. But I swear, after 7 or 8 rappels, that thin line felt like we were trying to pull on dental floss, both for being difficult to grasp and for slicing painfully into your hands. Have you seriously never found this to be an issue? Maybe our thin rope was just *too* thin.

I also wonder (maybe I've just had more stuck rappel ropes than the rest of you) how one might ascend the 7mm cord if something got hung up after you lose control of the end of the 10mm rope. Prussik with your shoe laces while belaying with the other end of the 7mm cord? ugh...

[Alex]

Forrest, I did agree with you what was best in general, but Colin already has the 9.4, which is why I suggested he get the 6mm.

As to the double/twin stuff, I climb on double ropes, but often clip then to both pieces (twin technique) when the route does not wander much. I do not agree with you that the strands increase the impact force much, as you must realize that even the best belayer with not have the ropes exaclty "matched up" through their device, which will unevenly load the strands initially during the fall, especially in the alpine where you are not necessarlity climbing within sight of your belayer, or have a tight belay. Well, thats what I think anyway, but have no proof. I've taken plenty of lead falls (!!) on doubles as doubles and doubles as twins (Dan Smith can personally attest to several screamers at Index), and have not noticed any difference.

You also point out that doubles can be used "singly" in lightweight applications and I agree, I routinely use a single strand of 8.5 for glacier travel and 4th class alpine routes.

I think all the posts here so far, Lowells idea (sounds very influenced by ski patrol practices I am familiar with), dbb, Forrest, all these systems are proven in the alpine, and it really does come down to personal preference.

[DPS]

Wow, some really good, considered opinions, all from climbers whom I greatly respect. I'll throw in my two cents: I use a 9.4 with a 7 mm line. My partner and I used this to good effect on the SW ridge of Hunter, making 22 60 meter rappels with no hang ups. The thin line can be hard to grasp and pull, but it never became a problem. One advantage that no one has mentioned is that the second can jumar the 9.4 line more safely than the double or twin rope. This was critical in my decision to use this system.

Many guides use a similar system (although they use a thicker lead line). They use the skinny line to belay the client as they rappel the fixed fat line.

That said, Mountain Gear is selling a sweet pair of double, 8.1 mm, 60 meter, dry ropes for something like $240.00. Wish I had some extra cash, those would be nice waterfall ropes.

 

Dan

[Lowell_Skoog]

Forrest Murphy said:

--

I swear, after 7 or 8 rappels, that thin line felt like we were trying to pull on dental floss, both for being difficult to grasp and for slicing painfully into your hands. Have you seriously never found this to be an issue? Maybe our thin rope was just *too* thin.

--

I've been using a 6mm line, which is even thinner than you mentioned. I agree that after 7 or 8 rappels this could become a pain. However, there are few alpine climbs in the Cascades that require 7 or 8 long rappels to descend. Usually it's more like 3 or 4, at most. If I expected to make a lot of long rappels over rocky ground, I might choose a different system. On the other hand, a thin pull rope works well on snow and ice rappels, due to the low friction.

 

[Guest]

I have done alot of research on this topic, including lengthy disussions with most of the rope manufactures. Forest has got it right. Twin ropes are for Twin rope technique and half(not double) are for Half rope technique. The only time you may want to clip both half ropes into the same piece is possibly into a bolt when you are close to the ground and a high impact fall is better than hitting the deck!!!

Posted by Dale R.

[Alex]

Cool, ok, I'll stop doing that...

Alex