rope traverses over river passage

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rope traverses over river passage

Postby gindling » Aug 29, 2013 10:15 pm

Ive got a question about traverses. Ive looked through the ACT bible and understand what they are saying but I was wondering about some personal preferences, everything in ACT is so Grand Prix Cars and Swiss Watches style rigging I wanted to know what people here in the states think. Weve got a river passage with 33-35F water, four sumps that you ascend over and rappel back down, and strong currents. Instead of full on swims and feet so numb they are like wood, I was looking to rig a traverse. All stainless 3/8 bolts and hangers and mallions.

How many feet would you think is acceptable between backed up anchors, or vise versa how many single bolts between double bolts. Nice rock.

How tight should the traverse line be? Should I need a ascender to get up to the next bolt past the mid point? Or should it be nice and taut like piano wire?

This is 20-30 feet above the river and we don't see any signs of flooding in the old overflow passages, since there are still old 70s innertubes laying about. And we will be bolting into the many leads up high and have no place below to belay from. Treading water and belaying sounds like a horrible idea. Thought we could use the bolts for the traverse as the starting off points for our bolt climbs. Like a hanging belay. Which of course would be one of the backed up bolts.

Any ideas or recommendations?

This is the Steele Traverse, I think he channeled a goat and danced across. We would rather not bolt from the bottom of the rope behind Kat down to the river passage and instead begin traversing from near here.
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Re: rope traverses over river passage

Postby Stridergdm » Aug 30, 2013 12:12 am

I think the rock would make a huge difference in the answer to where to place your bolts. I'm hardly qualified to answer, but I suspect few would answer without more details or seeing the rock in person.

As for taut or not. No. The forces multiply tremendously the tighter a rope gets.

If there's a 120 degree angle in the rope in the center, each leg will see about 100% of the load.
If it's a 150 degrees, that jumps to 200% of the load
at 170 degrees (which is about as tight as you could get it) 575% of the load.

In other words, if you weighed 100kg. EACH anchor would be seeing 575kg.

I'd go with a nice easy angle and plan on using an ascender.
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Re: rope traverses over river passage

Postby Tlaloc » Aug 30, 2013 9:23 am

gindling wrote:...Instead of full on swims and feet so numb they are like wood...


You could wear a wetsuit, including feet.
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Re: rope traverses over river passage

Postby Scott McCrea » Aug 30, 2013 9:33 am

The simple answer is "it depends." Usually the goal is to set as few bolts as possible. It just easier to rig and traverse and it's less expensive. It also depends on how adventurous you are. If you can reach out and drill and set the next bolt 4-5 feet away, so be it. But, if you can sling a stal or horn or place some pro so you can reach out 10-15 or more feet, even better.

The tightness also depends. Tighter is easier, but it can make it awkward to have more than one person on the traverse at a time, since you can pull on each other. If there is enough slack, multiple people can be on rope with two bolts between them. Too much slack and you'll dip in the water or make getting up to the next bolt/anchor difficult.

Try to plan ahead with bolt/anchor placement and don't be afraid to back up and remove then reset a bolt if it makes the route better. But, also, don't fret too much. Just get it done safely and get exploring.
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Re: rope traverses over river passage

Postby gindling » Aug 30, 2013 10:36 am

Thanks Tlaloc. We do wear wetsuits and they keep us very warm, though everyone in our group had numb feet even with thick neoprene wetsuit socks on, maybe i have bad circulation. But like I said, We will be bolting up from the traverse lines so we don't have to start bolting while treading water, and I really don't want to try boltclimbing in my wetsuit as fun as that sounds, the wind howls when you are 20-30ft over the river.

So Ive only belayed for boltclimbing while standing on Terra Firma, and once I was on a hanging belay on a A3 route on granite here in Idaho, some cams and a chock... But ive never done a hanging belay in a cave. Double bolts would be standard practice I assume for the belay station? There are very few places we would be doing this, and hopefully we can find a way around it, but if not, any suggestions for the belay?

As for the rock for the traverses, its very solid with no minor beds of clay or shale or anything, no wall crusts or formations of any kind, and usually no ledges. Just nice ellipsoid passages above a river canyon in massive Dearborn/Damnation Cambrian limestone. Thanks Stridergdm for the forces involved, A few degrees makes a big difference, and I want this done once and done right.
Last edited by gindling on Aug 30, 2013 12:15 pm, edited 2 times in total.
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Re: rope traverses over river passage

Postby CaverCSE » Aug 30, 2013 10:39 am

We have been doing something similar to stay out of the water in a cave I found. We attempted J rappels but, they are such a pain. Now we just have a slack rope across the canyons and we just clip in and sorta hang on it while stepping across. I know having thicker rope helps a lot. I considered using a Postman Bridge; I used to build them in my backyard when I was a kid. They aren't too bad when you get used to crossing one. I also considered the red neck method of using wood post wedged in the passage to make a bridge (with a safety rope). It wouldn't look cool or sophisticated but, it would be blazing fast compared to any other method. If I set the bolt and it's a good bolt in good rock then I don't mind hanging from just one bolt but, if I don't know the history of the bolt then I usually try to back up to a natural or at least one or two other bolts.
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Re: rope traverses over river passage

Postby Scott McCrea » Aug 30, 2013 11:02 am

Put two bolts/anchors at the ends. Mid-bolts/anchors only need one. The adjacent bolts are the back ups.
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Re: rope traverses over river passage

Postby chh » Sep 6, 2013 10:34 am

How is the traverse? Are the footholds good for the most part, or are you really weighting the rope full time? Is your traverse line fall protection or fall prevention?

I'm usually a proponent of tighter traverse lines. Hand tight, nothing crazy. We're not building high lines here. This is mostly because in the event of a fall the caver doesn't have as far to go (provided the bolts were placed correctly in the first place) and it's easier to get back on your footholds. In good rock, rigging for J rappels just to stay inside your 60 degree anchor vector is going to slow everyone down and be a waste of time. Plus, it might put you back in the river;) In fact, for traverses I like to stay away from rigging that involves anything more than a cowstail to negotiate if it's at all possible.

As far as the belay anchors go, I certainly would want to start out of the water if possible as well. Have you thought about solo aid for the leads? It's not much slower than a standard aid lead and it makes it possible for your partners to sit maybe at the start of the traverse and have some hot food, stay comfortable, catch up on sketching, or something else productive. I would think this would be nice, especially in a cold cave. That way, if the lead goes on longer than you want to be up there, you hang the rack and drill, rap down and trade off with another in your party who is now warm, fed, and ready to go, rather than freezing from siting and belaying you for however long. Plus they've warmed up your seat and made you lunch!
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Re: rope traverses over river passage

Postby gindling » Sep 6, 2013 10:51 am

There aren't really any footholds on the traverses, so they are full weighted for the most part. Just trying to make it easier to get back to the leads up the river which haven't been visited in many years due to the amount of swimming and sumps to negotiate. And once you're up there a lot of those leads aren't very doable in most wetsuits since at this temp the wetsuits need to be pretty thick. I was at one of the leads that had been spoken about in the 70s where the wind is strong enough that it kept blowing out their carbide lamps and I could hear cascading water just on the other side of a duck under but I couldn't get to the damn thing because my wetsuit added just enough thickness that I couldn't squeeze through the canyon. So with the traverses we should be able to wear normal caving gear and use a boat for the lakes where a traverse wouldn't be very useful. So what do you use to solo aid?
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Re: rope traverses over river passage

Postby chh » Sep 6, 2013 1:52 pm

For what it's worth, in good rock, I would feel totally comfortable pulling myself along on a hand tightened traverse line. Are you loading the bolts with more than 1/2 your body weight. Yes. Are you still operating within safe parameters? Yes. Achieving a 170 degree angle on a loaded rope is actually quite difficult and would involve something more than hand tightening. Also, if you're worried about magnifying loads on your traverse line, instead of using knots on your intermediate bolts you could use prusik knots. That way you could dial the tension between intermediate bolts more easily and also have the added advantage of some slippage in a severe loading scenario. Though anything that would cause them to slip would already have caused damage to you, so again, probably not worth worrying about.

For solo aid I use a gri-gri. There are lots of different ways to go about solo aid and each depends on the personal preference, terrain, and how much crap you want to haul into your leads and how comfortable you want to be. Most of my aid experience is on natural lines, but if you are planning on bolting the whole way, I think that is actually a lot simpler. Provided you are on vertical terrain (as opposed to overhanging) and the lead isn't terribly long, you can get away with as little as a single aider and a gri-gri, in addition to your lead rope, drill, draws or free biners for the lead. Adding more trinkets will make you more comfortable, but it's not absolutely necessary. I'm not going to write about solo aid here, because I'm not that patient and would likely be answering questions that you probably already know, but if you want to pm me we can chat about process and preferences and all that.
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Re: rope traverses over river passage

Postby Extremeophile » Sep 6, 2013 2:03 pm

chh wrote:For solo aid I use a gri-gri.

I've done a lot of solo big-wall aid climbing with a modified 1st gen Gri-gri ... and always with backup knots (figure-8 on a bight or clove hitch). This attaches between a seat and chest harness and the rope feeds automatically as you climb. I haven't used this system in a cave though, and probably wouldn't trust it if things got terribly wet or muddy. I always prefer a belayer when available. There's better impact absorption when belayed from a harness, and psychologically it's nice to have another person to talk to when leading. It helps take the mind off any fear or frustration.

Never do what these guys were doing:
http://www.caves.org/section/vertical/nh/45/ivyaccrpt.html
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Re: rope traverses over river passage

Postby gindling » Sep 7, 2013 9:47 am

Thanks to you both for the replies on solo aid. Coming back from my trip thinking about bolt climbing into those leads got me reading about what can go wrong and I came across that article about Joe... I love to tinker with my gear and make new things but this shows how wrong it can go.

There is a sandstone quarry in Boise that allows bolting and rock climbing so I wont mar any cliffs with lines of bolts as I practice. Though I agree Derek, its always nice to have someone around to talk to and keep your mind from wandering as you're hanging from a few inches of steel rod hammered into a rock.

So while reading about the deciphering of cuneiform by Sir Henry Rawlinson in 1837 I came across what may be one of the earliest documented aid climbs/traverses Ive ever come across. Having already transcribed the Susian and Old Persian texts he was at a loss as to how to get to the Babylonian script which was the highest of the three texts carved into a rock cliff 500ft above the ground, and the one without a handy ledge.

" Rawlinson was at a loss until a wild Kurdish boy volunteered to reach the inscriptions. Climbing up a cleft to the left of the inscriptions, he drove in a wooden peg with a rope attached and, taking the other end of the rope, traversed across the almost smooth rock of the overhang above the inscription. At the other side he drove in another peg, and, with a loop of rope thus hanging free across the inscription, could fix up a swinging seat, like a painters cradle." Geoffrey Bibby--- Looking for Dilmun
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