Jump to content

Opinions:Static vs. Dynamic for top rope


Billygoat

Recommended Posts

Since top roping done right allows the person climbing to fall without creating a lot of force, I should be able to use a static line for greater abrasion and degradation at the bend resistance. Any opinions/experience with that?

 

Also, knots in your glacier rope, between people, in order to help slow or stop by catching the lip of the crevasse:

1) does it work

2) if yes to one, what knot is recommended

3) how does one get the knot out, under load, in order to ascend said rope? or does one have to be hauled out at that point?!

Link to comment
Share on other sites

  • Replies 23
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Putting knots in the rope between climbers while walking on a glacier seems like a bad idea. I'd much rather have an unknotted section of rope to work with while hauling a fallen partner out of a crevasse. I just don't see how a knot is possibly going to prevent a crevasse fall, and any effort spent on tying intermediate knots would better be spent practicing your self-arrest skills.

 

Are you going to a top-rope-only crag? I suppose you could TR on a static rope, but I wouldn't want to, since I can't always trust that my belayer, however attentive and cautious, will always pull up every bit of slack. I don't want to fall on a static line from any height, thanks.

 

I'd rather bring a dynamic rope so I could lead, anyway. Carrying a second static line for TR seems like too much work.

Link to comment
Share on other sites

Since the top rope fall factor is about 0.01, I dont think it matters much if the rope is static or dynamic. In the climbing gym I used to work at we used to take "demo falls" as part of the intro to climbing session, and fall on about 10 feet of slack on about 50 feet of static rope out of the roof of the lead cave... 0.2 fall factor - no problem. After all a Gri Gri is a 100% static belay anyways. But I'd be scared to take a lead fall on one. Its not the force on YOU thats the problem, its the force on the pro... statics rip out even bomber gear, and/or break biners, with a large fall factor......

Link to comment
Share on other sites

knots in the rope would be a pain in the ass! They would catch on rime chunks and stuff and be a general annoyance and probably would saw into the lip even more than usual. Not to mention how annoying it would be to stand in the cold tying knots in the rope and stuff. Can't imagine why anyone would do this.

Link to comment
Share on other sites

On the topic of putting knots in the rope for glacier travel, I take a different view. The knots in the rope is a technique used for rope teams of two. Has anyone ever tried to hold a crevasse fall alone? Especially when you are not expecting it? Even with good self arrest skills, it CAN be very hard to hold a crevasse fall. (like getting pulled onto your back) The knots should dig into the snow, relieving the arrester of some of the forces. The worst case condition is if both people fall in and anything to help prevent this is a good thing.

 

As to the problem with hauling and ascending the rope with knots in it, yes this can be a problem. But each climber should have enough rope in rescue coils to reach the other. This would be true wether or not you use knots in the rope. The surface climber needs to be able to rappel to the victim and down prussiking is not a option. So with this rescue coil rope, simply clear a lip to the side, throw down the extra rope and let the climber prussik out on the clean knotless line. Or haul with this line.

 

I can see no disadvantage of using the knots in the line (maybe the knots getting stuck in weird chunkies, but have never experienced it myself) and only advantages in helping me arrest the fall. Of course knots would not be needed for teams of three or more. Also, of course there in no excuse for traveling roped up on a glacier without good self arrest skills.

 

I usually use a simple overhand knot (which can not be undone when weighted) about halfway between the climbers and then another about 6 feet to either side. You generally need a long (60m) rope to be able to give enough room between climbers and still have enough rope for the rescue coils. rescue coil (75 feet each) and between climbers (50 feet plus a few knots)

 

Better yet, don't fall in. smile.gif

Link to comment
Share on other sites

Regarding the static vrs. dynamic:

 

If primarily using it to climb on I would get a sturdy Dynamic rope. Check out the Sterling Marathon line, their sheaths are extra tough, I can vouch for the durablity...plus you can lead on it.

 

However, a good static rope is nice to have. I'm not sure if your planning to do much aid climbing, but hauling and fixing pitches with a static is the way to go.

 

Never used the knot technique, and don't think I ever would. Hauling past knots is a pain in the ass.

Link to comment
Share on other sites

Good responses! We do alot of top roping at our local crag because of a lack of gear placements and the overall chossy conditions. I was talking to Larry at Mouuntain Tool and he was encouraging me to use a static line for all my top roping and saving my dynamic rope for trad leads and alpine routes on the mainland. Static rope is less expensive and can take alot more abuse. Larry was saying that the rope gets pretty well damaged from constant lowering over the tight bend of two biners. More money on gear but better application and longer rope lives. My regular belayers for the most part are on it so I don't fear the fall.

 

On the knots in the glacier rope issue, I've seen it presented in magazines and books as additional insurance for rope teams of two. I've seen the alpine butterfly knot encouraged as well as others. The concept makes sense on paper but may not in practice, especially if one uses a short, 30m, rope. I could only see problems trying to bypass the knots while ascending or when yarding on a z-pulley. I'm just wondering if anyone has heard or experienced the knot thing working in the real world...

Link to comment
Share on other sites

I think the static rope can be a good idea if tr'ing is all you use it for. It's strong, safe, and lasts a long time.

 

The knots: I think they would work a lot better if you put some sort of spikey things into them, like maybe even tent-spikes, or maybe something like sawed-off hammer heads? confused.gif I think if you tied these in in a strategic manner, they could definitely slow you down.

Or even heavy weights could slow you down. Tie on a couple of those old iron weights, maybe twenty-five pounders, every thirty feet. I think that would help slow you down in case of a fall? Good luck.

Link to comment
Share on other sites

Good ideas SC! I think the tent peg as a marlin spike or fid is brilliant, however the whole tying on of weights seems a bit tiring. I think a better idea would be to tie in a couple of retired lawyers and doctors to the middle of my two person rope team as self propelled weights/chocks. I'm sure one of them would catch just nicely on the lip of a crevasse. Hell, they may even pay me for the experience. wink.gif

Link to comment
Share on other sites

maybe some snow shovels dangling from the knots? say, 15 between each partner? or dangling horsecock which could be consumed during glacier crossing. this would of course require a glacier where the real dangers lie early on. Maybe for descents where you pass through the firn line and back into the dry stuff.

Link to comment
Share on other sites

Billygoat said:

Keg of beer! would roll/slide nicely and keep one well hydrated bigdrink.gif

 

I think Billygoat is onto something here.

 

As for the static rope thing. If you know you are going to TR a ton at a specific crag you can buy a static line cut to the length needed for that crag. My brother once got a short static rope specifically for TR'n at the collums in Eugene. Nice and compact and you don't have 50 extra feet laying around for some gumby to step on.

Link to comment
Share on other sites

it seems gene and i are the only people who support this, but i am with him - knots in the rope are a great idea and they work.

 

however, id be picky about which knot you choose. we've actually done live-body tests into crevasses to see if the knots work, and they certainly do. however, one knot was clearly superior - the butterfly knot. we tried butterfly knots, figure 8s, and overhands and the butterfly knots were definitely better. in fact, sometimes the other knots didnt even catch, whereas the butterfly always did. i dont know exactly why, thats just what happened. of course i wouldnt count on them in ALL conditions, but in MOST conditions they work.

 

also, ive used them a lot (everytime i rope up on a glacier since doing that little test session) and ive never had them hang up on ice chunks, etc. if you are working through funky penitentes, etc. of course they could get hung up, but so could an unknotted rope.

 

in a team of two, i generally place a knot roughly (no science here) 1 1/2 - 2 meters from either climber, plus at least two more on each side of the middle just in case (for example if you break a long bridge near the end and the knot two meters away falls with you into crevasse).

 

in theory, you shouldnt really have to prussik out and pass the knot, because if the knot worked it should be stuck in the snow near the lip of the crevasse just above you, in which case you should only need to move up a step or two to whale-flop over the lip. but, as if in the above mentioned example, you break through a long bridge and it is one of the secondary knots that catches, passing the knot while prussiking isnt that complicated. prussik up to the knot. take another sling, etc. and secure it (klemheist, prussik, etc.) above the knot, stand up in foot prussik and leave old waist prussik slack, slide new one above the knot up, weight it (of course knot will now be unweighted), undo the knot and the old waist prussik and continue prussiking as normal. you might say, "well what if i dont have an extra sling?" well, i guess if youre going to use the knots in the rope, be sure to have an extra sling as well, in case you end up in this situation.

 

hope that helps!

Link to comment
Share on other sites

Good ideas Miller. I will try the butterfly knot sometime. I like your spacing of the knots as well. It is cool that you went out and gave it a real test.

 

As for the question of having an extra sling or prussik for ascending the rope, if it is team of two, each person should have enough gear to create a z-c pulley system. This means that in addition to the texas kick prussiks (or whatever system one chooses), one should also have a couple of short prussiks which could easily be used for jumping past the knot.

 

Someone mentioned earlier that they wouldn't use knots with a 30 meter "glacier " rope. A team of two using this short rope can find themselves in trouble. (with or without knots) Either the team is 90 feet apart or 50 feet apart and each carries 20 feet of rope. (of course the distance could be between 50 and 90 feet and this would change the amount carried but not the point)

If they are the full 30m apart, then there is no rope to make a z-pulley. Bad.

If they are 50 feet apart and have 20 feet extra, then there is not enough rope to rappel to the victim if need be. An unconscious upside down climber will die and needs to be uprighted and maybe given cpr. Does this happen often? Of course not. But it would suck if it did. IMO, I would rather be ready to handle the most likely hazard on the glacier than save the weight of 30m of 8.5 mil rope.

 

 

 

Link to comment
Share on other sites

FWIW I have also done the knot thing on a 2 person rope. But since we didn't find any crevasses I didn't test it, and my 'rescue' plan was to just scream until a few of the other 15 rope teams on the glacier came over to haul us out, rather than prussiking anyways. cantfocus.gif

 

 

Link to comment
Share on other sites

gene,

 

I usually use a 37 meter rope when with 2 people. We "fold" it in thrids with a few extra fet on the slack end and tie in. This makes our coils ong enough to reach each other. I think it puts us far enough apart from each other, but have alway kinda wondered about that. What do you think, not far enough?

 

Of course, then again I only usulay get on glaciers with one partner in late summer when the crevase danger is easily managable.

Link to comment
Share on other sites

Good point about leaving enough slack for a z pulley. How close do you all think a rope team of two could safely travel together given the average size of the crevasses in a maritime location like the North Cascades? I really like my 35 meter, 8.2mm rope. I guess I could bring two, they are so light. That definitely would be a consideration recognizing the possible need to rappel into the hole to check on ones partner. Glad to hear the knot theory has been tested. Butterfly knot seems to be the stopper of choice. I think I'll set up a scenario in the back yard and test it a couple times. Extra slings and tiblocs should be carried. They are really not that heavy.

 

Cheers

bigdrink.gif

Link to comment
Share on other sites

the way I convert it, 1/3 of that 35m rope is 38 ft. That would put a 2 person team approx 35 feet apart....a bit too close for my comfort. 50 ft is about the min I like to go, but that's just my opinion. I prefer to have more time (distance=time) to react when there's a problem.

 

Of course, distance also translates into the potential for greater speed (of your falling partner)....and potentially a greater force once the rope comes tight.

 

Another consideration would be the difficulty of the route. I may want the flexibility of a longer rope if I were doing a (semi?) technical climb that requires the use of running protection and/or belays.

 

And on a completely different subject.....I TR'd on static rope for a couple of years in the midwest before I ever climbed on a dynamic rope. Never had a problem at all with an anchor, stresses on myself, or anything else. Static is definitely cheaper if you do a lot of TRing.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...