Multidirectional gear?

rgold wrote: Disregarding friction over the carabiner, the pulley effect means that the horizontal load is equal in magnitude to the vertical load at all instants.  One of them can’t in any sense “win out” over the other. (If we take carabiner friction into account, the horizontal load will be roughly 70% of the vertical load, which still means neither can “win out” in the sense that they remain in a fixed proportion.) Just as in the case of anchors, the "v" angle determines both the magnitude and the direction of the load on the protection piece, so it certainly remains "in play."

The anchor and gear situations are in some sense inverse to each other. Yes, both share a “v” configuration. But in the anchor situation, you have a given load applied at the vertex of  the “v” and you want to understand the tension in each leg of the “v” required to balance the applied load.  In the gear situation,  the tensions in each leg of the “v” are determined by the fall dynamics and you want to know the magnitude and direction of the resultant load at the vertex, which describes the magnitude and direction of the force on the single protection point.  So while the "v" configuration is a feature of both situations, the problem "inputs" and "outputs" are reversed.

Without, I hope, sounding too snarky, all of this is basic vector analysis (and elementary trigonometry for numerical results) of the sort interested students can  learn in high school. (However, the situation for a three-point anchor is significantly more complex and vector methods, by themselves, are inadequate.)

Speaking of numerical results, there is nothing particularly special about the 90 degree angle between anchor strands—other than perhaps the simplicity of recognizing it.  For the 90 degree angle, the leg tensions are each about 70% of the applied load, which is ok but not notable in any other sense. It is typical to suggest that the "v" angle be less than 120 degrees in order to keep the load on each anchor piece lower than the load applied to the vertex.  If one is using nylon cord for the anchor, the focus on strand angles is to some degree misplaced, since the stretch in the cord under load significantly reduces the v-angle.

Thanks, sir! I confess, I was entirely through my "high school" math in junior high. Most all of it forgotten long ago. I enjoyed geometry, but loathed algebra, that much I can tell ya.....

I just realized, the anchor the leader builds at the end of the traverse, would also need to take that (potential) diagonal pull? Is that correct? And, hmm...would you change where the pieces are, or how you constructed it? Build it for the next pitch (normal up and down) but add a piece for the horizontal aspect of the traverse just finished? Trying to picture it...

Thanks! Interesting stuff, for sure.

Best, Helen

This thrtead would benefit from the simple diagrams in Robbins' "Advanced Rockcraft" that show how a wandering ropeline pulls on the gear at various angles. Sadly, my copy is long gone (if I'm remembering it properly at all).

Old lady H wrote: I just realized, the anchor the leader builds at the end of the traverse, would also need to take that (potential) diagonal pull? Is that correct? And, hmm...would you change where the pieces are, or how you constructed it? Build it for the next pitch (normal up and down) but add a piece for the horizontal aspect of the traverse just finished? Trying to picture it...

Thanks! Interesting stuff, for sure.

Best, Helen

If the pitch ends with a horizontal traverse with the anchor at the end of the horizontal, and a follower falls, the load will be straight toward the last piece of lead gear provided it holds.  So, a much more horizontal load (sideways, call it 3 o'clock).  

If the piece blows, the load will be initially horizontal while the piece holds, then the load vector will change from horizontal (sideways, call it 3 o'clock) to downwards as the follower swings toward the anchor ( call it 6 o'clock).  Not the same as the "diagonal" in the diagram.

So, the leader has to decide whether his/her anchor is adequate for both sideways and downward loads.  Belaying through a high redirect can mitigate the sideways load a bit and allow the belayer's body weight to counter the load somewhat.

Party of 3 caveat:  if using an auto block like an atc guide and the first follower falls after the last lead piece and is hanging on the auto block, the device is now useless if the second follower falls.  

Old lady H wrote:

... Two ropes are exactly what my partners go to would have been, in a different setting and with a different partner. I did think of that, but didn't realize you'd simply leave one unclipped...

I don't think I'm correctly following this part "simply leave one unclipped". Can you tell me what you meant to convey? Are you thinking that the leader clips his pro on one rope, leaving second rope unclipped as he/you're ascending (through the traverse), then fixing it to pro after going back vertical for a bit? If that's it, then I "got it" now, and that makes perfect sense. If not, then help? Thanks for the clarification. 

And I *really* want to go back there to climb someday. Was there in '16 after visiting Entreprises Climbing manufacturing in Bend, but as I was solo on my way back to Washington, I had no gear, no partner, etc. so I just amused myself by climbing the Misery Ridge Trail and admiring the view.

Gunkiemike wrote: This thrtead would benefit from the simple diagrams in Robbins' "Advanced Rockcraft" that show how a wandering ropeline pulls on the gear at various angles. Sadly, my copy is long gone (if I'm remembering it properly at all).

Maybe, but (as you well know) the load on pro is going to act (approximately) along the angle bisector of the rope angle (or "v") at the piece.  That's simple enough to visualize in the field.

However, if you don't understand forces as vector quantities, then the diagonal nature of these loads might be hiding the more critical fact that "some of the force" is acting along the crack where the gear is placed.  It is the force components acting along the crack that rotate cams out of shallow horizontal placements and lift nuts from vertical placements.

Helen, I'll let Rich handle all the math teaching, given he's a professor of mathematics. But on a practical level, I think what's just happened is by following a traverse you got a small taste of what it's like to be a leader on gear. There's nothing particularly special about the forces of a fall onto gear by a traversing 2nd. You intuited that as the angle of the rope as it bends through a piece of gear becomes tighter that creates some potential lateral pulling forces in a fall. Rope drag and protecting your 2nd so they don't end up hanging from the rope over something they can't get back on are much bigger concerns. Leaders wander left and right above gear all the time. It's a pretty rare trad route that just goes straight up. Even though you may pendulum a bit, the force from a fall (rather than from the pull of the rope toward a belayer) is always going to be downward. 

Greg D wrote:

If the pitch ends with a horizontal traverse with the anchor at the end of the horizontal, and a follower falls, the load will be straight toward the last piece of lead gear provided it holds.  So, a much more horizontal load (sideways, call it 3 o'clock).  

If the piece blows, the load will be initially horizontal while the piece holds, then the load vector will change from horizontal (sideways, call it 3 o'clock) to downwards as the follower swings toward the anchor ( call it 6 o'clock).  Not the same as the "diagonal" in the diagram.

So, the leader has to decide whether his/her anchor is adequate for both sideways and downward loads.  Belaying through a high redirect can mitigate the sideways load a bit and allow the belayer's body weight to counter the load somewhat.

Party of 3 caveat:  if using an auto block like an atc guide and the first follower falls after the last lead piece and is hanging on the auto block, the device is now useless if the second follower falls.  

A lot of this can be mitigated by:

1. belay the 2nd off your harness, not the anchor
2. don't have two followers climbing simultaneously; go old-school trad and have the party climb the pitch one at a time: climber - rope - climber - rope - climber.

Russ Keane wrote: See "Rope would be loaded straight to the side" for why I spoke up.  Non sensical.  As for the forces laterally. I would imagine iin the diagram the force greatly increases within th e arc for where force begins to where it is highest.  In otherwords, the forces at the far end  of th e arc are insignificant compared to those at the bottom.,

and when the force of the hanging climber is at the bottom in a situation where the rope at the piece above him runs horizontally to another piece, or the belay, what is the net vector going to look like?  hint: it's going to have a fair amount of lateral load to it.

a while back one of my partners fell on a route that had a significant traverse in it.  he tried to sling it the best he could, given the situation (double rope technique would have been a big help here).  when he fell, it jerked two pieces out.  one of them came unclipped from the rope and shot like a bullet straight to the right.  it took us forever to find it because it was about 100' away, up in a tree.  seems like a significant lateral force to me...

rgold wrote:

Maybe, but (as you well know) the load on pro is going to act (approximately) along the angle bisector of the rope angle (or "v") at the piece.  That's simple enough to visualize in the field.

However, if you don't understand forces as vector quantities, then the diagonal nature of these loads might be hiding the more critical fact that "some of the force" is acting along the crack where the gear is placed.  It is the force components acting along the crack that rotate cams out of shallow horizontal placements and lift nuts from vertical placements.

it can also work to the benefit of some pieces and the detriment to others, as greg D pointed out above.  in particular, stoppers or hexes that are slid in from one side that opens significantly.  if the second isn't a very strong climber, the leader needs to realize this and deal with it accordingly.  this might mean placing extra pieces, or dropping down a fixed piece of rope to provide a toprope through the section.

rgold wrote:

Maybe, but (as you well know) the load on pro is going to act (approximately) along the angle bisector of the rope angle (or "v") at the piece.  That's simple enough to visualize in the field.

Some of the back-and-forth in this thread leads me to believe that maybe not everyone can visualize the resultant forces.  Again, my memory may be faulty, but I thought that's what the diagram in AR showed (as the rope goes taut in a fall). The point being that nuts in vertical placements can lift upwards. Nutcraft 101 stuff, to be sure.

Marc801 C wrote:

A lot of this can be mitigated by:

1. belay the 2nd off your harness, not the anchor

Sure.  That can work. But then the load goes straight to the belayer which could be uncomfortable if it’s big enough. And then it would get transferred to the anchor anyway. But I really hope your anchor is adequate for a sideways top rope load anyway. 

2. don't have two followers climbing simultaneously; go old-school trad and have the party climb the pitch one at a time: climber - rope - climber - rope - climber.

 Yes you could do that too if you want to go at a snails pace and clog up the route.  Alternately, you could just keep your hand on the brake which will be adequate to stop a follower,  just don’t go hands-free. 

Grandpa Dave wrote:

I don't think I'm correctly following this part "simply leave one unclipped". Can you tell me what you meant to convey? Are you thinking that the leader clips his pro on one rope, leaving second rope unclipped as he/you're ascending (through the traverse), then fixing it to pro after going back vertical for a bit? If that's it, then I "got it" now, and that makes perfect sense. If not, then help? Thanks for the clarification. 

And I *really* want to go back there to climb someday. Was there in '16 after visiting Entreprises Climbing manufacturing in Bend, but as I was solo on my way back to Washington, I had no gear, no partner, etc. so I just amused myself by climbing the Misery Ridge Trail and admiring the view.

https://cdn2.apstatic.com/forum/73247.jpg

Hopefully this loads the excellent photo from page one!

Thanks, all! Helen

Marc801 C wrote: A lot of this can be mitigated by:
1. belay the 2nd off your harness, not the anchor

Greg D wrote: Sure.  That can work. But then the load goes straight to the belayer which could be uncomfortable if it’s big enough.

And this is different from belaying a leader how? (Other than the vastly lower forces involved.)

 And then it would get transferred to the anchor anyway.

Maybe, maybe not, but again, minimal from the anchor viewpoint.

 But I really hope your anchor is adequate for a sideways top rope load anyway.

Belay anchors are (had better be) omnidirectional.

Marc801 C wrote: 2. don't have two followers climbing simultaneously; go old-school trad and have the party climb the pitch one at a time: climber - rope - climber - rope - climber.

Greg D wrote: Yes you could do that too if you want to go at a snails pace and clog up the route.

I suppose......if the party is inefficient and doesn't know what they're doing. I'll admit to quite a bit of personal bias here. I climbed a lot with the same group of people and a lot of the time it was in parties of 3. We became very efficient and had it really dialed. We passed three parties of two on the regular route on Fairview Dome and were back at the car before the highest of the parties we passed had topped out.At the Gunks we did Arrow, Limelight, and Three Doves in the time it took another party to climb Arrow (passed them on the GT ledge).
So no, it doesn't mean a snail's pace or clogging a route - if you're efficient and don't dick around with something-o-lettes, quads, guide mode, redirects, belaying off the anchor, and taking selfies.

Wow! Force vectors and all sorts of info.  Sort of makes me want to forget about ever leading or following a pitch with a real traverse! But, sort of back to the point here's my (simple) 2 cents worth:

Old Lady H asked: "What placements would you look for, in a perfect universe?
     The most multidirectional I could think of, would be not cams, but nuts or hexes in a true keyhole sort of slot, where the only way in or out was up. Helen..you've got the basic idea correct; but if the slot/keyhole/vertical crack is good, cams are probably a bit better than nuts, but only marginally.
     Or, similarly, a chicken head sort of thing to sling. You mean sling/tie-off a chickenhead....Only on "chickenheads" like sometimes found on sandstone, granite-type chickenheads (a la SD's Needles) are probably best used only for downward falls, if then!
     Would you extend the pieces? "Depends": If the leader is climbing upwards at the end of the traverse, for the LAST PIECE more probably "yes" than "no", more to reduce rope drag ; but for the pieces on the traverse itself.... again "that depends" on rope drag, but generally "no". (Here the math-and-physics majors may have another opinion; but I try to keep the slings short, figuring the length of the sling adds to the length of the fall / pendulum....Is this correct, you physics guys & gals ?
      How would any of this apply to roofs, the other big pendulum opportunity? "  On a roof the second swings into space.   My #1 thought upon going over a roof (especially one that comes late in the pitch where there might be less "opportunity" to lower the second back down to the cliff face, or belay) is: " Can my second prussic?"  #2 is; "How is / will the rope run over the edge and how sharp is that edge?"

Old lady H wrote: Pitch two, I confess, caught me by surprise. Yes, the book said "traverse", but somehow I just wasn't expecting totally horizontal.

You'd just love On The Lamb in Tuolumne - 4 pitches, 100% horizontal. Protected mostly with cams along with some stoppers and some opposition.

Marc801 C wrote: And this is different from belaying a leader how? (Other than the vastly lower forces involved.)

Belaying a leader is vastly different.  Different direction of forces, different techniques to mitigate loads, different awareness of magnitude of forces.  But, you know this.  Flex some more if you need to.  Any other questions?

Maybe, maybe not, but again, minimal from the anchor viewpoint.

Belay anchors are (had better be) omnidirectional.

Really?  "better be omni directional"?  Sometimes, yes.  But, not an accurate blanket statement.

I suppose......if the party is inefficient and doesn't know what they're doing. I'll admit to quite a bit of personal bias here. I climbed a lot with the same group of people and a lot of the time it was in parties of 3. We became very efficient and had it really dialed. We passed three parties of two on the regular route on Fairview Dome and were back at the car before the highest of the parties we passed had topped out.At the Gunks we did Arrow, Limelight, and Three Doves in the time it took another party to climb Arrow (passed them on the GT ledge).
So no, it doesn't mean a snail's pace or clogging a route - if you're efficient and don't dick around with something-o-lettes, quads, guide mode, redirects, belaying off the anchor, and taking selfies.

Thanks for showing off your prowess.  You guys are awesome.  

Serious question:  Would your super awesome, super efficient party of three be faster with your followers climbing one at a time or climbing simultaneously?   We already know the answer.

Greg D wrote: 
Belaying a leader is vastly different.  Different direction of forces, different techniques to mitigate loads, different awareness of magnitude of forces.  But, you know this.

I have to explain your own statements to you? You missed the point. I suggested belaying the second, with only TR forces involved, directly off the harness. You wrote:

Sure.  That can work. But then the load goes straight to the belayer which could be uncomfortable if it’s big enough. 

My point was that lead fall forces are a lot higher and that the slight discomfort a belayer might face in a TR fall is totally inconsequential.

Flex some more if you need to.  Any other questions?

What's with the attitude?

Really?  "better be omni directional"?  Sometimes, yes.  But, not an accurate blanket statement.

Quick, who feels good about an approach where an omni-directional anchor is a sometimes thing?

Thanks for showing off your prowess.  You guys are awesome.  

No showing off, and I thought I added enough of a disclaimer, to point out that a party of three is not automatically slower than a party of two.

Serious question:  Would your super awesome, super efficient party of three be faster with your followers climbing one at a time or climbing simultaneously?   We already know the answer.

Yeah, maybe we could have saved a whole 30 minutes on a 1K' route. We always found that to be more trouble than it's worth, and we're talking about cragging, not big alpine days. That isn't the question anyway. We were always more concerned with enjoying the route and moving just fast enough to avoid epics and darkness. We weren't hellbent on being fastest.

Old lady H wrote:

https://cdn2.apstatic.com/forum/73247.jpg

Hopefully this loads the excellent photo from page one!

Thanks, all! Helen

Yeah, that pic is what caused me to ask, one rope for leader, one rope for 2nd? Is that the gist of it? Thanks.

 It's just doubles but being set up with a mind to protect the second. Nothing really would stop the leader for using rope 1 for the traverse than rope 2 after the traverse when movement is more vertical, depending on situation. The follower will  likely most benefit from rope 2 being belayed from above in case of a swing. The leader could also use rope 1 for an initial vertical part of the pitch, and rope 2 for a traverse finish. Same idea. Reminds me of rope technique for scary gritstone.

Or at least that's how i understand it. (Novice that i am)

Grandpa Dave, long ranger, and anyone else, I remembered this older thread, which had quite a bit of good information on pendulum falls:

https://www.mountainproject.com/forum/topic/112165540/pendulum-swings

Very early in our climbing careers, my son and I learning together, there was a fatality in Idaho, a pendulum fall. It was one of my son's earliest SAR missions as a tech team guy. That accident is actually how I first found Mountain Project. So. Yeah. Mom had that possibility to get her head around on this traverse.

But? At the last gear to clean? I paused, thought it all through, reasonably, got calmed down, sussed out where I'd be putting hands and feet, and just did it. Sheesh. 5.4.

I was chatting with my son about this today, and he talked about his trip to Yosemite. That's what he was thinking about, there, on "easy" terrain. Until it kills you.

Dunno why, but we both truly love this thing we do, although we are going somewhat different directions now. He is involved with tech rope rescue, and deep into the geeky joy of serious rigging, and heaps and heaps of training his crews so they can stay on top of it. Me? Conquering 5.4s, that was my first ever, at the grade!

Thanks all for the generosity of your time and experience. Much appreciated by this perpetual beginner who enjoys learning.

Best, Helen