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Estimating vs. Measuring Rap Distances
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By Bill Lawry
From New Mexico
Jun 14, 2013

For those out there who post rap distances, how are you measuring them?

Of course, an accurate rap measurement is only half the picture for a marginal rap. The other is an accurate measurement of the rope itself and "same length" ropes do vary. Ignoring the rope-length part, what can be done? ...

a) An electronic rangefinder similar to the Vendetta Bow Rangefinder ? Might have to take a couple measurements if no line of sight between rap stations.

b) Long static cord ...use pairs of knots to record distances and measure between them later? Hmmm ... visions of a tangled mess. :-/

c) Seems like the common GPS unit isn't really accurate enough vertically for these purposes.

d) Doesn't matter that much? Most of the time, just posting that an XX meter rope will reach is enough? And if it doesn't work for someone they'll need to improvise with cordelette, slings, insitu anchor, free-solo down climbing, etc.

This is not a question burning itself in my mind ... perhaps just a mental exercise. Electrons are cheap. :-)


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By The Stoned Master
Administrator
From Pennsylvania
Jun 14, 2013
Day Lily.

" For those out there who post rap distances, how are you measuring them?"


If I've posted a route that requires a rappel descent I have climbed/rappelled it before and I don't put exact measurements I note wether one 60m is enough, or two or 70m, etc.

If multiple rappels I note via just visualization (because I pay/paid attention during my experience) how far down the next station is (40ft, etc) and where the station (bolts/rings, webbing, etc) is in relation to the natural line/hang of the rope (so to the left or right and then describe the next station: webbing and rings around tree on obvious ledge, etc).

So I don't figure out the facts, I estimate/deduce visually.


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By BSheriden
Jun 14, 2013

Wtf is this a serious question? Range finders!? Lol how about just estimating with the rope. A 60m rope either reaches or it doesn't why on earth would you need to know the EXACT length. This has to be one of the dumbest questions I have read on here... And that's saying a lot!


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By Bill Lawry
From New Mexico
Jun 14, 2013

BSheriden wrote:
Wtf is this a serious question? Range finders!? Lol how about just estimating with the rope. A 60m rope either reaches or it doesn't why on earth would you need to know the EXACT length. This has to be one of the dumbest questions I have read on here... And that's saying a lot!

I'll take this as option 'd'. :-)


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By Jeff J
From Bozeman
Jun 14, 2013

I go simply look before I leap.
Unless the guide book tells me that an rope of XX meters will reach the ground/next rap station. . . I find the middle of the rope, toss my rope and get ready to rap and ALWAYS check to see is I can see the ends go to a safe point. If not re-think my decent.


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By Allen Corneau
From Houston, TX
Jun 14, 2013

BSheriden wrote:
Wtf is this a serious question? Range finders!? Lol how about just estimating with the rope. A 60m rope either reaches or it doesn't why on earth would you need to know the EXACT length. This has to be one of the dumbest questions I have read on here... And that's saying a lot!



What about folks that have chopped 10 or 20 feet off their rope?

If you just say, "A 60m rope will reach", does that mean a 57m rope will? What about a 55m rope?

I don't think more accurate measurements could be anything other than beneficial. Baring actual measurements a comment like, "60m will reach with 20' to spare" should be good enough.


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By nicelegs
From Denver
Jun 14, 2013

Allen Corneau wrote:
What about folks that have chopped 10 or 20 feet off their rope? If you just say, "A 60m rope will reach", does that mean a 57m rope will? What about a 55m rope? I don't think more accurate measurements could be anything other than beneficial. Baring actual measurements a comment like, "60m will reach with 20' to spare" should be good enough.


No.

Few people have an accurate measurement of the amount they chopped off a rope. They didn't have an exact length when new and they didn't know how much they cut. Your idea of precision is silly.

Can I get down with a 50, 60, or 70? Everything else is just minutia.


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By bearbreeder
Jun 14, 2013

1. find the exact middle ... on ropes you dont know do this the old fashioned way

2. if yr uncertain ... tie knots at the end ... or at the very least make sure you keep a fcukang eye on em and dont go zooming down like the road runner being chased by a coyote

3. learn and practice how to reascend a rap .

thats all there is to it folks ;)


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By DannyUncanny
From Vancouver
Jun 14, 2013

BSheriden wrote:
Wtf is this a serious question? Range finders!? Lol how about just estimating with the rope. A 60m rope either reaches or it doesn't why on earth would you need to know the EXACT length. This has to be one of the dumbest questions I have read on here... And that's saying a lot!


I recall quite a few raps in Potrero Chico where our "60 m" would only get to the next rap station if the heaviest person went to the very end (with knots) and flipped upside down to reach the next anchors. Whoever bolted the routes simply bolted the full length of their rope which was a bit longer than our rope.


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By John Wilder
From Las Vegas, NV
Jun 14, 2013

Allen Corneau wrote:
What about folks that have chopped 10 or 20 feet off their rope? If you just say, "A 60m rope will reach", does that mean a 57m rope will? What about a 55m rope? I don't think more accurate measurements could be anything other than beneficial. Baring actual measurements a comment like, "60m will reach with 20' to spare" should be good enough.


Yeah, but how long was their 60m rope in the first place? All manufacturers cut long to accomodate rope shrinkage (all ropes shrink with age). And all manufacturers cut differently, sometimes even in the same brand!

Basically, you cannot really know with any true certainty how long the rope you are climbing on is- only that it is roughly 60m (or 70m or whatever).

The example of Potrero is a good one- Levitation 29 and Crimson are both another- those routes can be rappelled with newish 70m lines (max length, probably 72-73m). If you have an old 70m (69m-ish), you may come up short on one or two of the rappels.

YMMV, as always!


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By Bill Lawry
From New Mexico
Jun 14, 2013

bearbreeder wrote:
3. learn and practice how to reascend a rap

+1


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By Greg G
From SLC, UT
Jun 14, 2013
The route in it's entirety.

One thing that irk's me is how Rap's aren't measured in METERS. Why would you list a rappel in Feet when our ropes are measured in Meters?! Obviously after years of climbing and rappelling we've all learned to guesstimate rap lengths, and convert. But that still irks me.


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By Greg D
From Here
Jun 14, 2013
Out of the blue.  Photo by Mike W. <br />

Funny question!

The more precisely someone tries to publish the distance, the more accurately they need to be in their estimate. Or we could say a 60 meter rope just barely works if you weigh more than 190 and your rope's static elongation is greater than 9% and you have 18 lbs of gear and you are in a high gravity area, ad infinitum.

OR

Take responsibility for yourself. All published info is merely a suggestion. Look before you leap!


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By Buff Johnson
Jun 14, 2013
smiley face

My raps are typically 6.342x10^-15 light years,

or 1.944x10^-15 parsecs, if that makes it simpler.


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By Mike Mooney
Jun 14, 2013

Hi Bill,
I'd like to know distance so I don't go 10 meters past with my 70 m rope.


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By Guy Keesee
From Moorpark, CA
Jun 14, 2013
Big Boulder, just a bit downhill from Temple of Kali. Alabama Hills, CA.

Funny Question....

As long as they go to the next station, what difference does it make.

The REAL question is this: What to do when they don't reach????


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By Colonel Mustard
From Reno, NV
Jun 14, 2013
Colonel Mustard

Mike Mooney wrote:
Hi Bill, I'd like to know distance so I don't go 10 meters past with my 70 m rope.


Wouldn't you only go 5 meters past with a 70m rope?

I see your point though.


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By Old and Busted
From Centennial, CO
Jun 14, 2013
Stabby

I go to Google Earth, drop down to ground view, bring up the sideways view of the crag, then use the line/distance app.


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By s.price
From PS,CO
Jun 14, 2013
 Morning Dew ,self portrait

Mike Lane wrote:
I go to Google Earth, drop down to ground view, bring up the sideways view of the crag, then use the line/distance app.


I thought I was the only one who did that. How ya doin Mike?


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By Bill Lawry
From New Mexico
Jun 14, 2013

Mike Mooney wrote:
Hi Bill, I'd like to know distance so I don't go 10 meters past with my 70 m rope.


Hi Mike, I'd considered rallying folks to require land owners enforce a 24 +/- 1 meter distance between raps ... or maybe with the longer ropes these days that should be 34 +/-1 meter. But I'm worried its a hostile crowd here. Bill (good to hear from you)


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By Old and Busted
From Centennial, CO
Jun 14, 2013
Stabby

s.price wrote:
I thought I was the only one who did that. How ya doin Mike?

I seem to keep rapping off the end of my rope. Don't know why. How's your whiskey coming along?


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By VerticalUrge
Jun 15, 2013

post should be be retitled "Estimating vs. Measuring DBs on MP". I would have estimated a lot less, but since some of ya'll have left it without question, the measurement will proabably come out a little higher than originally thought.

Who cares if the OP is curious about this? If its such a ridiculous question, don't post up.

I usually just estimate the amount of rope I used to rappel and tell friends what length ropes will get them down (i.e. if they had a 60m, but cut 10m off and rappel requires 60m, they will not make it down). If they don't understand the idea that cutting off x length of rope makes their former 60m rope a now 60m-x rope, they probably deserve to rap off the ends.


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By Ellenore Zimmerman
Jun 15, 2013
me

I rely on beta provided in the guide book , or that I collect at the base of the crag by talking to other climbers or eye estimating the route. Lately we have been climbing a lot with 60 m twins which makes it easier to rap a route in general. For longer routes or for routes with a lot of rope eating flakes and or trees it's adviseable to use a single rope rap. I tie an autoblock and a knot at the end of both rope ends to go down first as I scout for rap stations and/or trees. Rope is marked in the middle of course. In case of an "overshot" I ascend the rope using the autoblock for in search of better rap options.


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By David Appelhans
From Lafayette
Jun 15, 2013
Imaginate

craghead wrote:
I rely on beta provided in the guide book , or that I collect at the base of the crag by talking to other climbers or eye estimating the route. Lately we have been climbing a lot with 60 m twins which makes it easier to rap a route in general. For longer routes or for routes with a lot of rope eating flakes and or trees it's adviseable to use a single rope rap. I tie an autoblock and a knot at the end of both rope ends to go down first as I scout for rap stations and/or trees. Rope is marked in the middle of course. In case of an "overshot" I ascend the rope using the autoblock for in search of better rap options.


Thank you for answering a question that wasn't asked. So glad you could join us elanor.


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By Ellenore Zimmerman
Jun 15, 2013
me

Letting the leader know " half way" is also one of the methods in anticipation of potential rap route. I don't per say " measure it" . Climbing is an applied science and a lot of things are going on in leader's and belayer's heads from start to finish. That said, planning for rap vs walk off / retreat starts from the getgo, and adding another gaget to the system is not feasable.


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By Bill Lawry
From New Mexico
Jun 15, 2013

A couple of clarifications: I wasn't serious about mandating all rappel distances to be 34 +/- 1 meter. And I'm totally on-board with using your head about rappelling and assuming the responsibility to deal with coming up short one day.


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