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Estimating vs. Measuring Rap Distances

Original Post
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812

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. :-)

William Sonoma · · Unknown Hometown · Joined Dec 2012 · Points: 3,550

" 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.

BSheriden · · Unknown Hometown · Joined May 2013 · Points: 0

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!

Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
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'. :-)
Jeff Johnston · · Bozeman, MT · Joined Sep 2010 · Points: 110

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.

Allen Corneau · · Houston, TX · Joined May 2008 · Points: 80
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.
highaltitudeflatulentexpulsion · · Colorado · Joined Oct 2012 · Points: 35
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.
bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065

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 ;)

DannyUncanny · · Vancouver · Joined Aug 2010 · Points: 100
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.
Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
bearbreeder wrote:3. learn and practice how to reascend a rap
+1
Greg Gavin · · SLC, UT · Joined Oct 2008 · Points: 888

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.

Greg D · · Here · Joined Apr 2006 · Points: 883

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!

Buff Johnson · · Unknown Hometown · Joined Dec 2005 · Points: 1,145

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

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

Mike Mooney · · Silverthorne, CO · Joined Mar 2006 · Points: 0

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

Guy Keesee · · Moorpark, CA · Joined Mar 2008 · Points: 349

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????

Colonel Mustard · · Sacramento, CA · Joined Sep 2005 · Points: 1,241
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.
Mike Lane · · AnCapistan · Joined Jan 2006 · Points: 880

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

Bill Lawry · · Albuquerque, NM · Joined Apr 2006 · Points: 1,812
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)
Mike Lane · · AnCapistan · Joined Jan 2006 · Points: 880
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?
fluff head · · Unknown Hometown · Joined Sep 2011 · Points: 65

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.

Ellenore Zimmerman · · Unknown Hometown · Joined May 2013 · Points: 75

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.

Guideline #1: Don't be a jerk.

General Climbing
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