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Thread: Judging Height and Distance

  1. #1

    Judging Height and Distance

    Just curious if anybody knows of any type of electronic measuring device that can measure height and distance. I know hunters use some sort of range finder to measure distance laterally, but is there something that could measure distance vertically? Say you are Dennis Turville in Heaps Canyon in 1978 and you come to the end and want to know exactly how far it is to the ground, but you don't want to pull out your rope and try to measure it the hard way. What the hell is out there on the market today to complete the task? I know if you are Dennis, you are SOL as far as technology goes in 1978.

    Reedus

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  3. #2

  4. #3
    I had an epiphany. The range finder would do the job quite well. You would just have to compute the Pythagoreum equation to get an accurate height measurment. Measure the hypotenuse to the top of the drop from where you are standing. Then measure the distance to the base of the drop from where you are standing. Hypotenuse squared minus the base squared equals the square root of the height of the drop. If you were at the top, a simple shot of the laser to the ground would put you in the ballpark. Now, is it worth the money to spend on one. Probably not if its sole intent is canyoneering.

    Reedus

  5. #4
    How about just using a rock and a stop watch. Toss a small rock off the top of the cliff and time it......

    Gravity is 32 ft/sec here on good ol mother earth. It will only fall 16' the first second because it has to accelerate...... we had to do this in High School Physics and you can estimate to within a couple of feet if you use a little bit of care.

    Dang..... smart and good looking..... who would have thought........

  6. #5
    Good thinking on the Pythagorean Equation. Your Math 1010 teacher would be proud

    I've found that my height judgment has gotten better as I've done more and more rappels and taken note of how high they are vs. how high they look. Its surprising how bad a judge of height we are sometimes. I'm still not very good at it, but at least I can call my friends when they say they "jumped off an 80 foot cliff" and show me the pictures of the 40 foot cliff to prove it.

    I went canyoneering with a couple guys who had done a betaless canyon in powell with a huge drop at the end on their second descent of the canyon. First time down, they had no idea exactly how high the drop was (ended up being about 280 feet if I remember right) or how far back from the drop they would be able to build an anchor. They ended up carrying a BUNCH of extra rope through the canyon, not sure how much, I want to say 800 feet total or so between the two of them. The second time through was much more relaxed and fun since they new exactly what gear they needed, and they could bask in the glory of showing their friends their sweet find. Doing new canyons is serious business, ask Shane, Scott, Jason, Ram, etc.... I've done a few, and its been fun, but very serious. Nothing like doing a canyon where you basically know where you're up against beforehand.

    I was reading one of the Canyoneering books by S. Allen a few days ago (he's the Chuck Norris of canyoneering-- he does several thousand new canyons every month ) In his chapter on tech. canyons, he emphasizes the principles of Escapability and Reversability when doing a new technical canyon. Being the first time I'd really heard of this, some of you might find it interesting or useful. The point was: on an unknown canyon, if you can't escape the route and you haven't left ropes to reverse it, you are taking a big chance... one that he supposedly doesn't often take. Basically the approach is to scout the rim for escape routes and verify them when you get to them in the canyon. Between escape routes, you leave a rope at each drop so you can reverse the route if you hit an impossible obstacle of some sort. Once you complete a section, you go through again and clean your ropes and move on to the next section. Takes a lot of rope and a lot of time. Due to its impracticality, some people don't follow Allen's system all the time and prefer to scout it out as best they can, load up for bear, and take what comes. It seems they occasionally get bitten in the butt by it with a scary escape (Sandthrax, Alcatraz), or an uncomfortable bivy (Psycho D.). Either way you go, it takes a much bigger toolbox (both skills and gear and balls) to do new routes than established ones.

  7. #6
    Quote Originally Posted by Iceaxe
    How about just using a rock and a stop watch. Toss a small rock off the top of the cliff and time it......

    Actually, I used this method to determine the height of a cliff that to guys were dropping in wolverine cirque. I was skiing with Bob Athey and some others about to ski figure 8 hill. We looked up to a cliff band on northwest ridge of the cirque where two guys were smoothing out a ramp and two others were setting up for some photo/video. Bob thought the cliff was maybe 60-70 feet. Another thought 150.

    We ate lunch and waited till they went.

    One guy timed it with a stop watch.
    the two guys dropped it pulling iron crosses and made two enormous bomb holes. sure was impressive...

    ANYWAY....the guy felt *pretty* accurate on the stopwatch and he measured about 3 seconds.

    if you do the physics....3 seconds is about 144 feet. at least it gives an order of magnitude estimate.

    we found out later that a year earlier this was first jumped by jamie pierre and it has been dubbed 160ft cliff.


    stefan

  8. #7
    Allen's method of always fixing an escape is referred to a "Siege Style". Its a common practice on big walls or big mountains. Everest is climbed using siege tactics where they build base camps up the mountain...... the other method of light, fast and relaying on your skill is called "Alpine Style".

    Talk about loading up for bear.... the first time we did Zero-G it was alpine style and without beta. In addition to a ton of gear we were also carrying 600' of rope. Those who have done the route now know that it can be done without a rope by a skilled climber or a 60' rope by all others.


    .

  9. #8
    600 feet of rope in Zero G...
    "The worst enemy that the Negro has is the white man that runs around here drooling at the mouth, professing to love Negros and calling himself a liberal." -Malcolm X

  10. #9
    Yeah, orginally we only had 400', but we tossed in an extra 200' at the last minute just to be safe

  11. #10
    Thanks for the Physics lesson Ice. Does it matter how heavy the object is that you throw? I know that gravity acts the same on all objects, but a feather isn't going to drop at the same rate as a bowling ball. Do you have to take into account the weight of the object? Damn it, I knew I should have taken that physics class in highschool. How would you guesstimate the distance of a cliff from the bottom?

    Reedus

  12. #11
    For example: Never having been here before, what techniques could be used to assess the height of this waterfall without hiking to the top and throwing rocks off?
    Attached Images Attached Images  

  13. #12
    Well duh! That one's easy! It's Heaps, so it's ~300 feet!

    Seriously though, I think your rangefinder idea to get horizontal distances to the top and bottom of the drop, then calculate the vertical distance using Pythagorean Theorem is probably the best idea. Rock_Ski also made a good point when he said that after awhile you just develop an eye for distances, and can guesstimate them pretty good.
    "The worst enemy that the Negro has is the white man that runs around here drooling at the mouth, professing to love Negros and calling himself a liberal." -Malcolm X

  14. #13
    Quote Originally Posted by Reedus
    Thanks for the Physics lesson Ice. Does it matter how heavy the object is that you throw? I know that gravity acts the same on all objects, but a feather isn't going to drop at the same rate as a bowling ball. Do you have to take into account the weight of the object? Damn it, I knew I should have taken that physics class in highschool. How would you guesstimate the distance of a cliff from the bottom?

    Reedus
    I am intrigued by this discussion. Good ideas being shared all around. I can't chime in from a practical application point of view, but I can chime in from a physics point of view.

    Regarding the rock drop from the top. Any rock will do. The mass (weight) of the rock does not really matter, but a more substantial rock would likely be easier to hear at the bottom. All objects, feathers, pennies and rocks, accelerate to the earth due to gravity at 32.2 ft/s^2. The only thing that changes this is the drag due to air. Round rocks should generally have the same drag. The height in feet) is equal to 16.1 times the drop time squared (in seconds). y=(1/2)*(32.2)*(t)^2

    How to estimate the height from the botton. A little trigonometry should work. You would first measure an angle to the top of the rim using a sextant or other angle measuring tool. Then pace of the distance from where you measured the angle to the base of the cliff. The height in ft will be the number of feet to the base of the cliff times the tangent of the angle you just measured plus your height. y=x*Tan(theta)+height

    Here is a homemade sextant. http://www.tecepe.com.br/nav/CDSextantProject.htm

  15. #14
    When dropping an object all sorts of other factors come into play, mostly air resistance. But if you use a golf ball size rock you can just use the Distance Equation found here.

    http://www.school-for-champions.com/...vity_earth.htm

    From the bottom you could actually use trig if you had a tape measure and a cheap protractor to measure the angle. You could use your climbing rope as the tape if you know its true length. I bet I could guess within a couple of feet with a climbing rope and a $3 protractor.


  16. #15
    Here's another idea. You could take a picture of the drop you want to measure, with someone standing at the base of the drop. If you know the height of the person standing at the base, you can calculate the total height of the drop by scaling the height of the drop versus the height of your buddy in the photo. This will require a photo that includes the entire length of the drop however, which would be very difficult in the case of Heaps.
    "The worst enemy that the Negro has is the white man that runs around here drooling at the mouth, professing to love Negros and calling himself a liberal." -Malcolm X

  17. #16
    Quote Originally Posted by hike2kolob
    How to estimate the height from the botton. A little trigonometry should work. You would first measure an angle to the top of the rim using a sextant or other angle measureing tool. Then pace of the distance from where you measured the angle to the base of the cliff. The height in ft will be the number of feet to the base of the cliff times the tangent of the angle you just measured plus your height. y=x*Tan(theta)+height

    Here is a homemade sextant. http://www.tecepe.com.br/nav/CDSextantProject.htm
    That's another great idea.
    "The worst enemy that the Negro has is the white man that runs around here drooling at the mouth, professing to love Negros and calling himself a liberal." -Malcolm X

  18. #17
    I'm just laughing thinking about the kid in class who asked the teacher..... "But, when will we ever use this stuff in real life?"

    And not only that, but these are story problems

  19. #18
    Quote Originally Posted by Iceaxe
    I'm just laughing thinking about the kid in class who asked the teacher..... "But, when will we ever use this stuff in real life?"

    And not only that, but these are story problems
    I used to hate story problems. Now I eat em for breakfast!
    "The worst enemy that the Negro has is the white man that runs around here drooling at the mouth, professing to love Negros and calling himself a liberal." -Malcolm X

  20. #19
    Think I will hold off on the range finder. Thinking is cheaper

  21. #20
    Anther method..... practice on things you know..... or take a guess before you deploy the rope and then see how accurate you are. With some practice you can get really good.

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