Maximum length for climbing ropes
Kedamono
I'm working on a story, that involves the characters trying to climb into
a largish chamber: one mile tall, and the sides are very, far away, over
500 feet away, and smooth as glass. They need to descend to the bottom of
this chamber, and I don't know if convential climbing rope would be able
to support their weight.
They are at this location, with their normal gear, which would include top
of the line climbing ropes. But, as I said, they will have to do the
entire climb on a rope, with no place to further support their lines, and
have to do the entire one mile climb down with the rope only supported at
the top.
Is it possible?
--
The Kedamono Dragon | The "Anthill Inside" Page is at:
Keda...@concentric.net | http://www.concentric.net/~kedamono
Keda...@aol.com |
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Hal Fred Murray
In article <kedamono-270...@cnc096072.concentric.net>, keda...@concentric.net (Kedamono) writes:
[snip - wants to rappel 1 mile with no intermediate anchors ]
> Is it possible?
Climbing ropes weight about 7 pounds for 150 feet. 5000 ft would
require 33 ropes. That's only 231 pounds. No problem, at least
as far as rope strength is concerned.
I believe some crazy cavers have actually rappelled off the top of
El Cap. That's ~3000 ft.
Mike Faff
keda...@concentric.net (Kedamono) wrote:
>I'm working on a story, that involves the characters trying to climb into
>a largish chamber: one mile tall, and the sides are very, far away, over
>500 feet away, and smooth as glass. They need to descend to the bottom of
>this chamber, and I don't know if convential climbing rope would be able
>to support their weight.
>They are at this location, with their normal gear, which would include top
>of the line climbing ropes. But, as I said, they will have to do the
>entire climb on a rope, with no place to further support their lines, and
>have to do the entire one mile climb down with the rope only supported at
>the top.
are they actually going to climb anything here? sounds like just one
huge rappel. If thats what you want, I know some cavers who use 1000+
foot static ropes for huge rappels. I guess a climbing rope might
work, but I don't think you want to immagine the price of 5000 ft of
dynaminc rope.
--
Mike Faff
gt0...@prism.gatech.edu
http://www.prism.gatech.edu/~gt0743b/
Tony Bubb
> I'm working on a story, that involves the characters trying to climb into
> a largish chamber: one mile tall, and the sides are very, far away, over
> 500 feet away, and smooth as glass. They need to descend to the bottom of
> this chamber, and I don't know if convential climbing rope would be able
> to support their weight.
>
> They are at this location, with their normal gear, which would include top
> of the line climbing ropes. But, as I said, they will have to do the
> entire climb on a rope, with no place to further support their lines, and
> have to do the entire one mile climb down with the rope only supported at
> the top.
>
Rope drag would be a Bitch.
-T.
Chris Weaver
Hal Fred Murray wrote:
> Climbing ropes weight about 7 pounds for 150 feet. 5000 ft would
> require 33 ropes. That's only 231 pounds. No problem, at least
> as far as rope strength is concerned.
Which brings up another question: How the hell do you rap on a rope that heavy?
I've had a hard time on some 200 foot rapells with actually pulling the rope up
to be able to get it to run through the rap device. To actually descend on a
231 pound rope, you would either need special equipment or a REALLY strong
brake arm!
Chris
--
_____________________________________________________________
/ /|
/ _/_/ _/ _/_/_/_/ _/ _/ _/_/_/_/ _/_/ =)'
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(___________________________________________________________'-----.\ / /
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/\_//
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\\.
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'-'
Erik Max Francis
Kedamono wrote:
> They are at this location, with their normal gear, which would include
> top
> of the line climbing ropes. But, as I said, they will have to do the
> entire climb on a rope, with no place to further support their lines, and
> have to do the entire one mile climb down with the rope only supported at
> the top.
>
> Is it possible?
There are no physics preventing it from being possible. Whether or not the
characters can do it is another question.
--
Erik Max Francis, &tSftDotIotE / email: m...@alcyone.com
Alcyone Systems / web: http://www.alcyone.com/max/
San Jose, California, United States / icbm: 37 20 07 N 121 53 38 W
\
"Gods are born and die, / but the atom endures."
/ (Alexander Chase)
Evan L. Craig
Writer -
The issue you're getting at here is the weight of the rope itself, and the
likelihood that it will break.
Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
trivializes the weight of your characters, I assume, unless they are giants,
which will be a required modification to their attributes if they are to carry
their own rope.
Rope fibers are pretty strong; probably able to bear 30,000 lb per square inch
of cross section. This means it can support around 2,000 lb (I'm assuming a
60% solid volume ratio), INCLUDING ITS OWN WEIGHT. If the rope were kevlar, it
might do twice as well or so. As you can see, the rope would break off in their
hands before your characters even finished lowering it to the floor.
Manufacturers of synthetic fibers (from which rope is made) sometimes quote a
free hanging length, which is this same calculation.
The other consideration is the likelihood that there might be a small flaw in
the rope that would compromise even the best calculated strength of the rope.
The chance that there might be a flaw is predicted by the Weibold distribution,
which essentially says that the longer it is, the greater the chance that it's
no good.
As a far more prictical matter, if you want your characters to actually be able
to AFFORD some low stretch polyester rope for a more modest cavern, they should
whip out their radio modem equipped laptops, and order it from:
http://members.aol.com/grizzgear
at around half the prices they'd pay if they trooped all the way back to the
outfitters. For a modest fee, they could have it delivered before the reader
gets to the end of the story!
Evan
Tony Bubb wrote:
>
> > I'm working on a story, that involves the characters trying to climb into
> > a largish chamber: one mile tall, and the sides are very, far away, over
> > 500 feet away, and smooth as glass. They need to descend to the bottom of
> > this chamber, and I don't know if convential climbing rope would be able
> > to support their weight.
> >
> > They are at this location, with their normal gear, which would include top
> > of the line climbing ropes. But, as I said, they will have to do the
> > entire climb on a rope, with no place to further support their lines, and
> > have to do the entire one mile climb down with the rope only supported at
> > the top.
> >
> > Is it possible?
>
Linus
It's been a slow day at work, so, using the specs for a standard 11mil:
Static breaking strength = 2,200 kg
Weight/m = 72g
So, 1 mile of rope = 133 kg approx, leaving plenty of margin for the climbers +
kit.
Unless I've worked it out wrong it should certainly be possible within the
limits of normal ropes. However, a few points should be borne in mind:
1) There'll be a bitch of a lot of rope drag from having a hundred or so kg
below the rap device, so they'll need to use a special descender such as a
five-bar rack.
2) The amount of heat generated from friction (even with a 5-bar) will mean
rapping very slowly and stopping at regular intervals to allow the device to
cool down.
3) If they're using a dynamic rope it will stretch (approx. 133 metres on the
specs I'm using). This means there will be a lot of bounce on the bottom of the
rope.
4) Not many manufacturers make ropes a mile long as standard, so it would have
to be ordered specially. If so, they might be better off getting something like
7mil spectre which is lighter (approx. 68kg/mile), stronger (breaks at 2,600
kg) and won't stretch as much. The thinner diameter will also make rapping
easier to start with, although they'll have to be more careful with the heat
build-up due to a lower melting point.
I imagine the least realistic point would be that of having a mile long rope
(or 31 normal 60m ropes) but I expect you can find a way round that. Happy
writing!
bs...@umich.edu
Tony Bubb wrote:
>
> > I'm working on a story, that involves the characters trying to climb into
> > a largish chamber: one mile tall, and the sides are very, far away, over
> > 500 feet away, and smooth as glass. They need to descend to the bottom of
> > this chamber, and I don't know if convential climbing rope would be able
> > to support their weight.
> >
> > They are at this location, with their normal gear, which would include top
> > of the line climbing ropes. But, as I said, they will have to do the
> > entire climb on a rope, with no place to further support their lines, and
> > have to do the entire one mile climb down with the rope only supported at
> > the top.
> >
> > Is it possible?
>
> Rope drag would be a Bitch.
>
> -T.
Need to use a sticht plate or other belay plate for such a long rappel.
Bill
Mike Faff
"Evan L. Craig" <a...@interaccess.com> wrote:
>Writer -
>The issue you're getting at here is the weight of the rope itself, and the
>likelihood that it will break.
>Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
>weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
>trivializes the weight of your characters, I assume, unless they are giants,
>which will be a required modification to their attributes if they are to carry
>their own rope.
hmmm.... I think you screwed up in your calculations. if 10mm REALLY
DID weigh 1.3 lb/ft then my 50M rope would weigh about 150 lbs. I
don't think it is quite that heavy.
Mike Faff
Chris Weaver <cwe...@erols.com> wrote:
>Hal Fred Murray wrote:
>> Climbing ropes weight about 7 pounds for 150 feet. 5000 ft would
>> require 33 ropes. That's only 231 pounds. No problem, at least
>> as far as rope strength is concerned.
>Which brings up another question: How the hell do you rap on a rope that heavy?
>I've had a hard time on some 200 foot rapells with actually pulling the rope up
>to be able to get it to run through the rap device. To actually descend on a
>231 pound rope, you would either need special equipment or a REALLY strong
>brake arm!
yeah a rappel rack... seen them used for _long_ raps. But they are
kinda pointless for short (~50 M) raps.
George Bell
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
> weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb.
Yikes, I hope you never plan an expedition!! Rope weight in pounds per
cubic inch?? What do you measure your walking speed in, light years
per fortnight?? ;-)
The mile vertical span is doable, no question.
A harder and much more interesting question is this:
Is any rope (or cable) strong and light enough to "suspend" it from a satellite
in earth orbit so that it would reach the ground, allowing astronaut/climbers
to "jumar into space"?? What is the requirement for this rope, some
minimum tensile strength divided by weight per meter??
A great subject for a SF book - too bad Arthur C. Clarke already beat us to it.
-George
Robert Ternes
In article <32EE5F...@interaccess.com>,#Writer -
#
#The issue you're getting at here is the weight of the rope itself, and the
#likelihood that it will break.
#
#Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
#weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
#trivializes the weight of your characters, I assume, unless they are giants,
#which will be a required modification to their attributes if they are to
*SNIP*
Are you INSANE???? Napping in front of the ION SHIELD???? Man, PAINT CHIPS
aren't the same as TOSTITOS!!!! 1.3 lb per FOOT? Man, get a clue. That means
that the average 165 foot climbing rope would weigh around 200 pounds.
Consider this: my first climbing rope (a BURLY 11mil) weighed in at a
relatively HEFTY 72 grams per meter. that's around 3 oz.
Do you know that if you spout a bunch of meaningless numbers, 75% of the time
over 80% of people will beleive you.
Robert "It's called dyscalcula, and 20% of the population who live within .3
miles of power lines have it" Ternes
rte...@u.arizona.edu
Nate
Hal Fred Murray wrote:
> I believe some crazy cavers have actually rappelled off the top of
> El Cap. That's ~3000 ft.
Right off the Dawn wall. Rope didn't touch the whole way. Few deaths
over the years from this annual event. One guy lost control - rope cut
off some body parts. His face was a big "flapper" according to a friend
on SAR who bagged him. Pretty wild.
--
Nathanial Beckwith - Boulder, CO
http://www.tc.umn.edu/nlhome/g032/beckw007/
George Bell
In article <32EE1F...@erols.com>, Chris Weaver <cwe...@erols.com> writes:
> Hal Fred Murray wrote:
> > Climbing ropes weight about 7 pounds for 150 feet. 5000 ft would
> > require 33 ropes. That's only 231 pounds. No problem, at least
> > as far as rope strength is concerned.
>
> Which brings up another question: How the hell do you rap on a rope that heavy?
> I've had a hard time on some 200 foot rapells with actually pulling the rope up
> to be able to get it to run through the rap device. To actually descend on a
> 231 pound rope, you would either need special equipment or a REALLY strong
> brake arm!
You need a special rap device to be able to move down at all
at the top. That's why "professional" rapellers use these
special devices with lots of bars for rapping - they allow you to vary
the friction. Aren't they called bar tacks or something??
Basically your first problem is pulling up the 231 pound rope, probably
need a bunch of extra people for that!! Then you have the problem of
moving down at all, hopefully you set your rap device with low enough friction
to accomplish it. The final and most serious problem is that the friction
decreases as you descend, because the rope weight below you decreases.
If you are not careful you'll get out of control like that guy who
died rapping El Cap some years ago.
-George
Climbnjump
where did this guy get his specs on rope?
cartoonland?
i was'nt aware my 10.5 60m rope weighed
260 pounds.......geez, and he sounded like he actually
knew what he was talking about.
Chuck Spiekerman
"Evan L. Craig" <a...@interaccess.com> wrote
>Writer -
>
>The issue you're getting at here is the weight of the rope itself, and the
>likelihood that it will break.
>
>Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
>weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb.
So let's see...my rope is 165 feet long (10.5 mm) so according to this
formula it weighs...let's see...1.3 X 165 = 214.5! More than 214.5 lbs!!!!
No wonder those approaches seem so long. No wonder it's so hard to pull
up the rope to clip.
(I think you've made a mistake somewhere Evan)
Chuck
Christopher C. Lamb
Kedamono wrote:
>
> I'm working on a story, that involves the characters trying to climb into
> a largish chamber: one mile tall, and the sides are very, far away, over
> 500 feet away, and smooth as glass. They need to descend to the bottom of
> this chamber, and I don't know if convential climbing rope would be able
> to support their weight.
>
> They are at this location, with their normal gear, which would include top
> of the line climbing ropes. But, as I said, they will have to do the
> entire climb on a rope, with no place to further support their lines, and
> have to do the entire one mile climb down with the rope only supported at
> the top.
>
> Is it possible?
>
> The Kedamono Dragon | The "Anthill Inside" Page is at:
> Keda...@concentric.net | http://www.concentric.net/~kedamono
> Keda...@aol.com |
> ---------------------------------------------------------------------
> Take a look at the Alternate History Travel Guides! | Ook!
> http://users.aol.com/kedamono/sliders/alterguides.html | Gleep!
> ---------------------------------------------------------------------
> All shall quail before me! For I am the Mentos! The Freshmaker!
Nope. Not with only one anchor. Ropes just aren't that long.
--
Christopher C. Lamb
cl...@mrcabq.com
Andrew Gale
Evan L. Craig wrote:
>
> Writer -
>
> The issue you're getting at here is the weight of the rope itself, and the
> likelihood that it will break.
>
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
> trivializes the weight of your characters, I assume, unless they are giants,
> their own rope.
If you thought about this for a minute it would be obvious that your
math is incorrect here. You are saying that a standard 50 meter climbing rope
(165 feet) would weigh 214.5 pounds (1.3 lb/ft) obviously this is not the case.
:)
Andy
--
*******************************************************
Andrew Gale The Scripps Research Institute
ag...@scripps.edu La Jolla, CA
**********http://minihelix.mit.edu/andy/ ***************
John Glick
Evan L. Craig wrote:
>
> Writer -
>
> The issue you're getting at here is the weight of the rope itself, and the
> likelihood that it will break.
>
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
> weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
Yeah, and my 50m climbing rope weighs 1.3 lb/ft X 165ft = 214.5 lbs.
BZZZZZZ!
Thank you for playing evan, we have some really nice prizes for you
anyway...
:)
John
Kedamono
Information overload! Thanks everybody! I thought I might get one or two
responses, but Oy! I'll doublecheck everything, so I get it right.
Anyway, I got more questions: a 5000' rope is right out, I take it, so
then the characters will have to splice/tie together multiple standard
ropes to do the climb. No straight rapelling, but cruise, bump, slip over
knot, cruise, bump, repeat. How dangerous will it be to move over the knot
in the line?
Now, what if these jokers don't all use the same type of line?
I'm assuming people who have some knowledge of climbing, but have
different tastes. So some have 11mil and some have 7mil lines, say 60/40.
Bad idea? or is it doable?
Drop the mix of rope, let them be smart, and use the same type, but the
ropes are at different ages and levels of wear and tear. Do I want the
cruddiest ropes at the bottom, or not use them at all if there is a
choice?
Somebody mentioned that the rope will stretch, which I knew already, but
by how much, 50', 100', or more feet?
Now the hard part, climbing back up. Estimate of time? All day? Couple of
hours? Potty breaks? (let it fly and watch out below?) And since no hole
in a collapsed roof is perfect, what can they do to keep the rope from
fraying along the edge? Lay down some mats, wood, or other methods of
"smoothing out" the rough edge. The estimate of the edge is a fine cheese
grater in spots, in others standard broken rock.
Thanks again, in advance!
Hal Murray
In article <kedamono-280...@cnc096070.concentric.net>, keda...@concentric.net (Kedamono) writes:
>
> Information overload! Thanks everybody! I thought I might get one or two
> responses, but Oy! I'll doublecheck everything, so I get it right.
[many more questions snipped]
Climbers generally have more sense than to do monster rappels. You want
to get in touch with cavers. They publish a pretty good book. I think
that "On Rope" is the title. It probably has more than you want to know.
I'm sure there are others too.
David...@cern.ch
In article <32EE5F...@interaccess.com> "Evan L. Craig"
> Writer -
>
> The issue you're getting at here is the weight of the rope itself, and
the
> likelihood that it will break.
>
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope
therefore
> weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb.,
which
This is clearly nonsense. A 45 metre (150 foot) rope does not way
200 pounds! Calculators have destroyed the school system. They seem
to give such impressively accurate results that people no longer stop
and ask themselves if the numbers make any sense...
David M.
==========================================================================
Dr. D.R. Myers, Tel: +41 22 7674646
ECP Division, CERN, Fax: +41 22 7674400
CH-1211 Geneva 23, Switzerland. EMail: David...@cern.ch
==========================================================================
M.R. Hartley
>A harder and much more interesting question is this:
>Is any rope (or cable) strong and light enough to "suspend" it from a satellite
>in earth orbit so that it would reach the ground, allowing astronaut/climbers
>to "jumar into space"?? What is the requirement for this rope, some
>minimum tensile strength divided by weight per meter??
The satellite would have to be in a perfect geostationary orbit before you
started, and then as soon as you attached the rope you would drag the
satellite out of this orbit (unless the rope was massless and infinitely thin
to avoid drag on the atmosphere). Even if you could attach the rope, you'd
have to jumar pretty damn quick to get into space before the satellite got
down to you.....
Matt
Guy R. Thomas
Evan L. Craig wrote:
>
> Writer -
>
> The issue you're getting at here is the weight of the rope itself, and the
> likelihood that it will break.
>
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
> weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
> which will be a required modification to their attributes if they are to carry>
Edelrid 11mm Perfect-MD dry
72g/m or 115.2 kg for 1.6 kn about 120 kg per mile or about 250 lb/mile
Mammut 10mm Galaxy dry
64g/m or 102kg.4 kg for 1.6km about 105kg per mile or about 225 lb/mile
But that is a dynamic rope. I have no info on static ropes.
Also no info on what lengths are available ( other than standard climbing lengths
like 50 55 and 60 m).
Mike Faff
keda...@concentric.net (Kedamono) wrote:
>Anyway, I got more questions: a 5000' rope is right out, I take it, so
>then the characters will have to splice/tie together multiple standard
>ropes to do the climb. No straight rapelling, but cruise, bump, slip over
>knot, cruise, bump, repeat. How dangerous will it be to move over the knot
>in the line?
I think you could buy a 5000' rope. You would have to special order
it and it would take quite a while to arrive. But you should still be
able to buy one.
>Somebody mentioned that the rope will stretch, which I knew already, but
>by how much, 50', 100', or more feet?
the streching rope part was primarialy from dynamic climbing rope.
Which would stretch a lot. If you had static (non-stretchy) rope. It
would still stretch, but not that much.
>Now the hard part, climbing back up. Estimate of time? All day? Couple of
>hours? Potty breaks? (let it fly and watch out below?) And since no hole
>in a collapsed roof is perfect, what can they do to keep the rope from
>fraying along the edge? Lay down some mats, wood, or other methods of
>"smoothing out" the rough edge. The estimate of the edge is a fine cheese
>grater in spots, in others standard broken rock.
climbing up with ascenders would take a long time, but you could
always sit back in the harness and rest for a while.
yes, using straw mats would be a good idea to help protect the rope.
Tony Bubb
Kedamono wrote:
>
> Information overload! Thanks everybody! I thought I might get one or two
> responses, but Oy! I'll doublecheck everything, so I get it right.
>
> then the characters will have to splice/tie together multiple standard
> ropes to do the climb. No straight rapelling, but cruise, bump, slip over
> knot, cruise, bump, repeat. How dangerous will it be to move over the knot
> in the line?
>
>
> I'm assuming people who have some knowledge of climbing, but have
> different tastes. So some have 11mil and some have 7mil lines, say 60/40.
> Bad idea? or is it doable?
>
> Drop the mix of rope, let them be smart, and use the same type, but the
> ropes are at different ages and levels of wear and tear. Do I want the
> cruddiest ropes at the bottom, or not use them at all if there is a
> choice?
>
> by how much, 50', 100', or more feet?
>
> hours? Potty breaks? (let it fly and watch out below?) And since no hole
> in a collapsed roof is perfect, what can they do to keep the rope from
> fraying along the edge? Lay down some mats, wood, or other methods of
> "smoothing out" the rough edge. The estimate of the edge is a fine cheese
> grater in spots, in others standard broken rock.
Well, a kevlar sheath over the edge would stopp from cutting the rope.
Knots can be passed on rap with some time, but certainly not with anyone
on the rope below you.
Ascending will take a day, but everyone can do it at once. CV-ly,
you can handle a foot per second for a short while, so if they're
real athletes... Passing knots while ascending is a small amount
of time. It can be done at a cost of less than 30 seconds.
thin line at the top for reduced friction, thick at the bottom.
old ropes stretch a lot more.
-T.
Tony Bubb
Mike Faff wrote:
>
> keda...@concentric.net (Kedamono) wrote:
>
> >Anyway, I got more questions: a 5000' rope is right out, I take it, so
> >then the characters will have to splice/tie together multiple standard
> >ropes to do the climb. No straight rapelling, but cruise, bump, slip over
> >knot, cruise, bump, repeat. How dangerous will it be to move over the knot
> >in the line?
>
> it and it would take quite a while to arrive. But you should still be
> able to buy one.
Who's packing that monster in?
-T.
Chris Weaver
Kedamono wrote:
> Anyway, I got more questions: a 5000' rope is right out, I take it, so
> then the characters will have to splice/tie together multiple standard
> ropes to do the climb. No straight rapelling, but cruise, bump, slip over
> knot, cruise, bump, repeat. How dangerous will it be to move over the knot
> in the line?
Not dangerous at all if your characters know what they are doing and are
cautious.
> I'm assuming people who have some knowledge of climbing, but have
> different tastes. So some have 11mil and some have 7mil lines, say 60/40.
> Bad idea? or is it doable?
Doable, but rapelling on a single 7 mil will usually require a different
device or configuration for the rapell, as there is less friction produced.
> Drop the mix of rope, let them be smart, and use the same type, but the
> ropes are at different ages and levels of wear and tear. Do I want the
> cruddiest ropes at the bottom, or not use them at all if there is a
> choice?
Yes, cruddiest at the bottom. The less time you are hanging on a frayed rope
core, the better. Yes, don't use them at all if there is a choice. (common
sense) By the way: some big wall climbers repair damaged rope sheaths with
duct tape if absolutely necessary - you could write that into the story.
Another way to deal with it is to tie a knot in the rope which isolates the
damaged section so that it takes no weight.
> Somebody mentioned that the rope will stretch, which I knew already, but
> by how much, 50', 100', or more feet?
Let's see: A full length rapell on a 200 foot, 10 mm diameter rope will
probably stretch about 10-20 feet (I think). Use that figure to determine the
stretch of your final rope length. Its possible, I suppose that rope would not
stretch at a logorithmic rate relative to its length, since weight of the
rapeller would be constant. If this were true, rope stretch might not be as
great as if you were to figure it as 5-10% of rope length. Some of our
climber/engineers might enlighten us on this.
> Now the hard part, climbing back up. Estimate of time? All day?
Probably.
> Potty breaks? (let it fly and watch out below?)
Yep. Or bring a big-wall "poop tube." Just dookie into a paper bag, then shove
the bag in the tube. More info available if necessary.
> what can they do to keep the rope from
> fraying along the edge? Lay down some mats, wood, or other methods of
> "smoothing out" the rough edge. The estimate of the edge is a fine cheese
> grater in spots, in others standard broken rock.
Those ideas sound fine. Common sense is all you will need for that
determination. Remember that ropes cut easily when weighted over sharp or
coarse edges.
Are your characters going to climb out the opposite side of this theoretical
room, or out the same side on the original rope? If its the opposite side and
the wall is made of glass or other smooth material, there will be no way to
ascend short of altering the surface with bolts, chipping, etc.
Good luck with your story.
Chris Weaver
Linus
keda...@concentric.net (Kedamono) wrote:
>Anyway, I got more questions: a 5000' rope is right out, I take it, so
>then the characters will have to splice/tie together multiple standard
>ropes to do the climb.
Depends. If the characters knew they were going to need a rope that long they
could probably order one from the manufacturers. Tying 31 standard ropes together
would be a hassle, as well as making the trip less safe. If they ordered direct,
they'd probably also get a bulk-buy discount, cutting down on the cost
>Do I want the cruddiest ropes at the bottom, or not use them at all if there
>is a choice?
Yes and yes.
>Somebody mentioned that the rope will stretch, which I knew already, but
>by how much, 50', 100', or more feet?
The figures for dynamic ropes vary from about 7 to 7.5 percent elongation.
>Now the hard part, climbing back up. Estimate of time? All day? Couple of
>hours?
I'd hate to think, but certainly a long time. I can manage 50m in a couple of
minutes, but I doubt I'd have enough stamina to keep that pace up for a mile.
>Potty breaks? (let it fly and watch out below?)
I think they should use a porta-potty type device. Much nicer than all that waste
flying around loose!
>what can they do to keep the rope from fraying along the edge?
Put something under the rope - old carpet does well, or a FishProds Grain Tamer
(gratuitous commercial reference!)
Damian Smith
> are they actually going to climb anything here? sounds like just one
> huge rappel. If thats what you want, I know some cavers who use 1000+
> foot static ropes for huge rappels. I guess a climbing rope might
> work, but I don't think you want to immagine the price of 5000 ft of
> dynaminc rope.
Nor treading out the slack when prussiking up it.
Damo
Mike Faff
Tony Bubb <bu...@qntm.com> wrote:
>Mike Faff wrote:
>>
>> keda...@concentric.net (Kedamono) wrote:
>>
>> >Anyway, I got more questions: a 5000' rope is right out, I take it, so
>> >then the characters will have to splice/tie together multiple standard
>> >ropes to do the climb. No straight rapelling, but cruise, bump, slip over
>> >knot, cruise, bump, repeat. How dangerous will it be to move over the knot
>> >in the line?
>>
>> I think you could buy a 5000' rope. You would have to special order
>> it and it would take quite a while to arrive. But you should still be
>> able to buy one.
>Who's packing that monster in?
I said buy, not carry. I'll leave that part up to my partner :)
Steve LaSala
In article <kedamono-280...@cnc096070.concentric.net>,
Kedamono <keda...@concentric.net> wrote:
>
>Information overload! Thanks everybody! I thought I might get one or two
>responses, but Oy! I'll doublecheck everything, so I get it right.
>
>then the characters will have to splice/tie together multiple standard
>ropes to do the climb. No straight rapelling, but cruise, bump, slip over
>knot, cruise, bump, repeat. How dangerous will it be to move over the knot
>in the line?
Cavers doing deep pits routinely buy entire spools of uncut rope
from the factory. Certainly multiple hundreds, if not thousands of feet.
A rap device should not slip over a knot. You have to tie off,
remove the device, pass the knot, and get back on. Perhaps a good time to
let the device cool off without melting the nylon rope sheath. Research
some of the fancy Petzl devices, as well; stop, shunt, chest-mounted
ascender.
>Now, what if these jokers don't all use the same type of line?
>
>I'm assuming people who have some knowledge of climbing, but have
>different tastes. So some have 11mil and some have 7mil lines, say 60/40.
>Bad idea? or is it doable?
Possible, if you use the right knots. The 7mm will not be
dynamic.
>Drop the mix of rope, let them be smart, and use the same type, but the
>ropes are at different ages and levels of wear and tear. Do I want the
>cruddiest ropes at the bottom, or not use them at all if there is a
>choice?
Smaller ropes at the top makes for less drag through the device,
smaller at the bottom makes for less weight on the small ropes. Of
course, use the best ropes possible, and the least reliable at the bottom.
>Somebody mentioned that the rope will stretch, which I knew already, but
>by how much, 50', 100', or more feet?
Given as part of the spec of a particular brand and model. Don't
use dynamic ropes for this purpose. Static is much better, for ascending
in particular.
>Now the hard part, climbing back up. Estimate of time? All day? Couple of
>hours? Potty breaks? (let it fly and watch out below?) And since no hole
Bottle (w/funnel for women) or bag, then throw clear, or put in
pack. How many people on the rope at a time? What method of ascent;
prusiks, ascenders, ropewalker? Consider rest time during what is
essentially a couple of thousand squats with a pack on.
>in a collapsed roof is perfect, what can they do to keep the rope from
>fraying along the edge? Lay down some mats, wood, or other methods of
>"smoothing out" the rough edge. The estimate of the edge is a fine cheese
>grater in spots, in others standard broken rock.
Pads, rope "sheaths", edge rollers. Standard SAR or SWAT
equipment. Catalogs exist; try J.Weinel Rescue Equip., somewhere in PA,
or ask your fire department.
Talk with some cavers. And try the following books:
Mountaineering; The Freedom of the Hills - Seattle Mountaineers
Wilderness Search and Rescue - Setnika
On Rope - ????????????????
Steve LaSala
Seattle, WA
George Bell
In article <32EF6E...@qntm.com>, Tony Bubb <bu...@qntm.com> writes:
> > I think you could buy a 5000' rope. You would have to special order
> > it and it would take quite a while to arrive. But you should still be
> > able to buy one.
>
> Who's packing that monster in?
Keep it on a big spool in the back of your van. With the monster, even
El Cap becomes a "one pitch belay off the steering wheel" crag. Course
you would also need a rack big enough to lead 34 pitches in a row. ;-)
-George
Conversation overheard in a climbing store: (no I am not making this up)
Customer: I need an 800 foot long rope.
Employee: What do you need that for?
Customer: Because the guidebook says this climb is 800 ft long.
James R Dunson
In article <5cnm4r$n...@smash.gatech.edu>, gt0...@prism.gatech.edu (Mike
Faff) wrote:
> keda...@concentric.net (Kedamono) wrote:
>
> >Anyway, I got more questions: a 5000' rope is right out, I take it, so
> >then the characters will have to splice/tie together multiple standard
> >ropes to do the climb. No straight rapelling, but cruise, bump, slip over
> >knot, cruise, bump, repeat. How dangerous will it be to move over the knot
> >in the line?
>
> I think you could buy a 5000' rope. You would have to special order
> it and it would take quite a while to arrive. But you should still be
> able to buy one.
I recall from what I believe was from a factual account of an expadition
down one of those amazing jungle sinkhole/caves that they *had* special
ordered an extra long rope, stressing the need for it to be
a single piece, and that they found out quite late in the process
that someone along the line thought that it couldn't be a real
requirement, someone was just specing it because they didn't
know better, and spliced two of the largest semi-standard
reels they had to meet the order. Some similar mishap could
make for good drama.
** James **
--
James R Dunson
jdu...@vt.edu
David Rea
I haven't read _all_ the other responses, so these 2 points might
have been made:
1) Only one person can rappel at a time. Otherwise the
added weight will prevent the upper person/persons from moving.
(Assuming they've found a way around the original problem of
lifting 250 pounds of rope.) Jugging up, though, can be done
simultaneously.
2) They don't have to use dynamic rope. Static rope has
very little stretch. Makes those leader falls hurt, though.
(Kind of like falling on those worn out cables they use in
the Boulder Rock Club!)
--David
Jim Davies
keda...@concentric.net (Kedamono) wrote:
>I'm working on a story, that involves the characters trying to climb into
>a largish chamber: one mile tall, and the sides are very, far away, over
>500 feet away, and smooth as glass. They need to descend to the bottom of
>this chamber, and I don't know if convential climbing rope would be able
>to support their weight.
Wouldn't a parachute be simpler? Getting out again might be tricky, of
course.
Dr Jim Davies
----------------------------------------------
But if ifs were buts and buts were ifs,
we'd all be something or other.
Simon Isbister u
Tony Bubb (bu...@qntm.com) wrote:
:
: Knots can be passed on rap with some time, but certainly not with anyone
: on the rope below you.
That's irrelevant- you can't rap with anyone on the rope below you, so
who cares if you can pass a knot?
:
: old ropes stretch a lot more.
:
Huh? An old rope becomes more dynamic? You just keep telling yourself
that, all the way to the spinal trauma ward.
-simon-
Eric Coomer
In article <5codcs$h...@news.advtech.uswest.com>,
George Bell <be...@uswest.com> wrote:
>
>Keep it on a big spool in the back of your van. With the monster, even
>El Cap becomes a "one pitch belay off the steering wheel" crag. Course
>you would also need a rack big enough to lead 34 pitches in a row. ;-)
Nonsense- just back clean... :)
Cheers
Eric
Garf
Kedamono <keda...@concentric.net> wrote in article
<kedamono-270...@cnc096072.concentric.net>...
> I'm working on a story, that involves the characters trying to climb into
> a largish chamber: one mile tall,
SNIPAGE
>
> Is it possible?
>
> --
> All shall quail before me! For I am the Mentos! The Freshmaker!
>
Ok, I missed the news for one day, came back to 231 messages, and this
severley ridiculous thread.
29 messages about a, I have to admit, fairly interesting question. 9
messages devoted to telling some math wiz that my 50m rope weighs 214.5
lbs. Dead horse flogged, but here I go...
I remember reading a book about some wild-assed cable, and shuttles, and
anchoring a stationary sattelite. Ah, here it is,
Quote from page 14:
"Agreed. The item of interest is a cable recently extruded by Falling Angel
Enterprises. Put as simply as possible, the cable is a strand of
single-crystal iron filaments locked in an epoxy matrix.... It is eight
tenths of a milimeter thick, and fourteen hundred kilometers long."
The Descent of Anansi, Copyright 1982 by Larry Niven and Steven Barnes.
So, if we are talking sci-fi, why don't our heros just manufacture a
similar single-crystal (or single molecular strand for that matter) cable,
attach some funky magnet rappelling device and
go?
I motion that we make a new newsgroup called rec.climbing.sci-fi, and cram
all of this worthless sh*t into it.
Really, I hope Kedamono appreciates us doing his homework for him.
Garf
phil stuart-jones
[ rec.arts.sf.science dropped ]
It appears that George Bell (be...@uswest.com) wrote:
> Keep it on a big spool in the back of your van. With the monster, even
> El Cap becomes a "one pitch belay off the steering wheel" crag. Course
> you would also need a rack big enough to lead 34 pitches in a row. ;-)
Not if you can drive to the top. "I'm sure I can lead this thing if I get
it wired..."
> Conversation overheard in a climbing store: (no I am not making this up)
> Customer: I need an 800 foot long rope.
> Employee: What do you need that for?
> Customer: Because the guidebook says this climb is 800 ft long.
Scary. But I'd have thought they'd be going for a 1600' rope.
Pah! A mere gym route. Where's the fixed grigri? Huh? What do you mean
'I have to put the rope up myself'?!?
phil
* NO COMMERCIAL EMAIL. I pay for ALL email (in AND out); please respect it *
* Any commercial email received by me will be proofread at $NZ100 per line *
* Posting email to this address denotes total acceptance of this condition *
Kedamono
In article <01bc0e5b$13523a20$379685ce@garf>, "Garf" <ga...@sprintmail.com>
wrote:
> Quote from page 14:
>
> "Agreed. The item of interest is a cable recently extruded by Falling Angel
> Enterprises. Put as simply as possible, the cable is a strand of
> single-crystal iron filaments locked in an epoxy matrix.... It is eight
> tenths of a milimeter thick, and fourteen hundred kilometers long."
>
> The Descent of Anansi, Copyright 1982 by Larry Niven and Steven Barnes.
>
>
> So, if we are talking sci-fi, why don't our heros just manufacture a
> similar single-crystal (or single molecular strand for that matter) cable,
> attach some funky magnet rappelling device and
> go?
Well, the story involves finding a largish monument on an alternate
world... Getting to the top shouldn't be a problem, traditional climbing
methods should work, but then they find that the thing's hollow... This is
the reason I'm trying to find out about stringing together multiple ropes
and things like tensile strength, stretch, etc.
>
> I motion that we make a new newsgroup called rec.climbing.sci-fi, and cram
> all of this worthless sh*t into it.
I'm for it, you can throw things into it, like what it would take to climb
a beanstalk cable to the *top*. (If you don't know, a beanstalk cable
would be about 36,000 *miles* long.)
>
> Really, I hope Kedamono appreciates us doing his homework for him.
>
> Garf
I do, I do Garf! And I do want to thank everyone who has contributed to
this thread. I figured I could look up the numbers, but it's not the same
as getting the flavor from people who do it for fun and for a living. At
the very least I'll include a big thank you in my work to you guys. Any
objections to me listing names? (No email addresses, unless I get
permission from you folks first.)
--
The Kedamono Dragon | The "Anthill Inside" Page is at:
Keda...@concentric.net | http://www.concentric.net/~kedamono
Keda...@aol.com |
---------------------------------------------------------------------
Take a look at the Alternate History Travel Guides! | Ook!
http://users.aol.com/kedamono/sliders/alterguides.html | Gleep!
---------------------------------------------------------------------
Brian Davis
alt.caving could answer this question a little easier. Cavers have done
both El Cap, as well as Mt Thor (4000'+?) in (I think) Greenland. They had
a rope special-ordered. They used long rappel racks, and varied the number
of bars on them as they went down (a common practice for long drops).
5000' wouldn't be too much different from this. If they are rappeling over
an edge at the top, however, you'll probably want a 2nd rope rigged at the
lib. While ascending or decending over the lib, you use the short
(therefore light) rope. Below the lip you switch over to the long rope,
and away you go.
Other tricks: to avoid overheating the rappel rack, try a hair-misting
bottle filled with water. You just spray it on the rack to cool it. Used
on long (surface) rappels in Mexico.
Another fun twist to put in your story? If you go too fast, and start
to overheat, you may not want to just stop and cool down. While you
decend, the heat damamge is limited (no one section of the rope is exposed
for more than an instant), but if you stop the rope could be damaged by
steady exposure to the heat. You might have a character that *must* decend
rapidly, to avoid burning through the rope.
Once again, ask on alt.caving - I don't have the copy of the newsletter
that talks about the Mt thor adventure, but somebody there will. The book
"On Rope" might also mention it.
-Brian Davis
Tony Bubb
Simon Isbister u wrote:
>
> Tony Bubb (bu...@qntm.com) wrote:
> :
> : Knots can be passed on rap with some time, but certainly not with anyone
> : on the rope below you.
>
> That's irrelevant- you can't rap with anyone on the rope below you, so
> who cares if you can pass a knot?
You stepped on the wrong dog's tail, Simon. You can rap with someone
below you, and I have, provided you have few enough bars on your rap-
rack. If you can do it with 300lb of rope below you, you can do it
with 300lb of person below you. Now, passing a knot is different.
> :
> : old ropes stretch a lot more.
> :
>
> Huh? An old rope becomes more dynamic? You just keep telling yourself
> that, all the way to the spinal trauma ward.
Simon, Simon, Simon... Did I say more dynamic? No, I did not.
An old rope does stretch a lot more though, STATICALLY. You just
keep arguing that with me, all the way to being burnt to a flaming
crisp. I am not the type to make an assertation without thinking.
Simon, a rope shortens as it wears and relaxes, that shortening comes
right back out when statically weighted. 'Fuzzy' isn't the only reason
why an old rope is a fat rope.
-T.
Tommy the Terrorist
In article <01bc0e5b$13523a20$379685ce@garf> Garf, ga...@sprintmail.com
writes:
>"Agreed. The item of interest is a cable recently extruded by Falling Angel
>Enterprises. Put as simply as possible, the cable is a strand of
>single-crystal iron filaments locked in an epoxy matrix.... It is eight
>tenths of a milimeter thick, and fourteen hundred kilometers long."
Awww, man, you have a bunch of alternate universe adventurers and you
wanna saddle 'em down with this kind of Iron Age technology? ;)
Besides, the length of the rope is really quite irrelevant, as long as
it's long enough... ;)
What I'm imagining for openers is a collection of those buckytubes
recently tested (as someone mentioned on r.a.s.f already) which can hold
2 tons on a millimeter line. This ought to be plenty (though to make it
easy to handle you might want it larger).
Next, we want the bundles of buckytubes to be adorned to be Studly In
Combat. So use some fancy deposition process, and surround the
graphite-like sheets of the buckytube with a region of diamond carbon
isoform, so it resists damage; then react to make a Teflon-like surface
layer to avoid corrosion.
The resulting rope should be ultra-sturdy, resistant to cuts, and
chemically inert. You could heat it up with a rappel, but As Far As I
Know the graphite structure of the buckytubes ought to (?) conduct heat
up and down the rope very easily, and what's more, it is stable to some
ridiculously hot temperature.
But --- a rappel? --- only for neo-primitives! The most important
selling point of any tech-rope is the FEATURES. First and foremost, the
buckytube graphite structure ought to conduct electricity really well up
and down. So with even the crudest sort of electrical interruption
measurement, you should have warning if the rope suffers even a few
nanometers of damage. But a good rope ought to have micropatterned
circuits built in all up and down, after the fashion of archaic silicon
chips, but running on a roller arrangement, and perhaps even based on a
doped carbon/silicon matrix so as to be more conveniently integral to the
structure of the fibers. Such a circuit also should include a fair
number of effectors, of which varicoloured LED's on the micrometer scale
and electromagnetic spindles for fiber manipulation are perhaps most
important. The rope also should work quite well for radio reception and
transmission, especially at very low frequencies. (Convenient for retro
expeditions, like caving and coring). Some of the filaments may be
designed for detachability/spoolability, permitting them to serve as
micrometer-scale extensions to the rope for broadcasting purposes (or as
the basis of a wire transmission network); more usefully, the independent
manipulability of some filaments allows them to store quite a bit of
energy via piezoelectric mechanisms, eliminating the need for external
power storage. Interlayer resolution of high-energy states should allow
the rope to recover a fair amount of power photoelectrically as well.
The significant advantages of such a rope should include (but are by no
means limited to - ask the sales brochure for more information) such
conveniences as the ability to remotely command the release of the far
end of the rope; automatic spooling and unspooling; extrusion (via
electromagnetically induced voids) of "texture" along the sides of the
rope, so that one can ascend or descend simply by grasping the rope;
safety protocols to interrupt accidental falls; amusing and informative
light displays along the length of the rope, such as one's rate of
progress or climbing goal (in retro-manual mode). Advanced features
include "autoclimb", a program in which the rope unspools while
maintaining dynamic equilibrium, either to form an unanchored tower
conformation, or to recognize and establish specific anchor points (ask
the brochure about the special expansion kit for mass driver mode);
"parachute", in which the rope forms a dynamically established horizontal
layer, with high-resolution chaos resolution algorithms to ensure maximum
turbulence backflow for a slow, smooth descent; and the "mariner" suite
of applications, in which the rope emulates up to 21 British, Spanish, or
American seamen from the Age of Conquest, complete with voice emulation,
historically accurate implementation of spoken rigging commands, and
several entertaining extras history never included, such as the
"propellar" transport and tower basing mode.
John P Norman
: [many more questions snipped]
: Climbers generally have more sense than to do monster rappels. You want
: to get in touch with cavers. They publish a pretty good book. I think
: that "On Rope" is the title. It probably has more than you want to know.
: I'm sure there are others too.
Agreed. From my background with caving techniques and equipment, I
would say a very long, continuous piece of static rope and a full,
aluminum bar rack would be employed here. Normal climbing ropes are 50 or
60m, and would not be practical to either tie together in such a length or
use at at this scale, since the stretch built in to them would sned you
yo-yo'ing, particularly when you tried to climb out. As far as climbing
out, a well-adjusted, specialized system such as a ropewalker would
probably be employed. In any case, you would be looking at the equivalent
of 10 approximately 18" diameter sppols of static rope. (This stuff
nromally comes in 600' spools.) Cavers are fond of the Golondrinas (sp?)
pit in Mexico, which is well over a 1000' rappell. They usually buy one
huge, continuous rope and either cut it up into useful pieces or sell it
to another group when they're done. Cehck in alt.caving for info on huge
rappells. The alternative would be to have your characters down-climb
this huge pit, which in real life would be dangerous and difficult.
(Climbers usually climb up, and lower or rappell down on rope.) In any
case, good luck!
John
John P Norman
: I think you could buy a 5000' rope. You would have to special order
: it and it would take quite a while to arrive. But you should still be
: able to buy one.
According to the caving dealers that sell PMI and BW, youi can
special order pieces from teh factory in ANY length you want. I know that
1200+ foot pieces are routine.
: >Now the hard part, climbing back up. Estimate of time? All day? Couple of
: >hours? Potty breaks? (let it fly and watch out below?) And since no hole
: >in a collapsed roof is perfect, what can they do to keep the rope from
: >fraying along the edge? Lay down some mats, wood, or other methods of
: >"smoothing out" the rough edge. The estimate of the edge is a fine cheese
: >grater in spots, in others standard broken rock.
With the cavers, there are two schools of thought here. One is the
American, in which the rope is laid out straight and pads (often made of
old blue jeans or bought commercially) are placed under or wrapped around
the rope to protect it. The pads are either tied to the rock or the rope,
and some are designed to encase the rope, with velcro closure that can be
done and undone when passign over the rope. The other type of rigging is
the European/alpine, where the rope is redirected with bolts, protection,
etc connected to carabiners to keep it from contacting the rock in any
place.
: climbing up with ascenders would take a long time, but you could
: always sit back in the harness and rest for a while.
Climbing 5000' would probably take a fit person at least a couple of
days. You would need seevral days to geta party out, since you would not
want everone on the rope at once. Two would probably be doable.
John
Daniel S. Becker
Evan Craig stated that a rope weighs however many lb per 50 cubic
inches, and thus weighs 1.3lb. per foot. Since I've seen numerous
people flame him for this, let me clarify (as I read it) what he is
saying. When he says something is in cubic inches or cubic feet, he
just that. THus, rope can weigh 1.3lb per foot, but a 165 foot rope
does not need to weigh 214lbs because it is not 165 cubic feet. I
don't know if it really is 1.3lb per cubic foot, but I see no reason
not to believe this.
Dan
Chris Lawson
keda...@concentric.net (Kedamono) wrote:
>Well, the story involves finding a largish monument on an alternate
>world... Getting to the top shouldn't be a problem, traditional climbing
>methods should work, but then they find that the thing's hollow... This is
>the reason I'm trying to find out about stringing together multiple ropes
>and things like tensile strength, stretch, etc.
What's the gravity of this world? I assume (but may be totally wrong)
that any physical limits of the rope would be inversely proportional
to the gravity on the planet surface.
regards,
Chris
_____________________
Chris Lawson
cl...@ozemail.com.au
Kedamono
In article <5d234g$m...@proxy5.ozemail.com.au>, cl...@ozemail.com.au (Chris
Lawson) wrote:
> What's the gravity of this world? I assume (but may be totally wrong)
> that any physical limits of the rope would be inversely proportional
> to the gravity on the planet surface.
I'm making my life simple: It's an alternate Earth.
1G and all that.
Leonard Erickson
isbi...@mach1.wlu.ca (Simon Isbister u) writes:
> Tony Bubb (bu...@qntm.com) wrote:
> :
> : old ropes stretch a lot more.
> :
>
> Huh? An old rope becomes more dynamic? You just keep telling yourself
> that, all the way to the spinal trauma ward.
I think he means that a rope that has been used winds up longer than it
started out. That too is stretching. It just doesn't spring back.
--
Leonard Erickson (aka Shadow)
sha...@krypton.rain.com <--preferred
leo...@qiclab.scn.rain.com <--last resort
George Bell
In article <5cvsdo$jhe$1...@dartvax.dartmouth.edu>, Daniel....@dartmouth.edu (Daniel S. Becker) writes:
> I don't know if it really is 1.3lb per cubic foot, but I see no reason
> not to believe this.
You don't, eh?? Try using your head. A quick back of the envelope
calculation will tell you rope weighs considerably MORE than 1.3 pound per
cubic foot (yes, _cubic_ foot). I won't bore anyone with details.
Evan Craig's post was pure fiction, start to end. Why defend him rather
than doing a simple check of his figures?
-George
Kenneth Cline
In article <32EF74...@erols.com>, Chris Weaver <cwe...@erols.com> writes:
|> Kedamono wrote:
|> > Anyway, I got more questions: a 5000' rope is right out, I take it, so
|> > then the characters will have to splice/tie together multiple standard
|> > ropes to do the climb. No straight rapelling, but cruise, bump, slip over
|> > knot, cruise, bump, repeat. How dangerous will it be to move over the knot
|> > in the line?
|>
|> cautious.
Where do you come up with these answers? It's pretty obvious that
there is risk in just about any rappel. Knowledge and caution reduce
risk, not eliminate it.
|> > I'm assuming people who have some knowledge of climbing, but have
|> > different tastes. So some have 11mil and some have 7mil lines, say 60/40.
|> > Bad idea? or is it doable?
|>
|> Doable, but rapelling on a single 7 mil will usually require a different
|> device or configuration for the rapell, as there is less friction produced.
Are you suggesting that standard climbing rappel setups would work if
fatter ropes were chosen? I don't think so.
|> > Somebody mentioned that the rope will stretch, which I knew already, but
|> > by how much, 50', 100', or more feet?
|>
|> Let's see: A full length rapell on a 200 foot, 10 mm diameter rope will
|> probably stretch about 10-20 feet (I think). Use that figure to determine the
|> stretch of your final rope length. Its possible, I suppose that rope would not
|> stretch at a logorithmic rate relative to its length, since weight of the
|> rapeller would be constant. If this were true, rope stretch might not be as
|> great as if you were to figure it as 5-10% of rope length. Some of our
|> climber/engineers might enlighten us on this.
Huh? The weight of the rope creates additional stretching force.
There will be more stretch (percentage-wise), due to this weight, then
on a short rappel.
|> Are your characters going to climb out the opposite side of this theoretical
|> room, or out the same side on the original rope? If its the opposite side and
|> the wall is made of glass or other smooth material, there will be no way to
|> ascend short of altering the surface with bolts, chipping, etc.
Ever hear of suction cups?
Sheesh.
Ken
Eric Coomer
In article <5d5f5k$r...@news.advtech.uswest.com>,
George Bell <be...@uswest.com> wrote:
>In article <5cvsdo$jhe$1...@dartvax.dartmouth.edu>, Daniel....@dartmouth.edu (Daniel S. Becker) writes:
>
>> I don't know if it really is 1.3lb per cubic foot, but I see no reason
>> not to believe this.
>
>You don't, eh?? Try using your head. A quick back of the envelope
>calculation will tell you rope weighs considerably MORE than 1.3 pound per
>cubic foot (yes, _cubic_ foot). I won't bore anyone with details.
George, don't be so obtuse. This is usenet man. Why would anyone waste
any sort of mental effort when a good dose of guessing and gut feeling
will do just fine?
Back of the envelope- isn't that the part you get to lick????
Cheers
Eric
Andrew Gale
Daniel S. Becker wrote:
>
> Evan Craig stated that a rope weighs however many lb per 50 cubic
> inches, and thus weighs 1.3lb. per foot. Since I've seen numerous
> people flame him for this, let me clarify (as I read it) what he is
> saying. When he says something is in cubic inches or cubic feet, he
> just that. THus, rope can weigh 1.3lb per foot, but a 165 foot rope
> don't know if it really is 1.3lb per cubic foot, but I see no reason
> not to believe this.
Sorry to continue this inane thread but, cubic feet is most definitely
not what he meant. Below is what he said.
Evan Craig wrote:
> Rope weighs around 1 pound per 50 cubic inches. Ten millimeter rope therefore
> weighs around 1.3 lb. per ft., and 5280 ft of it would weigh 7,000 lb., which
> trivializes the weight of your characters, I assume, unless they are giants,
> which will be a required modification to their attributes if they are to carry
> their own rope.
He translates 1 lb /50 cubic inches to 1.3 lb per ft. If he meant per cubic foot
it would be about 34 lbs. (1728 cubic inches/cubic ft). Of course this would
even be more incredibly stupid. He then concludes that 5280 ft of rope
would weight 7000 lbs (5280*1.3) therefore he is clearly referring
to feet as in distance not cubic feet as in volume since the original question was
about a 1 mile long rope. Besides which, who the hell would ever measure rope in
cubic feet!!
Enough of this stupidity. Jeesh!
Andy
--
*******************************************************
Andrew Gale The Scripps Research Institute
ag...@scripps.edu La Jolla, CA
**********http://minihelix.mit.edu/andy/ ***************
Thad Lamphier
Daniel S. Becker wrote:
>
> Evan Craig stated that a rope weighs however many lb per 50 cubic
> inches, and thus weighs 1.3lb. per foot. Since I've seen numerous
> people flame him for this, let me clarify (as I read it) what he is
> saying. When he says something is in cubic inches or cubic feet, he
> just that. THus, rope can weigh 1.3lb per foot, but a 165 foot rope
> does not need to weigh 214lbs because it is not 165 cubic feet. I
> don't know if it really is 1.3lb per cubic foot, but I see no reason
> not to believe this.
> Dan
Ah! that does make sense now!
--
Thad Lamphier
lamp...@craft.clarkson.edu
tha...@aol.com
tha...@geocities.com
http://www.clarkson.edu/~lamphitr
http://www.geocities.com/yosemite/trails/1317/
"To dream great dreams, is itself an act of daring" -Shipton/Tilman
You can get more of what you want with a kind word and a gun than you
can with just a kind word.
-- Bumper Sticker
TradMan
<lots of talk about ropeweight snipped>
Yes, but if you cut a rope in 1 foot lengths and stack them tightly
in a 1 cubic foot box, then pour in two quarts of molasses, about 200
bees, and 1 teaspoon of iron filings, then store it in a dark place for
about three months, then remove the mixture and press it out flat and
cut it into 1 inch squares, you'll have a delicious treat to take to
the crag!
TM
Paddy Iyer
In article <32F7C0...@chattanooga.net>, tra...@chattanooga.net says...
hi tradman,
you been smoking those funny cigarettes again, have you ?
cheers
paddy
Simon Isbister u
Thad Lamphier (lamp...@craft.clarkson.edu) wrote:
: Daniel S. Becker wrote:
: > does not need to weigh 214lbs because it is not 165 cubic feet. I
: > don't know if it really is 1.3lb per cubic foot, but I see no reason
: Ah! that does make sense now!
It still doesn't make any sense to measure the weight of rope in lbs per
cubic foot, or the size of a rope in cubic feet or inches.
When you make a climbing wall, do you measure the plywood in 11mm planks?
-simon-
Hugh B. McNeil
I mark the middle of my rope at the 6.8 pound mark.
[*hic*]
Matti A Jokinen
Too many answers to this theme to read all through... Has anybody
answered to the original question 'what is the maximum length of
rappeling rope?'. As the length increases the total weight of the rope
increases too until the rope breaks. The weight of the rope, however, is
not the same higher up when the gravitational force of the Earth
lessens. Could you connect the Earth to the Moon with a climbing rope
provided the factories could manufacture such an endless cord?
-MJokinen
George Bell
In article <5didj3$8...@oravannahka.Helsinki.FI>, mxjo...@cc.helsinki.fi (Matti A Jokinen) writes:
> Has anybody answered to the original question 'what is the maximum
> length of rappeling rope?'.
I don't think this WAS the original question, but ...
Suppose we take a standard 11mm climbing rope, weight of 4kg per 50m
and static breaking strength approx 2500kg. Under constant gravity,
the thing would break under it's own weight when it was about 30km
or 18 miles long. Even if we used spectra I don't believe a rope
longer than 100 miles could survive under it's own weight.
> The weight of the rope, however, is
> not the same higher up when the gravitational force of the Earth
> lessens.
This is true, but I do not believe that g is even 10% less 18 miles up.
For example, in a commercial airliner, or atop Mt. Everest, you are
5-6 miles up and don't notice any significant decrease in g.
> Could you connect the Earth to the Moon with a climbing rope
> provided the factories could manufacture such an endless cord?
Not a good idea, as the rope would immediately wind itself around the
earth, breaking the rope, or if not, pulling the moon into the earth!
-George
Dave Newton
George Bell wrote:
> Not a good idea, as the rope would immediately wind itself around the
> earth, breaking the rope, or if not, pulling the moon into the earth!
Okay, here's one: What's the actual force generated by the moon during a
factor 2 fall when belayed by a gri-gri? Would a cam pull? Would the wire on
a nut break? Could you lessen the force by providing a dynamic belay using
a figure-8 in rappell mode? How do you mark the middle of the moon? Is
pulling the moon into the earth actually a bad idea?
--
Dave Newton | TOFU | (voice) (970) 225-4841
Symbios Logic, Inc. | Real Food for Real People. | (fax) (970) 226-9582
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Kenny
On 8 Feb 1997, Matti A Jokinen wrote:
> 'what is the maximum length of rappeling rope?'.
As the length increases the total weight of the rope
> increases too until the rope breaks.
I read an aritcle in todays paper about the worlds longest indoor rappel.
This last week in an elevator shaft in a group training session the world
trade building was rappeled. Thats 1400' the rope was so heavy it was
lowered by means of a stretcher.
This says that really there is no maximum length. Or so there is no place
high enough to justify looking for it.
What really determines maximum length is your ability to be able to
transport that much weight.
-Ken
HCW
This reminds me, I am curious about how large rappels on single ropes are
performed, eg. rapping El Cap with a single cord. The dangling rope must
weigh about 80+ pounds, so how do you fit it into a rap device (a pretty
strong arm is needed to lift it) and then prevent the weight of it from
locking you off, making the rope impossible to feed? I assume standard
belay devices are not used. Must be some kind of adjustable bar rap
device, no?