Cave: Frog System Taking Over America
BXTAL1
It looks like the Frog System is rapidly taking over in US caving.
Is it my imagination?
Many people who have been stalwart users of the Mitchell, Ropewalker, and
Texas have repented recently. It seems that a majority of new cavers are
starting out with the Frog as well.
Do you know someone who has made the big switch recently?
Are you next?
"Come Over To The Dark Side, Luke Skywalker"
Bonnie Crystal
Virtual Caver
Global Grotto
Walt Pirie
In article <53ss2e$7...@newsbf02.news.aol.com>,
bxt...@aol.com (BXTAL1) wrote:
:It looks like the Frog System is rapidly taking over in US caving.
:Is it my imagination?
:Many people who have been stalwart users of the Mitchell, Ropewalker,
and
:Texas have repented recently. It seems that a majority of new cavers
are
:starting out with the Frog as well.
:
:Do you know someone who has made the big switch recently?
:
:Are you next?
Yup. I ordered one from Mike Artz at OTR, but I haven't had time to
pick it up yet. Probably next weekend at VAR. But don't gloat yet.
I'll still prefer a ropewalker for deep free-fall pits.
Walt
Walt Pirie
In article <53ss2e$7...@newsbf02.news.aol.com>,
bxt...@aol.com (BXTAL1) wrote:
:It looks like the Frog System is rapidly taking over in US caving.
:Bonnie Crystal
:Virtual Caver
:Global Grotto
Welcome back Bonnie. Going to give us a report on your little
tourist trip?
Walt
mancus
In <53umo1$3p4...@wltpirie.vt.edu>, wltp...@vt.edu (Walt Pirie) writes:
>Yup. I ordered [a frog] from Mike Artz at OTR, but I haven't had time to
Who else is going to VAR? I packed my caving gear last night....
Walt, feel free to stop by the Triangle Trogs area and say hi.
--Cathy Mancus <ca...@zorac.cary.nc.us>
Hank Moon
In article <53umo1$3p4...@wltpirie.vt.edu>, wltp...@vt.edu says...
>
>In article <53ss2e$7...@newsbf02.news.aol.com>,
> bxt...@aol.com (BXTAL1) wrote:
>:It looks like the Frog System is rapidly taking over in US caving.
>:Many people who have been stalwart users of the Mitchell, Ropewalker,
>and
>:Texas have repented recently. It seems that a majority of new cavers
>are
>:starting out with the Frog as well.
It has been a long struggle, frogfriends, but the veil of ignorance cast
by Padgett and Smith 10 years ago is at long last lifting. Let's pause for
a moment to revisit those dark times with a brief verse from "On Rope",
the so-called "bible" of vertical caving techniques.
(from pg. 160)
"Even though the system is heavy, bulky and relatively slow, it is an
essential part of the European style of ropework and has become the
dominant climbing system used by an entire continent."
Early calls for repentance from this igmo stance were met with
indifference. I now hear from the southern marshes that the two antifrogs
have seen the light and will present a more balanced view in the new
bible. True believers may now say 10 Hail Froggies or 20 "Chop
Ropewalkers."
--
Hank "Don't believe everything you read" Moon
PMI-Petzl Distribution, Inc.
hm...@pmi-petzl.com
706.764.1437 ext. 274
-----------------------------------------------------------------------
DISCLAIMER: Unless otherwise indicated, this correspondence is personal
opinion and NOT an official statement of PMI-Petzl Distribution, Inc.
-----------------------------------------------------------------------
Walt Pirie
In article <5401je$k...@rtpnews.raleigh.ibm.com>, mancus@ wrote:
:In <53umo1$3p4...@wltpirie.vt.edu>, wltp...@vt.edu (Walt Pirie)
Will do Cathy. I do have several friends in the Triangle Trogs.
Walt
bxt...@aol.com
Subject: Re: Cave: Frog System Taking Over America
Hank Moon sez:
>a brief verse from "On Rope", (from pg. 160)
>"Even though the system is heavy, bulky and relatively slow..."
As for the heavy, bulky part, one wonders if any of them ever weighed or
measured the cubic volume of a Mitchell system or Ropewalker before
printing that.
Sure, the speed demons of the underworld would exceed the slow but sure
pace of my frog on a freehanging contest rope in a gym.
What, me worry?
I would carry one of them up the rope in a cave using my frog mechanical
advantage setup if they ever needed it. Could they return the favor?
Scott A Askey
Bonnie, What is your mechanical advantage set up ?
JHOLL4
Based on comments seen here and information heard elsewhere,
it appears that a frog might be superior to the Texas I'm
currently using. However, some people have indicated that
it is very difficult to get the rope lengths right such that
a frog can be used with a rack.
I'm interested in building and experimenting with a frog,
but I refuse to give up my rack for another type of descender.
Has anyone out there used a frog/rack combination? If so,
could you shed some light on the workarounds, preferred lengths, etc?
--Cathy Mancus <man...@vnet.ibm.com>
Jared Cuneo
What a joke!
As if the Frog will ever be as safe as a Ropewalker...
Get a second job if ya can't afford the Microscenders....
Laughin my arse off in TAG,
JC
Underground Technologies
bxt...@aol.com
JC sez:
>What a joke!
>As if the Frog will ever be as safe as a Ropewalker...
You may want to revise your statement a little after you get some factual
info on the difference in vertical system failure modes, which include
high fall factors for both the Ropewalker and the Inchworm.
G. Lowe
In article <567vsq$1n...@rtpnews.raleigh.ibm.com>, <man...@vnet.ibm.com> wrote:
>
> Based on comments seen here and information heard elsewhere,
>it appears that a frog might be superior to the Texas I'm
>currently using. However, some people have indicated that
>it is very difficult to get the rope lengths right such that
>a frog can be used with a rack.
The one manoeuvre where using a rack with a frog system is difficult is doing
changeovers: here, because of the length of the rack, you have to make sure
that you attach the rack with no slack above it. Practice this in a gym, or
out of a tree, until you get the hang of it. (I can't see how rope lengths
have much of an influence on this.)
Concerning rope lengths:
* Your footloops should be of a length such that when you stand up, your legs
straighten comfortably, and your jammers just touch.
* Your safety (attaching your top jammer to your harness) should be long
enough to allow you to take long prussik steps, but short enough that you can
always reach the jammer.
* Your long cows tail should also be short enough that you can always reach
the end.
* Your short cows-tail should be as short as possible, to make rebelays
easier--I tie mine so that the knots are actually touching.
Hope this helps,
Gavin
--
Gavin Lowe, Department of Mathematics and Computer Science,
University of Leicester, University Road, Leicester, LE1 7RH, UK.
Phone: +44 116 252 3903. Fax: +44 116 252 3915.
E-mail: gavin...@mcs.le.ac.uk
Jared Cuneo
Why don't you send some "factual" info this way then...
The system we use here is impossible to load with a factor 1 fall...
unless you start climbing rock instead of rope, which is a foolish
move with any system...
Personally, I don't see how you could possibly get enough slack in the
rope to even come close to a factor 1 fall....
Even more threatening is the inherent bounce in a Frog system.
To each his own, we'll continue practicing graceful climbing here in
TAG...
BTW, our systems are designed to make hanging by the ankles near
impossible and the third point (a bombproof Microscender attached
directly to the harness, which is self-running) prevents any slack from
developing.
Ciao,
JC
Underground Technologies
JHOLL4
In <19961112015...@ladder01.news.aol.com>, bxt...@aol.com writes:
>JC sez:
>>What a joke!
>>As if the Frog will ever be as safe as a Ropewalker...
>You may want to revise your statement a little after you get some factual
>info on the difference in vertical system failure modes, which include
>high fall factors for both the Ropewalker and the Inchworm.
Did you mean "fall" or "fail"? I don't see how any single
failure of the ropewalker system can cause a fall. A one-point
failure should not be dangerous. And it can be made safer
if you use a shoulder Gibbs for the upper attachment instead
of a roller or box on a chest harness.
I don't know anyone who uses an inchworm. It looks interesting
in the book, but difficult to make. Does anyone out there use
it for non-experimental work?
--Cathy Mancus <man...@vnet.ibm.com>
bxt...@aol.com
<man...@vnet.ibm.com> sez
>
> Based on comments seen here and information heard elsewhere,
>it appears that a frog might be superior to the Texas I'm
>currently using. However, some people have indicated that
>it is very difficult to get the rope lengths right such that
>a frog can be used with a rack.
Why bother with a rack at all when using the frog?
The cumbersome nature of the rack when involved in midrope manuevers or
rebelay crossing tends to make me wonder why I ever tried it in the first
place. (It's good to experience difficulty... it improves one's ingenuity)
There are a number of good descenders which can be used with the frog (or
any other system for that matter) which have a higher degree of
flexibility in the kind of situations which are encountered in
real-life-caving.
Caves which are more well suited to the rack/texas/ropewalker are the ones
where IRT (Indestructable Rope Technique) is used. If the caver doesn't
know what kind of rigging system will be encountered in the cave, the
default vertical system applied should encorporate the highest degree of
flexibility at the common denominator: ability to smoothly handle any type
of rigging situation or emergency.
alexs...@aol.com
In article <56cl74$k...@rtpnews.raleigh.ibm.com>, JHOLL4@ writes:
> I don't know anyone who uses an inchworm. It looks interesting
>in the book, but difficult to make. Does anyone out there use
>it for non-experimental work?
Guess I'm showing my age again, but in the early days of TAG vertical
caving (before the Mitchel and Ropewalker were 'invented'), I used an
Inchworm system exclusively for several years.
I made the harness from a surplus parachute harness; with minimal
modification, it was rigged to hold a Jumar in the center of my chest,
much as a Frog or Texas rig does -- suspended between the seat and chest
components. The second ascender was the foot component, created by making
a footbar of 1" angle-aluminum, which was bolted to the spine of a Jumar.
It was just wide enough to insert the feet in, and had a nylon strap
across the top and through the upper hole of the Jumar, creating a foot
loop which was used to raise the ascender.
It was a very comfortable rig because, when attached to the rope, you
could 'lay back' in the harness, thus transmitting all the force of your
leg thrusts directly into upward motion of the chest Jumar (which was much
higher than in a Frog). It was probably more efficient than a Frog (which
isn't saying much), as an assist from the hands was not necessary (but was
generally used, anyway).
I always carried a cowstail/Jumar safety, but it was generally used only
for crossing lips (which was a bitch!) and not as a full-time backup.
Looking back on those days, it makes my toes curl to think how far out on
the edge I was. If the chest Jumar had failed (and they were, and are,
made of *cast* aluminum), I would have gone into an immediate, but very
short-lived, heel-hang (toe-hang?), followed by a nose-dive, as there was
nothing to keep my feet in the footbar (indeed, it had to be kicked off to
negotiate a lip, and pulled up later). Still, I am not aware of any
mishaps attributed to an Inchworm.
A Frog is safer than an Inchworm only because a safety can be connected
between the seat and the foot ascender, resulting in no catastrophic
result from the failure of either ascender (save a lack of locomotion).
I don't recommend the Inchworm because (aside from the obvious risk factor
above), it doesn't do anything a Frog can't do as well or better.
Alex
........................................................................
Alex Sproul, NSS 8086RL/FE INNER MOUNTAIN OUTFITTERS
Richmond Area Speleo. Society Caving, Climbing, & Rescue Equipment
NSS Video Committee/Video Section Catalog available on request
........................................................................
Cindy Kay Heazlit
In <19961113193...@ladder01.news.aol.com> bxt...@aol.com
writes:
> If the caver doesn't know what kind of rigging system will be
>encountered in the cave, the default vertical system applied should
>encorporate the highest degree of flexibility at the common
>denominator: ability to smoothly handle any type of rigging situation
>or emergency.
>
In other words, the one you know how to use, and are comfortable with.
Shirley Sotona
>In article <567vsq$1n...@rtpnews.raleigh.ibm.com>, JHOLL4@ wrote:
>:
>: Based on comments seen here and information heard elsewhere,
>:it appears that a frog might be superior to the Texas I'm
>:currently using. However, some people have indicated that
>:it is very difficult to get the rope lengths right such that
>:a frog can be used with a rack.
>: I'm interested in building and experimenting with a frog,
>:but I refuse to give up my rack for another type of descender.
>:Has anyone out there used a frog/rack combination? If so,
>:could you shed some light on the workarounds, preferred lengths, etc?
>Cathy:
My system has always been a frog/rack combination. It's very doable, but you
must be able to get on rope while setting the system up so that you can
determine what length the tether and cows' tails should be. They will need to
be long enough to allow you to changeover and to pass intermediate anchors,
but not so long that you cannot reach your upper ascender when you are hanging
from it. In my case, I am 5 feet 8 inches tall and the length from the
top of my upper ascender to the end of the tether that is linked directly into
my seat harness maillon is 35 inches (89 cm). My footloop ensemble from the
top of my upper ascender to the bottom of the loop (stretched out flat) is
51-1/2 inches (131 cm). My short cow's tail is about 15 inches (38 cm), not
including 'biners. Your mileage may vary.
Good luck,
Shirley Sotona
JHOLL4
In <19961114005...@ladder01.news.aol.com>, alexs...@aol.com writes:
>>[discussing Inchworm system]
>If the chest Jumar had failed (and they were, and are,
>made of *cast* aluminum), I would have gone into an immediate, but very
>short-lived, heel-hang (toe-hang?), followed by a nose-dive, as there was
>A Frog is safer than an Inchworm only because a safety can be connected
>between the seat and the foot ascender...
Hmm. I don't have On Rope in front of me, but I thought their
inchworm discussion included mention of a safety between the caver's
harness and the footbar.
The only advantage I see over the frog is that the inchworm leaves
your hands free; that's about it.
--Cathy Mancus <man...@vnet.ibm.com>
Walt Pirie
In article <19961110233...@ladder01.news.aol.com>,
bxt...@aol.com wrote:
: Subject: Re: Cave: Frog System Taking Over America
:
:Hank Moon sez:
:>a brief verse from "On Rope", (from pg. 160)
:>"Even though the system is heavy, bulky and relatively slow..."
:
:As for the heavy, bulky part, one wonders if any of them ever weighed
or
:measured the cubic volume of a Mitchell system or Ropewalker before
:printing that.
:
:Sure, the speed demons of the underworld would exceed the slow but
sure
:pace of my frog on a freehanging contest rope in a gym.
:What, me worry?
:
:I would carry one of them up the rope in a cave using my frog
mechanical
:advantage setup if they ever needed it. Could they return the favor?
Hmmmm. Most drops yes, but Ellison's? probably not, but should 5000
people switch because every ten years one of them may get to do it?
Walt
Walt Pirie
In article <567vsq$1n...@rtpnews.raleigh.ibm.com>, JHOLL4@ wrote:
:
: Based on comments seen here and information heard elsewhere,
:it appears that a frog might be superior to the Texas I'm
:currently using. However, some people have indicated that
:it is very difficult to get the rope lengths right such that
:a frog can be used with a rack.
: I'm interested in building and experimenting with a frog,
:but I refuse to give up my rack for another type of descender.
:Has anyone out there used a frog/rack combination? If so,
:could you shed some light on the workarounds, preferred lengths, etc?
Cathy:
Regular readers here will know I'm not a frog expert, having just
recently tried it for the first time. So I'm not familiar with the
difficulty of the rack/frog difficulty issue. But have you ever tried
a Petzl stop? I'd think it would be an ideal descender at your weight.
Enjoyed seeing you at VAR.
Walt
Sherry Mayo
Jared Cuneo wrote:
>
> What a joke!
>
> As if the Frog will ever be as safe as a Ropewalker...
I'm dying to know...
Why is a ropewalker inherently safer that a frog rig?
At least you can't end up hanging by your ankles with frog.
I 'spose one possible reason why it might be considered safer is
because of the use of three rather than 2 jammers in
some set-ups. Is this a standard? I've seen rigs which
only a rollerbox for the upper attachment. But even if
you use three, surely the possible increase in safety resulting
from the 3rd ascender is somewhat offset by the fact that
2 ascenders are down by your foot & knee (higher shock load
in the event of failure of the upper jammer/roller, more
difficult (upside down) position for the caver to extracate
themselves from).
Sherry
--
Sheridan C. Mayo | Crystallography, Diffuse Scattering
RSC, ANU, Australia | http://rschp2.anu.edu.au:8080/Welcome.html
scm...@rschp2.anu.edu.au | Caving, Crypto & PGP, X-files, and more.
Wookey
g...@pc5.mcs.le.ac.uk (G. Lowe) wrote:
>The one manoeuvre where using a rack with a frog system is difficult is doing
>changeovers:
You can also get trouble with rebelays if they were rigged tight by someone using a
stop (guilty Mlud!)- there just isn't enough rope to move your weight from the rack
to your short cowstail so you struggle to extract the rack. Not impossible, but very
annoying.
>Concerning rope lengths:
>* Your long cows tail should also be short enough that you can always reach
>the end.
I like mine longer than that. Makes lots of stuff easier if you have a really long
long CT (eg getting off pitch heads with fat tackle sacks). If you ever end up
hanging from it with it out of reach then you can always prussik back up it to sort
things out. This minor, virtually theoretical, disadvantage is not sufficient to
justify the often quoted rule above IMHO. Maybe the above is a good rule for novii.
Apart from this nit-picking I agree with gavin's comments.
--
Wookey
--
734 Newmarket Rd CAMBRIDGE, CB5 8RS, UK. 01223 504881
Sherry Mayo
NO!
Please don't try and cope with "european" style rigging with a
rope-walking rig unless you are an expert at this particular
combination. While a frog can be used (maybe more slowly) on
most rigging styles, the reverse is not true. Ropewalkers are
poorly suited to European rigging and some varieties are
plain dangerous. The main problem is the large number of manoeuvres
requiring tranfer of jammers from one rope to another. This is
very difficult when the jammers are by your feet, and can be
particularly dangerous for wide rebelays and pendules. It also
requires far more strength than if you are using a frog.
Example - Our US caving friend passed a wide rebelay fairly easily
using a frog for the first time, and being talked through it.
Earlier she'd tried to pass a wide rebelay on a rope walker,
which proved to be effectively impossible without one of us clipping
into her and helping. Nothing wrong with her experience or
caving technique - just her ascending rig being incompatable with
the rigging.
G. Lowe
>As if the Frog will ever be as safe as a Ropewalker...
Could you justify that comment, please? What do you think is unsafe about the
frog system?
JHOLL4
In <56n7hu$rg_...@wltpirie.vt.edu>, wltp...@vt.edu (Walt Pirie) writes:
>Cathy Mancus wrote:
>> I'm interested in building and experimenting with a frog,
>>but I refuse to give up my rack for another type of descender.
>Regular readers here will know I'm not a frog expert, having just
>recently tried it for the first time. So I'm not familiar with the
>difficulty of the rack/frog difficulty issue. But have you ever tried
>a Petzl stop? I'd think it would be an ideal descender at your weight.
Basically, I learned with a rack, got comfortable with it, and
given my inexperience, I'm a little reluctant to switch. Eventually,
once I have more experience and more confidence, I'll go back and
revisit some of my earlier decisions. Also, no one in my grotto
uses a stop, so I've never seen one in action.
>Enjoyed seeing you at VAR.
Looking forward to caving with you someday.
--Cathy Mancus <man...@vnet.ibm.com>
JHOLL4
In <56pr78$d...@dfw-ixnews12.ix.netcom.com>, chea...@ix.netcom.com(Cindy Kay Heazlit) writes:
>I will argure that slamming someone into an unfamiliar, but "correct"
>ascending system is still more dangerous than letting them cross a
>rebelay in one which they are familiar with.
I would argue that taking someone on a rebelay trip without
training them in rebelay techniques is a mistake. The argument
of "unfamiliar but suitable rig vs familiar but unsuitable rig"
misses the point. Learn to use what's appropriate for your
situation before you use it.
--Cathy Mancus <man...@vnet.ibm.com>
Sherry Mayo
Cindy Kay Heazlit wrote:
>
> In <328FA5...@rschp2.anu.edu.au> Sherry Mayo
> <scm...@rschp2.anu.edu.au> writes:
> [stuff on ropewalker problems on rebelay deleted...]
>
> I will admit to it being *much* more difficult to use a ropewalker on
> rebelay, but it has been done. It definately falls into the "yuccky"
> category.
This is a bit dependant on the ropewalker & the nature of the rebelay.
A straightforward rebelay can be passed (though "yukky" as you say),
but a wide rebelay or pendule can be impossible on some ascending rigs
without considerable improvisation and/or help. This was the problem
our friend was encountering. Basically she would have needed to either
be immensely strong or to have completely re-arranged her rig in situ.
[NB more slack would have helped - but a cave rigged by froggers won't
*have* more slack because the froggers don't need it and also try to
avoid excess slack to reduce fall-factors]
> I will argure that slamming someone into an unfamiliar, but "correct"
> ascending system is still more dangerous than letting them cross a
> rebelay in one which they are familiar with.
We didn't slam her into an unfamiliar
system and then say "off you go". We made sure it was well set
up and talked her through the manoeuvres from nearby ledges
(where we could have assisted if anything went wrong). She
managed fine, being an experienced caver (she was also keen to
try frogging). This isn't the kind of situation I'm worrying
about though as we were aware there might be problems and
were always on hand to help.
What worries me is a caver maybe overestimating
their own abilities and experience attempting to do a cave
with the "other" style of rigging, perhaps with people who
don't know them that well. A frogger caver like this on "TAG"
rigging will probably just be slow and irritating. Their
ropewalking opposite tackling euro-rigging however may well
endanger their lives. It isn't a symmetrical situation and
rope-walking cavers should be aware of the difficulties they
may encounter on tackling a euro-rigged cave (unless they're
used to it of course) so they can make an informed decision
about going down it.
--
Sheridan C. Mayo | Crystallography, Crypto, Caving
RSC, ANU, Australia | http://rschp2.anu.edu.au:8080/Welcome.html
scmayo @rschp2.anu.edu.au <-- remove space for correct address
Cindy Kay Heazlit
In <56ssq7$k...@rtpnews.raleigh.ibm.com> JHOLL4@ writes:
> I would argue that taking someone on a rebelay trip without
>training them in rebelay techniques is a mistake. The argument
>of "unfamiliar but suitable rig vs familiar but unsuitable rig"
>misses the point. Learn to use what's appropriate for your
>situation before you use it.
I think the point is, that it is difficult to prepare for the
unexpected. Of *course* you should never take them on a rebelay trip
without them training for it. Look at the death in Cheve. Chris
shouldn't have hidden the fact that he was unfamiliar with rebelay.
Now he's dead. But... sometimes it is impossible to know what is up
ahead. This is especially true on exploration trips comprised of
multinational teams. Sometimes you have to run with what you have.
In regard to Sherry's post-- It should be noted that there was one
death here in the states that was a least partly attributed to using a
frog rig with IRT rigging (including alpine rope). As I have
previously posted, mixing modes is hazardous.
I'm also surprized that no one has mentioned one of the biggest
drawbacks of the frog - Harness Compression Syndrome. The incidence
and death rate is much higher with frogs than with other ascending
systems (although it occurs in all systems). Perhaps this has to do
with what happens when you pass out. In a frog, it is almost always in
an arch type position. With ropewalkers and Mitchells, there is a
greater tendency to pass out in collapsed ball, or just flopped over.
Unfortunately right now, the frog is "in fashion" among certain sets in
the US. Some are using it because it is what the Cheve and Huatla
cavers are using (a poor reason) and also Matt Oliphants article in thw
NSS News (a better reason). Several Cheve cavers were snickering about
it at the convention. This too shall pass. Remember:
Racks clipped sideways to the sit harness
Dual light mounting brackets
Double Bungee ropewalkers
In the end, there are assets and drawbacks to every rig, and rigging
system. There are conditions where each performs "best". An
intelligent caver will try to assess the situation, and select the
appropriate tools for the job.
Walt Pirie
In article <56cl74$k...@rtpnews.raleigh.ibm.com>, JHOLL4@ wrote:
:In <19961112015...@ladder01.news.aol.com>, bxt...@aol.com
:>JC sez:
:>>What a joke!
: Did you mean "fall" or "fail"? I don't see how any single
:failure of the ropewalker system can cause a fall. A one-point
:failure should not be dangerous. And it can be made safer
:if you use a shoulder Gibbs for the upper attachment instead
:of a roller or box on a chest harness.
Does anyone still use that old shoulder Gibbs system? I was glad to
give it up for a roller with a floating cam above it.
Walt.
James Zeirke
Cindy Kay Heazlit wrote:
> I'm also surprized that no one has mentioned one of the biggest
> drawbacks of the frog - Harness Compression Syndrome. The incidence
> and death rate is much higher with frogs than with other ascending
> systems (although it occurs in all systems). Perhaps this has to do
> with what happens when you pass out. In a frog, it is almost always in
> an arch type position. With ropewalkers and Mitchells, there is a
> greater tendency to pass out in collapsed ball, or just flopped over.
>
Syndrome. Could someone post a good overview in plain language?
Jim
Jared Cuneo
What's unsafe?
Well for starters, I've watched cavers from all over use the inherent
bounce in their favor. What they don't realize is that they are slowly
destroying their rope.
We conducted a couple of simple experiments here in Huntsville wherein
we attached a rope to a 300lb scale and slung the other end off a
short (20ft) rooftop. Next, 2 climbers were weighed with their gear on.
BTW, both climbers were experienced, safe, and certifiable by NCRC
standards. We then had them climb the rope using a single-bungee rope-
walker. In no case did the scale read higher than 10% more than the
climbers body(+gear) weight (even when they were asked to climb jerky)
When the climbers donned their Frog's readings were quite disturbing...
In 3 instances we achived more than a 40% increase in climber load..
Granted, the climbers were instructed to use the bounce/pull/bounce
rythm that most froggers use...
These results are weak I admit, we don't have endless funds for digital
scales and such, however these preliminary results should make you guys
want to go out and try it for yourself...
Which brings me to something that really pisses me off....
People piss and moan when something goes wrong or says there was nothing
you could have done....BULLSHIT.
Its just like buying a car....take that sucker to an empty parking lot
and make it lose control, spin it in circles, take hard turns till you
lose control and lock those brakes a few times.
WHY? because most people don't know what their car (or climbing system)
is and is not capable of. If you know your limits in advance or know
how to react when certain situations arise you will be live caver
(driver) instead of dead caver (driver).
Take those systems out and (if you sew yourself) cut stitches out one
at a time and climb with it (in a safe tree) until it fails...You'll
be suprised how far you can climb with 4 stiches! Also, simulate each
attachment (not just the cams) failing, learn how to tie an emergency
prussik to all three points, and try climbing sans one ascender...
Bottom line is, you will know what "failure mode" looks like and can
deal with it with a clear head cause you've seen it before...
JC
Underground Technologies
All flames cheerfully ignored...
http://ro.com/~n4caves
Jared Cuneo
STOP IT!!!
damnit, this has gone too far....How in the hell can a system with 2
ascenders be safer than one with 3????
I don't know where you people get your recipies for ropewalkers but
send me an SASE and I'll be glad to let you see the system UT cavers
here in TAG use...
BTW, its IMPOSSIBLE to become inverted in our systems (unless you
experience multiple (at least 2 major) failures Also, we have designed
them to reduce aforementioned compression syndrome even in an
unconcious caver...
If you want a mailing address, email me privately...we sell these
systems turnkey but to prove a point, I'll give the plans for free for
a limited time...
JC
Underground Technologies
http://ro.com/~n4caves
Jared Cuneo
From what I gather, death from compression results from a buildup of
toxins produced by the restricted blood. In fact, I hear-tell that it's
actually not caused until the constriction is released thereby releasing
the toxins into the bloodsupply and contaminating the brain.
Now, onto the real "guts", there is a drug (look around, I forget the
name) that can be administered BEFORE release that *can* prevent
compression syndrome deaths...(not all cases) by eliminating the toxins.
However, since we already carry a first-aid kit containing a couple
syringes, Lidocaine, and morphine, we might as well see if we can obtain
medical training on the use of this technique. Since not many PhD's
have time to go caving with us, we gotta take matters into our own hands
David Gibson
In article <56u6un$f...@sjx-ixn4.ix.netcom.com>, onWed, 20 Nov 1996
Cindy Kay Heazlit <chea...@ix.netcom.com> writes
>I'm also surprized that no one has mentioned one of the biggest
>drawbacks of the frog - Harness Compression Syndrome. The incidence
>and death rate is much higher with frogs than with other ascending
>systems (although it occurs in all systems).
That seems, on the face of it, an extraordinary statement. I guess that,
world-wide, there must have been quite a few deaths with several types
of harness as contributory factor in order to show this as a statistic?
Here in the UK the number of SRT fatalities is far too low to draw any
conclusions, and I dont think there's been a single "harness" death. But
it is, of course, known that hanging in a sit-harness is not good for
you.
--
David Gibson **** Newsgroup <uk.rec.caving> now created!
**** Archives at <http://www.mcrosolv.demon.co.uk/caving/>
David Gibson
In article <329346...@ro.com>, onWed, 20 Nov 1996
Jared Cuneo <n4c...@ro.com> writes
>From what I gather, death from compression results from a buildup of
>toxins produced by the restricted blood. In fact, I hear-tell that it's
>actually not caused until the constriction is released thereby releasing
>the toxins into the bloodsupply and contaminating the brain.
There is a similar problem due to crush injuries caused when buildings
collapse in earthquakes or bombings (now called "incidents" in the UK
:-). After the Brighton "incident" a few years ago where the IRA bombed
the Conservative Party Conference, I recall - FWIW - some comment about
drugs used to treat crush injuries before the source of the crush was
removed.
Cindy Kay Heazlit
In <571kvd$p...@falcon.le.ac.uk> g...@pc5.mcs.le.ac.uk (G. Lowe) writes:
>Cindy Kay Heazlit <chea...@ix.netcom.com> wrote:
>>In regard to Sherry's post-- It should be noted that there was one
>>death here in the states that was a least partly attributed to using
>>a frog rig with IRT rigging (including alpine rope). As I have
>>previously posted, mixing modes is hazardous.
>
>what weakness in the frog system contributed to this incident; I can't
>think how using a frog system with IRT rigging can be more dangerous.
>
Jared mentioned it in his post... It has to do with bounce. Many
cavers tend to bounce up the rope using the frog, for added leverage.
In this case, with the IRT rigging, the bounces either 1) caused a rock
to fall on the rope, where it ran over the edge or 2) caused the rope
to saw through at the edge. The "evidence" was: 1) cut rope, 2) rock
at bottom of drop 3) dead caver at bottom of drop. It was in ACA
several years ago, Steve Knutson did a rather controversial article on
it.
Its a lot harder to bounce with a ropewalker or Mitchell, even when
climbing jerkily.
>
>>I'm also surprized that no one has mentioned one of the biggest
>>drawbacks of the frog - Harness Compression Syndrome. The incidence
>>and death rate is much higher with frogs than with other ascending
>>systems (although it occurs in all systems). Perhaps this has to do
>>with what happens when you pass out. In a frog, it is almost always
>>in an arch type position. With ropewalkers and Mitchells, there is a
>>greater tendency to pass out in collapsed ball, or just flopped over.
>
>Again, could you give more details, please; how do cavers end up
>suffering from Harness Compression Syndrome?
>
Again, Jared gave a reasonable description. The French have done a lot
of work in this area. Toxins build up at pressure points when someone
hangs for a long perios of time. Then they are released. Boom! There
have been (I beleive) only a couple of deaths here in the state. Many
more in Europe.
It is enough of a problem that it is certainly mentioned in NCRC
training (the one Bonnie just went through). While it doesn't occur
often, the consequences are so awful that it really has to be placed
into the "risks" category, when doing comparisons of rigs.
non...@psu.edu
In article <56u6un$f...@sjx-ixn4.ix.netcom.com>,
chea...@ix.netcom.com(Cindy Kay Heazlit) wrote:
>
> In regard to Sherry's post-- It should be noted that there was one
> death here in the states that was a least partly attributed to using a
> frog rig with IRT rigging (including alpine rope). As I have
> previously posted, mixing modes is hazardous.
>
Off the cuff I would be more suspicious of the alpine rope with the IRT
rigging than the frog with the IRT rigging. Where might a more detailed
report of this accident be found?
Scott Askey
saa...@psu.edu
Scott Linn
Cindy Kay Heazlit (chea...@ix.netcom.com) wrote:
: Again, Jared gave a reasonable description. The French have done a lot
: of work in this area. Toxins build up at pressure points when someone
: hangs for a long perios of time. Then they are released. Boom! There
: have been (I beleive) only a couple of deaths here in the state. Many
: more in Europe.
Not to mention the in-hospital testing done by the French where they almost
lost some test subjects...
Any volunteers for testing US rigs?
--
________________________________________________________________________
Scott Linn
CMOS IC Design Engineer
Hewlett-Packard Integrated Circuits Business Division - Corvallis, OR
e-mail: sc...@cv.hp.com phone: (541)715-4033 fax: (541)715-2145
________________________________________________________________________
G. Lowe
Cindy Kay Heazlit <chea...@ix.netcom.com> wrote:
>In regard to Sherry's post-- It should be noted that there was one
>death here in the states that was a least partly attributed to using a
>frog rig with IRT rigging (including alpine rope). As I have
>previously posted, mixing modes is hazardous.
Cindy, could you possibly give more details. I'm wanting to learn what
weakness in the frog system contributed to this incident; I can't think how
using a frog system with IRT rigging can be more dangerous.
>I'm also surprized that no one has mentioned one of the biggest
>drawbacks of the frog - Harness Compression Syndrome. The incidence
>and death rate is much higher with frogs than with other ascending
>systems (although it occurs in all systems). Perhaps this has to do
>with what happens when you pass out. In a frog, it is almost always in
>an arch type position. With ropewalkers and Mitchells, there is a
>greater tendency to pass out in collapsed ball, or just flopped over.
Again, could you give more details, please; how do cavers end up suffering
from Harness Compression Syndrome?
Gavin
Jared Cuneo
No tests are needed if everyone would quit whining about weight and
bulkiness. My whole 3pt ropewalker fits in my camera bag if necessary.
While the plans in On Rope are quite workable they are by no means
definitive.
We've discussed this weight issue before on the spare light thing,
American soldiers carry more than 40lbs of gear most every day, are you
actually telling me that a 10lb pack is gonna kill you? It just may save
you or your buddies life...Don't settle for good enough...get the best
when your life depends on it...
JC
Underground Technologies
Jared Cuneo
Ok, ok...
I just a scale a weighed a frog and my ropewalker (simmons on a plate,
2 gibbs, 1 microscender, and associated webbing; the frog, a croll, a
jumar, handle, and webbing)
The difference is 23.9 ounces.....I suspect any configuration would be
fairly close....go figure
24 ounces is worth my piece of mind...as for walking to caves....well
maybe we don't have 11,000 ft mountains here but I've walked more
than 6 miles to do 1500ft chest compressor crawls...
And the extra 24 ounces didn't make one iota of difference...
Take them beers out of your packs...(not directed to anyone in
particular ;)
JC
Underground Technologies
Cindy Kay Heazlit
In <3294B2...@ro.com> Jared Cuneo <n4c...@ro.com> writes:
>
>No tests are needed if everyone would quit whining about weight and
>bulkiness. My whole 3pt ropewalker fits in my camera bag if necessary.
>While the plans in On Rope are quite workable they are by no means
>definitive.
>
Easy to say if you're living in an area where you don't have far to
walk to caves, and if the cave passages are large enough to stand up
in.
But...
What if you have to haul 70lbs of gear up to base camp at 11,000 feet?
What if you have to haul a fat 25lb cave pack through body size
openings for hours at a time? (using mostly your arms, as opposed to
carrying it on your back)
All of a sudden weight/size become important, because they are tiring
you out!! When you get tired, you get sloppy, clumsy, cold -- all
factors for inducing an accident. So yes, gear weight and size ARE
important.
Just one more variable in the equation for selecting equipment.
Cindy Kay Heazlit
In <32952D...@ro.com> Jared Cuneo <n4c...@ro.com> writes:
>
>24 ounces is worth my piece of mind...as for walking to caves....well
>maybe we don't have 11,000 ft mountains here but I've walked more
>than 6 miles to do 1500ft chest compressor crawls...
>
sleeping bag, tent (mountain weather), extra clothes ( 34 degree cave),
stove, food, instruments, sometimes wetsuit, sometimes dive gear,
sometimes lead rack... it addes up. 24oz extra isn't much when it is 1
item. When it is several, it starts to add into pounds. You start
looking at everything when looking to trim weight.
>Take them beers out of your packs...(not directed to anyone in
>particular ;)
Not a big fan of beer. Guess I'm not a *real* caver.
bxt...@aol.com
David Gibson <gib...@mcrosolv.demon.co.uk> sez:
>>...[regarding statistical analysis of Harness Syndrome]
>I guess that,
>world-wide, there must have been quite a few deaths
>with several types of harness as contributory factor
>in order to show this as a statistic?
The only medically coordinated testing regarding the cause or nature of
"Harness Syndrome" that have been widely propagated are the tests done in
Europe using (you guessed it...) European seat harnesses. If there have
been any medically conducted tests in the US using Mitchell or ropewalker
systems, where have they been published?
>Here in the UK the number of SRT fatalities is far
>too low to draw any conclusions, and I dont
>think there's been a single "harness" death. But
>it is, of course, known that hanging in a sit-harness
> is not good for you.
True, and how many of us use a chest harness to keep us uprightly oriented
when descending?
All "Frog Harnesses" are not created equal.
Some Frog users prefer to use shoulder or chest harnesses which maintain
the body in an upright orientation when relaxed.
On the other hand:
One wonders how long some users of extremely tight ropewalker chest box
harnesses would maintain breathing capability in an unconcious state.
These types of chest harnesses are common and many have witnessed them
being regularly used by ropewalking champions on caving trips.
Bonnie Crystal
Virtual Caver
Global Grotto
hasb...@ix.netcom.com
I've found a way to inprove the efficinecy of my frog rig. I have attached
a loop from the back of my chest harness to the back of my seat harness.
Not the croll in front is kept at better position. Perhaps a full body
harness would be good for a frog.
Jared, I agree that three ascenders is safer than two, but I always carry a
spare ascender and extra webbing. I have no problem with field repair. Even
if I had another system, I'd still carry a spare ascender. I like the idea
of using micro ascenders, and will get a chance to try them out soon.
I'm taking you up on the offer to see your ropewalker plans. (Email is
coming).
Marc Hasbrouck, Caver
MLG, NSS
Its only a hobby...only a hobby...only...
Paul Lydon
In article: <3pgvffAu...@mcrosolv.demon.co.uk> David Gibson
>
> In article <56u6un$f...@sjx-ixn4.ix.netcom.com>, onWed, 20 Nov 1996
> Cindy Kay Heazlit <chea...@ix.netcom.com> writes
>
> >drawbacks of the frog - Harness Compression Syndrome. The incidence
> >and death rate is much higher with frogs than with other ascending
> >systems (although it occurs in all systems).
>
> world-wide, there must have been quite a few deaths with several types
> of harness as contributory factor in order to show this as a statistic?
>
> conclusions, and I dont think there's been a single "harness" death. But
> it is, of course, known that hanging in a sit-harness is not good for
> you.
>
FWIW I remember reading years ago about some experiments carried out with
climbers and 'sit' type harnesses as opposed to full-body harnesses - these will
be very similar to caving SRT sit harnesses.
It appears that if somebody is left suspended in a sit-harness and remains
immobile for a longish time, they sometimes lose consciousness. . .
There wasn't an explanation given at the time, one theory being a drop in blood
pressure being the cause.
--
*******************************
* Paul Lydon *
* Brassington, Derbyshire, UK *
* pa...@palydon.demon.co.uk *
*******************************
hasb...@ix.netcom.com
chea...@ix.netcom.com(Cindy Kay Heazlit) wrote:
>Not a big fan of beer. Guess I'm not a *real* caver.
Cindy,
This is CA. We'er supposed to be wine drinkers. (Even though I'm not.)
If you're talking about caving area I think you are, CA's longest is there,
I'm with you on the weight reduction issue. Not many of us could afford a
string of pack animals with all the gear and supplies we want. (I'm from
MLG, the mammoth lunch grotto).
Alan Sheehan
In article <32930F...@execpc.com>, James Zeirke <jze...@execpc.com> says:
>
>Cindy Kay Heazlit wrote:
>
>> I'm also surprized that no one has mentioned one of the biggest
>> drawbacks of the frog - Harness Compression Syndrome. The incidence
>> and death rate is much higher with frogs than with other ascending
>> with what happens when you pass out. In a frog, it is almost always in
>> an arch type position. With ropewalkers and Mitchells, there is a
>> greater tendency to pass out in collapsed ball, or just flopped over.
>>
>Syndrome. Could someone post a good overview in plain language?
>
>Jim
By "harness compression syndrome" I assume you mean Compartment Syndrome?
Compartment syndrome is when the veins leaving a muscle are restricted
(say by pressure from harness) and bruising also develops (say also from
the harness). I'm told this can develop over extended periods in a harness.
Particularly if ill fitting.
As the bruising(bleeding) into the muscle (which is encased in a water(blood)
proof membrane continues, pressure inside the muscle increases. This further
restricts blood flow out of the muscle. It can result in complete loss of
circulation. It is extremely painful, and once achieved can only be fixed
by surgery!
I hope I've done this justice as I'm a one hour lecture expert on the subject!
;o)
Alan Sheehan
a...@ix.net.au
Olaf W=?iso-8859-1?Q?=FCndrich
recently we spent some days in a cave with lots of luggage. it was
difficult to transport, slowed us down and made us weak.
an interesting idea would be to change the battery drill to a
gas or butan powered drill. on big quests underground, where one
needs to put in much ropes and therefor spits, this would be
much beter than a hand drill (i hate hand drills!)
a challenge for me right now is perfecting bivoauc equipment.
and: lower weight means less parts and less can go wrong.
ole, wu...@merkur.hrz.tu-freiberg.de (krautland)
turner
When you lose circulation while in a harness, toxins accumulate, your
electrolyte balance and pH change...When your circulation is restored after
a long period, all of these toxins and altered blood chemistry go flooding
back into the rest of your body and the shock of this can cause a heart attack
in the supposedly rescued victim..
This was discussed a while back in the NSS NEWS or the BULLETIN and I think
it was also discussed on Cavers Digest..
The gist of what I got was that if properly trained and prepared medical or
paramedics are prepared to deal with this situation, they can administer
medical treatment just before or during the time that the victim is rescued
such that the damage is minimized or prevented
However, this is just what my feeble memory covered with scar tissue from
opinionated flame attacks can regurgitate....
Mark Turner
NSS23231 (JM,SU)
Roger Haley
Gavin I have to agree with you. Cindy give us the details!!
I know of only one Compression Syndrome death in the states in the past
10 years
That was in TAG where a caver was using a Mitchell system with no seat
harness
on and could not get over the lip.
--r
G. Lowe wrote:
>
> Cindy Kay Heazlit <chea...@ix.netcom.com> wrote:
> >In regard to Sherry's post-- It should be noted that there was one
> >death here in the states that was a least partly attributed to using a
> >frog rig with IRT rigging (including alpine rope). As I have
> >previously posted, mixing modes is hazardous.
>
> Cindy, could you possibly give more details. I'm wanting to learn what
> weakness in the frog system contributed to this incident; I can't think how
> using a frog system with IRT rigging can be more dangerous.
>
> >I'm also surprized that no one has mentioned one of the biggest
> >drawbacks of the frog - Harness Compression Syndrome. The incidence
> >and death rate is much higher with frogs than with other ascending
> >systems (although it occurs in all systems). Perhaps this has to do
> >with what happens when you pass out. In a frog, it is almost always in
> >an arch type position. With ropewalkers and Mitchells, there is a
> >greater tendency to pass out in collapsed ball, or just flopped over.
>
Sherry Mayo
> G. Lowe wrote:
> >
> > Cindy Kay Heazlit <chea...@ix.netcom.com> wrote:
> > >In regard to Sherry's post-- It should be noted that there was one
> > >death here in the states that was a least partly attributed to using a
> > >frog rig with IRT rigging (including alpine rope). As I have
> > >previously posted, mixing modes is hazardous.
> >
> > Cindy, could you possibly give more details. I'm wanting to learn what
> > weakness in the frog system contributed to this incident; I can't think how
> > using a frog system with IRT rigging can be more dangerous.
I've just had an email exchange with Cindy about this - maybe it'll turn
up on the newsgroup but propogation to Australia seems a bit lame at
the moment so I'll reply to this here.
In my post (entitled "frog dangerous on IRT?") I outlined my
opinion why I thought the accident Cindy mentions above (which was
described in more detail in the rest of her post) wasn't a
particularly convincing argument against frog on IRT. However
it turns out that the problem was that he used *thin rope* to do
IRT-type rigging. (this is what Cindy means by her reference to
"alpine rope" in the above quote - I didn't get this and others
may well have missed it too).
I will be the first to proclaim from the roof-tops that doing IRT
rigging with the diameters of rope (commonly 8-9mm) used in
"euro"-rigging is an *extrememly* poor idea. However using a
ropewalker rather than a frog to climb up this poor rigging will
do little to save you from its deficiencies! *Indestructable rope*
is a rather salient feature of Indestructable Rope Technique.
Cindy says "there was one death here in the states that was a least
partly attributed to using a frog rig with IRT rigging (including
alpine rope)" . I would say it was the rope rather than the ascending
rig that was the likely culprit.
I think Cindy may have some better examples of frog on (genuine) IRT
problems, but I'll address those when they finally propogate down-
under on the newsgroup.
Sherry
Sherry Mayo
Olaf Wündrich wrote:
> recently we spent some days in a cave with lots of luggage. it was
> difficult to transport, slowed us down and made us weak.
> an interesting idea would be to change the battery drill to a
> gas or butan powered drill. on big quests underground, where one
> needs to put in much ropes and therefor spits, this would be
> much beter than a hand drill (i hate hand drills!)
We have used a petrol powered Ryobe drill for placing bolts
which we found very good. It was quite fuel efficient and
it is easy to carry more fuel. There are a few exhaust fumes,
but these aren't too bad as the hole can be drilled very quickly
so you don't need to run the drill for long, and in caves with
a draught or caves of a reasonable size the fumes disperse very
quickly, and probably wouldn't be noticeable. I haven't carried
this drill on long trips, but it wasn't any heavier than the electric
Bosch drills that many groups use for caving.
cav...@aol.com
for those of us in the 100 lb weight range, gear can be quite dangerous if
it pulls you off center while you're on an exposed climb. At least one
death has happened this way. Anything that saves weight is a plus.
bxt...@aol.com
Sherry Mayo sez:
>I will be the first to proclaim from the roof-tops that
>doing IRT rigging with the diameters of rope
> (commonly 8-9mm) used in
>"euro"-rigging is an *extrememly* poor idea.
> However using a ropewalker rather than a frog
> to climb up this poor rigging will do little to save
> you from its deficiencies!
> *Indestructable rope* is a rather salient feature of
>Indestructable Rope Technique.
Totally agree. IRT requires proper rope and techniques for rope
protection. There are even limits for how much abrasion even the most
wonderful 11mm rope can endure. Theoretically, rope pads would be applied
at high abrasion points. (Theoretically... is it done universally?)
But it also seems that the inverse system applications are not equal. (IRT
vertical systems on SRT rigging vs. Frog system on IRT rigging)
Sherry so appropriately pointed out the difference between familiarity and
appropriateness in her earlier post about the American who failed to
negotiate the rebelay with the familiar ropewalker but successfully passed
it with a fresh Frog system.
Just because one is aquainted and familiar with a certain climbing system
for IRT, doesn't make it the best climbing system for them for all unknown
situations. In fact, it could spell big trouble if they are arrogant
enough to think they can use it in all rigging situations without knowing
the limits of it.
Many of us have seen American cavers *struggle* to pass rebelays,
change-overs, (or even bolted pitch heads with horizontal safety ropes
leading to them) with their ropewalkers, double/single bungie-whatever.
It's no secret! Who are we trying to kid? Many of them are forced to
cave only where the rigging will be known and assured to them beforehand.
Sure, ropewalker buffs can eventually master the techniques needed to
perform any midrope manuever, after much practice.
On the other hand, there have not been shown to be any IRT techniques
which are unwieldy to perform using a Frog, other than winning the
speed-demon contest at the convention.
Which leads to these conclusions:
1. Use of a ropewalker on real SRT rigging may tend toward adverse
consequences for non-expert IRT cavers.
2. Use of a Frog on real IRT rigging is not likely to cause adverse
consequences for non-expert SRT cavers.
Cindy Kay Heazlit
In <19961128124...@ladder01.news.aol.com> bxt...@aol.com
writes:
>On the other hand, there have not been shown to be any IRT techniques
>which are unwieldy to perform using a Frog, other than winning the
>speed-demon contest at the convention.
What an absoulute bunch of drivel! I've seen problems with it lots of
times! I saw an incident at Devils Sinkhole where a frog user got
seriously stuck trying to go over the edge while climbing. (Devils
sink is **severely** undercut at the top, with a right angle edge).
They finally had to clip into her and *haul* her over the edge.
Its a pain on sloping drops.
Overweight cavers also have severe problems using the frog. I had a
wonderful discussion with Andy Eavis (Cave Safe videos) and Matt
Oliphant at the convention on this. Andy agreed on this.
> Use of a Frog on real IRT rigging is not likely to cause adverse
>consequences for non-expert SRT cavers.
The examples above shows you are quite wrong.
Wookey
chea...@ix.netcom.com(Cindy Kay Heazlit) wrote:
> I had a
>wonderful discussion with Andy Eavis (Cave Safe videos)
(Andy Eavis is the China caves project main man)
--
Wookey
--
734 Newmarket Rd CAMBRIDGE, CB5 8RS, UK. 01223 504881
Ian Grindey
On 28 Nov 1996 17:21:32 GMT, chea...@ix.netcom.com(Cindy Kay Heazlit)
wrote:
>What an absoulute bunch of drivel! I've seen problems with it lots of
>times! I saw an incident at Devils Sinkhole where a frog user got
>seriously stuck trying to go over the edge while climbing. (Devils
>sink is **severely** undercut at the top, with a right angle edge).
>They finally had to clip into her and *haul* her over the edge.
I quote you from the above
What an absolute bunch of drivel!
>Its a pain on sloping drops.
If you rig *properly *then any undercut pitches will have a rebelay to
prevent rope rubbing on an edge,then Frog rig is easy then to climb
undercut pitch heads speaking from personal experience
>Overweight cavers also have severe problems using the frog.
I am a little over ( well more than a little at the moment)16 stone the
only problems I have are due to gravity not frog ,in that I have to lift
my own weight which ever system I use.
>> Use of a Frog on real IRT rigging is not likely to cause adverse
>>consequences for non-expert SRT cavers.
>
I would venture that IRT rigging is likely to have adverse consequences
on any body using it.what ever SRT rig they are using
I am now doning my asbestos underpants as this will surly get a few
flames, but as a matter of safety .Rub points are not permit able in any
form of SRT rigging ,nothing is indestructible remember the Titanic
,they said that couldn't sink!
Some one once said to me that the test of any SRT system is how easy it
is to pass a knot in a rope going downward ,when that knot is in free
space that is away from any part of the cave .
You gessed , it can be done on frog ( I used to be able to do it )if you
intend to try this do it in a tree where someone can get you down ,and
don't send me the hospital bill.
There are many ways of prevention of rub points the best being a secure
rebelay the worst a canvas rope protector (asking for trouble
eventually) via a deviation to move the line of the rope away from a rub
point
The people I cave with ,and members of my club will not allow rope to
rub for any reason,and I think most British cavers would agree with that
statement, I personally would not cave with any that don't agree.
On this side of the pond it is an unwritten law that we don't allow rub
points ,even if we do on the odd occasion, you tend to live allot longer
that way
Ian Grindey <i...@grindey.demon.co.uk> pgp key available
Macclesfield
hasb...@ix.netcom.com
chea...@ix.netcom.com(Cindy Kay Heazlit) wrote:
>Overweight cavers also have severe problems using the frog. I had a
>wonderful discussion with Andy Eavis (Cave Safe videos) and Matt
>Oliphant at the convention on this. Andy agreed on this.
Well, a large caver with a high center of gravity can have problems with a
frog. One of ours recently converted over to a Mitchell with an extra
ascender (a gibbs) just above the chest box.
Not being so shaped (more bottom than top heavy) I still like my frog in
tight climbs and on lips. The spare handled ascender on my cow's tail
provides similar utility to the third ascender of a Mitchell. A regular
Mitchell would be more efficient by holding me to the rope closer, but I
want all the ascenders to attach to my seat if I have to undo the chest box
to manuver. With my frog, all the ascenders do this and I usually don't
have to undo the chest croll to come up over a lip.
James Zeirke
Alan Sheehan wrote:
>
> In article <32930F...@execpc.com>, James Zeirke <jze...@execpc.com> says:
> >
> >Cindy Kay Heazlit wrote:
> >
> >> drawbacks of the frog - Harness Compression Syndrome. The incidence
> >> and death rate is much higher with frogs than with other ascending
> >> systems (although it occurs in all systems). Perhaps this has to do
> >> with what happens when you pass out. In a frog, it is almost always in
> >> an arch type position. With ropewalkers and Mitchells, there is a
> >> greater tendency to pass out in collapsed ball, or just flopped over.
> >>
> >Syndrome. Could someone post a good overview in plain language?
> >
> >Jim
>
> By "harness compression syndrome" I assume you mean Compartment Syndrome?
>
> Compartment syndrome is when the veins leaving a muscle are restricted
> (say by pressure from harness) and bruising also develops (say also from
> the harness). I'm told this can develop over extended periods in a harness.
> Particularly if ill fitting.
>
> As the bruising(bleeding) into the muscle (which is encased in a water(blood)
> proof membrane continues, pressure inside the muscle increases. This further
> restricts blood flow out of the muscle. It can result in complete loss of
> circulation. It is extremely painful, and once achieved can only be fixed
> by surgery!
>
> I hope I've done this justice as I'm a one hour lecture expert on the subject!
> ;o)
>
> Alan Sheehan
> a...@ix.net.au
Alan,
Is there any proof that one model or brand of harness is better at
avoiding this than any other? I use a Petzl Choucas, but friends of
mine use CMC rescue harnesses because the wide padded leg bands are so
comfortable over a long hang. I have to admit that after a period of
time the Choucas becomes a bit of a "pain in the leg".
Jim
Bonnie Xtal
Sherry Mayo wrote:
> Just a quick note to say that such problems are all the more
> reason to learn self-rescue techniques to move a stuck person
> from a rope (called a "pick-off" in the US I think). Even someone
> who hasn't got as far as getting the full compression syndrome can
> get nasty injuries from hanging around.
This points to the need to practice the "pick-off/carry" to help your
fellow caver up the rope. Most of the American techniques have focused
upon descending with the patient. Descending may be the least desirable
option in a lot of exploration scenarios. Water-bottom pitches are a
typical example.
> By the way, having thrashed out the relative risk of frog vs
> ropewalkers for compression syndrome, I should mention a new peril
> namely: Sports-Bra Compression Syndrome,
Wow Sherry, SBCS is serious! Do you think ropewalker users are more at
risk for this life-threatening spandex scenario? Might Frog users
survive due to the CYH (Cross Your Heart) effect?
We may need to commission a Blue Ribbon Expert panel at the
International Congress to write a feasibility study to determine what
steps should be taken to scientifically examine the cost/benefit ratio
and/or risk management factors.
Bonnie
Bonnie (BXTAL1@aohell.com)
Sherry Mayo sez:
> Undercuts can be passed with Frog. You
> just push out a bit to get the upper ascender past.
Mitchell and Ropewalker users are sometimes forced to remove their chest
rollers from the rope upon reaching the lip.
I remember a friend of mine who had a very difficult time at the Devil's
Sinkhole lip with his Mitchell. Shortly after that he was asking me
about advice on switching over to the Frog system.
"Come over to the Dark Side, Luke Ropewalker..."
Another caver I know was stuck temporarily on the lip of Devil's
Sinkhole on descent using a J-bar rack descender, when the rack jammed
at an angle with the rope pressing between the lip and a bar, thus
pushing the bar up with leverage and cinching the rope.
Good IRT rigging procedure for overhung/undercut lips dictates either an
etrier or another short rope tail hung over the lip with a knotted loop
in the end.
Bonnie
Sherry Mayo
turner wrote:
>
> When you lose circulation while in a harness, toxins accumulate, your
> electrolyte balance and pH change...When your circulation is restored after
> a long period, all of these toxins and altered blood chemistry go flooding
> back into the rest of your body and the shock of this can cause a heart attack
> in the supposedly rescued victim..
Just a quick note to say that such problems are all the more
reason to learn self-rescue techniques to move a stuck person
from a rope (called a "pick-off" in the US I think). Even someone
who hasn't got as far as getting the full compression syndrome can
get nasty injuries from hanging around.
By the way, having thrashed out the relative risk of frog vs
ropewalkers for compression syndrome, I should mention a new peril
namely: Sports-Bra Compression Syndrome, yes having recently
purchased on of these I've found they have a fiendish piece
of elastic round the bottom that seems designed to prevent you
breathing - presumably this increases the value of any cardio-vascular
excersize you undertake while wearing it.
Please note, however, that attempts to rescue people from sports-bra
compression syndrome are unlikely to be well received!
Sherry
Sherry Mayo
Yeah, I get to play Cindy's devil's advocate again ;-)
Cindy Kay Heazlit wrote (in reply to Bonnie Xtal):
> What an absoulute bunch of drivel! I've seen problems with it lots of
> times! I saw an incident at Devils Sinkhole where a frog user got
> seriously stuck trying to go over the edge while climbing. (Devils
> sink is **severely** undercut at the top, with a right angle edge).
> They finally had to clip into her and *haul* her over the edge.
Undercuts can be passed with Frog. You
just push out a bit to get the upper ascender past. I imagine
ropewalkers do something similar with their upper roller/gibbs,
Prabably it is easier with a ropewalker as you have both hands free,
but it's perfectly passable with a frog. A few years back many
UK cavers used frog with IRT style rigging & rope, and strangely
enough, people didn't need to be hauled past obstacles on a regular
basis. The fancier rigging styles came later.
> Its a pain on sloping drops.
It's fine, you just kick one or both feet out of the footloops.
> Overweight cavers also have severe problems using the frog. I had a
> wonderful discussion with Andy Eavis (Cave Safe videos) and Matt
> Oliphant at the convention on this. Andy agreed on this.
This is a good point (although there are plenty of large froggers
around). I think the size of the paunch may actually be the deciding
factor here, rather than weight per se as it can interfere with the
chest croll positioning and movement. Any big cavers care to comment?
> The examples above shows you are quite wrong.
I'll bear that in mind.
Bonnie(BXTAL1@aohell.com)Crystal
Ian Grindey wrote:
> What an absolute bunch of drivel!
>this side of the pond it is an unwritten law that we don't allow rub
> points ,even if we do on the odd occasion, you tend to live allot longer
> that way
Oh, good shot, Ian.
Not to defend IRT techniques, but there are some really different
situations in the USA and elsewhere where IRT techniques are the best of
the viable alternatives.
Some regulations prevent the installation of bolts. Other times, there
is no available strong rock to bolt or connect a natural anchor to.
Granted, with some pre-knowledge and forethought, aircraft cable or
slings could be arranged to provide a bomber deviation or hanging
rebelay anchor. But these subtleties are not considered by some IRT
riggers. After all, would it be inconvenient to pass a rebelay at an
undercut lip with a ropewalker/rack system? For the most part, many IRT
riggers in the USA just "Throw that rope down the pit!" and go.
If a rope pad is needed, it is likely to be only applied near the top or
other places if really absolutely required and convenient. The IRT
caver must be ready to respond to this type of rigging and know how to
deal with it. Sounds scary to the SRT caver; it is, until one gets used
to it.
Bonnie
Virtual Caver
Global Grotto
Bonnie(BXTAL1@aohell.com)Crystal
Roger Haley wrote:
> I know of only one Compression Syndrome death in the states in the past
> 10 years
> That was in TAG where a caver was using a Mitchell system with no seat
> harness
> on and could not get over the lip.
Good case against Frog bashing.
No one would consider climbing without a seat harness in a Frog system.
Bonnie
Douglas Moore
-> Good case against Frog bashing.
-> No one would consider climbing without a seat harness in a Frog
-> system.
If they do then they shouldn't be climbing. As for using an ascending
system without a harness, I've seen two people who thought they knew
what they were doing rope walking without a harness while at a practice
session. There was also a rescue on 11/29/96 involving a pseudo caver
almost falling out of a tied webbing harness.
Doug
Karst Sports
-----------------------------------------------------------------------------
Internet: dougla...@svis.org (Douglas Moore)
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Bonnie(BXTAL1@aohell.com)Crystal
> which are unwieldy to perform using a Frog, other than winning the
> speed-demon contest at the convention.
>
>
> 1. Use of a ropewalker on real SRT rigging may tend toward adverse
> consequences for non-expert IRT cavers.
> consequences for non-expert SRT cavers.
>
> Virtual Caver
> Global Grotto
repost due to propagation
DONALD G. DAVIS
"Bonnie (BXT...@aohell.com)" <BXT...@aohell.com> writes:
>Good IRT rigging procedure for overhung/undercut lips dictates either an
>etrier or another short rope tail hung over the lip with a knotted loop
>in the end.
That is what we had to do to get out of "Lip Service," a large
room reached by an overhung drop in Lechuguilla Cave. The lip there is
the most profoundly projecting I've ever seen: a horizontal shelf about
6 feet wide but only 1 foot thick. Even my ropewalker system, which is
good for passing most overhangs, required assistance from stepping in the
rope-tail loop.
--Donald Davis
Aaron Birenboim
Bonnie (BXT...@aohell.com) (BXT...@aohell.com) wrote:
: Mitchell and Ropewalker users are sometimes forced to remove their chest
: rollers from the rope upon reaching the lip.
yea. Is that a problem? I find lips trivial on a ropewalker
by simply releasing the roler. Thats a BENEFIT, not a problem, IMOHO.
: ...advice on switching over to the Frog system.
I recently started playing with the frog... and have had
lip crossing problems. I carry a spare ascender (from my
rope walker...) which I attach over the lip, then I dis-connect
my foot ascender, re-connect over the lip, then clomb on.
Is there any better advice?
With the rope walker, I found that I could usually just lock my
arms on the lip to keep the rope off the pad, and walk
on over. If that failed, just dis-connet the top safety
(I still hace 3 attachments), re-place over the lip, dis-connect
the chest box (down to 3 attachments again) and walk on over.
Are there similar frog tricks I should hear about?
Aaron "Both TAG and NM are ropewalker country" Birenboim
NSS 32699
Sandia Grotto
--
Aaron Birenboim | aa...@ptree.abq.nm.us | Albuquerque, NM
http://www.swcp.com/~aaron RESUME> http://www.swcp.com/~aaron/res.html
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