Absurdly good gear since 1983

Rope Stuff

From the manufacturers catalog:

 Accessory Cords  Strength (approx)
 4mm  340 kgs
 5mm  530 kgs
 6mm  1150 kgs
 7mm  1360 kgs
 8mm  1650 kgs
 9mm  1700 kgs
 5.5 Sterling Vectran  3800 lbs knotted
 5.5 BD Gemini  3900 lbs knotted
 5/16" static 4000 lbs
7/16" static 6500 lbs
1/2" static 9000 lbs

Note: kn = 224.8 lbs +/-

For BlueWater's take on ropes try this:

Subject: Re: knots for two-rope rappells

From - Tue Jun 15 10:22:27 1999
Sender: cline@xxxxxxxx
Newsgroups: rec.climbing

Charles Danforth <danforth@xxxxxxxxxxxx> writes:

> OK, I'm in need of some wisdom here (yeah, I know this may not be the best
> place to look). We just returned from Seneca and have been arguing about
> the best knot to use for a long two-rope double roped rap. Steve argues
> for the traditional double fisherman's knot with backups. I maintain that
> a two-rope figure eight (i.e. lay the ropes with the ends facing the same
> direction and just tie an 8) has advantages when it comes to pulling it
> down and extricating it from cracks. Sure it looks a bit wierd.
> Any opinions?
> Charles

This is a frequent topic here and someone will probably disagree with
me - ignore them they don't know what they are spewing.

You are right, though you can do better. Use an overhand (with tails
coming out the same side of the knot) since it is simpler and better
than an eight in for this purpose. Always leave enough tail to allow
the knot to invert, though this won't happen if you tighten it
properly in the first place. Leaving too much tail is a mistake - you
don't want to mistake the tails for the working ropes. Check the knot
before each rappel during multi-pitch descents.

Although the overhand (also figure eight) knot can invert, it is
plenty strong for rappelling. It is also safer because, as you
mentioned, it is less likely to get hung up during retrieval.


(NOTE: The fig. 8 knot described here (lay ends parallel etc) seems to have caused at least one death due to the knot slipping and coming undone. Some have said this can happen at loads as low as 50Kg..... that is 110lbs for the metrically challenged.)

Subject: Re: setting up a top rope - 3 questions
Sender: cline@xxxxxxxxxx
Newsgroups: rec.climbing

mdimeo@xxxxxxxxxxxx writes:
> In article <u7ls0i9cq.fsf@xxxxxxxxxxxxxx>,
> > As if TR on static rope results in forces on the same order as lead
> > falls. You'd have to seriously screw up for that to happen.
> They say (but you know the kind of things that "they" say) that
> forces of 1000 lbf have been measured at toprope anchors with
> dynamic rope (whether the belayer "screwed up", seriously or
> otherwise, I don't know). That's around 4.5kN. What's your guess as
> to how much static rope would increase that? Double? 9kN is where
> crossloaded or open-gate biners can be expected to break. And I'd
> bet double is way too optimistic. If it's as much as quadruple,
> girth hitched slings could break where biner-linked slings might
> not.

The short answer is that fall force is not linear with free-fall
distance or rope characteristics, and top roping on static rope won't
result in equipment failure and death. A 200 pound slingshot top
roper will load the anchor with about 660 pounds of force in a fall
with zero slack, regardless of whether the rope is dynamic, static,
bungee, or steel cable. As you add free-fall, the force felt by the
anchor starts to depend on the type of rope, but the transition isn't
all that abrupt for the types of rope that climbers use.

In testing, static ropes appear to be about 3 times as stiff as
dynamic ropes at body weight loads: the modulus of elasticity for
static ropes at bodyweight loads is around 16000-20000 lbf/ft/ft,
while dynamic ropes check in around 4000-8000 [Stephen W. Attaway,
Rope System Analysis]. You might expect worst case forces to be 3
times as high for static rope, but testing on Blue Water ropes [CWIG
Standards Development Basic Research Summary, 1993] shows only a
factor of 2 for HARD falls. Note that for mild falls, like those
encountered in top-roping, will not result in as large a factor of
difference between static and dynamic ropes.

For example, the 1000 lbf anchor force fall you mentioned is easily
generated on dynamic rope under the following conditions: 30 foot rope
with static belay, 200 lb climber, and 1.5 feet of slack. With static
rope, these same conditions will result in a force of about 1500
pounds. Note that most belay devices will begin to slip under these
conditions, reducing the actual force on the anchor. Now increase the
slack to 6 feet and what do you expect? If you think this body-length
fall on a short static rope will generate dangerously high forces, you
are mistaken. In fact, these severe static rope TR conditions will
result in only 1/3 or so more force, about 2000 pounds total on the
anchor. Even a girth hitch tied in Karl's old supertape would hold

These numbers assume that ropes behave like springs (an assumption
supported by the literature and verified by my own analysis of fall
force data), a 200 lb climber, static rope with modulus of elasticity
of 18000 lbf/ft/ft, and a force ratio of 1:0.6 over the carabiner.
The normal laws of physics apply.

Any questions?


Subject: Figure 9 Rappel & Tie-In Knot Test
From: ratagonia@xxxxxxxxxxxxxxx
Newsgroups: rec.climbing
Date: Fri, 07 May 1999 00:06:53 GMT

Someone out there proposed the Figure 9 knot as a superior Rappel Knot. The
loading situation is the same as using your rope tie-in loop as a belay loop.
A figure 9 knot is like a figure 8, but you go a half-turn further before
finishing it.

BD Test Doc # TD 15025 4-28-99 Tom Jones

Load Speed 8"/minute. 10mm steel pins top and bottom.

Test was performed using a slightly used 10.5mm Yellow rope. A figure 9 knot
was tied forming a short loop. Two pins were inserted into the loop and
pulled apart. Performance was compared to a Figure 8 knot tested under the
same conditions.

Fig 9 Results: The rope stretched and the knot tightened as usual. Unlike a
fig 8 knot, the fig 9 does not creep down the free ends - the knot
essentially has a built in backup knot. Under loading, the knot "looks like"
two knots - a front knot and a back knot. At about 2900 lbs, the front knot
inverts over the back knot, and the load drops to about 2700 lbs. Loading
continues and the load increases fairly smoothly up to 4000 lbs, where the
sheath breaks on one side. Max load achieved was 4398 lbs. Neglible creep at
the free ends was experienced.

Fig 8 (with backup knot ) Results: loads up and stretches. At 1500 lbs, the
knot inverts, and the load drops to about 1000 lbs. Reloads slowly, but it
creeps along the free ends at a load of about 1000 lbs until it hits the
backup knot. Then it loads fairly evenly to 4509 lbs where one side of the
sheath breaks. Max load was 4509 lbs.

My Conclusions:
A. Figure 8 knot should be used with a backup knot.
B. Figure 9 knot is essentially a backed up figure 8.
C. Maybe I'll use a fig 9 next time.

Tom Jones
Black Diamond Equipment, Ltd.

Disclaimer: These are my personal opinions and recommendations, and may or may
not be shared by Black Diamond.

Subject: Re: Old Slings-how Strong? DEET
From: csoles@xxxxxxxxxxxx (Clyde Soles)
Newsgroups: rec.climbing

Jason Huckaby <huckaby@xxxxxxxxxxxx> wrote:
> What type of nylon does
> DEET not affect?

nylon 6 and nylon 6,6

> What type of nylon is your rope made from?

nylon 6,6 just like all the other climbing ropes. The tests have been
done...deet is not a concern.

DISCLAIMER: Unless otherwise indicated, this post is personal
opinion and NOT an official statement of my employer.


Subject: My Dan Osman Rope Failure Analysis
From: Chris Harmston <chrish@xxxxxxxxxxxxx>
Newsgroups: rec.climbing
Date: Fri, 16 Jul 1999 12:09:11 -0600

I think it is time I spoke up publicly. I have reviewed Dano's rope in
some detail. My findings and theory support those published by Kevin
Worrall in Climbing (No 183, March 1999, Pg 90).

This statement is mine personally and NOT that of Black Diamond Equipment!
This is obvious as you read below.

Irrelevant Background:
I am a Materials Engineer with BS degrees in Physics and Materials
Engineering and a ME in Materials Engineering (I nearly finished a PhD but
bailed once I learned I did not enjoy being a scientist any longer). I
know lots about atomic layer semiconductor crystal growth. I have been
the Quality Assurance Manager for Black Diamond Equipment for 6 years. My
primary responsibility is the testing and analysis of climbing equipment,
among other stuff. I have been involved in the ASTM climbing and
mountaineering standards development for the last 4 years. I investigate
all accidents I hear of involving equipment failure, whether they are BD's
or not. I review rec.climbing every day looking specifically for posts
related to accidents, gear, misuses of gear, issues about BD, etc. I, and
others at BD, go out of our way on this news group to publish information
above and beyond what is required by the standards that climbing gear is
designed to (see the recent lame thread on "Gear Safety" which I will not
respond to specifically. See Karl Lew's web site. Search under my name
on dejanews for examples). I do not post to this news group as a general
rule unless I think that posts from various people are specifically wrong
or misleading, as is the current case (in fact I try to avoid posting
because of commercial conflict of interest). I respond to individuals on
this news group constantly and my comments to these people come back into
this group (see the current RP thread on soldering cable fatigue). I
respond in detail to individuals who ask me questions, even when they do
not like what BD is about (see recent Camalot threads and failure analysis
associated with this thread).

Even more irrelevant background:
I have been rock climbing since 1981, and am primarily a trad climber. I
am a risk taker because I climb. Climbing IS dangerous and anyone who
thinks otherwise if fooling themselves. Anyone who climbs is a risk taker
in my opinion. I climb 5.12 on any rock type (that I have been on) and
style (except offwidth, so far) and have onsighted up to 12c/d. I climb
WI6 and possibly harder (ice is either hard or easy to me and is my
primary passion). I climb M8. I establish new rock, ice and mixed
routes ground up with and without bolts. I have no aid or alpine
experience. I weight 190 lbs and take upside-down 40 to 60 footers
without my helmet on. I have nearly killed myself several times due to
falling off 5.8. I am a climber, climbing eventually involves falling,
which may very well kill or maim me. Most people, including myself, would
consider me to be reckless because of how I climb. I climb for my own
reasons and no one else's. I don't care what people think about me in
general. Why Dano jumped off cliffs is his own personal choice that
nobody has a right to argue against, even if he had children in my
opinion. I certainly have no right to judge his reasons for doing what he
did. I respect Dano for pushing the limits way way beyond where they had
been previously. I met Dano twice but did not know him. I know many of
his friends.

Relevant Background:
My expertise in the analysis of broken climbing ropes is very limited.
This is due to the fact that climbing ropes very rarely break or cut in
actual use. The only previous experience I have with rope failure
analysis was that of Matt Baxter who died on El Cap several years ago when
his rope was cut by a flake after a carabiner had broken (see dejanews for
more info on this, send a Freedom of Information Request to the NPS-I
recommend you do it for the Dano accident as well and then you can have a
copy of my official report, or look at ANAM). I have also reviewed
several ropes with sheaths shredded due to the open back regular carabiner
gates in minor axis. This lack of experience could indicate that my
findings are incorrect or suspect.

I first became involved in Dano's accident when news of Dano's death
spread across this news group with the associated rumors that the NPS
might have purposely cut his rope. On December 9, 1998 I sent an email to
John Dill (YOSAR director) letting him know of these rumors on this news
group and offered my assistance in the analysis of Dano's equipment. John
responded back that Yosemite Law Enforcement (YLE) was investigating the
accident and that they had to finish their investigation before I might be
able to see the ropes (they too knew of the rumors of murder and were
investigating this as well I suspect). As you all should know Dan's ropes
stayed on the wall for over a month and YLE was unable to recover them.
Given the rumors of tampering by the NPS a climber took matters into his
own hands. He recovered the ropes and sent them directly to BD. As soon
as I received the ropes I contacted YLE because I was in possession of
stolen federal evidence from an active investigation. I was told to
return the ropes immediately and reveal the name of the person who sent me
the ropes. While on the phone with the lead investigator another phone
call came into BD from "someone within YLE" stating that the FBI would be
at BD to arrest me if I did not send the ropes back the next day. I was
freaking out to say the least. Meanwhile I looked at the rope in some
detail. It was melted through. It looked as if there were the
possibility that someone had hot cut the rope. When I called YLE back and
told them this they wanted me to conduct my full investigation and allowed
me to keep the rope for two weeks. No FBI showed up to haul me away.


I only saw the one section of rope that was cut down and contained the
failure point. I did not see the rigging, retrieval rope, or the section
that was attached to Dan directly.

Everything I did was visual examination. I did not untie any knot or
tamper with the rope in any way other than prying the knots to see inside.
With some insight from Doug Heinrich I concluded that the failure of Dan's
rope was not due to tensile overload or from being tampered with. I
strongly believe that Dan did miscalculate on his last jump. For some
reason he moved his jump site. In doing so he crossed the ropes (either
on the retrieval line or on the main jump line). When he jumped the first
knot above the one he was tied in with slid down a section of rope several
lengths up. The sheath was heavily melted and removed in several sections
on this upper part of the rope. The knot that slid down the rope was
melted in multiple locations and was melted nearly completely through,
deep inside the knot. This knot was not tight, yet others in the system
were (this is the one open question that is unresolved as far as I know).
It is my conclusion that Dan's rope was cut by his own rope sliding
against itself. Use of a magnifying glass indicated to me that the cut
surface was due to sliding action in one direction. There was no evidence
of hot cutting with a knife or other type of instrument. I conducted
further experiments in my lab to see if tensile overload could have caused
this failure. The samples I tested were significantly different in that
they were heavily frayed and tattered. My analysis of Dan's ropes in
general was that they were in great condition. There was no evidence to
me of damage due to previous falls, uv exposure, or weather. I would have
climbed on these ropes without any hesitation had they not been from this
accident. I do not believe that the condition of the ropes had anything
at all to do with the failure of the ropes. Nor do I believe that Dan's
basic shock absorbing setup was incorrect. Crossing the ropes was the

I was asked by YLE not to make my findings public until they had finished
their criminal investigation. They forced me to tell them who sent me the
rope and they pressed charges against this individual (I will have to live
with the fact that I was unable to keep this information confidential). I
still have not heard back from YLE about closure of this accident and
decided to make my findings public now due to the vast numbers of
misinformed posts relative to this subject. Maybe my analysis will stop
some of the useless bickering many of you are currently engaged in.

What is to be learned from this accident? NEVER LET NYLON SLIDE AGAINST
NYLON! You should already know this.

I also know that Dano's rigging setup was reviewed by more than a couple
of technically competent people. I also know that he tested it multiple
times. I personally do not think that what Dan was doing (when done
properly as he had done on earlier jumps) was any more dangerous than
modern ice climbers doing hard thin ice routes (like in Maple Canyon and
elsewhere), in fact his setup was most likely safer in my personal
opinion. Dan's death was a tragedy and an accident.

Again, this summary is mine personally and not that of Black Diamond.

Chris Harmston (chrish@xxxxxxxxxxxx).
Quality Assurance Manager. Materials Engineer BS, ME.
Black Diamond Equipment Ltd.
2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552

DISCLAIMER: Unless otherwise indicated, this correspondence is personal
opinion and NOT an official statement of Black Diamond Equipment Ltd.

Rope Edge Tests

From: csoles@xxxxxxxxxxx (Clyde Soles)
Newsgroups: rec.climbing
Subject: Re: Rope cut and Death of Steve Garvey
Date: Fri, 20 Aug 1999 17:20:54 -0600

<mfletcher4280@xxxxxxxxxxxxxx> wrote:
> The UIAA does have an edge test, but some rope
> companies, Edelwiess and Roca, have tested their
> ropes for surviving a fall over an even sharper
> (0.75 mm radius) 90 degree edge than the UIAA
> test. The UIAA does not require this sharper edge
> test. Only two rope types in the world, that I am
> aware of, pass this sharper edge test, the
> Edelwiess Stratos and the Roca Tasmania. Perhaps
> the UIAA should impose this sharper edge test in
> light of accidents such as this.

I knew this was coming. No, there has never been an official UIAA or CEN
edge test but the one Edelweiss developed to market their rope is
becoming somewhat standard. Several brands of plain-old 11mm ropes will
pass this test (I witnessed them). None of the 10.5's other than the
Stratos and Tasmania will survive. No rope will survive 2 edge falls
(until Mammut's new 11 comes out next year).

No rope (including "cut-resistant" models) will survive the fall when
the edge is reduced to 0.5mm. Many more ropes will pass on a 1.0mm edge.
It's the arbitrary "cut-off," if you'll excuse the pun, at 0.75mm that
has kept a standard from being passed. Many glaciers move faster than
the UIAA.

Given the description of the tragedy, it sounds like a pair of Stratos
9's might have been the best bet...but there are no guarantees.

DISCLAIMER: Unless otherwise indicated, this post is personal
opinion and NOT an official statement of my employer.

Subject: Test Report - Fig 8 Tie In Knot
From: ratagonia@xxxxxxxxxxxx
Newsgroups: rec.climbing
Date: Fri, 22 Jan 1999 23:02:50 GMT

I tested a figure 8 as a tie in knot using the test machine at Black Diamond.
This was to see how strong the 'belay loop' formed by your tie in knot is.

Rope: slightly used 9.7mm single rope
Knot: follow through figure 8 like when tieing in
Date: Dec 16, 1998

Setup: pulled at 4"/minute. Pulled as a loop with the knot in the center of
one of the strands. Used 1" pins both ends.

Results: Knot loads steadily and tightens up to 2200 lbf. At this point, the
knot starts to roll, and the force drops to 1500 lbf. Then the stiff end of
the rope where it is taped started to get sucked into the knot, and the
rolling action stops. Load increased steadily to 4050 lbf, where the sheath
on the non-knot side broke. Force drops to 3400 lbf. Load increased steadily
to 4050 lbf, where the sheath on the knot side, upper strand broke. Force
drops to 3750 lbf. Load increased steadily to 4884 lbf, where the core broke
at the knot, breaking the loop.

Conclusions: Figure 8 knot can roll in this loading configuration ( belay
loop on harness or when used as quick rappel knot ) at a load on the order of
1500 - 2000 lbs. It will continue to roll until some mechanism stops it. A
backup knot on a figure 8 in a pulled-apart loading configuration actual does
something. I will use these from now on when rappelling. Ultimate strength of
loop is > 16kN belay loop strength.

Additional Comments:
One data sample only gives you a general idea of what is going on. Loads for
rolling and for breaking can be expected to vary quite a bit with rope size,
surface conditions and loading sequence. Having one side jammed up against a
chain or rappel ring may also effect this. Take this with a grain of salt,

Opinions expressed are my own, and may or may not be shared by my employer.

Jratus Utahnus.

Subject: Rope Life--Some Data
From: Chris Harmston <chrish@xxxxxxxxxxx>
Newsgroups: rec.climbing
Date: Tue, 19 Jan 1999 14:00:41 -0700

Here is some test data from an investigation I conducted last summer.
Ropes were provided by a customer who was asking similar questions as you
all are.

All ropes were used slightly. I conducted a pull test on a loop of rope
with an overhand followthrough knot (used this knot to minimize knot
tightening and test machine travel). I did not conduct drop tests because
we do not have this capability at this time.

1) 1986 Chouinard 8.8 mm. 3240 lbf @ knot. (this is a half rope)
2) 1986 Chouinard 11 mm. 5944 lbf @ knot.
3) 25 year old 11 mm Edelrid. 5141 lbf @ knot.

Conclusions. Don't know how strong these ropes were when new. Single
strand strength of these ropes is conservatively half the loop strength
(big assumption on my part). I would say this is pretty good overall. I
do not know what the dynamic properties of these ropes were nor do I know
how time affects the dynamic properties. My recommendation to the
customer was to not take any chances with the ropes in lead climbing. I
would use them for top roping without any reservations.

Data from a test I conducted on 12/22/98 (research into Dan Osman's failed
rope--to be published later so don't ask questions about this right now
please). Loop, knot was a quad followthrough figure 8 (I have a new
machine now and can test with longer travel).

All ropes are BD ropes. New condition 1997 ropes.

1) 11 mm. 6643 lbf @ knot.
2) 11 mm. 6803 lbf @ knot.
3) 10 mm. 4596 lbf @ knot.
4) 10 mm. 4765 lbf @ knot.
5) 10 mm. 4952 lbf @ knot.

Conclusions: very strong.

My Conclusions and Recommendations. Rope strength does not appear to
decrease with time. I don't trust old ropes because I do not know how the
elastic properties change with time. This needs further research. Chris.

Chris Harmston
Quality Assurance Manager/Materials Engineer BS. ME.
Black Diamond Equipment Ltd.
2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552

Subject: Re: Rope Life--Some Data
From: Chris Harmston <chrish@xxxxxxxxxxxxx>
Newsgroups: rec.climbing
Date: Wed, 20 Jan 1999 08:22:08 -0700

I would have to forget to add the important fact that I tested all my
samples over 3 inch diameter steel pulley's, duh!. Had I tested over 10
mm diameter pins the failure would have been lower and would have been at
the pin as Mr. Davis has observed in his tests. Thanks for asking John.

On Wed, 20 Jan 1999, John Davis wrote:
>Chris - a quick question, what kind of fittings did you use for the load
>application points?
>I ran some tests on webbing and ropes last year on our Instrom (shit, no
>point having it if you can't play with it:-). Anyway, one of the samples
>was a really sad old 11mm rope. It was approximately 10 years old, and
>heavily used, both for climbing and for caving. Apparently it'd also been
>used to tow a couple of cars since it's retirement too!!!! We tied a chunk
>into a loop using double fishermans knots, and used 10mm steel rod for the
>load points (to simulate loading on a carabiner). The sample failed at about
>1500kg (3300lbf), which is about what we expected (like I said, it was a
>stuffed rope), but what we didn't expect was that it went at the load point,
>_not_ at the knot. I'm sure we could have got higher figures and failure at
>the knot if we'd used larger diameter stock for the fittings, but that
>seemed a bit silly (since I don't normally used 20mm diam krabs:-).

>Elongation was impressive - including stretch and knot slippage the loop was
>about 3 times the initial size when it went. The photos of it near breaking
>point are very cool, and enough to convince most skeptics that even old
>ropes are pretty strong!

Chris Harmston (chrish@xxxxxxxxxxx).
Quality Assurance Manager. Materials Engineer BS, ME.
Black Diamond Equipment Ltd.
2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552

cumulative damage on ropes 
Author: Al Black
Email:   al@xxxxxxxxxxxxx
Date: 1995/12/08
Forums: rec.climbing

There is an implicit idea in the falls on a discussion that I've never
been able to figure out. What is the cumulative relationship of number of
fall to rope damage over time. In other words, does a factor 1 fall cause
the same amount of damage to a rope when its had few falls on it as when
the rope has had say 15 factor 1 falls on it.

The usual sources seem to suggest an additive or a least linear
relationship between rope damage and number of falls of a given force. My
intuition suggests that a curvelinear or exponential relationship would be
more accuate description.
George, Clyde, and other rope physics guys, what gives?

Re: cumulative damage on ropes 
Author: Clyde Soles
Email:   Clyde_Soles@xxxxxxxxxx
Date: 1995/12/08
Forums: rec.climbing

In message ID <4a8kgu$gg0@crc-news.doc.ca> on 12/7/95, Al Black
<al@xxxxxxxxxxxx> wrote:

> There is an implicit idea in the falls on a discussion that I've never
> been able to figure out. What is the cumulative relationship of number of
> fall to rope damage over time. In other words, does a factor 1 fall cause
> the same amount of damage to a rope when its had few falls on it as when
> the rope has had say 15 factor 1 falls on it.
> The usual sources seem to suggest an additive or a least linear
> relationship between rope damage and number of falls of a given force. My
> intuition suggests that a curvelinear or exponential relationship would be
> more accuate description.
> George, Clyde, and other rope physics guys, what gives?

Sorry, I failed the same physics class twice in college (hey it was boring, why
bother? I was more into climbing.). Actually I looked into this when I did the
article and nobody had done any serious research (read: takes a lot of time and
money). The tests by Bluewater on "sport falls" (high repitition, low fall
factor) did seem to indicate the rope damage was curvilinear but they did not do
enough tests to be statistically valid.

Re: cumulative damage on ropes 
Author: Elmar Stefke
Email:   elmar@xxxxxxxxxxxxx
Date: 1995/12/18
Forums: rec.climbing

In article <006B2C9F.fc@nile.com>, Clyde Soles <Clyde_Soles@xxxxxxxxxxxx> wrote:
>money). The tests by Bluewater on "sport falls" (high repitition, low fall
>factor) did seem to indicate the rope damage was curvilinear but they did not do

The tests by the DAV (similar to BW - low fall factor falls) showed serious
rope damage after 80 falls (pretty much anybody would have retired the rope
by that point), however the rope held more than 200 falls before breaking.


Re: cumulative damage on ropes 
Author: Loui C
Email:   102332.2263@xxxxxxxxxxxxxxxx
Date: 1995/12/10
Forums: rec.climbing

Interesting POV... and you are right. A rope loses its'
ability to withstand the force of a fall in somthing other than a
linear manner; however, I am not sure that it can be expressed
exponentially, either. After the very FIRST fall (let's use
factor 2 as an example, since the UIAA tests are rather close to
that) a rope will lose much of its' elasticity, thereby SUDDENLY
losing much of it's capacity for force absorption. After that one
fall, the rope loses less elasticity with each fall (there's less
to lose!), and what is happening during the rest of the drops is
that the fibers are taking the damage. This is nearly impossible
to quantify, though, since the fibers are ameliorating this
damage randomly over a long length of rope.
Take this concept to your climbing rope and it gets even
less definable, since you (probably) fall on a different length
of rope each time with a different fall factor...
DISCLAIMER >> PMI/PETZL signs my paychecks but, unless otherwise
stated, opinions and statements herein are my own . . .

Re: New theory on rope dynamics / fall factor... 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxx
Date: 1996/11/11
Forums: rec.climbing

Hugh B. McNeil <ch937@Fxxxxxxxxxxxx> wrote:
> It occurs to me (heat shields up) that in a leader fall, that
> the fibres of the rope "pinch" each other, and causing some
> isolation of the sections of rope passing between the belayer and
> the carabiner over which the rope bends, and the climber's
> section of rope which goes from his belt to the carabiner at
> the high point.

There is some validity to this but it is minor to other factors. FWIW
all of the rope companies send their dry ropes for the UIAA
certification because they yield slightly lower impact forces and one to
two extra drops over the standard ropes. This is due to the lubricity of
the dry treatement. The effect is greatly diminshed once the ropes get

> With a dynamic rope, the implication is that the section of
> rope closest to the climber will undergo the most stress, and
> (barring defects or damage) the rope will always break (if ever)
> on the climber's side of the rope.

This is absolutely true. The difference between the theoretical fall
factor and the effective fall factor is significant but is's mostly due
to friction in the system. It's not practical to calculate however so
nobody does. In the drop test, the rope always breaks at the orifice.

> More interesting, perhaps it is this factor (if it is) that
> is more responsible for the differences in impact experienced by
> the climber and the belayer, than friction at the high point
> carabiner is...

Don't think so. Friction is the main culprit not only at the top biner
but all those below it and rope against rock.

> If the rope is in fact pinching itself at the high poin
> carabiner, then another implication is that fall factor is
> misunderstoodd as it applies to overall effects on rope
> damage.

Hell most climber's don't understand fall factors enough to be able to
misunderstand them.

> Also, is there efectively a higher fall factor
> experienced by the climber's side of the rope than the belayer's?


Re: Impact force [warning - even more boring technical info] 
Author: Clyde Soles
Email:   csoles@xxxxxxxxx
Date: 1998/03/02
Forums: rec.climbing

Schalk W. Cronje <schalkc@xxxxxxxxxxx> wrote:

> No, friction is unrelated to fall factor. Friction in the system
> occurs because of
> 1. Friction of the rope running over the top karabiner
> 2. Slippage of the rope through the belay device
> This reduces the effective impact force in the system. Even the
> harnesses worn by both the leader and belayer contributes to reducing
> the impact force.

Actually the effective impact force on the climber will always be higher
in the real world than the theoretical impact force because of friction.
The friction over rock and through each carabiner reduces the ropes
ability to absorb the force of a fall. IOW, you may fall on 20m of rope
but are only getting the equivalent of say 15m that is catching the
fall. What this really means is all the formulas are worthless from a
practical standpoint. BTW tests have shown the effect of harnesses and
knots is minimal at best.

Re: Rope Twist
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxxxxx
Date: 1998/11/30
Forums: rec.climbing

Mark Hinman <icedog@magicnet.net> wrote:
> Perhaps some of the great minds assembled here could enlighten me as to
> a "twist of fate" I've encountered with my new rope.
> I bought a Blue Water 9.6x60, dry finish. I flaked it out to inspect it <<snip>>

Stop right there. The problem has nothing to do with the rope and
everything to do with how you handled it. This is a common mistake by
climbers over-anxious to play with their new rope (brand matters not).
All the kinks were introduced by flaking out the new rope instead of
unwinding it. Using a round coil didn't help either.

Now that the deed is done, that rope is cursed for life...or until you
make several long raps with it.

Re: UIAA rope test results 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxxx
Date: 1998/10/22
Forums: rec.climbing

Haven't seen the report but there isn't much I wasn't aware of

Al Black <al@xxxxxxxxxxxxxxx> wrote: quoting the Alpine Club of Canada for their work on the UIAA safety commission, and the Fall 98 ACC Gazette:
> Anyhow the the dirt is:
> 1) Gasoline, diesel fuel, camp gas, sea water, coca cola, and strong
> vinegar do not damage ropes . Urine dropped the number of falls held in
> the standard test drops by 50%.

Old news but it doesn't seem like a good idea to soak your rope in gas
anyways (what about all the additives?). Acid is the big no-no.

> 2) "An American product (Sharpie) specifically sold for marking the middle
> of ropes reduces the strength of the rope (only at the point of marking
> however and only when this point is loaded over the test edge) by as much
> as 50%."

Actually Sharpies are not marketed for marking ropes (can you say
"liability" ;-) and it even says on the pen "not for cloth." The only
pen I know of sold for ropes is Bluewaters and they control the solvent

> 3) "It appears it is not possible to damage ropes by walking on them with
> heavy boots even when the rope lies on sharp edges. Even walking on the
> rope with crampons does not weaken the rope." ...

Yep, but I still don't like someone walking on *my* lifeline.

> 4)... "wet or iced ropes experience a major drop in edge strength (falls
> for half rope go from 9 to 3) regardless of whether they are dry treated
> or not."

There is no official edge test so stuff like this has to be taken with a
grain of salt. The bigger question is what happens to impact forces?

> 5) Recent comparison testing of climbing ropes among various labs
> has shown that the results are all over the map (up to 100%) on a variety
> of parameters.

I reported this years ago and Mammut/Edelrid recently showed how
pervasive the problem is. The UIAA never calibrated/cross-checked the
official labs, duh. It basically means the reported stats are not
reliable between brands until the UIAA gets their act together. Some
companies have been accused of manipulating the data for marketing but
there is no way to verify this. Caveat Emptor.

> 6) Ropes used for top roping lose strength over an edge very quickly. "They
> should not be used for field work."

No surprise. Same reason sport climbing is so hard on ropes.

> 7) The official position of the Safety Commission regarding rope use for
> glacier travel is that one strand of a half rope or twin rope is perfectly
> adequate.

Nice of them to acknowledge what everyone has done for ages.

Re: Fall Rating?
Author: Clyde Soles
Email:   csoles@xxxxxxxxxx
Date: 1998/09/28
Forums: rec.climbing

tony <tony@celnetwest.com> wrote:
> This may sound like a dumb question, but what exactly is meant by the fall
> rating? If a rope is rated at 10 falls, and it is fallen on 10 times, is it
> time to get a new rope? That doesn't seem right. Or is the information
> simply to use in making comparisons of different ropes? Does a rope get a
> lot weaker as it's fallen on more and more often? What are the specifics?

It's mostly a number used by the marketing departments to hype their
product. In the real world, it has almost no meaning and should be given
little importance when selecting ropes. See R&I #68 if you want the

Re: Rope age 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxxxxt
Date: 1997/12/27
Forums: rec.climbing

C & V WALKER <cvwalker@xxxxxxxxxxxxxxx> wrote:
> Clyde thank you for your prompt reply.

Taking a break from my deadline. Bah humbug.

>I understand that rope ages but by
> what mechanisim? Many polymers contain volitile plasticisers that evaporate
> with time and temperature. My understanding of nylons are that they do not
> need plasticisers and therefore only age when the long chains are broken by
> chemicals or UV light.

They do use plasticizers in nylon but it depends on the application.
Case in point: high-quality sunglass frames (eg. Vuarnet) are made of
"French" nylon which has a much higher plasticizer content than the
cheap drugstore variety (also nylon) that are prone to snapping,
especially after a year. This material does leach out with time.
Research has shown that UV degradation is less of a factor in climbing
ropes than ozone.

> The following is an excerpt from BlueWater's web page;
> "Shelf life Although there is no conclusive evidence from nylon
> manufacturers, we recommend the shelf life of an unused rope to be five
> years."
> It maybe that some softeners/plasticisers are used or that the polymers
> breakdone by other means. If I find any further information I'll post it'
> in the mean time does any one else have any thing to add?

The polyamid used in ropes is nylon 6,6 but that is just part of the
recipe, there are additives (UV inhibitors, dyes, etc.) and coatings
applied as well. Testing the raw material has little meaning to a final
rope, hence BW' statement. Much of a rope's characteristics are
determined by twisting of the core fibers and the all-important heat
set. This cooking of the rope stabilizes the nylon (it shrinks) but it
is hardly permanent.

Re: Rope age 
Author: Clyde Soles
Email:   csoles@xxxxxxxxx
Date: 1997/12/26
Forums: rec.climbing

C & V WALKER <cvwalker@xxxxxxxxxxxxx wrote:
> Does some one have any evidence of how a rope ages without use? This
> question stems from reports suggeting that ropes should be retired after
> five years even if they have had little use and checkout good. The reports
> all apear to come form parties that sell or produce rope, and do not
> contain supporting evidence.

There is quite a bit of evidence to back up that suggestion...it isn't
just to sell rope. The reason is because nylon loses its elasticity with
age so the forces placed on gear and body go up. Retiring only means
from lead use; you don't have to throw it away.

Re: Cutting rope 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxx
Date: 1996/09/17
Forums: rec.climbing

Flip <jesundee@xxxxxxxxxxx> wrote:
> I have a bad section of rope, only about 5 feet from the end, where the
> sheath has been torn and you can barely see the core. I'd like to cut
> that 5 feet off and re-seal the end. What should I use for cutting the
> rope and "melting" the end to seal the braiding from coming loose? From
> experience with cutting static-line for cams and hexes, I've found that
> it's really hard to cut it without getting "messy" with loose braids
> running around.
> What should I use to cut it and melt the end cleanly?

Wrap 1" cloth tape (or similar) tightly around where you intend to cut.
Use a cutting board and a sharp knife through the middle of the tape.
Seal the ends on a hot electric stove burner (don't inhale). Ignore
Ternes, his thorazine ran out.

Re: Rope Question "with some new data" 
Author: Chris Harmston
Email:   chrish@xxxxxxxxxxxxx
Date: 1998/03/17
Forums: rec.climbing

Here is an interesting summary of one rope that was very heavily used,
abused, retired, and then tested. Don't take this information to mean
that you should not retire your ropes after severe falls or heavy abuse.

BD gave a 10 mm rope to Merill Bitter. Merill climbs more than anyone I
know. You could say that he is anal about keeping records of his
climbing. Merill is one of the best climbers in Utah and has redpointed
5.14 and has put up numerous 5.12 trad routes in the area. The following
data is from his climbing log. This rope was manufactured in 1996.
Merill weighs about 125 lbs (my guess).

rope used during 71 days of hard sport climhbing-
628 Falls (2 to 25 feet)
625 Lead Climbs
198 Top Ropes
1242 Hangs or "takes"
636 lowers from anchors
2 double line rappels
1 Jumar pitch

2 sections of rope were cut off (15 feet from each end) due to core shots
suffered from the above abuse."

I took Merill's rope and had it tested according to the UIAA/CEN rope
standards. Two tests were done. One from the end of the rope and one
from the middle of the rope. I thank BEAL Cordes for this testing.

The UIAA test is a 1.78 fall factor with 178 lbs. This is an extremely
hard fall with static belay!

Sample 1 (end of the rope).
Number of falls to cause failure: 1
Impact Force 7.45 kN (1674 lbf)

Sample 2 (middle of the rope).
Number of falls to cause failure: 3
Impact Force on 1st drop 7.41 kN
Impact Force on 2nd drop 9.20 kN
Impact Force on 3rd drop 10.45 kN.

This demonstrates that the impact force increases rapidly with repeated
falls. It also shows that this rope performed very well considering the
amount of use it has seen. I certainly don't recommend that anyone use a
rope to this extreme. When new these ropes would hold between 7 and 10
falls and the impact forces on the first drop were in the 6.5 kN range.
It is amazing that the impact forces on this rope are as low as they are.
Note, BD ropes have some of the lowest impact forces on the market (our
ropes are manufactured by Beal and PMI) so don't assume that your rope
will perform the same as this one has. Lower impact force ropes equate to
lower forces on the gear which increases the probability that the gear
will hold the fall. Note, the impact force is that felt by the "climber"
or the tension in the rope. The protection would have felt about 1.6
times the force stated. For the third fall above the protection would
have felt about 3700 pounds of force (greater than 16 kN) which is more
than enough to break stoppers, Camalot Jr's, carabiners in open or closed
gate, etc. In real life the forces will be significantly lower due to
energy absorbtion due to belay device slippage (friction), two bodys
involved instead of steel and a static belay. FWIW.

Chris Harmston (chrish@xxxxxxxxxx).
Quality Assurance Manager. Materials Engineer BS, ME.
Black Diamond Equipment Ltd.
2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552

On 16 Mar 1998, Kenneth Cline wrote:

> I'd be reluctant to accept that low ff falls do no damage without
> further verification.
> Here's why:
> First of all factor 1 falls are pretty severe. I don't recall the
> estimates I've made, but the tension produced in the rope is
> significantly more than half the tension in a factor 2 fall. The
> nylon doesn't absorb as much energy per fall, but it seems likely
> that some inelastic work is done in factor 1 falls. If I took
> multiple falls close to factor 1, I'd start thinking about a new
> rope.
> Secondly, the last time I checked, manufacturers said they did not
> have a good understanding of what happens to a rope that has
> sustained many moderate falls, and I haven't seen any guidelines
> that cover this use. Concern over this has been expressed, though.
> Maybe manufactureres have new recommendations on this subject - if
> so, I'd love to hear them.
> One thing is clear: After holding a fall, a rope's shock-absorbency
> is reduced, though it may be (partially) restored if allowed to
> rest. It has been hypothesized that this reduction in
> shock-absorbency has contributed to the breaking of carabiners that
> occasionally occurs during falls. Even if the rope doesn't break
> (climbing rope failure is, after all, extraordinarily rare), an worn
> out rope might contribute to an accident.
> There is one thing I do agree with wholeheartedly: Use your
> judgement. Retiring a rope is cheap compared to serious injury or
> death, but, fortunately, these are not often caused by rope failure.
> In article <350D5F2F.C843251C@xxxxxxx>, Christ <cstpierr@xxxxxxxxxx> writes:
> |> When a manufacturer specifies the number of falls a rope can take, it refers
> |> to the UIAA falls as mentionned previously.
> |>
> |> But how can you transpose this number of fall on the terrain? The number of
> |> falls refers to the fall factor. A fall of factor 1 means that the length
> |> of your fall equals the length of rope that separates you from your belayer.
> |> Example: you have climbed 5 vertical meters and your last pro is 2.5 meters
> |> below you, then your fall factor is 1. Falls of factor less than 1 should
> |> not be considered as dammaging for equipment but you have to use your own
> |> judgement here. With a fall of factor 2 (the highest fall factor in free
> |> climbing...), you should consider replacing your climbing material.....
> |> Petzl www site (http://www.petzl.com/) gives technical notes about fall
> |> factors and the Freedom of The Hills bible will tel you a lot about it too.
> |> Note that fall factors more than 2 can happen in some situations (for
> |> example, in Via ferratas http://www.petzl.com/english/dir/zyper.html#1).
> |> I hope that this will help.....
> |> See also the page: http://www.petzl.com/english/dir/shock.html
> |> Any other comment?
> |> Good Climbing.....
> |> Christ.

Re: Rope Question "with some new data" 
Author: Chris Harmston
Email:   chrish@xxxxxxxxxx
Date: 1998/03/19
Forums: rec.climbing

On 19 Mar 1998, Tom wrote:
> My interpretation of these results are much worse for two reasons:
> 1) In actual use, the rope would have failed on the very first fall at
> "7.45 kN (1674 lbf)" based on "Sample 1 (end of the rope)" results
> since the rest of the rope ("Sample 2 (middle of the rope)" would
> have been attached to it and I assume to the belayer, etc.
> Admittedly, it would have been a "1.78 fall factor with 178 lbs"
> though.
> I am not impressed at all.

It is certainly possible that this rope could have failed in the field. I
doubt it because of the fact that the UIAA setup is far more severe than
what you can do with people and belay devices. If this rope were used for
aid soloing then I would be very concerned. Aid soloing in my opinion is
the most dangerous form of climbing because people usually have a static
belay and use large diameter high impact force ropes. This rope was used
far in excess of what I would call safe practice. However, I see this
level of use on ropes routinely. I too have used my ropes to this extent
but, I recognize this risk. Understanding the limitations of the gear is
critical here. I would not use a rope with this type of use where the
chance of a high fall factor was high. If I had no choice I would ensure
that my belayer was aware of this and gave a soft belay by allowing the
rope to slip instead of locking it off in the event of a fall. The point
of my message is that people need to be very aware of the gear they use,
the technique they employ, and the abilities of their partners to also
recognize these two issues. I would agree that I am not impressed with
the rope because it broke on the first fall. However, this is exactly
what I expected to see happen. I also expected to see the section in the
middle fail on the first drop but it held two falls and broke on the
third. I also expected the impact forces on each of these drops to be in
excess of 10 kN and they were really quite close to when the rope was new.

Here is another example of some "uncontrolled" testing I have been
involved with.

Last winter Craig Luebben and I conducted some drop tests on ice. Craig
published an article in Climbing Mag on some of these results and results
of his static tests. I have also written an article on static tests I
have conducted in the lab (email me if anyone wants a copy). Anyway, we
set up our tests under the bridge in Ouray. This was in pretty bad ice
actually and for the most part the gear did not hold. Our setup was with
a static belay, a new 10.5 mm BD rope, fall factors in the 1.5 to 1.8
range, and 185 pounds of steel. With this setup the only thing that
actually held was a 10 cm screw. Everything else ripped out OR carabiners
broke! I attribute this to the bad ice and that the 10 cm screw that
held was probably in the only good ice we found.

We decided to conduct a series of tests where we used the same section of
rope over again. The first three tests the gear ripped out. On the
fourth drop we about keeled over in disbelief. We had a Snarg as the test
piece connected to the rope with a draw with BD QS2 biners. A few feet
below this was two equalized screws (BD and a Grivel). They were equalized
with a single 24" sling and a locked Big Easy was connected to the rope.
The biner on the snarg broke, the hanger on the Grivel screw sheared along
its long bend, then the big easy locked biner broke! This is three pieces
of hardware that broke on one fall. Now, I am assuming that these were
not defective products (a solid assumption based on my knowledge of all
the gear and the systems to produce it, and a review of the fracture
surfaces of the parts we actually recovered). This means that the forces
generated were well in excess of 5000 pounds (multiple times!). Now the
tricky part. Conducting a static test on a new rope with the same diameter
with the same type of knots caused the rope to break in the 3500 pound
range. I don't know why the gear broke and why the rope did not. There
was about one hour between drops so the rope had some reasonable time to

Now the good news. When we placed an ATC in the system (i.e. some dynamic
aspects) every test we conducted held except for a couple of tests with

What does this mean? Dynamic belays are your friend! Climbers have known
this for about a century now. Many climbers today do not understand this
very well. This is why I am relating these types of info to this news
group. I am purposely trying to get this group to discuss this stuff in
detail and learn something from it. So Tom, thanks for your response and

> 2)Since, "2 sections of rope were cut off (15 feet from each end)
> due to core shots", these results are even worse! . . . because
> I interpret the cutting off of these sections to mean they had been
> thrown away sometime before the testing while it was being used
> by Merill Bitter. The 2 sections apparently were even more abused
> and would have failed well before "7.45 kN (1674 lbf)" had they
> been included in the testing.
> How's my logic ?
> Tom

Your logic is fine as I can tell. Yes, the two sections Merill cut off
were not tested. These were thrown out (I actually saw one of them and it
was severely abused and had a large core shot). It is certainly possible
that they would have failed at even lower forces. We couldn't test them
because they were too short.

Overall, I am impressed with how well Merill's rope performed. However, I
do think that it was used beyond what was reasonably safe for the majority
of climbers.

Re: Bowline vs. Figure-8 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxx
Date: 1997/09/26
Forums: rec.climbing

David Underwood <davidlkayp@xxxxxxxxxxx> wrote:
> Th ebowline is a knot that is designed to be easy to adjust. It is fine
> as a belay knot such as around a tree or a bollard but it is not a tie
> in knot. The idea in climbing is to use as few knots as possible so as
> to avoid errors, the bowline is not a foolproof tie in knot. It is
> generally considered poor practice to use it for that pupse as it could
> come untied.

In a word: nonsense. IMHO the single bowline backed up is the ideal knot
for tying in. You aren't a real climber if you don't have this knot
perfected. You can tie it one-handed in the dark with a mitten while
mildy hypothermic. It is easy to loosen after numerous falls on a sport
route. It is more than strong enough, easy to visually check on a
partner from a distance, and plenty bombproof *if tied properly.* It is
less bulky and uses less rope than other tie-in knots.

>Even when tying in with a figure eight you need to back it up.

Also nonsense. Can't hurt but also absolutely unnecessary.

Re: Knot failure 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxx
Date: 1997/09/25
Forums: rec.climbing

Hendo <hensnell@xxxxxxxxxxxxx> wrote:
> I don't use an overhand myself but my curiosity was piqued by yesterday's NPS
> post so I began playing with an overhand this morning to see what could
> possibly go wrong. The reason I don't use it is that I had heard it can
> "invert" under pressure. So I loosely tied one, put pressure on it and saw two
> of the strands distort. I gave them a bit of help to invert them and guess
> what I ended up with? Another overhand knot!
> However, this one was a little closer to the tails. I inverted that one and
> the new knot was right on the tails and fell apart when loaded.

Sorry David, I really don't think improperly tying a knot is a good way
to test it. *Any* loosely tied knot is simply unsafe and can be made to
fail. A properly set overhand is far stronger than any amount of force
you can generate on rappel, even when an 8mm and 11mm are used -- I have
pull tested this combo and many others.

> We're speculating here but yes, the knot could have been tied too close to the
> tails, as you suggested, or even tied to close to just one tail. Or perhaps a
> strand of the knot hooked on a rock nubbin or a tree as it was loaded and
> loosened during the rappel.

None of these scenarios are possible if the overhand is hand
tightened...it gets even tighter when you load it and does not invert. A
figure-8 with both ends on one side OTOH *will* invert when loaded
(albeit at several hundred lbs.) and should not be used for raps.

I have never heard of a properly tied, and appropriately used, knot of
any type failing in a climbing situation. Operator error has always been
the culprit. If you (or anyone else) knows otherwise, please send me the

I suspect (sorry, no hard figures) more deaths have resulted from stuck
rappel ropes than knots coming untied. Bulky knot gets jammed in crack,
climber tries to jug rope, knot pops loose, climber takes the big ride.
There have certainly been countless epics which resulted from stuck
ropes, quite a few of which could have been prevented by a better knot
and rope management.

Re: Bowline vs. Figure-8 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxx
Date: 1997/10/04
Forums: rec.climbing

Rob Williams <rlwilli@xxxxxxxxxxxxxxx> wrote:
> doesnt the figure eight help absorb some of the shock if you fall
> as well??? I have always thought so....


Re: Clip-In vs. Tie-In to Harness 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxxxxx
Date: 1997/04/17
Forums: rec.climbing

Cragking <cragking@xxxxxxxxxxxxx> wrote:
> All I know is that the force of a fall can break a biner(most of them can
> only take 20-40 kn),where as "tie-in" can take the max force of your
> harness and rope.

Time to go back to school. The max force a rope can put on the top
carabiner *is* 20 kN. The max force on a harness will never be more than
12 kN. Tieing directly to your harness is smart but not for the reasons
Cragking (dumb name) sited.

Re: Rappel knots (Possible dangerous situation!) 
Author: Clyde Soles
Email:   csoles@xxxxxxxxxx
Date: 1996/10/29
Forums: rec.climbing

TradMan <tradman@xxxxxxxxxxxxxx> wrote:
> Hello Rock and Ice,
> I was enjoying my newly arrived copy of R&I #76 and came
> across a bit of information that could be very dangerous if interpreted
> incorrectly by lesser experienced climbers. On page 114, in the midst
> of a rope comparison article, is a group of 3 photos of two ropes tied
> with an overhand knot. The accompanying text says, "The Overhand Knot is
> the best choice for joining two rappel ropes.,etc..."
> I assume the meaning of this statement is to use the overhand
> knot to join the LOOSE ends(to prevent rapping off of the ends) and not
> the UPPER ends of the ropes as would be required at the top of a
> two-rope rappel; the current standard being the double or triple
> fishermen's knot(sometimes called the grapevine knot) backed up by
> knotting the tails also.

Nope, I meant what it says...the overhand is the best knot of all for
tying two rappel ropes together at the top. I leave tails at least 9"
long and snug the knot as tight as I can. Your so-called standard knot
is much more prone to jamming in cracks, is a pain in the ass to untie,
and certainly doesn't need a backup. BTW I had an 11 mm and 7 mm (worst
likely case) connected with an overhand and they finally broke at about
1800 lbs. without slipping. YMMV.

It's a bad idea to connect the bottom of the rappel ropes together; that
prevents them from unwinding and results in nasty tangles. A better way
IMHO is to put big knots in the end of each rope...just don't use
figure-8's and remember to untie them before pulling the rap ;-)

Re: Rappel knots
From: "Eric D. Coomer" <coomer@xxxxxxxxxxxxxx>
Newsgroups: rec.climbing
Subject: Re: knot for double rope rapel
Date: Wed, 6 Jan 1999 09:28:35 -0700

Geraint Maddison wrote in message ...
>When loaded across the base, any knot such as the bouble figure eight
>tied in this manner has the ability to work over itself, becoming a
>totally different, and possibly unsafe knot.
>IMHO, knots such as the double sheet bend (backed up with double
>fishermans if you like), the double fishermans, or figure eight tied in
>follow through fashion (with load on either end of the knot) are better,
>safer options.
>Just my thoughts ......
>G. Maddison.

Geez, this topic just hasn't been discussed enough I guess. The 8 CAN
walk over itself. Clyde(I believe) posted some figures for the force at
which this happens. The Double Overhand DOES NOT invert under
load. It actually tightens itself.
It's a fantastic knot- easy to tie, easy to untie, safe, and less prone to
up on edges. I wrapped many pitches with a haul bag with this knot.
Sure, other knots are just as good but can take longer to tie/untie, hang easier
etc. If you're going to post on the subject, at LEAST have you facts straight.

Re: Knot Strength Ratings & Fall Forces 
Author: TradMan
Email:   tradman@xxxxxxxxxxxxx
Date: 1996/04/27
Forums: rec.climbing

Hey Kevin,
I'm looking at a copy of "Knots for Climbers" by Craig
Luebben, Chockstone Press 1993. Here's a chart in the book:
Knot Strength
Knot Relative strength
No Knot 100%
Figure Eight 70 to 75%
Double Bowline 70 to 75%
Dble. Fishermans 65 to 70%
Water Knot 60 to 70%
Overhand Knot 60 to 65%
Clove hitch 60 to 65%
Square Knot 45%

I have no idea how these figures were reached, but thought I'd
pass them along for what they're worth. For fall forces, Petzl has
full page details on fall forces in the climbing magazines occasionally
and in their catalogs also.

Re: Three points vs two (cordelettes):
From: Tim Howe <th3i@xxxxxxxxxxxxxxx
Wed Jan 6 14:52:20 1999
Newsgroups: rec.climbing

I started working out the math for the general case with 3 perfectly
equalized anchors onto a loop of known length and discovered it is a pain
in the ass to solve (non-linear, 6 unknowns at last count). So if someone
else wants to do it by hand go for it, otherwise I am going to wait till
the next time I am near a computer with mathematica.

Instead I did it with a bunch of arbitrary restrictions which should at
least give you an idea of what kind of forces we are dealing with.

Assume that you have your anchors placed in a straight line, equally
spaced and that force being applied to the cordelette is perpendicular to
the wall and the line in the direction of force passes through the center

A1_______A2 _______A3
\ | /
\ | /
\ | /
L1 \ L2| /L1
\ | /
\ | /
\ @| @/
\ | /
| F

these calculations assume that the cordelette is perfectly equalized, this
is very important!!!

note that L1+L1+L2 = L the total length of your cordelette (Ignore the

we need to know how far the tie in point is from the wall so solve for L2
to get
2L +- (4L^2 + 12(L^2 - 4D^2))^1/2
L2 = --------------------------------

so if you know how far the tie in point (i.e. you as the belayer) are from
the wall (L2) you can calculate L1 = (L - L2) / 2 and from that calculate
the angle @ = arccos(L2/L1).

Since the cordelette is equalized the tension on all the strands is equal
and so their components in the direction of the force must be equal.

T+2Tcos(@) = F


T= F / (1+2cos(@))

so if you had a 20 ft cordelette and had your anchors placed 3 ft apart in
a line you would be standing about 6.2ft from the wall. The angle @ would
be a little over 26 degrees and the Tension would be F / 2.8

which means that in a serious fall (5000 lbs) the Tension on each L would
be about 1786 lbs and on each strand (remember they are doubled) would be
893 lbs.

The problem is that even with a good knot or other setup it is diffucult
to get a properly equalized cordelette. and with even a 60 degree angle
you are getting close to the breaking strength of 6mm cord (1200 lbs).

And if one of your anchors blow, forget about it.

It is easier to just get the strong stuff, pay the extra cash, and live
to tell us all about that nice whipper. please feel free to poke holes in or fun at my calculations.
climb safe, cleanup's a bitch


>> you are getting close to the breaking strength of 6mm cord (1200 lbs).

> Where did you get your 1200 lbs? REI's catalog says 8 kN for 6mm.
> If I did the conversion right, that's 1800 lbs. They say 5 mm cord
> is good for 5.6 kN which is 1258 pounds.

From: Tim Howe <th3i@andrew.cmu.edu>
sorry this was unclear, I meant that the cord would have to hold 1200 lbs
in this case not that it would break at that load.

I noticed that right after I sent it and was wondering if someone would
call me on it. 3 points for you!

in any case a good knot can be expected to hold something like 80% of the
breaking strength of the cord. (this of course depends on the knot, cord
flexability, etc. etc.). 80% of 1800 is 1440 lbs. which means that a
brand new cord would only barely hold if one of the anchors worked free.

note: the cord would break at one of the bends in the knot, not come


Re: Rope Strength/ sulpher triox
Author: Charles Arthur
Email:   carthur@xxxxxxxxxxxxxxxx
Date: 1998/10/19
Forums: rec.climbing

In article <01bde2cb$cced8ac0$63aa9bcf@default>, "Rich Dobbs"
<rldobbs@xxxxxxxxxxxxxxx> wrote:

> I wouldn't count on a nylon stuff sack to protect your rope from damage
> if the rope was stored for a long time in a trunk with a car battery.
> Battery acid is sulfuric acid - H2SO4. H2S04 is a combination of SO3
> gas with H2O - water.

Hmm. Tell me about this sulphur trioxide gas, professor. I have heard of
sulphurous oxide (SO) and sulphur dioxide (SO2) but this sulphur trioxide
you have discovered will revolutionise our chemistry and production
processes. I guess SO3 is made - what, by just adding two parts oxygen to
two parts SO2. And then add water. Why, this stuff is a doddle! Why do they
bother with those big factories?

> Although sulfuric acid tends to pull water from the air (in the
> process diluting itself) to some extent it will also release S03 back
into the
> air.

Grasshopper, it does not do to fall asleep in your chemistry classes. Grab
the pebble from my hand and then go back and do your Chemistry 101 test
again. Try to revise this time, instead of staring at the computer typing

> This S03 gas can diffuse
> through your nylon bag into the core of your rope where it could be
> absorbed by water in the damp rope.

Truly your understanding of this process is magical. That is, it doesn't exist.

> Now you've got sulfuric acid inside of
> your rope damaging its core. A water proof coating on your stuff sack should
> slow the rate at
> which the S03 gas diffuses into your rope, but it wouldn't stop it.
> Of course I don't know of anybody who keeps a car battery in there
> trunk for a long time. And you keep your rope in house most of the time. So
> this is mostly a hypothetical quibble.

More hypothetical than you realise, mate.
Charles the apothecary

Chemistry lesson for Charles Arthur
Author: Madeleine
Email:   schultz@xxxxxxxxxxxxx
Date: 1998/10/19
Forums: rec.climbing

Dear Charles,

I just had to respond to your rude and sarcastic post and support Rich.
I picked up the three closest books to me here in my lab and I will
quote them.

<rldobbs@xxxxxxxxxxxxx> wrote:
> > Battery acid is sulfuric acid - H2SO4. H2S04 is a combination of SO3 gas with H2O -
> > water.

Charles wrote:
> Hmm. Tell me about this sulphur trioxide gas, professor. I have heard of sulphurous oxide >(SO) and sulphur dioxide (SO2) but this sulphur trioxide you have discovered will >revolutionise our chemistry and production processes. I guess SO3 is made - what, by just >adding two parts oxygen to two parts SO2. And then add water. Why, this stuff is a doddle! >Why do they bother with those big factories?

SO3: CAS #[7446-11-9] can be bought from Aldrich ($64.90 for 40 g of
99%) and other chemical manufacturers. At room temperature it exists as
a dimer, (SO3)2, in colourless crstalline prisms, which melt at 15
degrees (C) and boil at 45 degrees (C). The solid is rapidly decomposed
by water to form sulfuric acid.

SO3 is prepared by a contact process, ie by the action of oxygen on
sulfur dioxide in the presence of catalysts such as platinized asbestos,
platinized magnesium sulfate, ferric oxide, or vanadium compounds. It
may be prepared in the lab by heating fuming sulfuric acid and
collecting the sublimate in a cooled receiver. Depending on the
conditions of condensation (temperature and pressure) there are three
different forms, alpha, beta and gamma with different melting points and
vapour pressures.

It is an intermediate in sulfuric acid manufacture.

> > Although sulfuric acid tends to pull water from the air (in the
process diluting itself) to some extent it will also release S03 back
into the air.

> Grasshopper, it does not do to fall asleep in your chemistry classes. Grab the pebble from my >hand and then go back and do your Chemistry 101 test again. Try to revise this time, instead >of staring at the computer typing rubbish.

Rather than insulting the poster, Charles, you could have pointed out
that the gas most likely released from sulfuric acid is SO2, sulfur
dioxide, which does react with water to produce sulfurous acid (H2SO3),
which reacts with organic materials and could damage a rope. However,
given the possibly hot conditions in a car, you could also release SO3
which would rapidly recombine with any water to form sulfuric acid.

> > This S03 gas can diffuse through your nylon bag into the core of your rope where it could be absorbed by water in the damp rope.

> Truly your understanding of this process is magical. That is, it doesn't exist.

I would suggest that you do not understand the process either, Charles.
Check out Merck, Hackh's Chemical Dictionary, Aldrich catalogue, or even
Fairlie, _Sulfuric Acid Manufacture_, ACS Monograph Series no. 69 (New
York, 1936) for more details.

> Charles the apothecary

Madeleine the chemist, not just for fun, not just to insult people, but
as a lifestyle choice.

Re: How to Mend Rope Ends? 
Author: ratagonia
Email:   ratagonia@xxxxxxxxxxxx
Date: 1998/10/01
Forums: rec.climbing

Ben Craft <bcraft@xxxxxxxxxxxxx> wrote:
> Is it really necessary to chop the end off of the rope? Does any one know
> how much the sheath actually adds to the strength of the rope?

Contrary to popular belief, the sheath holds 1/3 to 1/2 of the total strength
of the rope. So, core shots are a big problem, don't just tape over them.

Re: Would you trust this rope? 
Author: Ken.Cline@xxxxxxxxxxxxx
Date: Mon Feb 19 12:22:19 2001
Forums: rec.climbing

David Kastrup <dak@xxxxxxxxxxxxxxx> writes:

> Jugging is not good on the sheath, but the sheath is not that much
> security relevant with regard to catching a fall. Rappeling is
> pretty harmless on a rope if done with a suitable device. The most
> wear you get from toproping, especially lowering which kneads the
> core under full weight over a biner.

David, you have an extremely creative imagination, but this advice is
just not right. Most importantly, where in the world did you get the
notion that toproping harms a rope by "kneading" the core. If I were
grading your essay, I'd give you an "A" for imagination and a "D" for
accuracy. In reality, toproping is much harder on a rope's sheath,
which should come as no surprise since ropes ARE DESIGNED TO WEAR OUT

I don't know where to begin criticizing your claim that a rope's
sheath is not "that much security relevant". The sheath is woven
tighter than the core and (as mentioned above) wears more rapidly than
the core. This means that the core will likely be in OK shape even if
the sheath has been damaged, however both components act together to
give the rope its energy absorption and strength.

> Anyhow, your rope does not sound like much wear judging from your
> description. Shelf life is harmless if stored in a suitable area (no
> battery acid and the like). Bear in mind that I am not that much
^ ^^ ^^^ ^^^^ ^^^^
> experienced, so hear what the others have to say, as well. And of
^^^^^^^^^^^, ^^ ^^^^ ^^^^ ^^^ ^^^^^^ ^^^^ ^^ ^^^
> course, the visual inspection has been yours, only.


Please, please, please wait for answers from people who do have
experience. Also, PLEASE, refrain from posting wild speculation as if
it is fact!


Subject: Re: Cleaning Climbing Ropes
From: Ken.Cline@xxxxxxxxxxxxxxxx
Date Wed Apr 5 09:32:54 2000
Newsgroups: rec.climbing

AAron Berlin <amberlin@xxxxxxxxxxxx> writes:

> I have a fairly new dry rope that has gotten extremely dirty from the
> carabiners used to top rope. It is starting to turn my hands black when
> I belay and I was wondering would would be a good way to clean it with
> out damaging it or hurting the dry treatment?

Did your rope come with care instruction? If not, have you asked the
manufacturer. These are more reliable sources of information that

Here's what Beal Ropes recommends:

Ropes should be washed periodically to help remove sharp particles
from the sheath and so prevent them penetrating to the core where
they can cut the fibres. Use a mild detergent (as might be used for
delicate fabrics) in cold water. Dry slowly, and store away from
sources of heat and out if direct sunlight. This applies to the
storage of all fibre products - store in a cool, dry place away
from direct sunlight and all possible contaminants (if you're
really keen, store in an inert environment like nitrogen ; )


They show a picture of a faucet and scrub brush. I put the rope in a
mesh bag and toss it in a front loading washing machine. Tossing a
loose rope in a washing machine will result in a gordian knot.

There are wash-in dry treatments you can use to increase water


Subject: Re: What to do with new static rope ?
Date - Tue Jun 13 18:28:23 2000
From: madbolter@xxxxxxxxxxxx (Rex Pieper)
Newsgroups: rec.climbing

Allright you wiseasses...if YOU don't know how to use them either
then don't rag on Mr. Strock for actually asking a smart question.

Hank's comments below are great. I'd also add that if it came on a
spool, follow the manufacturer's specs on uncoiling it. Usually you
want to roll the entire length off rather than pulling it off as the
latter will introduce kinks. I just do that into a tub of water and begin
the soaking process. Flake out in the shade to dry, then bag the line
instead of coiling it.

It's also good to know that a static line will shrink after getting
wet (or with age) between 5% and 10% of its length. So that's
why I buy my stat lines much longer than the final size I want them.
But this is a little too late in your case...good luck.

-Rex Pieper

Hank Moon wrote:
>Michael Strck wrote in message ...
>>I just bought a new static 10mm rope. Is it ready
>>for use, or is it advisable to treat it somehow ?

>Soak it overnight in water to remove lubricants used in production and
>tighten the sheath. The rope will stiffen somewhat sooner (i.e. before
>its first outdoor bath), but soaking reduces or eliminates sheath
>slippage in most new static ropes (ancient caver trick).

Subject: Re: Retired Rope Rugs
Date- Sat Feb 26 10:48:15 2000
From: Dave Andersen <angio@xxxxxxxxxxxxx>
Newsgroups: rec.climbing

DeadV3rtic <deadv3rtic@axxxxxxxxxxx> wrote:
> Some time ago there was in Rock and Ice or Climbing there was the name of
> someone who would weave ur old rope into a rug. Does any one have a number or
> address for this guy or someone else who would do this. or better yet
> instructions. i just cant bear to throw it away.

Mmmm. Deja.com.

Okay, that aside:

* http://www.roperugs.com/
* Weave your own with an oval weave called an "ocean platt"
* Get "Ashley's Book of Knots" - it has a few ways to weave rugs
* Get "The Morrow Guide to Knots"
* This guy: http://www.yuccadune.com/aisle190.html
buys old ropes for trade-in.

Subject: Re: Rope mat
Date - Mon Nov 1 09:56:14 1999
From: Ken Cline <cline@xxxxxxxxxxxxxxxt>
Newsgroups: rec.climbing

Michael Dickson <michael@xxxxxxxxxxxxxxx> writes:
> Anybody have a pointer to how to make a mat out of an old rope? I've
> seen the info (or links to it) posted here before, but can't find it
> now.

Look at the photos at http://www.roperugs.com/rugphotos.html and
figure it out. You can even design your own pattern - I drew mine on
graph paper and made my rug to fit my doorstep exactly.

Better still, send your rope and $30 to Tom Cleary (see the URL above)
and save yourself some frustration.


Subject: Re: How do I know if it is still safe?
Date - Mon Dec 13 10:13:06 1999
From: Tom Moyer <tmoyer@xxxxxxxxxxxxx>
Newsgroups: rec.climbing

Ben Craft <bcraft@xxxxxxxxxxxx> wrote:
> Contrary to popular belief, the sheath holds 1/3 to 1/2 of the total
> strength of the rope.

I can back Ben up on this. Here the results of some testing I did a while
back. All these are on *static* rope, so the results may not necessarily
carry-over to dynamic, but I'd guess that on a dynamic rope, the sheath would
carry *more* of the load than on static, not less (because the core of a
dynamic rope is more elastic, but the sheath is the same). These are one
sample only on each test, so no statistical data, but I think it still proves
Ben's point. I have no idea why the sheath carries so much of the load.
Doesn't really seem to make sense, but there's the test results to prove it.

PMI Max wear 7/16" (11 mm) - sheath cut
rated strength: 6050 lb
failed at: 3900 lb
strength loss: 36%

PMI EZ Bend 7/16" (11 mm) - sheath cut
rated strength: 6050 lb
failed at: 4425 lb
strength loss: 27%

Blue Water II Plus - sheath cut
rated strength: 5620 lb
failed at: 3750 lb
strength loss: 33%

- Tom Moyer

Subject: Euro Death Knot Testing
Date - Wed Nov 10 16:23:52 1999
From: Tom Moyer <tmoyer@xxxxxxxxxxx>
Newsgroups: rec.climbing

I know this has been the subject of lots of flaming already, but since I
actually have some information (not that that's really a requirement for
posting on rec.climbing), here goes ...

I learned this weekend at the International Technical Rescue Symposium
that the figure eight version of the Euro Death Knot is being actively
taught to climbers in Canada. I had thought that only the overhand
version was in widespread use and that everyone pretty much recognized
the figure eight to have the potential to be a really quick trip to the
bottom of the crag.

For those who don't know what this knot is, check out the drawings at

Failure of the figure eight version of this knot has already caused a
fatality in1994 at Seneca Rocks and an accident in 1995 in Salt Lake.

Both of these knots would politely be called "mis-loaded" and impolitely
would be called, well - the "Euro Death Knot". The failure mode for the
figure eight version is to flip/invert/capsize, which then becomes the
identical twin of the first knot, just with shorter tails. After enough
of these events there are no tails left and the knot fails. Leaving at
least a foot of tail is recommended.

I spent a few hours yesterday in my front yard with a come-a-long and a
load cell to try to get some decent information on this. The results
still leave room for plenty of argument. People who don't like the
figure eight will say, "See, it slips at really low loads!" People who
do like it will say, "See, if you dress it right, pretension it well,
and leave long tails, it doesn't fail. Besides, I've been using it for
years and I'm still alive!"

If you're too impatient to wade through the results below, the short
answer is that if you do all those things, you should be ok. My question
is - why would you take the chance? If you're in a situation where a
stuck rope would be catastrophic, use the overhand. It has all the same
advantages and not nearly as much risk.

Be safe - the body we have to scape off the rock may be yours.

- Tom Moyer
Salt Lake County Search and Rescue

Rope A: Mammut 11 mm static - used
Rope B: Unknown manufacturer red 11 mm dynamic - used
Rope C: ABC/Sterling 11 mm static - new
Rope D: Blue Water II+ 11 mm static - new
Rope E: ABC 8mm static - new
Rope F: 1" Tubular Webbing

Test #1: RopeA/RopeA - figure 8 - well dressed and pretensioned
Capsized at 750 lb, Rope broke at 2520 lb

Test #2: RopeB/RopeB - figure 8 - well dressed and pretensioned
Capsized at 590 lb, Capsized at 2280 lb, Rope broke at 2560 lb

Test #3: RopeB/RopeB - figure 8 - well dressed, pretensioned loosely
Capsized at 290 lb, Stopped Test at 2800 lb

Test #4: RopeB/RopeB - figure 8 - sloppy, crossing strands and loose
Capsized at 110 lb, Capsized at 140 lb, Capsized at 340 lb,
Capsized at 420 lb, Capsized at 530 lb, Stopped Test at 2500 lb

Test #5: RopeB/RopeB - overhand - well dressed and pretensioned
Capsized at 1400 lb, Capsized at 1940 lb, Capsized at 1990 lb,
Rope Broke at 2070 lb

Test #6: RopeA/RopeA - overhand - well dressed and pretensioned
Stopped Test at 2540 lb

Test #7: RopeC/RopeC - figure 8 - well dressed and pretensioned
Stopped Test at 2500 lb

Test #8: RopeD/RopeD - figure 8 - well dressed and pretensioned
Capsized at 2170 lb, Stopped Test at 2550 lb

Test #9: RopeB(11mm)/RopeE(8mm) - figure 8 - well dressed and
Capsized at 1330 lb, Capsized at 1550 lb, 8mm broke at 2700 lb

Test #10: RopeB/RopeB - figure 8 - well dressed and pretensioned - WET
Capsized at 470 lb, Rope broke at 2790 lb

Test #11: RopeB/RopeB - figure 8 - well dressed, pretensioned loosely -
Capsized at 290 lb, Rope broke at 2470 lb

Test 12: RopeF/RopeF (webbing) - well dressed and pretensioned
Webbing broke at 2070 lb

Subject: Re: Euro Death Knot Testing
Date - Thu Nov 11 11:51:24 1999
From: Tom Moyer <tmoyer@xxxxxxxxxxxxxxx>
Newsgroups: rec.climbing

Ok - here's the next round of tests. Should add a little more fuel to the

Some comments:
When the overhand inverts, it doesn't really do the same thing as the 8 does.
The 8 flips completely around and it's really obvious. It also eats a huge
chunk of the tails when it does. The overhand kind of twists a little, some
more rope goes through the knot, and the force goes down. Any time I pulled on
the come-a-long and the force went *down* a few hundred pounds or more, I noted
the peak force before it happened. I'm going to change my terms and call it
"rolled" to differentiate it from way the figure-eight behaves.

As before, all rope breaks (with one exception noted below) happened at the
knot being tested.

Tests 18, 19, and 20 are on double fisherman's knots, pretty much the gold
standard for comparison. As before, the load is on a single strand, with a
figure eight on a bight at each end. For #19 and #20, the double fisherman's is
loose and mis-tied in every way I can think of that you could still sort of
call it a double fisherman's knot. Definitely the worst excuse for a DFK I've
ever seen.

A friend of mine (a Canuck) talked this morning to a director with the
Association of Canadian Mountain Guides and he told me that they have stopped
recommending the figure 8 version. The accepted practice now is the overhand
version, although some folks continue to use the figure 8 style.

It's pretty clear that both versions of the EDK suck if you don't tie them
cleanly and pretension them well.

Again -

Rope A: Mammut 11 mm static - used
Rope B: Unknown manufacturer red 11 mm dynamic - used
Rope C: ABC/Sterling 11 mm static - new
Rope D: Blue Water II+ 11 mm static - new
Rope E: ABC 8mm static - new
Rope F: 1" Tubular Webbing
Rope G: Mammut 8mm static - new

Test #13: RopeB/RopeB - overhand - well dressed, pretensioned loosely
Rolled at 1070 lb, Rolled at 1120 lb, Rolled at 1470 lb, Rolled at 1870 lb,
Rolled at 2000 lb, Rope broke at 2100 lb

Test #14: RopeB/RopeB - overhand - sloppy, crossing strands & loose
Rolled at 200 lb, Rolled at 370 lb, Rolled at 1400 lb, Rope broke at 2100 lb

Test #15: RopeB(11mm)/RopeG(8mm) - overhand - well dressed & pretensioned
Rolled at 1230 lb, Rolled at 1610 lb, Rolled at 1930 lb, Rolled at 1840 lb,
8mm broke at 1770 lb

Test #16: RopeB/RopeB - overhand - sloppy, crossing strands & loose (again)
Rolled at 300 lb, Rolled at 420 lb, Rolled at 1440 lb, Rolled at 1520 lb,
Rope broke at 1830 lb

Test #17: RopeB(11mm)/RopeG(8mm) - overhand - well dressed & pretensioned - WET

Rolled at 950 lb, Rolled at 1300 lb, Rolled at 1160 lb, Rolled at 1130 lb,
Rolled at 1070 lb, Rolled at 1110 lb, Rolled at 1200 lb,
Rolled and 11mm sheath broke at 1460 lb, Rolled at 1230 lb,
Rolled at 1450 lb, End of tail pulled through knot at 1410 lb

Test #18: RopeB/RopeB - double fisherman's - well dressed & pretensioned
Rope broke at double fisherman's at 2880 lb

Test #19: RopeB/RopeB - double fisherman's - sloppy, mis-tied & loose
Rope broke at the figure-8 on a bight at 2580 lb

Test #20: RopeB/RopeB - double fisherman's - sloppy, mis-tied, loose & WET
Rope broke at double fisherman's at 2620 lb

Subject: Re: Euro Death Knot Testing
Date - Wed Nov 10 16:24:41 1999
Newsgroups: rec.climbing
From: csoles@xxxxxxxxxxx (Clyde Soles)

Tom Moyer <tmoyer@xxxxxxxxxxxx> wrote:

> If you're in a situation where a
> stuck rope would be catastrophic, use the overhand. It has all the same
> advantages and not nearly as much risk.

Yep, your results confirm mine that I posted here several years ago.
There is NO advantage of the fig-8 version. Pity people don't listen.
Both the AMGA and CMGA are guilty on this.
DISCLAIMER: Unless otherwise indicated, this post is personal
opinion and NOT an official statement of my employer.

The shelf life of static ropes, by Bateman and Toomer, 1998
Really good article on the strength of ropes over time and with various conditions. Click here for the PDF.

Comparative Testing of High Strength Cord
Tom Moyer
,Paul Tusting, Chris Harmston,
2000 International Technical Rescue Symposium
Many climbers carry an 18-foot length of accessory cord called a cordelette for rigging anchors and as a tool for self-rescue situations. In the past, this cord was usually 7mm Nylon. In recent years, many climbers have changed to using one of a number of high-strength materials in smaller diameters. Vectran, Technora, Spectra, Kevlar, Kevlar/Spectra blends and Spectra/Nylon webbing are all used for these purposes along with Nylon cord and Nylon webbing. (click here to get the rest of this fine article in PDF.)

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