2 rappel knots

10:16 p.m. on January 30, 2002 (EST)
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747 forum posts

Many pardons if I have missed recent posts about this. I am suggesting two "different" rappel knots to counter the European death knot, which to me seems like a cross loaded water knot - yuk... (:-<)

This "one way knot" is from Walt Wheelocks book Ropes, Knots & slings for climbers. A "One way knot" is a knot that can slide through a carabiner one way - like the "death kot". This knot is tied by first tying a figure of 8 in one rope, then sliding the other rope in through the figure of 8 and back out so that all of the tails are on one side. [kind of like a figure of 8 "Bend" with one loop left out of one "8" making it a "U" instead] The book further states that one might further secure the tail of the "U" end...
The other knot I have decided to use for my own rappeling in Yosemite is a double fishermans knot with the tail of the smaller rope pulled through the opposite knot such that all tails are on one side. [pull the large one] I think this might be easier to unty than a std fishermans knot. I'll do some drop testing on these.
Jim S

4:28 a.m. on January 31, 2002 (EST)
(Guest)

Prusik reppel safety info

Hi Jim,
Just more info for you. I don't have an opinion on it.
http://www.dtek.chalmers.se/Climbing/Hardware/prusik-on-rappel.html
Cheers, Les :-))

11:07 a.m. on January 31, 2002 (EST)
(Guest)

Not sure exactly what the knots are that you are considering using, and I'm not here to recommend one, but I would encourage you to 1) research the EDK before dismissing it and 2) research any other knots you are considering before using them. And I mean research more rigorous than looking at the appearance of the knot (or, for that matter, looking at the "name" of the knot). Looking at the EDK may make you think "cross loaded water knot - yuk", but that does not qualify as analysis of whether or not it is actually suitable for rapping. And it's easy to assume that it wouldn't be called the "Death Knot" unless it has killed people, but does anyone have any actual statistics?

Rap knots have several characteristics to think about. The most obvious (and critical) is whether or not it is sufficiently strong. Will it stay tied? Will it tend to get hung up upon retrieval? How hard is it to untie once weighted? How hard is it to tie? How easy is it to tie it incorrectly by mistake?

I have found that there is virtually no "real" data on how much force is generated in "typical" rappel scenarios (see my earlier post just a few days ago), but there is actually quite a bit of data about the strength of knots used to join two ropes. Probably the most thorough is at
http://www.xmission.com/~tmoyer/testing/EDK.html, but there's plenty more out there. And, regarding the appearance of the knots, take note of the fact that the Fig 8 version of the EDK, which would "seem" stronger than the overhand version to many of us when we look at it, is actually the inferior knot.

I'd also add that I haven't really been able to find out where the EDK got its name, but the reason does NOT appear to be that it has caused lots of death!

Good Luck!

12:01 p.m. on January 31, 2002 (EST)
37 reviewer rep
747 forum posts
Thanks Donn - good stuff!

Thanks for your very professional feedback to this group. I was interested in the testing done on the "beer knot".
Test #11: Test the beer knot. This is an alternative to the water-knot. It's tied as an overhand follow-though, but open up the tubular webbing and do the follow through inside the other piece. The load was applied to a loop of used 1" webbing tied with the beer knot.
Result: Webbing broke at shackle at 4750 lb.

Have you tested this Beer knot in dynamic rope?

The one way knot that I mentioned is a modified Sheet bend wherein the tail of the "twisted half" of the bend is looped back through - making that end into a figure 8.

As an engineer I love to rely on data but I have no ability to measure the failure point if I did do my own pull tests.
And you are right about the EDK - data speaks louder than observations.
Jim S (:->)

2:25 p.m. on January 31, 2002 (EST)
(Guest)

a.k.a. Paul R, Paul R., Paul Raphaelson, PaulR, PR

Do some research. There's a lot of hard information on the web (including the UIAA site) on the euro death knot.

it's a safe knot. with 9" tails it will not fail under any loads possible in rappeling. the rope will eventually fail at the knot at about 50% its breaking strength (vs. about 60% or 65% for a grapevine). This is thousands and thousands of pounds.

The knot is safe because it's unlikely to get stuck when ypu pull the ropes down. grapevines get stuck in crevices easily. lots of people have died or had epics because both their ropes got stuck in a bad place.

The knot gets its name from americans who thought it looked scary when they first saw it. it DOES look scary. but nobody has died.

 


Quote:

Not sure exactly what the knots are that you are considering using, and I'm not here to recommend one, but I would encourage you to 1) research the EDK before dismissing it and 2) research any other knots you are considering before using them. And I mean research more rigorous than looking at the appearance of the knot (or, for that matter, looking at the "name" of the knot). Looking at the EDK may make you think "cross loaded water knot - yuk", but that does not qualify as analysis of whether or not it is actually suitable for rapping. And it's easy to assume that it wouldn't be called the "Death Knot" unless it has killed people, but does anyone have any actual statistics?

Rap knots have several characteristics to think about. The most obvious (and critical) is whether or not it is sufficiently strong. Will it stay tied? Will it tend to get hung up upon retrieval? How hard is it to untie once weighted? How hard is it to tie? How easy is it to tie it incorrectly by mistake?

I have found that there is virtually no "real" data on how much force is generated in "typical" rappel scenarios (see my earlier post just a few days ago), but there is actually quite a bit of data about the strength of knots used to join two ropes. Probably the most thorough is at
http://www.xmission.com/~tmoyer/testing/EDK.html, but there's plenty more out there. And, regarding the appearance of the knots, take note of the fact that the Fig 8 version of the EDK, which would "seem" stronger than the overhand version to many of us when we look at it, is actually the inferior knot.

I'd also add that I haven't really been able to find out where the EDK got its name, but the reason does NOT appear to be that it has caused lots of death!

Good Luck!

2:15 a.m. on February 1, 2002 (EST)
(Guest)

Re: Thanks Donn - good stuff!

Quote:


Thanks for your very professional feedback to this group. I was interested in the testing done on the "beer knot".
Test #11: Test the beer knot. This is an alternative to the water-knot. It's tied as an overhand follow-though, but open up the tubular webbing and do the follow through inside the other piece. The load was applied to a loop of used 1" webbing tied with the beer knot.
Result: Webbing broke at shackle at 4750 lb.

Have you tested this Beer knot in dynamic rope?

Jim S (:->)

The beer knot is not possible in dynamic rope. It requires you to feed one end of tubular webbing through the "tube" in the opposite end as demonstrated here:

http://beerknot.20m.com/

Rob.

2:16 a.m. on February 1, 2002 (EST)
(Guest)

Re: Thanks Donn - good stuff!

Quote:


Thanks for your very professional feedback to this group. I was interested in the testing done on the "beer knot".
Test #11: Test the beer knot. This is an alternative to the water-knot. It's tied as an overhand follow-though, but open up the tubular webbing and do the follow through inside the other piece. The load was applied to a loop of used 1" webbing tied with the beer knot.
Result: Webbing broke at shackle at 4750 lb.

Have you tested this Beer knot in dynamic rope?

Jim S (:->)

The beer knot is not possible in dynamic rope. It requires you to feed one end of tubular webbing through the "tube" in the opposite end as demonstrated here:

http://beerknot.20m.com/

Rob.

2:28 a.m. on February 1, 2002 (EST)
(Guest)

Re: Thanks Donn - good stuff!

Quote:

Quote:

Have you tested this Beer knot in dynamic rope?

Jim S (:->)


Sorry about the double post - darn browser.

I wanted to add some info about the beer knot in tubular webbing.

I have tried it and it works well, other than it is a pain to tie. One aspect of the knot I did not like was that visual inspection was enough. If you glance at a sling tied with a water knot, you can pretty much verify its integrity. Integrity in a water knotted sling has to meet two personal criteria.
1. The water knot is cinched up tight
2. Both tails exceed 3 or 4 inches.

Non-empirical data suggests that water knot failure occurs from repeated load - unload cycles which seem to shorten the tails each time. I do use a water knot in webbing after performing the following:
1. Tie the water knot, then cinch up using body weight.
2. Tape/sew tails
3. Visually inspect the knot each time I use the sling.

Off topic, but I hope this is somewhat useful.

Rob.

2:31 a.m. on February 1, 2002 (EST)
(Guest)

Re: Thanks Donn - good stuff!

Quote:

One aspect of the knot I did not like was that visual inspection was enough.

This should have read "One aspect of the knot I did not like was that visual inspection was NOT enough."

9:02 a.m. on February 1, 2002 (EST)
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408 forum posts
overhand in line...

Quote:

Not sure exactly what the knots are that you are considering using, and I'm not here to recommend one, but I would encourage you to 1) research the EDK before dismissing it

I'll bolster that by makin' the bold statement that the in-line overhand, aka the EDK, should really be the only knot folks should be using to tie together two ropes for rappelling.

Part of the problem may be that it just looks too simple...

Quote:

I'd also add that I haven't really been able to find out where the EDK got its name, but the reason does NOT appear to be that it has caused lots of death!

I think there was some anomosity betwixt American guides and Euro in Europe perhaps which lead to callin' that knot the EDK (hazily recollect).

There was an interesting article in the ANAM two years ago (I think...ugh...that memory thing...) about a group in the Tetons who were rappelling and apparently had the knot in their rappel lines come undone. But...the feller apparently stopped mid way on rappel and may have retied (incorrectly) the knot. Seemed to be a fair amount of confustion on what really happened. I chatted with several rangers up there and they didn't know for sure, either. I anyone here knows, do tell!

Used the EDK yesterday on two 8.1mm ropes on a steep to overhanging rappel off a tree post ice climb (hey, Bill S aka the OGBO, is in town and we hooked up for some ice!). No problemo (as usual). Easy to untie even after our portly bodies weighted the rope.

Brian in SLC

11:17 a.m. on February 1, 2002 (EST)
(Guest)

Confussing at best to me

I use a overhand knot with 8" or so tails and then tie another overhand knot in just one of the tails snugged tightly up next to the main overhand knot. I learned AMGA that this is suppose to help keep the main knot from rolling.

I also tie the end of my rap ropes together, then clip a QD into just 1 strand and to my belay loop on my harness for safety. Not only is this the safetest, I never lose thougth of which rope to pull, its clipped with the QD. Yea, I know it causes twists but, an out of control fall while rappelling can generate enough force to blast those knots through the belay device, they dont match up, one knot then another. A 1000' up, the last thing I want to worry about is twisting my rope while rappelling.

Belay Off
John
Never Summer Ice Cimber

12:07 p.m. on February 1, 2002 (EST)
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408 forum posts
Knots in end of each rope?

Quote:

I use a overhand knot with 8" or so tails and then tie another overhand knot in just one of the tails snugged tightly up next to the main overhand knot. I learned AMGA that this is suppose to help keep the main knot from rolling.

I do two in-line overhands, second one snugged up tight against the first.

Quote:

I also tie the end of my rap ropes together

Wonder if its better (from a rope twist standpoint) to tie a figure eight on a bite on the end of each rope, rather than tie the rope ends together?

I like being able to clip into a loop at the end of the cord for safety, if I need to stop and set up especially a hanging rap station...rap down, clip end of rope to harness (remembering which end is jammed against the rap ring!), come back around the ATC and mule knot it off, set up rap station, clip in, yada yada...

Still don't like the thought of a knot gettin' jammed in a crack off the side of the rap...but...if its windy I try to stuff the rope in a sack or pack and feed it whilst rappin'. Rope bags are kinda nice too for tossing (and tying the rope into the bottom off). Easy for stuffin' and rappin' and feedin'.

Brian in SLC

9:16 p.m. on February 4, 2002 (EST)
(Guest)

Email me for data on forces generated during rapelling

Have a paper on this somewhere as well as looking at forcs generated during 'smooth' and 'inefficient' ascending.

Macca

8:46 p.m. on February 5, 2002 (EST)
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5,251 forum posts
Re: overhand in line...

Quote:

Used the EDK yesterday on two 8.1mm ropes on a steep to overhanging rappel off a tree post ice climb (hey, Bill S aka the OGBO, is in town and we hooked up for some ice!). No problemo (as usual). Easy to untie even after our portly bodies weighted the rope.

*** Speak for yourself, Brian! I'm only slightly over my fighting weight.

*** Only problem was when I started pulling the black rope and Brian said I should pull the other one (forget what color it was - darned senior moments anyway - oh yeah, it's called Alzheimers). But it really was the black one. Then again, the other problem was coming over the overhang and finding I was standing on a huge ice chandelier - time to walk to the left on the belay!

*** 8.1 mm, eh? I thought they were a bit on the thin side.

4:07 p.m. on February 6, 2002 (EST)
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408 forum posts
Portly schmortly!

Quote:

*** Speak for yourself, Brian! I'm only slightly over my fighting weight.

Yeah yeah...100 kilo's or bust!

Quote:

*** Only problem was when I started pulling the black rope and Brian said I should pull the other one (forget what color it was - darned senior moments anyway - oh yeah, it's called Alzheimers). But it really was the black one. Then again, the other problem was coming over the overhang and finding I was standing on a huge ice chandelier - time to walk to the left on the belay!

Had ya bottom belayed...just for kicks...and senior moments! Steeeeep bugger, eh?

Quote:

*** 8.1 mm, eh? I thought they were a bit on the thin side.

Thicker than I'm used to! Sterling 7.6mm or BW's Ice Floss 7.8mm make them BD (Beal) ropes look like fatties!

Fun fun fun...

Brian in SLC

12:09 p.m. on February 15, 2002 (EST)
(Guest)

Update

Quote:

Quote:

Wonder if its better (from a rope twist standpoint) to tie a figure eight on a bite on the end of each rope, rather than tie the rope ends together?

$ I learned from a safety view, its best to create a huge loop in the rope and clip a draw into 1 strand. There is no way you can rap off the end or blow the knot through the device (doubtful but have heard its happened) and I will always know which strand to pull. Yes, the rope twists but the last thing I worry about several hundred to a thousand feet up is, rope twist. I will say though, its only for the first down, then un-tie the knot if the sitution warrants it and then give them a bottom belay while they rap and let the rope un-twist.

Like has been said before, a board like this is hard to cover it all in specific skills, its a broad lesson at best.

Belay-Off
John

2:30 p.m. on March 7, 2002 (EST)
(Guest)

Right around january first I arrived at the last belay on Crimson Chrysalis and my buddy said: 'EDK or get stuck ropes.' I peered at the nauseating exposure and thought, no way. In twenty years of trad climbing and mountaineering I've always sworn on the double fisherman for integrity and safety. Never second guessed it. Just like a figure of eight goes on my harness, a DFM connects the rap lines. But this time I couldn't be blind to the facts. The route is a rope pulling epic waiting to happen, flakes, spikes, horns, heads all over. And more pressing: We had 30 minutes extra to deal with any set backs before darkness. 90 minutes if we didn't mind hiking out in at night. I agreed if my buddy would go first. He tied the EDK proper and backed it up with a tight fitting overhand knot so it couldn't rotate or roll. Off he went into the abyss. No hesitation. He obviously trusted this thing. Looking at it under load was not the nail biting oh-no experience I expected. I followed.
Nine raps and no hang ups later we were on the ground with the EDK looking exactly like when we started. No abrasion to the knot surface as you often see on the DFM after lots of rapping. No slippage. Easy to untie. Hmm..

Quote:

Not sure exactly what the knots are that you are considering using, and I'm not here to recommend one, but I would encourage you to 1) research the EDK before dismissing it and 2) research any other knots you are considering before using them. And I mean research more rigorous than looking at the appearance of the knot (or, for that matter, looking at the "name" of the knot). Looking at the EDK may make you think "cross loaded water knot - yuk", but that does not qualify as analysis of whether or not it is actually suitable for rapping. And it's easy to assume that it wouldn't be called the "Death Knot" unless it has killed people, but does anyone have any actual statistics?

Rap knots have several characteristics to think about. The most obvious (and critical) is whether or not it is sufficiently strong. Will it stay tied? Will it tend to get hung up upon retrieval? How hard is it to untie once weighted? How hard is it to tie? How easy is it to tie it incorrectly by mistake?

I have found that there is virtually no "real" data on how much force is generated in "typical" rappel scenarios (see my earlier post just a few days ago), but there is actually quite a bit of data about the strength of knots used to join two ropes. Probably the most thorough is at
http://www.xmission.com/~tmoyer/testing/EDK.html, but there's plenty more out there. And, regarding the appearance of the knots, take note of the fact that the Fig 8 version of the EDK, which would "seem" stronger than the overhand version to many of us when we look at it, is actually the inferior knot.

I'd also add that I haven't really been able to find out where the EDK got its name, but the reason does NOT appear to be that it has caused lots of death!

Good Luck!

July 25, 2014
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