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For decades I have used the double fishermans and reef knot for abseiling and have noticed increasing numbers using the simple overhand knot (which I like as it's small and neat and thus hopefully less likely to snag). My one query is about rope thickness, for example say you were abseiling on one 8.5mm rope tied (by the overhand knot) to a 9mm rope - is the overhand knot as safe ??
I ask this as I often climb with people who dont have the same rope as me and any advice would be gratefully received.
Thanking you all in anticipation !
I ask this as I often climb with people who dont have the same rope as me and any advice would be gratefully received.
Thanking you all in anticipation !
In reply to Allan McDonald (Gwydyr MC):
Tie a second overhand up against the first. This will stop the knot rolling over and moving down the tails as it is loaded.
Isn't the overhand otherwise know as the European Death Knot??
Tie a second overhand up against the first. This will stop the knot rolling over and moving down the tails as it is loaded.
Isn't the overhand otherwise know as the European Death Knot??
In reply to Allan McDonald (Gwydyr MC): My understanding is that an overhand knot is good for ropes of the same diameters, (with good length tails left) and the double fisherman's is good for ropes of different diameters.
In reply to maresia:
Think that's the figure8.
> (In reply to Allan McDonald (Gwydyr MC))
> Isn't the overhand otherwise know as the European Death Knot??
Think that's the figure8.
In reply to maresia:
Be careful to keep both knots tight together or you increase the risk of getting your ropes stuck
> (In reply to Allan McDonald (Gwydyr MC))
>
> Tie a second overhand up against the first. This will stop the knot rolling over and moving down the tails as it is loaded.
>
> Isn't the overhand otherwise know as the European Death Knot??
>
> Tie a second overhand up against the first. This will stop the knot rolling over and moving down the tails as it is loaded.
>
> Isn't the overhand otherwise know as the European Death Knot??
Be careful to keep both knots tight together or you increase the risk of getting your ropes stuck
In reply to Allan McDonald (Gwydyr MC):
For those rope diameters, for all practical purposes, yes (as in plenty strong enough):
http://www.ukclimbing.com/forums/t.php?t=355663
http://www.bdel.com/scene/beta/qc_kp_archive.php#123008
> My one query is about rope thickness, for example say you were abseiling on one 8.5mm rope tied (by the overhand knot) to a 9mm rope - is the overhand knot as safe ??
For those rope diameters, for all practical purposes, yes (as in plenty strong enough):
http://www.ukclimbing.com/forums/t.php?t=355663
http://www.bdel.com/scene/beta/qc_kp_archive.php#123008
In reply to Allan McDonald (Gwydyr MC):
You could try a figure of eight - harder for it to get undone and should still glide nicely. Adding a second overhand would be at least as bulky.
You could try a figure of eight - harder for it to get undone and should still glide nicely. Adding a second overhand would be at least as bulky.
In reply to Allan McDonald (Gwydyr MC):
I habitually join an 8.5 and a 9.3 with an overhand and no sign of any movement
I habitually join an 8.5 and a 9.3 with an overhand and no sign of any movement
In reply to Misha:
Aaaargh, I'd be careful about recommending using a figure8. Depends how you tie them. If tied with both ends of the rope coming out of the same side of the knot, they roll easily.
I think you need to make sure that the each rope comes out of opposite ends of the knot.
Aaaargh, I'd be careful about recommending using a figure8. Depends how you tie them. If tied with both ends of the rope coming out of the same side of the knot, they roll easily.
I think you need to make sure that the each rope comes out of opposite ends of the knot.
In reply to Misha:
A figure 8 is not a safe knot to use to tie the ends for an abseil. The knot is loaded incorrectly and this can cause it to roll over itself under even small loads. At least oneperson has been killed in this way.
A figure 8 is not a safe knot to use to tie the ends for an abseil. The knot is loaded incorrectly and this can cause it to roll over itself under even small loads. At least oneperson has been killed in this way.
In reply to liz j:
Just been trying to make a figure of eight roll, admittedly just by pulling on it rather than abseiling off the balcony. I suppose it's possible but seems unlikely, provided you've tightened the know and given the live ends a good tug in opposite directions. I've seen guides use a figure of eight on many occasions, so surely can't be that dangerous? Of course a double fisherman's is safer.
Just been trying to make a figure of eight roll, admittedly just by pulling on it rather than abseiling off the balcony. I suppose it's possible but seems unlikely, provided you've tightened the know and given the live ends a good tug in opposite directions. I've seen guides use a figure of eight on many occasions, so surely can't be that dangerous? Of course a double fisherman's is safer.
In reply to Queequeg:
Could you explain please - how would you have the dead ends coming out of different ends of the knot - do you mean looping one of the ends back through the knot?
Could you explain please - how would you have the dead ends coming out of different ends of the knot - do you mean looping one of the ends back through the knot?
In reply to Misha:
Yes, sorry I think that tied that way it's called a double figure of 8.
A normal figure of eight is definitely not safe, as others have said above, deaths have occured.
Yes, sorry I think that tied that way it's called a double figure of 8.
A normal figure of eight is definitely not safe, as others have said above, deaths have occured.
In reply to Allan McDonald (Gwydyr MC):
It's becoming more and more commonplace these days. It usually works fine.
You'll know if it slips if you send your mate down first. If you hear
" Aaaaaaaaaaaaaaaaaaaaaaaa-ggg-hhhhhhhh Splaat!!!!!" it's a sign it's slipped and you'll realise you shouldn't have listened to anyone on here with their fancy continental ideas.
It's becoming more and more commonplace these days. It usually works fine.
You'll know if it slips if you send your mate down first. If you hear
" Aaaaaaaaaaaaaaaaaaaaaaaa-ggg-hhhhhhhh Splaat!!!!!" it's a sign it's slipped and you'll realise you shouldn't have listened to anyone on here with their fancy continental ideas.
In reply to Misha:
Double figure of 8.
http://www.trailmeister.com/images/MAPS/Figure%208%20Bend8.jpg
Double figure of 8.
http://www.trailmeister.com/images/MAPS/Figure%208%20Bend8.jpg
In reply to Misha:
I too have seen the fig 8 tied, as for an overhand knot, and it used to be standard for a lot of climbers. I have actually pulled a fig 8 apart with my hands on a piece of cord. Once the knot flips, it doesn't stop. I have abseiled many hundreds of feet, on wet, icy and dry ropes, using an overhand and will continue to use it. As for the other method of using a fig 8, the double fig 8, it has no advantage over a reef knot plus double fishermans, indeed it is probably more difficult to untie. I would not know if it is stronger than a reef not in this situation.
As for the simple fig 8, tied as per overhand, don't go there!!!
I too have seen the fig 8 tied, as for an overhand knot, and it used to be standard for a lot of climbers. I have actually pulled a fig 8 apart with my hands on a piece of cord. Once the knot flips, it doesn't stop. I have abseiled many hundreds of feet, on wet, icy and dry ropes, using an overhand and will continue to use it. As for the other method of using a fig 8, the double fig 8, it has no advantage over a reef knot plus double fishermans, indeed it is probably more difficult to untie. I would not know if it is stronger than a reef not in this situation.
As for the simple fig 8, tied as per overhand, don't go there!!!
In reply to maresia: No The Euro Death knot is two overhands close on top of each other. Despite the name, it is very safe.
In reply to Allan McDonald (Gwydyr MC):
It's been approved and accepted by the BMC and the MLTE, thats good enough for me.
It's been approved and accepted by the BMC and the MLTE, thats good enough for me.
In reply to jonny2vests: Hhhmmmmm, think I will give the Overhand knot a go in future, thanks all !
In reply to Misha:
Not to be rude but that proves nothing about performance of the knot.
As unlikely as it may seem the figure of eight with tails both the same end of the knot really is that bad. You might get away with it a few times... then again, you might not.
jk
> Just been trying to make a figure of eight roll, admittedly just by pulling on it rather than abseiling off the balcony.
Not to be rude but that proves nothing about performance of the knot.
> I suppose it's possible but seems unlikely, provided you've tightened the know and given the live ends a good tug in opposite directions. I've seen guides use a figure of eight on many occasions, so surely can't be that dangerous? Of course a double fisherman's is safer.
As unlikely as it may seem the figure of eight with tails both the same end of the knot really is that bad. You might get away with it a few times... then again, you might not.
jk
In reply to Allan McDonald (Gwydyr MC):
No problem with the fishermans apart from the fact I can never undo it afterwards, but the reef knot is surely asking for trouble. The whole point of it is that it can be turned into a slip knot by simply pulling any two of the ends coming out of the same end of the knot. Wouldn't trust it with a barge poll... unless I were reefing a sail of course!
Overhand knot is sound as a pound... in a favourable economic environment.
> For decades I have used the double fishermans and reef knot for abseiling
No problem with the fishermans apart from the fact I can never undo it afterwards, but the reef knot is surely asking for trouble. The whole point of it is that it can be turned into a slip knot by simply pulling any two of the ends coming out of the same end of the knot. Wouldn't trust it with a barge poll... unless I were reefing a sail of course!
Overhand knot is sound as a pound... in a favourable economic environment.
In reply to Allan McDonald (Gwydyr MC):
I've happily used single overhands for much bigger rope discrepancies than that (8.5 and 10.5). I do make sure the knot is properly formed, though, with the strands not twisting round themselves in the knot and I've never witnessed any tendency to roll at all. My only concession is that I will not leave tails 0cm.
I've happily used single overhands for much bigger rope discrepancies than that (8.5 and 10.5). I do make sure the knot is properly formed, though, with the strands not twisting round themselves in the knot and I've never witnessed any tendency to roll at all. My only concession is that I will not leave tails 0cm.
In reply to Jon Dittman: I think Allan means a fishermans as well as a reef knot - the theory used to be that a reef knot in the middle of two fishermans made it easier to untie.
What I don't understand about this continuing debate is the speed aspect. If you are doing multiple abs then you still only tie and untie the ropes once, so any speed advantages of the EDK are minimised. Double fishermans for me I'm afraid!
What I don't understand about this continuing debate is the speed aspect. If you are doing multiple abs then you still only tie and untie the ropes once, so any speed advantages of the EDK are minimised. Double fishermans for me I'm afraid!
In reply to Allan McDonald (Gwydyr MC): With ropes of a different thickness ALWAYS USE THE DOUBLE FISHERMANS TO ABSEIL WITH. The overhand is only recommended with ropes of the same thickness. And always leave about a metre of tail when using the overhand.
In reply to billy.grant:
References, please. And not to some crank site either. I would like to know at what rope diameter discrepancy an overhand is shown to fail under abseil load and why on earth you need 1m of tail on one . And there is no need to shout.
> (In reply to Allan McDonald (Gwydyr MC)) With ropes of a different thickness ALWAYS USE THE DOUBLE FISHERMANS TO ABSEIL WITH. The overhand is only recommended with ropes of the same thickness. And always leave about a metre of tail when using the overhand.
References, please. And not to some crank site either. I would like to know at what rope diameter discrepancy an overhand is shown to fail under abseil load and why on earth you need 1m of tail on one . And there is no need to shout.
In reply to GrahamD:
I`ve used an overhand knot with different sized ropes many many times.
And i`m still here.
I`ve used an overhand knot with different sized ropes many many times.
And i`m still here.
In reply to Misha:
http://www.youtube.com/watch?v=H3Cg8homvoU&feature=PlayList&p=8EF11... look about 50 seconds in.
> (In reply to liz j)
> Just been trying to make a figure of eight roll, admittedly just by pulling on it rather than abseiling off the balcony. I suppose it's possible but seems unlikely [...]
> Just been trying to make a figure of eight roll, admittedly just by pulling on it rather than abseiling off the balcony. I suppose it's possible but seems unlikely [...]
http://www.youtube.com/watch?v=H3Cg8homvoU&feature=PlayList&p=8EF11... look about 50 seconds in.
In reply to Rob Exile Ward:
Fair dos, but the double fishermans does have the tendancy to get stuck as it is symetrical. It is also an absolute pig to undo, especially if you are knackered. The overhand knot is fine - it is just a psychological thing as to whether you can persuade yourself to trust it.
> What I don't understand about this continuing debate is the speed aspect. If you are doing multiple abs then you still only tie and untie the ropes once, so any speed advantages of the EDK are minimised. Double fishermans for me I'm afraid!
Fair dos, but the double fishermans does have the tendancy to get stuck as it is symetrical. It is also an absolute pig to undo, especially if you are knackered. The overhand knot is fine - it is just a psychological thing as to whether you can persuade yourself to trust it.
In reply to speekingleesh: Interesting video, but what were the forces involved here? Given that the rope broke before the knot came undone, I am guessing that a couple of tonnes of force were used. If you can reproduce that on abseil I would be very impressed!
In reply to billy.grant:
Hey it's in capitals it must be true...
Also a metre of tail is just plain overkill. The reason you leave tail is to guard against the knot flipping once (maybe twice) if it's flipping more than that then you've tied a fig 8. and are dead already. The six to ten inches that is the 'usual' (Kirkpatrick, BMC etc.) recommendation is about right.
The worst abseiling experience I ever had was trying to retreat off a sea-stack in the pissing rain only to find we couldn't pull the ropes through. Reason? We'd left far too much tail which had (in the wind) managed to wrap itself around the ropes and tangle everything up.
> With ropes of a different thickness ALWAYS USE THE DOUBLE FISHERMANS TO ABSEIL WITH. The overhand is only recommended with ropes of the same thickness. And always leave about a metre of tail when using the overhand.
Hey it's in capitals it must be true...
Also a metre of tail is just plain overkill. The reason you leave tail is to guard against the knot flipping once (maybe twice) if it's flipping more than that then you've tied a fig 8. and are dead already. The six to ten inches that is the 'usual' (Kirkpatrick, BMC etc.) recommendation is about right.
The worst abseiling experience I ever had was trying to retreat off a sea-stack in the pissing rain only to find we couldn't pull the ropes through. Reason? We'd left far too much tail which had (in the wind) managed to wrap itself around the ropes and tangle everything up.
In reply to GrahamD:
http://www.dailymail.co.uk/news/article-182999/Climber-dead-national-park.h...
This climber was known to me. He had set off on his own to a local crag to shunt a few routes. He had approached the crag from the top where there is a handy tree.
Colin was found at the base of the crag by two other climbers, his abseil plate attached to his harness with two long unknotted lengths of rope leading (what would have been) upwards out of this - one rope was thicker than the other. He was known to favour a single overhand knot for abbing.
No-one was present to witness the accident, but most people can work out the likely cause. He was an experienced and respected climber.
You are only likely to have one abseil accident. Try and put it off as long as possible...
Don't use a single overhand on different diameter ropes as a routine method.
> (In reply to billy.grant)
> [...]
>
> References, please. And not to some crank site either. I would like to know at what rope diameter discrepancy an overhand is shown to fail under abseil load and why on earth you need 1m of tail on one . And there is no need to shout.
> [...]
>
> References, please. And not to some crank site either. I would like to know at what rope diameter discrepancy an overhand is shown to fail under abseil load and why on earth you need 1m of tail on one . And there is no need to shout.
http://www.dailymail.co.uk/news/article-182999/Climber-dead-national-park.h...
This climber was known to me. He had set off on his own to a local crag to shunt a few routes. He had approached the crag from the top where there is a handy tree.
Colin was found at the base of the crag by two other climbers, his abseil plate attached to his harness with two long unknotted lengths of rope leading (what would have been) upwards out of this - one rope was thicker than the other. He was known to favour a single overhand knot for abbing.
No-one was present to witness the accident, but most people can work out the likely cause. He was an experienced and respected climber.
You are only likely to have one abseil accident. Try and put it off as long as possible...
Don't use a single overhand on different diameter ropes as a routine method.
In reply to Jon Dittman:
Fair point (though it is quite a nice demonstration of flipping at work).
These guys seem to think that flipping occurs between 0.4 and 3.3 kN (depending on how well you tied the knot).
http://www.xmission.com/~tmoyer/testing/EDK.html
They also seem to show that tying an overhand with a 11mm rope and a 8mm rope make little difference to the when it rolls. Though to be honest I'd want some more test's to show reproducibility...
> Interesting video, but what were the forces involved here?
Fair point (though it is quite a nice demonstration of flipping at work).
These guys seem to think that flipping occurs between 0.4 and 3.3 kN (depending on how well you tied the knot).
http://www.xmission.com/~tmoyer/testing/EDK.html
They also seem to show that tying an overhand with a 11mm rope and a 8mm rope make little difference to the when it rolls. Though to be honest I'd want some more test's to show reproducibility...
In reply to speekingleesh:
Andy K quotes a fig 8 failure at a mere 30kg!!!
Andy K quotes a fig 8 failure at a mere 30kg!!!
In reply to Ian Milward:
For Tick Tor, read Pic Tor. Reporters, eh?
There is a plaque in tribute at the base of the crag.
For Tick Tor, read Pic Tor. Reporters, eh?
There is a plaque in tribute at the base of the crag.
In reply to liz j:
Only just outside the range that Moyer came up with (0.3 as opposed 0.4 kN) but then they did freeze the knot to make it a worst case scenario.
> (In reply to speekingleesh)
> Andy K quotes a fig 8 failure at a mere 30kg!!!
> Andy K quotes a fig 8 failure at a mere 30kg!!!
Only just outside the range that Moyer came up with (0.3 as opposed 0.4 kN) but then they did freeze the knot to make it a worst case scenario.
In reply to Allan McDonald (Gwydyr MC):
I had this issue and the best answer i could get was that it should be ok, but Libby Peters states in her book that it should not be used for joining ropes of different diameters and some people don`t know what diameter their ropes are, so my solution was to buy a matching pair, problem solved.
Cheers Beds
I had this issue and the best answer i could get was that it should be ok, but Libby Peters states in her book that it should not be used for joining ropes of different diameters and some people don`t know what diameter their ropes are, so my solution was to buy a matching pair, problem solved.
Cheers Beds
In reply to Ian Milward:
This is the most important bit of the story though. No-one does know what happened. While it may make increase people's doubt about the technique it's hardly evidence that it's unsafe. There are many possible explanations that would fit the circumstances but only one of them is that the knot was the root cause.
The problem is that that explanation seems at odds with the available test data (the data in the previous link and also some testing done by Edelrid linked from that). Granted this is only a limited piece of testing but it does seem to indicate that for a properly tied overhand, difference in rope diameter doesn't make a difference.
> No-one was present to witness the accident, but most people can work out the likely cause.
This is the most important bit of the story though. No-one does know what happened. While it may make increase people's doubt about the technique it's hardly evidence that it's unsafe. There are many possible explanations that would fit the circumstances but only one of them is that the knot was the root cause.
The problem is that that explanation seems at odds with the available test data (the data in the previous link and also some testing done by Edelrid linked from that). Granted this is only a limited piece of testing but it does seem to indicate that for a properly tied overhand, difference in rope diameter doesn't make a difference.
> (In reply to Ian Milward)
> [...]
>
> This is the most important bit of the story though. No-one does know what happened....
> [...]
>
> This is the most important bit of the story though. No-one does know what happened....
In reply to speekingleesh:
No I suppose they don't. At the end of the day you are perfectly correct, however I suspect many others will not agree with what you consider to be the most important bit of the story I related in response to the OP.
I've no problem with anyone - including you - continuing to use a single overhand on different dia. ropes for abbing, particularly when they have been made aware of a potential problem with that arrangement.
In reply to J1234:
>....that it should not be used for joining ropes of different diameters and some people don`t know what diameter their ropes are
If you are joining two climbing ropes, typically between 8 and 11mm diamenter, then there is not really going to be a problem with slippage, so long as the tails are left long enough and you tighten the knot before loading it. It is tried and tested and works fine.
Slippage can occur when joining ropes of vastly different diameter - like a 5mm with 11mm rope, but even then, it's not a certainty.
>....that it should not be used for joining ropes of different diameters and some people don`t know what diameter their ropes are
If you are joining two climbing ropes, typically between 8 and 11mm diamenter, then there is not really going to be a problem with slippage, so long as the tails are left long enough and you tighten the knot before loading it. It is tried and tested and works fine.
Slippage can occur when joining ropes of vastly different diameter - like a 5mm with 11mm rope, but even then, it's not a certainty.
In reply to Allan McDonald (Gwydyr MC): Not qualified to give full answer though I use overhand knot-one practical issue with very long tails is placing them through abseil device in mistake for abseil rope-have witnessed this twice, though before person staarted the abseil.
Rich
Rich
In reply to Ian Milward:
I am sorry to hear about your friend. Disturbing though it is, it is still very circumstantial. Everyone can draw their own conclusions but the documented evidence (as in the link) is slim to non existant.
Until I see any evidence that a correctly tied overhand knot can simply undo itself, I'm happy to go with my experiences.
I am sorry to hear about your friend. Disturbing though it is, it is still very circumstantial. Everyone can draw their own conclusions but the documented evidence (as in the link) is slim to non existant.
Until I see any evidence that a correctly tied overhand knot can simply undo itself, I'm happy to go with my experiences.
In reply to GrahamD: In response to your ealier reply: my understanding is that the knot on the right is AKA European Death Knot?
http://www.ukclimbing.com/images/dbpage.php?id=13909
(Needs longer tails, obviously.)
http://www.ukclimbing.com/images/dbpage.php?id=13909
(Needs longer tails, obviously.)
In reply to Anonymous:
See my posts above.
I believe the ropes in that incident were 9mm and 11mm.
As has been pointed out, no-one was there to witness the incident, just the aftermath, but I think it would be a shame if another climber died as a result of being unaware, before abbing on one, of the potential for a single overhand on different dia. ropes to roll out.
I feel I've responded responsibly to the OP, and, being aware of this accident, my conscience is clear having passed on this information to others.
See my posts above.
I believe the ropes in that incident were 9mm and 11mm.
As has been pointed out, no-one was there to witness the incident, just the aftermath, but I think it would be a shame if another climber died as a result of being unaware, before abbing on one, of the potential for a single overhand on different dia. ropes to roll out.
I feel I've responded responsibly to the OP, and, being aware of this accident, my conscience is clear having passed on this information to others.
In reply to everyone:
This is a very useful summary of Ab knot options with some good test data.
http://www.needlesports.com/advice/abseilknots.htm
This is a very useful summary of Ab knot options with some good test data.
http://www.needlesports.com/advice/abseilknots.htm
In reply to GrahamD:
I don't necessarily consider a properly-tied single overhand as risky, provided, as stated by others, it is tightened and has long tails. Occasionaly I use them myself.
The OP was asking about one tied in different ropes which is why I felt compelled to respond.
Personally I would NEVER use a single overhand on two different diameter ropes.
P.S. If Colin had a user profile, it would have been similar to yours at the time of his death, except he climbed up to E5 in his day and had more kids. He can't now pass on his experience to others personally. I'm sure he wouldn't mind me doing it for him.
I don't necessarily consider a properly-tied single overhand as risky, provided, as stated by others, it is tightened and has long tails. Occasionaly I use them myself.
The OP was asking about one tied in different ropes which is why I felt compelled to respond.
Personally I would NEVER use a single overhand on two different diameter ropes.
P.S. If Colin had a user profile, it would have been similar to yours at the time of his death, except he climbed up to E5 in his day and had more kids. He can't now pass on his experience to others personally. I'm sure he wouldn't mind me doing it for him.
In reply to Anonymous:
Greatest respect but your anonymous and using the phrases "not really" and "so long as" so not exactly Libby Peters saying hey Beds 9mm and a 10mm with an overhand, no problem.
Some people call me risk averse, now that seems a good attitude in climbing to me, so i`ll stay with my matched ropes unless circumstances dictate i have to make an educated compromise.
However I don`t know why but I sense from your posting that if I knew who you are I`d take your advice.
> (In reply to bedspring)
>
> If you are joining two climbing ropes, typically between 8 and 11mm diamenter, then there is not really going to be a problem with slippage, so long as the tails are left long enough and you tighten the knot before loading it. It is tried and tested and works fine.
>
>> If you are joining two climbing ropes, typically between 8 and 11mm diamenter, then there is not really going to be a problem with slippage, so long as the tails are left long enough and you tighten the knot before loading it. It is tried and tested and works fine.
>
Greatest respect but your anonymous and using the phrases "not really" and "so long as" so not exactly Libby Peters saying hey Beds 9mm and a 10mm with an overhand, no problem.
Some people call me risk averse, now that seems a good attitude in climbing to me, so i`ll stay with my matched ropes unless circumstances dictate i have to make an educated compromise.
However I don`t know why but I sense from your posting that if I knew who you are I`d take your advice.
In reply to Rob Exile Ward:
The knot on the left is usually called a Water Knot (though normally used with tape not cord).
> In response to your ealier reply: my understanding is that the knot on the right is AKA European Death Knot?
>
> http://www.ukclimbing.com/images/dbpage.php?id=13909
>
>
> http://www.ukclimbing.com/images/dbpage.php?id=13909
>
The knot on the left is usually called a Water Knot (though normally used with tape not cord).
In reply to speekingleesh:
The moniker EDK has been applied to a number of knots, including the basic overhand and the figure of 8. Because of this it is an emmotive title with very little value.
The moniker EDK has been applied to a number of knots, including the basic overhand and the figure of 8. Because of this it is an emmotive title with very little value.
In reply to GrahamD: 'EDK is not the overhand knot. As any fule no.' I think you'll find that you are wrong. Google it if you like.
In reply to speekingleesh: I'd call it a tape knot (when in tape!) Peter Cliff calls it an overhand knot in his books and alpine climbing and ski touring, I used to wonder whether people weren't mixing it up with the EDK, but perhaps not.
In reply to Misha: A figure of eight is very unsafe used in this situation as the knot is loaded in the wrong direction and will roll towards the tails!
In reply to Rob Exile Ward:
EDK has been used to refer to all sorts of knots, not just the overhand. Its one of those throw away terms used by someone to mean any knot they don't prsonally endorse, irrespective of the safety of the knot.
EDK has been used to refer to all sorts of knots, not just the overhand. Its one of those throw away terms used by someone to mean any knot they don't prsonally endorse, irrespective of the safety of the knot.
In reply to Allan McDonald (Gwydyr MC):
http://alpineinstitute.blogspot.com/2009/03/euro-death-knot.html
You might find this helpfull,it's by the American Alpine Institute,and it's got a video on how to tie the knot safely.
Cheers
Tim
http://alpineinstitute.blogspot.com/2009/03/euro-death-knot.html
You might find this helpfull,it's by the American Alpine Institute,and it's got a video on how to tie the knot safely.
Cheers
Tim
In reply to Timmd: Cheers everyone for all the above.
I am off to alps and expect we will be abbing at some point and will give the double overhand a go as it would be ok with a 9mm and 8.5mm I guess. Would not consider abbing with Overhand Knot (double or otherwise)if ropes had more than 1mm difference in diameter.
I am off to alps and expect we will be abbing at some point and will give the double overhand a go as it would be ok with a 9mm and 8.5mm I guess. Would not consider abbing with Overhand Knot (double or otherwise)if ropes had more than 1mm difference in diameter.
Interesting. Guess I'll have to try to remember to use an overhand. What is also clear is that how well the knot is tied and the condition of the rope are both important in determining the failure load. If it was really 30kg with a well tied know on a dry rope, quite a few people would be dead by now, myself included. I also wonder whether the know tightens when it flips, making subsequent flipping less likely. It would be useful to have some tests to compare the loads require for first time and subsequent flipping. The double overhand seems like a good idea - a bit bulkier but should still glide when being pulled through.
In reply :
Closed mind.
And so what? Some people claim WMD in Iraq, or UFOs, or ... ELVIS !
FIRSTLY, please note that the issue here is an ARJ knot --abseil-ropes joining.
The loads are body weight, roughly, on TWO ropes so joined (unless simul-rapping).
Those loads, and greater, are EASILY PRODUCED BY ANYONE concerned about
how some ARJ knot will behave in the particular combination of ropes at hand.
I.e., don't slap away at the keyboard with "I heard that ..." echoes of speculation,
go tie the knots and give 'em a good shake; make a quick'n'dirty 2:1 pulley with
a krab (better, a real pulley), and bounce on that, seeing what actually happens
to your knot of test. Does the infamous Offset Fig.8 bend really roll as easily
as some have asserted? --I echo those admonitions, but frankly haven't been
able to flip ("flype", better) the Offset-8. But I know it is less sure than a good
many alternatives.
It's not as though the concern is some Fall-Factor-2 force and breaking strength,
which of course few of us can test. No, here, the exact test is pretty simple,
and everyone should be doing it! (Of course, some several decades of usage
of the ORB can count for a thing or two, too.)
The OPer should've Searched this forum and found this prior discussion;
thanks to who pulled this up. I give more discussion about the proper use of
the ORB (and alternatives) there:
www.ukclimbing.com/forums/t.php?t=355663 --URLink to prior thread w/my full explanations
NB: This Wikipedia image
en.wikipedia.org/wiki/Euro_death-knot
shows a BAD orientation of diff-diameter ropes
--the thicker red rope is more likely to be pried out around the thinner green one;
rather, this orientation should be reversed, with consequent *improved* resistance
(improved over even equal-dia. ropes, i.e.) to such flyping.
Re the image contributed above:
www.ukclimbing.com/images/dbpage.html?id=13909 --nice images of the Ring & Offset Ring Bends
NB: the THINNERope should be in the position of the PURPLE ROPE in image;
and the end of this should be tied off around the other end with an Overhand knot.
No further precaution is necessary (i.p., one need not "leave long tails").
Alternatively, the purple rope of the image can be given a full turn around the
main lines at their entry point before its tail is tucked out beside the other.
Call this the "Offset 9-Oh", as the purple/thinner line which effects the strong
choke makes a Fig.9 form, married to the Overhand form of the thicker rope.
Not really: "EDK" is a gift from the States and refers to the Offset Ring Bend,
what many are calling "Overhand knot" (but that's wrong: that name refers to
the structure in a single line, not two (except for the throwing of the Reef knot,
but let's not go there)); "EDK-8" has been used to refer to the Offset Fig.8 bend.
"Offset" is what is needed in these discussions, to nail the aspect that's key
to their use (and their vulnerability); one can try the Offset Grapevine (Dbl.Fish)
e.g., which joint was proposed by Franz Bachmann and tested by Edelrid, as
is posted by Jost Gudelius (you do the Googling).
Please READ the following thread:
www.rockclimbing.com/cgi-bin/forum/gforum.cgi?post=2091962;search_string=Beyond%20the%20EDK;#2091962
(In the Gear Heads sub-form, thread "Beyond the 'EDK'=>'Offset 9-Oh' et al."
Different materials, different results; try flyping it in the materials of issue.
Tom Moyer did this with a slow-pull device, and you can see that his results
are mixed, including flyping that did stop, and held through rupture. Most of
his flypes/rolls/flips/capsizes occurred at very high forces, well beyond what
abseiling will generate.
*kN*
> Would not consider abbing with Overhand Knot (double or otherwise)
>if ropes had more than 1mm difference in diameter.Closed mind.
> Andy K quotes a fig 8 failure at a mere 30kg!!!
And so what? Some people claim WMD in Iraq, or UFOs, or ... ELVIS !
FIRSTLY, please note that the issue here is an ARJ knot --abseil-ropes joining.
The loads are body weight, roughly, on TWO ropes so joined (unless simul-rapping).
Those loads, and greater, are EASILY PRODUCED BY ANYONE concerned about
how some ARJ knot will behave in the particular combination of ropes at hand.
I.e., don't slap away at the keyboard with "I heard that ..." echoes of speculation,
go tie the knots and give 'em a good shake; make a quick'n'dirty 2:1 pulley with
a krab (better, a real pulley), and bounce on that, seeing what actually happens
to your knot of test. Does the infamous Offset Fig.8 bend really roll as easily
as some have asserted? --I echo those admonitions, but frankly haven't been
able to flip ("flype", better) the Offset-8. But I know it is less sure than a good
many alternatives.
It's not as though the concern is some Fall-Factor-2 force and breaking strength,
which of course few of us can test. No, here, the exact test is pretty simple,
and everyone should be doing it! (Of course, some several decades of usage
of the ORB can count for a thing or two, too.)
The OPer should've Searched this forum and found this prior discussion;
thanks to who pulled this up. I give more discussion about the proper use of
the ORB (and alternatives) there:
www.ukclimbing.com/forums/t.php?t=355663 --URLink to prior thread w/my full explanations
NB: This Wikipedia image
en.wikipedia.org/wiki/Euro_death-knot
shows a BAD orientation of diff-diameter ropes
--the thicker red rope is more likely to be pried out around the thinner green one;
rather, this orientation should be reversed, with consequent *improved* resistance
(improved over even equal-dia. ropes, i.e.) to such flyping.
Re the image contributed above:
www.ukclimbing.com/images/dbpage.html?id=13909 --nice images of the Ring & Offset Ring Bends
NB: the THINNERope should be in the position of the PURPLE ROPE in image;
and the end of this should be tied off around the other end with an Overhand knot.
No further precaution is necessary (i.p., one need not "leave long tails").
Alternatively, the purple rope of the image can be given a full turn around the
main lines at their entry point before its tail is tucked out beside the other.
Call this the "Offset 9-Oh", as the purple/thinner line which effects the strong
choke makes a Fig.9 form, married to the Overhand form of the thicker rope.
> EDK has been used to refer to all sorts of knots, ...
Not really: "EDK" is a gift from the States and refers to the Offset Ring Bend,
what many are calling "Overhand knot" (but that's wrong: that name refers to
the structure in a single line, not two (except for the throwing of the Reef knot,
but let's not go there)); "EDK-8" has been used to refer to the Offset Fig.8 bend.
"Offset" is what is needed in these discussions, to nail the aspect that's key
to their use (and their vulnerability); one can try the Offset Grapevine (Dbl.Fish)
e.g., which joint was proposed by Franz Bachmann and tested by Edelrid, as
is posted by Jost Gudelius (you do the Googling).
Please READ the following thread:
www.rockclimbing.com/cgi-bin/forum/gforum.cgi?post=2091962;search_string=Beyond%20the%20EDK;#2091962
(In the Gear Heads sub-form, thread "Beyond the 'EDK'=>'Offset 9-Oh' et al."
> I have actually pulled a fig 8 apart with my hands on a piece of cord.
> Once the knot flips, it doesn't stop
> Once the knot flips, it doesn't stop
Different materials, different results; try flyping it in the materials of issue.
Tom Moyer did this with a slow-pull device, and you can see that his results
are mixed, including flyping that did stop, and held through rupture. Most of
his flypes/rolls/flips/capsizes occurred at very high forces, well beyond what
abseiling will generate.
*kN*
In reply to knudeNoggin:
Did you copy all that off the web??
The cord that I used was 7mm, not that different to a pair of icelines really. Also, how many people have used a fig 8 to tie a piece of cord around a spike, something else to think about. I personally would never use a fig8 to join my ropes. I much prefer an overhand knot. Each to their own.
Did you copy all that off the web??
The cord that I used was 7mm, not that different to a pair of icelines really. Also, how many people have used a fig 8 to tie a piece of cord around a spike, something else to think about. I personally would never use a fig8 to join my ropes. I much prefer an overhand knot. Each to their own.
In reply to knudeNoggin:
EDK has been used to refer to both offset ring bend (standard overhand to most climbers) and to figure of 8 bends - both when the term was originally coined and on UKC threads. Therefore not only is it a needlesley emmotive (as in "death") term, it is ambiguous.
> Not really: "EDK" is a gift from the States and refers to the Offset Ring Bend,... "EDK-8" has been used to refer to the Offset Fig.8 bend.
EDK has been used to refer to both offset ring bend (standard overhand to most climbers) and to figure of 8 bends - both when the term was originally coined and on UKC threads. Therefore not only is it a needlesley emmotive (as in "death") term, it is ambiguous.
In reply to GrahamD: Wow - people here can get a bit obsessive, can't they! It's 'emotive' btw. And I'm not - I think EDK is quite an amusing term, and it's *almost* persuaded me to change my ways...
In reply to knudeNoggin:
>> Andy K quotes a fig 8 failure at a mere 30kg!!!
That isn't random speculation though that is Kirkpatrick quoting (one of the) results of a systematic test, which he then links to...
>> Andy K quotes a fig 8 failure at a mere 30kg!!!
> And so what? Some people claim WMD in Iraq, or UFOs, or ... ELVIS !
[...]> I.e., don't slap away at the keyboard with "I heard that ..." echoes of speculation.
That isn't random speculation though that is Kirkpatrick quoting (one of the) results of a systematic test, which he then links to...
In reply to Rob Exile Ward:
"Emotive". I sit corrected
Personally I see "EDK" as a typical 'Americanism' but I'm not really sure its helpful in what ought to be an objective discussion.
"Emotive". I sit corrected
Personally I see "EDK" as a typical 'Americanism' but I'm not really sure its helpful in what ought to be an objective discussion.
In reply to speekingleesh:
I don't see the URLink, but I'll guess it might be the Aussie Bushwalkers report.
The point remains, though: ALL can go out and do the pertinent testing
of exactly the ropes they might be tying together (well, in most cases);
there need not be this continual "he said 'boo'..." hysteria, which gets one
nowhere. YOU can generate way more than 30kg in the pulley bounce
test I recommended -- and when your Offset-8 doesn't seem interested
in flyping, what are you going to do? Question how it was, and in what
exact materials it was, that the same knot was found to go at 30kg!?
Again, there's good reason to not use the Offset Fig.8 as it does show
greater vulnerability to flyping--its extra half turn only providing that
much more material to yield to stretch and open--, and there are many
alternatives with better performance. (One can marry the Fig.8 & the
Overhand into an Offset 8-Oh which looks good--ends here point in
opposite directions (the half-turn difference between the two forms),
which gives different dynamics than with the known knots.)
---------
The qualities of materials that increase vulnerability of these offset knots
to flype are:
1) stiffness -- making it hard to set the knot into tight turns, snug ;
2) stretchiness -- which gives deformity under stress ;
3) rough/frictive surface -- which impedes the setting of a knot tightly;
which makes the draw on parts to pull open a knot more sure.
The typical thinner haul line will usually be opposite on aspects 1 & 2
-- flexible, so tightening well; low-elongation, so holding the choke.
Again, in different diameter ropes, there is an orientation --thinner rope
making the choke-- that is ADVANTAGEOUS to the knot's stability!
That, and the easy tying off of the thinner end around the other to put
a block on its being drawn out on loading, render a sure knot unwanting
of the usual (and hardly reassuring) precaution to "leave long tails".
(As in "oh, that dog's safe -- just stay 50' away".) Having the additional
Overhand tie-off in the thinner rope of course also adds less bulk (than
tying a full, 2nd ORB to back up the first).
----------------
a note about testing:
----------------
On this particular issue, the relevant testing isn't the traditional break
test with a slow-pull device, for (a) that doesn't model how the knot's
loaded in practice (more of low, varying loads) and (b) produces a result
that is irrelevant -- any knot will be strong enough.
In general, ask yourself if you have enough information from the test
report to replicate the testing! --typically, one does not: one doesn't
know the exact materials used, or the exact geometry of the knot.
(E.g., in testing of the Fig.8 eye-knot Lyon Equip. was careful to actually
specify the two main loadings --either of the parallel ends, i.e.-- in a
set of tied-with-a-bight eye knots; but these commonly tested knots
are usually NOT articulated to this simple degree, even. So we can still
wonder at what differences might obtain.
Ask if the loading is a good model for the intended practice. In this
case of the offset bends (ARJ knots), one might wonder if e.g. Moyer's
results where the knot flyped would be different were a suspended mass
producing the force instead of a test device with a constant-rate-of-pull
extension? --that on the knot's flype/roll, the subsequent loading would
be both quicker to bear and a bit of a shock ?!! With slow-pull, maybe
the knot has some chance to bind better.
(I've seen slow-pull tests break clove hitches around krabs;
but I recall that Jim Ewing of Sterling did some drop tests in which
the cloves spilled, the mass decked ! (Lyon found slow-pulled
cloves to break in one (one, not everyone--beyond their expenses!)
dynamic rope, but NOT hold in several low-elongation ropes.) )
*knudeNoggin*
> (In reply to knudeNoggin)
> >> Andy K quotes a fig 8 failure at a mere 30kg!!!
> > [... So what? ...]
> That isn't random speculation though that is Kirkpatrick quoting (one of the)
> results of a systematic test, which he then links to...
> >> Andy K quotes a fig 8 failure at a mere 30kg!!!
> > [... So what? ...]
> That isn't random speculation though that is Kirkpatrick quoting (one of the)
> results of a systematic test, which he then links to...
I don't see the URLink, but I'll guess it might be the Aussie Bushwalkers report.
The point remains, though: ALL can go out and do the pertinent testing
of exactly the ropes they might be tying together (well, in most cases);
there need not be this continual "he said 'boo'..." hysteria, which gets one
nowhere. YOU can generate way more than 30kg in the pulley bounce
test I recommended -- and when your Offset-8 doesn't seem interested
in flyping, what are you going to do? Question how it was, and in what
exact materials it was, that the same knot was found to go at 30kg!?
Again, there's good reason to not use the Offset Fig.8 as it does show
greater vulnerability to flyping--its extra half turn only providing that
much more material to yield to stretch and open--, and there are many
alternatives with better performance. (One can marry the Fig.8 & the
Overhand into an Offset 8-Oh which looks good--ends here point in
opposite directions (the half-turn difference between the two forms),
which gives different dynamics than with the known knots.)
---------
The qualities of materials that increase vulnerability of these offset knots
to flype are:
1) stiffness -- making it hard to set the knot into tight turns, snug ;
2) stretchiness -- which gives deformity under stress ;
3) rough/frictive surface -- which impedes the setting of a knot tightly;
which makes the draw on parts to pull open a knot more sure.
The typical thinner haul line will usually be opposite on aspects 1 & 2
-- flexible, so tightening well; low-elongation, so holding the choke.
Again, in different diameter ropes, there is an orientation --thinner rope
making the choke-- that is ADVANTAGEOUS to the knot's stability!
That, and the easy tying off of the thinner end around the other to put
a block on its being drawn out on loading, render a sure knot unwanting
of the usual (and hardly reassuring) precaution to "leave long tails".
(As in "oh, that dog's safe -- just stay 50' away".) Having the additional
Overhand tie-off in the thinner rope of course also adds less bulk (than
tying a full, 2nd ORB to back up the first).
----------------
a note about testing:
----------------
On this particular issue, the relevant testing isn't the traditional break
test with a slow-pull device, for (a) that doesn't model how the knot's
loaded in practice (more of low, varying loads) and (b) produces a result
that is irrelevant -- any knot will be strong enough.
In general, ask yourself if you have enough information from the test
report to replicate the testing! --typically, one does not: one doesn't
know the exact materials used, or the exact geometry of the knot.
(E.g., in testing of the Fig.8 eye-knot Lyon Equip. was careful to actually
specify the two main loadings --either of the parallel ends, i.e.-- in a
set of tied-with-a-bight eye knots; but these commonly tested knots
are usually NOT articulated to this simple degree, even. So we can still
wonder at what differences might obtain.
Ask if the loading is a good model for the intended practice. In this
case of the offset bends (ARJ knots), one might wonder if e.g. Moyer's
results where the knot flyped would be different were a suspended mass
producing the force instead of a test device with a constant-rate-of-pull
extension? --that on the knot's flype/roll, the subsequent loading would
be both quicker to bear and a bit of a shock ?!! With slow-pull, maybe
the knot has some chance to bind better.
(I've seen slow-pull tests break clove hitches around krabs;
but I recall that Jim Ewing of Sterling did some drop tests in which
the cloves spilled, the mass decked ! (Lyon found slow-pulled
cloves to break in one (one, not everyone--beyond their expenses!)
dynamic rope, but NOT hold in several low-elongation ropes.) )
*knudeNoggin*
In reply to knudeNoggin:
Out of interest, do you have a life outside knots and splices ? just curious
Out of interest, do you have a life outside knots and splices ? just curious
In reply to GrahamD: I think maybe a course in summarising conclusions might be appropriate.
In reply to GrahamD:
I was wondering that too, seems to like pasting though
> (In reply to knudeNoggin)
>
> Out of interest, do you have a life outside knots and splices ? just curious
>
> Out of interest, do you have a life outside knots and splices ? just curious
I was wondering that too, seems to like pasting though
In reply to Allan McDonald (Gwydyr MC):
I am surprised no one has mentioned the use of a reef knot, then backed up with a double fisherman's on each side for ropes of equal diameter. I believe it was the preferred method for many years as it is easier to undo then just a double fisherman's.
For ropes of unequal diameter the knot to use is a sheet bend , again finished off with a double fisherman's on each side. This knot will not slip and could be used to tie an 11mm rope and 8.5mm!
I am surprised no one has mentioned the use of a reef knot, then backed up with a double fisherman's on each side for ropes of equal diameter. I believe it was the preferred method for many years as it is easier to undo then just a double fisherman's.
For ropes of unequal diameter the knot to use is a sheet bend , again finished off with a double fisherman's on each side. This knot will not slip and could be used to tie an 11mm rope and 8.5mm!
In reply to Moses:
I'm always surprised that people complain that, although widely regarded as the 'safest' knot, the double fisherman's is hard to undo after loading. I can't say I've ever found this to be a major problem. I think there's a bit of a knack to untwisting the knot to loosen it. Or maybe I don't climb with anyone too heavy!
I'm always surprised that people complain that, although widely regarded as the 'safest' knot, the double fisherman's is hard to undo after loading. I can't say I've ever found this to be a major problem. I think there's a bit of a knack to untwisting the knot to loosen it. Or maybe I don't climb with anyone too heavy!
In reply to Allan McDonald (Gwydyr MC):
In the interests of scientific research (and in no way is this a reccomended configuration for actual abseiling) I did an experiment at the wall last night: I tied an 11mm single rope to a length of 5mm accessory cord (as used for prusics, abseil tat etc.) using a single overhand knot with 12" tails ('offset ring bend' or one manifestation of 'EDK' if you prefer). I tied the cord off to the first hanger and the 11mm rope to my harness.
I then gradually loaded my weight onto the rope and, when fully suspended, did a few simulated abseil 'bounces'. Note that in this configuration the knot is subject to my full 80kG weight, not half my weight as it would be in an abseil set up. Observing the knot, as it was loaded, it made half a turn - tightening as it did so - and was then solid from thereon in. This used maybe 1/2" of the available 12" of tail.
This experiment further reassures me (personally) that using an overhand knot to tie abseil ropes of slightly different diameters is a perfectly valid thing to do.
In the interests of scientific research (and in no way is this a reccomended configuration for actual abseiling) I did an experiment at the wall last night: I tied an 11mm single rope to a length of 5mm accessory cord (as used for prusics, abseil tat etc.) using a single overhand knot with 12" tails ('offset ring bend' or one manifestation of 'EDK' if you prefer). I tied the cord off to the first hanger and the 11mm rope to my harness.
I then gradually loaded my weight onto the rope and, when fully suspended, did a few simulated abseil 'bounces'. Note that in this configuration the knot is subject to my full 80kG weight, not half my weight as it would be in an abseil set up. Observing the knot, as it was loaded, it made half a turn - tightening as it did so - and was then solid from thereon in. This used maybe 1/2" of the available 12" of tail.
This experiment further reassures me (personally) that using an overhand knot to tie abseil ropes of slightly different diameters is a perfectly valid thing to do.
In reply to GrahamD:
One of the main reasons not to join two ropes of very difference diameters (eg 11mm and 6mm) when rapping is that they can pass through the belay plate at different rates. This could be fatal. You can get around the problem by joining the ropes with a screwgate that is also clipped to the fatter rope under the chains. You then rap on the fat rope only and pull the thin to get the rope down. For those that know it, this is the same set up as used to rap with a gri-gri.
One of the main reasons not to join two ropes of very difference diameters (eg 11mm and 6mm) when rapping is that they can pass through the belay plate at different rates. This could be fatal. You can get around the problem by joining the ropes with a screwgate that is also clipped to the fatter rope under the chains. You then rap on the fat rope only and pull the thin to get the rope down. For those that know it, this is the same set up as used to rap with a gri-gri.
In reply to David Coley (SDMC):
Obviously what I described was just to illustrate how strong the knot is even with very different diametre ropes.
As far as actually abbing off an 11mm and 5mm, I guess the biggest problem is actually keeping hold of the thinner rope ! I don't think the different rates is so much of an issue in itself provided one is aware that the end of one strand will arrive a way before the other. As you say, there are better ways to manage the thick + very thin rope scenario.
Obviously what I described was just to illustrate how strong the knot is even with very different diametre ropes.
As far as actually abbing off an 11mm and 5mm, I guess the biggest problem is actually keeping hold of the thinner rope ! I don't think the different rates is so much of an issue in itself provided one is aware that the end of one strand will arrive a way before the other. As you say, there are better ways to manage the thick + very thin rope scenario.
In reply to David Coley (SDMC):
I am sure you are right on this point, but it seemed to be fairly standard practice when I went climbing in Yosemite. You climb on a 10mm but drag up a 6mm dynamic rope for abseil purposes. Seemed to work fine to me and tied of course with the overhand knot!
> (In reply to GrahamD)
>
> One of the main reasons not to join two ropes of very difference diameters (eg 11mm and 6mm) when rapping is that they can pass through the belay plate at different rates. This could be fatal.
>
> One of the main reasons not to join two ropes of very difference diameters (eg 11mm and 6mm) when rapping is that they can pass through the belay plate at different rates. This could be fatal.
I am sure you are right on this point, but it seemed to be fairly standard practice when I went climbing in Yosemite. You climb on a 10mm but drag up a 6mm dynamic rope for abseil purposes. Seemed to work fine to me and tied of course with the overhand knot!
In reply to Jon Dittman:
With the 10mm/6mm combination, there is a way you can avoid tying the ropes together: Tie a krab into the end of the 10mm rope and secure to the anchor using a larksfoot. You can then ab only on the 10mm and use the 6mm to pull the krab down and retrieve the rope.
With the 10mm/6mm combination, there is a way you can avoid tying the ropes together: Tie a krab into the end of the 10mm rope and secure to the anchor using a larksfoot. You can then ab only on the 10mm and use the 6mm to pull the krab down and retrieve the rope.
In reply to Jon Dittman:
6 and 10mm seems to work fine unless one raps very fast. I have once given myself a real fright. Much thinner than 6mm and I think it best to link with a screw gate back clipped.
6 and 10mm seems to work fine unless one raps very fast. I have once given myself a real fright. Much thinner than 6mm and I think it best to link with a screw gate back clipped.
In reply to GrahamD:
THANKS!
Yes, but as I tried to very carefully explain/describe above
(to someone's apparent annoyance at so many keystrokes -- must be "pasting"??),
there are two obvious orientations here: either the thin (preferably)
or the thick rope will be making the immediate *choke* at the
entry of the two ropes into the knot. Again, I say that it should be
the thinner, more flexible one,
AND that (only) its tail should be subsequently tied off in an Overhand
around the thicker rope's tail, to preclude loosening under load.
Also, with a pretty short bit of material in load, to mitigate your bouncing!
With the usual increasingly long bit of doubled material between you and
the rap anchor, there will be much more material to mitigate shock.
Not sure of what you mean by "half a turn": at first I mis-read ' 1/2" ' as being
"1/2 OF... (12" = 6" consumed!)). But if at most an inch was consumed of
the tail, then you couldn't have rolled the knot.
I didn't take the added keystrokes ("pasting") above to further note that
the ORB can be set in a range of orientation --direction the tails point--
of about 180degrees. That is, if the ORB were tied in ropes stretched
left-to-right across a desk top at which you are seated, say, you could
reach out with a hand and rotate the knot (turning it clockwise/anti-clockwise
as viewed looking down upon the desktop) to various positions and it will
stay there when loaded. How much this aspect of orientation matters is
something I've yet to test. (At one extreme, the rope from the left will
be entering the knot and making a backward loop, and the other rope
a forward arch; in the mid-range position both ropes will rise abutting,
and arc perpendicularly from the axis of tension, and then turn ... ; and
then the opposite extreme of the range will see the left rope making the
forward arc to the right rope's backward loop.)
Yes, it's reassuring: for you've gone some way out of bounds of what
is normally asked -- i.e. using greater difference than usual, where "usual"
means 7mm + 10mm and sometimes less difference. And your bouncing
is probably more rigorous loading than usual rapping will deliver.
But, still, realize that the possible combinations of ropes is broad,
and the relevant aspects are more than just diameters.
(And, again, that you've not made clear the orientation vis-a-vis
thick/thin in tying the knot.)
THIS, and adding the Overhand stopper tie-off should put the ORB into
sound acceptance.
*kN*
> (In reply to Allan McDonald (Gwydyr MC))
>
> In the interests of scientific research ...
>
> In the interests of scientific research ...
THANKS!
> I tied an 11mm single rope to a length of 5mm accessory cord ...
> using a single overhand knot with 12" tails ('offset ring bend'
> using a single overhand knot with 12" tails ('offset ring bend'
Yes, but as I tried to very carefully explain/describe above
(to someone's apparent annoyance at so many keystrokes -- must be "pasting"??),
there are two obvious orientations here: either the thin (preferably)
or the thick rope will be making the immediate *choke* at the
entry of the two ropes into the knot. Again, I say that it should be
the thinner, more flexible one,
AND that (only) its tail should be subsequently tied off in an Overhand
around the thicker rope's tail, to preclude loosening under load.
> ... , did a few simulated abseil 'bounces'.
> Note that in this configuration the knot is subject to my full 80kG weight.
> not half my weight as it would be in an abseil set up.
> Note that in this configuration the knot is subject to my full 80kG weight.
> not half my weight as it would be in an abseil set up.
Also, with a pretty short bit of material in load, to mitigate your bouncing!
With the usual increasingly long bit of doubled material between you and
the rap anchor, there will be much more material to mitigate shock.
> Observing the knot, as it was loaded, it made half a turn
> - tightening as it did so - and was then solid from thereon in.
> This used maybe 1/2" of the available 12" of tail.
> - tightening as it did so - and was then solid from thereon in.
> This used maybe 1/2" of the available 12" of tail.
Not sure of what you mean by "half a turn": at first I mis-read ' 1/2" ' as being
"1/2 OF... (12" = 6" consumed!)). But if at most an inch was consumed of
the tail, then you couldn't have rolled the knot.
I didn't take the added keystrokes ("pasting") above to further note that
the ORB can be set in a range of orientation --direction the tails point--
of about 180degrees. That is, if the ORB were tied in ropes stretched
left-to-right across a desk top at which you are seated, say, you could
reach out with a hand and rotate the knot (turning it clockwise/anti-clockwise
as viewed looking down upon the desktop) to various positions and it will
stay there when loaded. How much this aspect of orientation matters is
something I've yet to test. (At one extreme, the rope from the left will
be entering the knot and making a backward loop, and the other rope
a forward arch; in the mid-range position both ropes will rise abutting,
and arc perpendicularly from the axis of tension, and then turn ... ; and
then the opposite extreme of the range will see the left rope making the
forward arc to the right rope's backward loop.)
> This experiment further reassures me (personally) that using an
> overhand knot to tie abseil ropes of slightly different diameters
> is a perfectly valid thing to do.
> overhand knot to tie abseil ropes of slightly different diameters
> is a perfectly valid thing to do.
Yes, it's reassuring: for you've gone some way out of bounds of what
is normally asked -- i.e. using greater difference than usual, where "usual"
means 7mm + 10mm and sometimes less difference. And your bouncing
is probably more rigorous loading than usual rapping will deliver.
But, still, realize that the possible combinations of ropes is broad,
and the relevant aspects are more than just diameters.
(And, again, that you've not made clear the orientation vis-a-vis
thick/thin in tying the knot.)
THIS, and adding the Overhand stopper tie-off should put the ORB into
sound acceptance.
*kN*
In reply to knudeNoggin:
Mate, you seriously need to get out more....climbing maybe???
Mate, you seriously need to get out more....climbing maybe???
In reply to jon:
I think she already did, the wrong ones
> (In reply to knudeNoggin)
>
> Oh no! NURSE, give him his pills NOW.
>
> Oh no! NURSE, give him his pills NOW.
I think she already did, the wrong ones
In reply to jon:
I really don't think he'd get of the ground, it would be dark by the time his fig8 tie in was perfectly orientated, and his mates would be in the pub already!!!!
> (In reply to liz j)
>
> No No, don't let him climb...
>
> No No, don't let him climb...
I really don't think he'd get of the ground, it would be dark by the time his fig8 tie in was perfectly orientated, and his mates would be in the pub already!!!!
In reply to knudeNoggin:
1/2" meaning half an inch - sorry if that wasn't clear. The knot basically settled into a stable position after loading and its hard to describe what happened to the knot other than to describe it as rolling half a turn. I guess it was just finding its most stable orientation ?
1/2" meaning half an inch - sorry if that wasn't clear. The knot basically settled into a stable position after loading and its hard to describe what happened to the knot other than to describe it as rolling half a turn. I guess it was just finding its most stable orientation ?
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