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Hello. First post here.
I'm going sport climbing at a new crag tomorrow. I've got a 3m length of 9mm static rope and wondered if the attached photo is an acceptable anchor should my 120cm nylon sling not be long enough. Double fisherman's for each screwgate at the bolts and a figure of 8 on a bite for the master point.
https://imgur.com/a/MHEqe
Thanks in advance!
I'm going sport climbing at a new crag tomorrow. I've got a 3m length of 9mm static rope and wondered if the attached photo is an acceptable anchor should my 120cm nylon sling not be long enough. Double fisherman's for each screwgate at the bolts and a figure of 8 on a bite for the master point.
https://imgur.com/a/MHEqe
Thanks in advance!
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In reply to martyn04:
I've got absolutely no qualification to 'approve' your top rope anchor but I can't see a problem with it.
I'd have figure eights rather than double fishermans and I'd tie your master point once you'd clipped it all in so you can equalise it.
I'd a bit out of touch with sport climbing but I think most people just bung a quick draw on each of the top bolts and top rope through those so I think your setup is fine.
I've got absolutely no qualification to 'approve' your top rope anchor but I can't see a problem with it.
I'd have figure eights rather than double fishermans and I'd tie your master point once you'd clipped it all in so you can equalise it.
I'd a bit out of touch with sport climbing but I think most people just bung a quick draw on each of the top bolts and top rope through those so I think your setup is fine.
Post edited at 11:20
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In reply to martyn04:
looks good, your barrel knots (1/2 a double fishermans) on the krabs are very secure
but tend to be hard to adjust and a bugger to undo!
You can use fo8s (or even clove hitches)
id also do the 2 lower lockers up as well
looks good, your barrel knots (1/2 a double fishermans) on the krabs are very secure
but tend to be hard to adjust and a bugger to undo!
You can use fo8s (or even clove hitches)
id also do the 2 lower lockers up as well
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Nice one. Cheers for the feedback. FO8s it is then.
I would normally use opposed quickdraws but it's good to know I can use something like this as an option if the bolts are staggered or I want to avoid the rope rubbing on an outcrop of rock near the anchor
I would normally use opposed quickdraws but it's good to know I can use something like this as an option if the bolts are staggered or I want to avoid the rope rubbing on an outcrop of rock near the anchor
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In reply to martyn04:
I'm not sure that's going to take a fall. That top line looks way too thin and how well is that bed anchored?
Would not trust.
I'm not sure that's going to take a fall. That top line looks way too thin and how well is that bed anchored?
Would not trust.
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In reply to martyn04:
Looks basically good. How long are the tails on those knots at the top though? The picture makes it look like they're about 20-30cm, which is probably fine, but I can't really tell from the perspective.
The choice of knots at the top will probably do for a top-rope anchor, but the other advice on this thread is good.
Looks basically good. How long are the tails on those knots at the top though? The picture makes it look like they're about 20-30cm, which is probably fine, but I can't really tell from the perspective.
The choice of knots at the top will probably do for a top-rope anchor, but the other advice on this thread is good.
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In reply to martyn04:
You don't need to worry too much about equalising bolt belays unless they look a bit dodgy, however when the bolts are at different levels there's always the risk that the rope double clips the lower draw. This can be avoided by having two opposing draws on the lower bolt or a draw with a screwgate.
You don't need to worry too much about equalising bolt belays unless they look a bit dodgy, however when the bolts are at different levels there's always the risk that the rope double clips the lower draw. This can be avoided by having two opposing draws on the lower bolt or a draw with a screwgate.
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In reply to martyn04:
It's possible to horribly cock up barrel knots while they look fine. Useful knot but not in this scenario, fig8 or clove hitch is what you want.
Also for sport just stick a quickdraw on each belay bolt or back to back draws on the ring.
jk
It's possible to horribly cock up barrel knots while they look fine. Useful knot but not in this scenario, fig8 or clove hitch is what you want.
Also for sport just stick a quickdraw on each belay bolt or back to back draws on the ring.
jk
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In reply to jkarran:
It's possible to horribly cock up barrel knots while they look fine. Useful knot but not in this scenario, fig8 or clove hitch is what you want.
Clove Hitch is definitely not the knot to use when there are rope tails present - Figure of Eight is probably the best option if a length of rope is used instead of a sling.
However, for the OP's benefit, the simplest and perfectly safe solution is to use quickdraws on the two bolts with opposing gates.
It's possible to horribly cock up barrel knots while they look fine. Useful knot but not in this scenario, fig8 or clove hitch is what you want.
Clove Hitch is definitely not the knot to use when there are rope tails present - Figure of Eight is probably the best option if a length of rope is used instead of a sling.
However, for the OP's benefit, the simplest and perfectly safe solution is to use quickdraws on the two bolts with opposing gates.
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In reply to martyn04:
Am I the only one intrigued as to the rope loops on the headboard
Fig 8s probably easier.
Am I the only one intrigued as to the rope loops on the headboard
Fig 8s probably easier.
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In reply to Kemics:
I'm a little bemused, everyone appears to be suggesting a fig 8 for anchor knots but I have never once done this. Only overhand knots for an end with a tail, or clove hitches if anchoring in with the rope. Obviously I know both are ok but am I still missing something? Did the overhand suddenly become knota non grata?
To the OP:
Minus the open gates on your carabiners the setup is ok, as others have said overhand or fig 8's are better as opposed to barrel knots. As others have also said, two opposing quick draws at the top anchor as opposed to an equalised sling or cord is also quite common.
Barrel/scaffold knots are quite good if you want to retain a carabiner at the end of the rope but I think they are largely unnecessary in climbing. Though I also sometimes employ a length of half rope with a barrel/scaffold knot at each end and equalise this to make nice spongy anchors in dodgy ice... tho I largely think its the thought that counts :^)
And for anyone else interested; this video about their dangers is worth a watch: youtube.com/watch?v=_Mv2apjIa5Q&
I'm a little bemused, everyone appears to be suggesting a fig 8 for anchor knots but I have never once done this. Only overhand knots for an end with a tail, or clove hitches if anchoring in with the rope. Obviously I know both are ok but am I still missing something? Did the overhand suddenly become knota non grata?
To the OP:
Minus the open gates on your carabiners the setup is ok, as others have said overhand or fig 8's are better as opposed to barrel knots. As others have also said, two opposing quick draws at the top anchor as opposed to an equalised sling or cord is also quite common.
Barrel/scaffold knots are quite good if you want to retain a carabiner at the end of the rope but I think they are largely unnecessary in climbing. Though I also sometimes employ a length of half rope with a barrel/scaffold knot at each end and equalise this to make nice spongy anchors in dodgy ice... tho I largely think its the thought that counts :^)
And for anyone else interested; this video about their dangers is worth a watch: youtube.com/watch?v=_Mv2apjIa5Q&
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In reply to FactorXXX:
Clove hitches are fine, not right at the ends of the rope but with reasonable tails present they're not a problem.
jk
Clove hitches are fine, not right at the ends of the rope but with reasonable tails present they're not a problem.
jk
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In reply to martyn04:
For the sake of suggesting something not already listed, I'd use a fig 8 with a double loop (sometimes called 'bunny ears') to clip the anchors. It's what I was taught at MRT, and requires only one knot rather than three.
For the sake of suggesting something not already listed, I'd use a fig 8 with a double loop (sometimes called 'bunny ears') to clip the anchors. It's what I was taught at MRT, and requires only one knot rather than three.
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In reply to planetmarshall:
Bunny ears are good for tying the end of a rope to an anchor, e.g. for bringing up a second. But if it's for a top-rope, maybe the OP needs something he can clip the middle of the rope into?
Bunny ears are good for tying the end of a rope to an anchor, e.g. for bringing up a second. But if it's for a top-rope, maybe the OP needs something he can clip the middle of the rope into?
I always put a bunny ears as my master point if I'm worried about rubbing or sharp edges as it adds some redundancy to the master point .
This probably wont be the case on most sport routes but some times I like the look of a big beefy knot at the mast point and its sometimes easier to untie than a welded fig 8 .
Also one way of getting your two anchors equalized is to connect to the first anchor with a fig 8 knot , tie your master point , put your climbing rope in the mast point and lower it off the climb , now you can use a clove hitch at the next anchor point to get equally tension .
The reason for doing it this way is the climbing rope gives some weight to the system and makes it easier to find the point were both anchors share a similar load
This probably wont be the case on most sport routes but some times I like the look of a big beefy knot at the mast point and its sometimes easier to untie than a welded fig 8 .
Also one way of getting your two anchors equalized is to connect to the first anchor with a fig 8 knot , tie your master point , put your climbing rope in the mast point and lower it off the climb , now you can use a clove hitch at the next anchor point to get equally tension .
The reason for doing it this way is the climbing rope gives some weight to the system and makes it easier to find the point were both anchors share a similar load
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In reply to martyn04:
You might find this easier.
http://i1.wp.com/chillinorockclimbing.com/wp-content/uploads/2016/02/3.jpg
use a figure of eight or figure 9,10,11 (just add extra twists) if you want it to be easier to undo afterwards.
you can also do the same with your rope just join the ends together to make a loop with a double fishermans.
Alternatively just use two quick draws. Sure its not screw gates and they may not be equalised but there is already redundancy in the system as there are two bolts and two quickdraws.
http://cdn.grindtv.com/uploads/2013/03/step5.jpg
You might find this easier.
http://i1.wp.com/chillinorockclimbing.com/wp-content/uploads/2016/02/3.jpg
use a figure of eight or figure 9,10,11 (just add extra twists) if you want it to be easier to undo afterwards.
you can also do the same with your rope just join the ends together to make a loop with a double fishermans.
Alternatively just use two quick draws. Sure its not screw gates and they may not be equalised but there is already redundancy in the system as there are two bolts and two quickdraws.
http://cdn.grindtv.com/uploads/2013/03/step5.jpg
Post edited at 11:49
In reply to martyn04:
Why not just use a 60cm sling with an ovehand knot placed at the equalisation point, clipping a screwgate through each side loop of the sling.
A sliding x could be an option too, but with a nylon sling, instead of dynema, so that in the unlikely event that 1 bolt failed, the other wouldn't be shock loaded so much.
But really, it's rare to see such a set up, unless maybe you are setting up a toprope for several climbers.
Most people just use quickdraws, you can more or less equalise the anchors with a mix of short 10-12cm, medium, + long 18-20cm. Perhaps still use screwgates on them if for a group.
Your set up requires less gear though.
Why not just use a 60cm sling with an ovehand knot placed at the equalisation point, clipping a screwgate through each side loop of the sling.
A sliding x could be an option too, but with a nylon sling, instead of dynema, so that in the unlikely event that 1 bolt failed, the other wouldn't be shock loaded so much.
But really, it's rare to see such a set up, unless maybe you are setting up a toprope for several climbers.
Most people just use quickdraws, you can more or less equalise the anchors with a mix of short 10-12cm, medium, + long 18-20cm. Perhaps still use screwgates on them if for a group.
Your set up requires less gear though.
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In reply to CurlyStevo:
The last photo is a pretty bad example...! The bolt screws are rusty, not in much rock, + well fair enough it's not trad gear, but still, the angles that the 2 short quickdraws have created are increasing the load to each bolt, american death triangle, by creating an angle of more than 60°....
Not good.
OP, if you are new to this, Google American Death Triangle, worth understanding it.
The last photo is a pretty bad example...! The bolt screws are rusty, not in much rock, + well fair enough it's not trad gear, but still, the angles that the 2 short quickdraws have created are increasing the load to each bolt, american death triangle, by creating an angle of more than 60°....
Not good.
OP, if you are new to this, Google American Death Triangle, worth understanding it.
Post edited at 14:21
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In reply to Rock to Fakey:
Sorry, I don't see it. Can you explain?
> ...the angles that the 2 short quickdraws have created are increasing the load to each bolt, american death triangle, by more than 60°....
Sorry, I don't see it. Can you explain?
In reply to Rock to Fakey:
Yes I know what an ADT is, I just don't see how two quickdraws in two bolts, as in the picture, forms one.
> Bit long winded surely u've heard of it, just Gongle it..
Yes I know what an ADT is, I just don't see how two quickdraws in two bolts, as in the picture, forms one.
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In reply to Rock to Fakey:
I didn’t post it for the condtion of the bolts. Buts it’s you that doesn’t seem to understand forces. Good bolts are rated 25kn or so. The load on each bolt in the QuickDraw configuration, with the bottom angle between the draws any less than 120 degrees (which that is) will be less than the load on the rope, which will be significantly less than the ratings of the bolts when top roping. The American death triangle is actually a slightly different thing it’s when the rope is threaded directly in to the anchors.
I didn’t post it for the condtion of the bolts. Buts it’s you that doesn’t seem to understand forces. Good bolts are rated 25kn or so. The load on each bolt in the QuickDraw configuration, with the bottom angle between the draws any less than 120 degrees (which that is) will be less than the load on the rope, which will be significantly less than the ratings of the bolts when top roping. The American death triangle is actually a slightly different thing it’s when the rope is threaded directly in to the anchors.
Post edited at 14:52
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In reply to planetmarshall:
Apologies, i might be incorrect comparing directly with Adt, but the angle between the qd's is greater than 60°, increasing the load to each anchor point considerably.
Was trying to find a good link. The pics in Libby Peters book explain it well.
In the meantime, here's a vid of advantages of rope compared to slings, for anchor points, but more trad hanging belay related, bit off topic?
youtube.com/watch?v=Vrgadjo9niY&
Apologies, i might be incorrect comparing directly with Adt, but the angle between the qd's is greater than 60°, increasing the load to each anchor point considerably.
Was trying to find a good link. The pics in Libby Peters book explain it well.
In the meantime, here's a vid of advantages of rope compared to slings, for anchor points, but more trad hanging belay related, bit off topic?
youtube.com/watch?v=Vrgadjo9niY&
Post edited at 14:51
In reply to planetmarshall:
Its more commonly referred to as vector forces, 120 deg is often accepted as the critical angle but better to try for 90 deg
https://books.google.co.uk/books?id=rRV5BgAAQBAJ&pg=PA5&lpg=PA5&...
Its more commonly referred to as vector forces, 120 deg is often accepted as the critical angle but better to try for 90 deg
https://books.google.co.uk/books?id=rRV5BgAAQBAJ&pg=PA5&lpg=PA5&...
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In reply to Rock to Fakey:
I don’t know where to start.
Firstly the bottom angle I think is less than 60 degrees. However it matters not as any less than 120 degrees the load to each bolt is less than the load on the rope. Even if it was 120 degrees it would still only be equal to the load on the rope.
http://www.stone-adventures.com/rock-climbing-anchor-forces---angles-and-fu...
Even a bit over 120 wouldn’t matter these are bolts we are talking about and it’s top roping with low loads. Sure I would advise to keep approx. less than 120 for this application as there is error in estimating angles. Using two bolts in this particular case isn't really for load sharing as the loads should be significantly lower than the bolts can hold, its for redundancy.
Yeah you are off topic, slings are fine for top roping sports climbs. As with anything you should check the condition of them after so many ascents if you have any doubt they could be rubbing on the rock (which is best avoided all together)
> Apologies, i might be incorrect comparing directly with Adt, but the angle between the qd's is greater than 60°, increasing the load to each anchor point considerably.
> Was trying to find a good link. The pics in Libby Peters book explain it well.
> In the meantime, here's a vid of advantages of rope compared to slings, for anchor points, but more trad hanging belay related, bit off topic?
I don’t know where to start.
Firstly the bottom angle I think is less than 60 degrees. However it matters not as any less than 120 degrees the load to each bolt is less than the load on the rope. Even if it was 120 degrees it would still only be equal to the load on the rope.
http://www.stone-adventures.com/rock-climbing-anchor-forces---angles-and-fu...
Even a bit over 120 wouldn’t matter these are bolts we are talking about and it’s top roping with low loads. Sure I would advise to keep approx. less than 120 for this application as there is error in estimating angles. Using two bolts in this particular case isn't really for load sharing as the loads should be significantly lower than the bolts can hold, its for redundancy.
Yeah you are off topic, slings are fine for top roping sports climbs. As with anything you should check the condition of them after so many ascents if you have any doubt they could be rubbing on the rock (which is best avoided all together)
Post edited at 15:19
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In reply to martyn04:
Must admit it seems overkill to me, I normally put a screwgate on each bolt and clip the rope through the two. I'd only do this if I needed to extend out the anchor to clear a ledge or similar.
Must admit it seems overkill to me, I normally put a screwgate on each bolt and clip the rope through the two. I'd only do this if I needed to extend out the anchor to clear a ledge or similar.
In reply to martyn04:
Can we have the OP flagged as a troll for making an inflammatory first post, please?
Can we have the OP flagged as a troll for making an inflammatory first post, please?
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In reply to CurlyStevo:
Cheers for the links. Perhaps a bit ott with bolts then. I think its good to work with the 60° figure. The bottom angle, which you say you think is less than 60°, looks between 60 and 90, closer to 90°?
In any event, better to lower the load on the anchors, even if bolts, at a twin bolt lower off, they will last longer. Bolts can fail, including those at lower offs.
Even though top roping, good to understand how loads on anchors are affected by angles created by linking them with rope, or slings.
Whilst this two quickdraws to the lower offs is not the same scenario, the angles referred to are still relevant... i could post many links to slings placed in ADT format through the adjacent bolts at lower offs in which the links warn against doing so, have a Google.
Cheers for the links. Perhaps a bit ott with bolts then. I think its good to work with the 60° figure. The bottom angle, which you say you think is less than 60°, looks between 60 and 90, closer to 90°?
In any event, better to lower the load on the anchors, even if bolts, at a twin bolt lower off, they will last longer. Bolts can fail, including those at lower offs.
Even though top roping, good to understand how loads on anchors are affected by angles created by linking them with rope, or slings.
Whilst this two quickdraws to the lower offs is not the same scenario, the angles referred to are still relevant... i could post many links to slings placed in ADT format through the adjacent bolts at lower offs in which the links warn against doing so, have a Google.
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In reply to Rock to Fakey:
"Whilst this two quickdraws to the lower offs is not the same scenario, the angles referred to are still relevant"
ADT is completely different the angles apply completely different loads to the quickdraw scenario.
https://en.wikipedia.org/wiki/American_death_triangle
With ADT at 60 degrees the load to each anchor is already equal to the load to the bottom of the triangle, at 120 its approx. doubled.
In short 60 degrees using the ADT is approximately equal to 120 on the quickdraw set up in terms of load to the anchors
"i could post many links to slings placed in ADT format through the adjacent bolts at lower offs in which the links warn against doing so, have a Google. "
Whilst I'm not condoning ADT the loads in top roping are tiny and bolt failure highly unlikely. Using ADT with a high angle for multipitch climbing were a climber could factor two on to the belay could have serious consequences.
"Whilst this two quickdraws to the lower offs is not the same scenario, the angles referred to are still relevant"
ADT is completely different the angles apply completely different loads to the quickdraw scenario.
https://en.wikipedia.org/wiki/American_death_triangle
With ADT at 60 degrees the load to each anchor is already equal to the load to the bottom of the triangle, at 120 its approx. doubled.
In short 60 degrees using the ADT is approximately equal to 120 on the quickdraw set up in terms of load to the anchors
"i could post many links to slings placed in ADT format through the adjacent bolts at lower offs in which the links warn against doing so, have a Google. "
Whilst I'm not condoning ADT the loads in top roping are tiny and bolt failure highly unlikely. Using ADT with a high angle for multipitch climbing were a climber could factor two on to the belay could have serious consequences.
Post edited at 15:54
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In reply to Rock to Fakey:
To my basic eye the angle of the quickdraw to the lower bolt in the photo looks about 45 degrees off the vertical, and the other one about 30 degrees off the vertical. Looks absolutely fine!
The use of two quickdraws means the two point belay is basically equalised and each bolt would do it's job independently from the other. The photo certainly has absolutely nothing to do with an American Death Triangle, the key feature of which is a lack of independent equalisation meaning a shock load to the remaining bolt if the other one were to fail.
I'm trying not to be rude, but please don't give advice without understanding the subject matter.
To my basic eye the angle of the quickdraw to the lower bolt in the photo looks about 45 degrees off the vertical, and the other one about 30 degrees off the vertical. Looks absolutely fine!
The use of two quickdraws means the two point belay is basically equalised and each bolt would do it's job independently from the other. The photo certainly has absolutely nothing to do with an American Death Triangle, the key feature of which is a lack of independent equalisation meaning a shock load to the remaining bolt if the other one were to fail.
I'm trying not to be rude, but please don't give advice without understanding the subject matter.
Post edited at 15:51
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In reply to springfall2008:
Whereas I think some of the replies are over analysing the situation somewhat, just using two screwgates does cause a potential problem because the screwgates will naturally try to sit flat to the rock. Putting the rope through two of them is likely to be twisting the krabs in the bolts and, if nothing else, is likely to twist the rope.
> Must admit it seems overkill to me, I normally put a screwgate on each bolt and clip the rope through the two. I'd only do this if I needed to extend out the anchor to clear a ledge or similar.
Whereas I think some of the replies are over analysing the situation somewhat, just using two screwgates does cause a potential problem because the screwgates will naturally try to sit flat to the rock. Putting the rope through two of them is likely to be twisting the krabs in the bolts and, if nothing else, is likely to twist the rope.
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In reply to springfall2008:
To be honest I think your right this is also fine, as long as your ropes to the belayer / climber are roughly parallel and not crossing the bottom angle is going to be so small that the load on the bolts is still going to share the overall load not multiply it. Done this many times before myself..
> Must admit it seems overkill to me, I normally put a screwgate on each bolt and clip the rope through the two. I'd only do this if I needed to extend out the anchor to clear a ledge or similar.
To be honest I think your right this is also fine, as long as your ropes to the belayer / climber are roughly parallel and not crossing the bottom angle is going to be so small that the load on the bolts is still going to share the overall load not multiply it. Done this many times before myself..
Post edited at 16:13
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In reply to CurlyStevo:
Thanks for clarifying.
Wiki link is useful with forces table, but there are better photo examples....
This is the weirdest...!
https://www.climbing.com/news/unbelayvable-the-entire-rope-anchor/
Plus an interesting thread from another forum on a similar theme, apologies in advance for creating more lines if enquiry + possible confusion... http://www.bogley.com/forum/showthread.php?74627-Anchoring-Death-Triangle
Thanks for clarifying.
Wiki link is useful with forces table, but there are better photo examples....
This is the weirdest...!
https://www.climbing.com/news/unbelayvable-the-entire-rope-anchor/
Plus an interesting thread from another forum on a similar theme, apologies in advance for creating more lines if enquiry + possible confusion... http://www.bogley.com/forum/showthread.php?74627-Anchoring-Death-Triangle
Post edited at 15:56
In reply to Rock to Fakey:
Graham D is correct, just clipping into karabiners will twist the rope in the same way that passing the rope directly through 2 x Maillons does. Personally I've never really worried about equalisation on bolt belays, IMO it's more of a redundancy thing although I do make some effort to do so if I can.
Al
Graham D is correct, just clipping into karabiners will twist the rope in the same way that passing the rope directly through 2 x Maillons does. Personally I've never really worried about equalisation on bolt belays, IMO it's more of a redundancy thing although I do make some effort to do so if I can.
Al
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In reply to GridNorth:
in the same way that lowering off two bolts does? which we do all the time..... I've not noticed much of a problem here TRing off two biners, but perhaps I am unobservant and not working routes much on TR
I carry a couple of sling draws normally for the top, so when TRing on roughly horizontally level anchors I typically use these, if not level then use a sling
in the same way that lowering off two bolts does? which we do all the time..... I've not noticed much of a problem here TRing off two biners, but perhaps I am unobservant and not working routes much on TR
I carry a couple of sling draws normally for the top, so when TRing on roughly horizontally level anchors I typically use these, if not level then use a sling
Post edited at 16:17
In reply to Michael Gordon:
Why would you want to be rude anyway?
Advice given was informative, although admitedly incorrect with direct reference to ADT, but similar scenario + correct , although not identical, i think, with reference to the quickdraws sharing the load on 2 anchors, having the potential to have an increasing load on each anchor.
Perhaps not so relevant with bolts, and i am always learning and being corrected on things previously misunderstood by reading + contributing to threads like this, as indeed are others here, but, the angle we are referring to, as shown by pics in Kimberleys helpful links, is the angle between the 2 clipped anchors points, and the point where the load hangs, in this case from where the other ends of the quickdraws / slung carabiners meet, and the top rope habgs from. That triangle shape. The V. The relevant angle is shown in Kimberleys link, and as explained in Curly's correction for me, i now understand it's not so very important with bolts, (but still relevant, as bolts can fail) as even when this angle is upto 120°, the load on each bolt is 100%. Above 120° the load on each bolt does increase, and below 120° it decreases to about 58% load at an angle of 60°.
The angle in the photo i referred to looks to me to be more than 60°, but looks less than a right angle, 90° , so the load on each anchor has increased ( above 58%, but perhaps not worryingly, as it's still below 100%), relevant when trying to keep the load low on trad gear, but perhaps not so much with bolts.
Which angle are you referring to, or perhaps i am still incorrect?
Re angles, you say "off the vertical"... This suggests you are thinking of a line between the anchor points to where the linking slings or quickdraws meet, but i understand the relevant angle to be the sum of these, ie, the angle between the arms of the V. Kimberleys link shows it that way too.
> I'm trying not to be rude, but please don't give advice without understanding the subject matter.
Why would you want to be rude anyway?
Advice given was informative, although admitedly incorrect with direct reference to ADT, but similar scenario + correct , although not identical, i think, with reference to the quickdraws sharing the load on 2 anchors, having the potential to have an increasing load on each anchor.
Perhaps not so relevant with bolts, and i am always learning and being corrected on things previously misunderstood by reading + contributing to threads like this, as indeed are others here, but, the angle we are referring to, as shown by pics in Kimberleys helpful links, is the angle between the 2 clipped anchors points, and the point where the load hangs, in this case from where the other ends of the quickdraws / slung carabiners meet, and the top rope habgs from. That triangle shape. The V. The relevant angle is shown in Kimberleys link, and as explained in Curly's correction for me, i now understand it's not so very important with bolts, (but still relevant, as bolts can fail) as even when this angle is upto 120°, the load on each bolt is 100%. Above 120° the load on each bolt does increase, and below 120° it decreases to about 58% load at an angle of 60°.
The angle in the photo i referred to looks to me to be more than 60°, but looks less than a right angle, 90° , so the load on each anchor has increased ( above 58%, but perhaps not worryingly, as it's still below 100%), relevant when trying to keep the load low on trad gear, but perhaps not so much with bolts.
Which angle are you referring to, or perhaps i am still incorrect?
Re angles, you say "off the vertical"... This suggests you are thinking of a line between the anchor points to where the linking slings or quickdraws meet, but i understand the relevant angle to be the sum of these, ie, the angle between the arms of the V. Kimberleys link shows it that way too.
Post edited at 17:21
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In reply to jkarran:
Clove hitches are fine, not right at the ends of the rope but with reasonable tails present they're not a problem.
Clove hitches are excellent for rigging as part of a system where they are equally loaded on both ends of the rope.
However, when tied with a free end they can potentially become dangerous:
1. If the knot isn't clinched tight, it can be undone by smoothly pulling on the 'long' end of the rope.
2. The knot can be unclinched by repeated jerks/pulls on the rope and once unclinched scenario 1 above applies.
I certainly wouldn't use them to set up an anchor as described and in a similar vein, wouldn't use one to abseil off. Anyway, why would you when there are by far better knots available?
Clove hitches are fine, not right at the ends of the rope but with reasonable tails present they're not a problem.
Clove hitches are excellent for rigging as part of a system where they are equally loaded on both ends of the rope.
However, when tied with a free end they can potentially become dangerous:
1. If the knot isn't clinched tight, it can be undone by smoothly pulling on the 'long' end of the rope.
2. The knot can be unclinched by repeated jerks/pulls on the rope and once unclinched scenario 1 above applies.
I certainly wouldn't use them to set up an anchor as described and in a similar vein, wouldn't use one to abseil off. Anyway, why would you when there are by far better knots available?
2
2
In reply to Rock to Fakey:
Remember 100% of a low force top roping scenario is still a low force, 200% is still a low force you need to be talking 5 times plus for it start to get worrying. What sort of loads do bolts get in typical falls? probably up to around 6kn or so. Whilst top roping your talking maybe up to 2kn. Even if the load was multiplied by 3 times its still a pretty normal load for a bolt which should be good for a lot more than that. Using two bolts in good condition in hard rock for a top rope belay is more about redundancy than load sharing for most rock types.
Remember 100% of a low force top roping scenario is still a low force, 200% is still a low force you need to be talking 5 times plus for it start to get worrying. What sort of loads do bolts get in typical falls? probably up to around 6kn or so. Whilst top roping your talking maybe up to 2kn. Even if the load was multiplied by 3 times its still a pretty normal load for a bolt which should be good for a lot more than that. Using two bolts in good condition in hard rock for a top rope belay is more about redundancy than load sharing for most rock types.
Post edited at 17:35
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In reply to Kimberley:
Scrolling down to the larks foot knot.. Worth seeing the pic of how to sling a larks foot / girth hitch, so that it's loaded correctly, hadn't thought of that before!
> Its more commonly referred to as vector forces, 120 deg is often accepted as the critical angle but better to try for 90 deg
Scrolling down to the larks foot knot.. Worth seeing the pic of how to sling a larks foot / girth hitch, so that it's loaded correctly, hadn't thought of that before!
1
In reply to Rock to Fakey:
I wouldn't! Hence trying to avoid it.
I was referring to the angle of pull on each bolt. I see you mean the angle between the bolts, but with an estimated 45 degree and 30 degree pull away from the vertical on respective bolts this would give a 75 degree bit inbetween (if my maths is correct). 90 degrees (45 degree pull on each bit) would be fine, and a regular occurrence on trad where the gear is not always exactly where you want it to be. I may be missing something, but to me the angle inbetween does not seem like the most important factor. Rightly or wrongly I tend to go by the angle on each piece away from the vertical - should be below 60 degrees, preferably below 45 degrees, and anything below that is a bonus. To return to the ADT, the thing with that is the pull is in two different directions on each bolt. Not the case here. In my understanding, the main concerns with a large angle away from the vertical are that (a) the sling is weaker when loaded in this way, (b) more violent pendulum onto the remaining piece if the other were to fail.
> Why would you want to be rude anyway?
I wouldn't! Hence trying to avoid it.
> The angle in the photo i referred to looks to me to be more than 60°, but looks less than a right angle, 90° , so the load on each anchor has increased ( above 58%, but perhaps not worryingly, as it's still below 100%), relevant when trying to keep the load low on trad gear, but perhaps not so much with bolts.
> Which angle are you referring to?
I was referring to the angle of pull on each bolt. I see you mean the angle between the bolts, but with an estimated 45 degree and 30 degree pull away from the vertical on respective bolts this would give a 75 degree bit inbetween (if my maths is correct). 90 degrees (45 degree pull on each bit) would be fine, and a regular occurrence on trad where the gear is not always exactly where you want it to be. I may be missing something, but to me the angle inbetween does not seem like the most important factor. Rightly or wrongly I tend to go by the angle on each piece away from the vertical - should be below 60 degrees, preferably below 45 degrees, and anything below that is a bonus. To return to the ADT, the thing with that is the pull is in two different directions on each bolt. Not the case here. In my understanding, the main concerns with a large angle away from the vertical are that (a) the sling is weaker when loaded in this way, (b) more violent pendulum onto the remaining piece if the other were to fail.
1
In reply to FactorXXX:
Never in the thousands of clove hitches I've tied in rope have I loaded both strands nor have I had one loosen or slip. Why use them: easy, quick and adjustable though for trivial rigging as shown I would tend toward fig8s unless there was some fiddly adjustment needed.
Jk
Never in the thousands of clove hitches I've tied in rope have I loaded both strands nor have I had one loosen or slip. Why use them: easy, quick and adjustable though for trivial rigging as shown I would tend toward fig8s unless there was some fiddly adjustment needed.
Jk
4
In reply to GrahamD:
Yes, perhaps a little but practically it hasn't ever caused caused me a big issue, especially if you use larger screwgates. If a bolt did fail then you are using dynamic rope which will mitigate any shock loading you could have although it would be minimal as the bolts are close together anyhow.
Sometimes I'll use quickdraws instead, but I'm generally paranoid about safety so prefer screwgates.
> Whereas I think some of the replies are over analysing the situation somewhat, just using two screwgates does cause a potential problem because the screwgates will naturally try to sit flat to the rock. Putting the rope through two of them is likely to be twisting the krabs in the bolts and, if nothing else, is likely to twist the rope.
Yes, perhaps a little but practically it hasn't ever caused caused me a big issue, especially if you use larger screwgates. If a bolt did fail then you are using dynamic rope which will mitigate any shock loading you could have although it would be minimal as the bolts are close together anyhow.
Sometimes I'll use quickdraws instead, but I'm generally paranoid about safety so prefer screwgates.
In reply to jkarran:
To make it stronger there could be two loops with one krab on each.That means there will be two lines of pull,where one line of pull could be abraded.
To make it stronger there could be two loops with one krab on each.That means there will be two lines of pull,where one line of pull could be abraded.
In reply to Michael Gordon:
I will agree with about 75° angle in the point of the "V". I haven't seen many books or diagrams that measured the angle from a vertical plane. When measuring the angles in triangles, which is what we are doing, you don't usually split them. Anyway...,
Ok so different "tolerances" between bolts n trad belays. Had read Libby's book + thought best to remember not to exceed 60° for ideal load sharing between anchors, trad anchors that is
I now understand this is good, and so is 90° (71% shared load) is ok but more risky, + upto 120° is still sharing the load, until at 120° each piece is taking full load, and beyond that they are loaded more than 100%.
And the ADT vectors have a similar pattern of increasing forces but more dangerously.
I will agree with about 75° angle in the point of the "V". I haven't seen many books or diagrams that measured the angle from a vertical plane. When measuring the angles in triangles, which is what we are doing, you don't usually split them. Anyway...,
Ok so different "tolerances" between bolts n trad belays. Had read Libby's book + thought best to remember not to exceed 60° for ideal load sharing between anchors, trad anchors that is
I now understand this is good, and so is 90° (71% shared load) is ok but more risky, + upto 120° is still sharing the load, until at 120° each piece is taking full load, and beyond that they are loaded more than 100%.
And the ADT vectors have a similar pattern of increasing forces but more dangerously.
Post edited at 19:05
1
In reply to Rock to Fakey:
The vertical plane is the ideal - a straight downwards pull. To explain my thinking, say the angle inbetween two points of an anchor is 90 degrees. This is absolutely fine if both points of the anchor are loaded at 45 degrees from the vertical, but obviously not very good if one is at 10 degrees and the other 80 degrees (so almost horizontal). Of course with enough rope to play with this could be adjusted to improve the angles, but this isn't always possible e.g. if the only gear opportunities are near the top of the crag but off to the side of the route.
> I will agree with about 75° angle in the point of the "V". I haven't seen many books or diagrams that measured the angle from a vertical plane. When measuring the angles in triangles, which is what we are doing, you don't usually split them. Anyway...,
>
>
The vertical plane is the ideal - a straight downwards pull. To explain my thinking, say the angle inbetween two points of an anchor is 90 degrees. This is absolutely fine if both points of the anchor are loaded at 45 degrees from the vertical, but obviously not very good if one is at 10 degrees and the other 80 degrees (so almost horizontal). Of course with enough rope to play with this could be adjusted to improve the angles, but this isn't always possible e.g. if the only gear opportunities are near the top of the crag but off to the side of the route.
Post edited at 20:02
In reply to Michael Gordon:
Cheers, i see what you are getting at, it could also be created by having a sliding x on a sling, and sliding the X almost to directly beneath just one anchor, leaving that with a short sling length + the other a long one, but still a 90° angle,... How do the forces on each anchor change now? Don't worry about answering! Diagrams + maths + physics input would be interesting but i'll try stick with KISS.
Cheers, i see what you are getting at, it could also be created by having a sliding x on a sling, and sliding the X almost to directly beneath just one anchor, leaving that with a short sling length + the other a long one, but still a 90° angle,... How do the forces on each anchor change now? Don't worry about answering! Diagrams + maths + physics input would be interesting but i'll try stick with KISS.
In reply to springfall2008:
Don't you find running the rope through two right angles causes horrendous kinking?
Chris
> Must admit it seems overkill to me, I normally put a screwgate on each bolt and clip the rope through the two. I'd only do this if I needed to extend out the anchor to clear a ledge or similar.
Don't you find running the rope through two right angles causes horrendous kinking?
Chris
1
In reply to Chris Craggs:
Not if whatever they're threaded through are parallel to each other. It's when you thread directly through rings that are each parallel to the rock that the kinky fun really starts.
> Don't you find running the rope through two right angles causes horrendous kinking?
Not if whatever they're threaded through are parallel to each other. It's when you thread directly through rings that are each parallel to the rock that the kinky fun really starts.
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In reply to Chris Craggs:
Not particularly noticed it in the past. But don’t tend to work routes much and I’ve used a mixture of setups from slings to screwgates on the bolts to quick draws. If it’s such an issue why have I not noticed it lowering off double staples at Portland etc?
Not particularly noticed it in the past. But don’t tend to work routes much and I’ve used a mixture of setups from slings to screwgates on the bolts to quick draws. If it’s such an issue why have I not noticed it lowering off double staples at Portland etc?
In reply to CurlyStevo:
Because they are angled at 90 degrees to the rock and the rope lays naturally.
Al
Because they are angled at 90 degrees to the rock and the rope lays naturally.
Al
2
In reply to Rock to Fakey:
its the angle at the power point i.e. from the rt line to the left line at the power point krab, nothing to do with from the vertical and nothing to do with the angle of pull on the anchor nut, bolt which can vary i.e. they can be different.. Above 120 deg the force on the anchor points increases beyond the load, it multiplies. You can increase this or decrease it by varying the distance from the anchor points e.g. the quick draws are a short distance, but could be increased by using a longer sling, of course this is not always practical.
So, in conclusion, as always with these debates, it depends... but if you want a ' golden rule' the angle at the power point i.e. where you attach the rope, it should not exceed 120deg otherwise it doesn't share the load but starts to multiply it.
There are some other posts relating to the actual forces generated by top roped climber and they are another matter but I would add that they are in fact relatively low and I would concur with those that suggest some of the solutions are indeed overkill in that situation.
So, you see, it depends.....
its the angle at the power point i.e. from the rt line to the left line at the power point krab, nothing to do with from the vertical and nothing to do with the angle of pull on the anchor nut, bolt which can vary i.e. they can be different.. Above 120 deg the force on the anchor points increases beyond the load, it multiplies. You can increase this or decrease it by varying the distance from the anchor points e.g. the quick draws are a short distance, but could be increased by using a longer sling, of course this is not always practical.
So, in conclusion, as always with these debates, it depends... but if you want a ' golden rule' the angle at the power point i.e. where you attach the rope, it should not exceed 120deg otherwise it doesn't share the load but starts to multiply it.
There are some other posts relating to the actual forces generated by top roped climber and they are another matter but I would add that they are in fact relatively low and I would concur with those that suggest some of the solutions are indeed overkill in that situation.
So, you see, it depends.....
In reply to martyn04:
Jesus people love to make things overly complicated
Just use two opposing QDs.
Jesus people love to make things overly complicated
Just use two opposing QDs.
3
In reply to Kimberley:
More accurately, with a 120° angle AND symetrical loading the force on both points is equal to the original. With other angles (asymetric loading) the force on one of the points can be even higher still. The angle of pull on the anchor DOES matter (if in fact any of it matters in the context of the OP´ s question, personally I´ d use a couple of draws) .
> its the angle at the power point i.e. from the rt line to the left line at the power point krab, nothing to do with from the vertical and nothing to do with the angle of pull on the anchor nut, bolt which can vary i.e. they can be different.. Above 120 deg the force on the anchor points increases beyond the load, it multiplies.
More accurately, with a 120° angle AND symetrical loading the force on both points is equal to the original. With other angles (asymetric loading) the force on one of the points can be even higher still. The angle of pull on the anchor DOES matter (if in fact any of it matters in the context of the OP´ s question, personally I´ d use a couple of draws) .
2
In reply to Cheese Monkey:
That works too
> Jesus people love to make things overly complicated
> Just use two opposing QDs.
That works too
1
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