This topic has been archived, and won't accept reply postings.
When I belay I keep the slack to a minimum without hindering the leader as my opinion is the drop should be kept to a minimum.
A regular partner pays out the slack without taking any in if for example you place gear above your head then climb up to it. As a leader, looking down and seeing the rope looping down from the belay device near to the floor is quite disconcerting - for me anyway - and it has psyched me out on a few harder routes. I tried to tactfully raise this and he talked about giving me a "soft catch".
Another climber then backed him up talking about the fall factor. The theory was that the more rope in the system the more dynamic the catch and the less force on the anchors. I didn't understand this as I would expect the further you fall the faster you fall which increases the force on the anchors.
I do understand wanting to minimise the force on marginal protection but when the gear is good/bolts and on slabby/ledgy routes I'd want the slack to a minimum.
I'd be interested to hear everyone's thoughts/opinions/experience on this subject.
A regular partner pays out the slack without taking any in if for example you place gear above your head then climb up to it. As a leader, looking down and seeing the rope looping down from the belay device near to the floor is quite disconcerting - for me anyway - and it has psyched me out on a few harder routes. I tried to tactfully raise this and he talked about giving me a "soft catch".
Another climber then backed him up talking about the fall factor. The theory was that the more rope in the system the more dynamic the catch and the less force on the anchors. I didn't understand this as I would expect the further you fall the faster you fall which increases the force on the anchors.
I do understand wanting to minimise the force on marginal protection but when the gear is good/bolts and on slabby/ledgy routes I'd want the slack to a minimum.
I'd be interested to hear everyone's thoughts/opinions/experience on this subject.
10
70
2
In reply to radddogg:
excuse for lazy belaying. Can just as easily give a soft catch by jumping or letting some rope slide through the belay device in control before locking it down.
more rope in the system does give a softer catch in that there is more rope out to stretch when you fall (Taking a fall on a sport route with 60m of rope out is the most relaxing fall I've ever had!) though as you say, I think loops near to the floor is a bit ridiculous
Honestly when I tray belay people I'm far more worried about them hitting features, slabs etc on the way down
excuse for lazy belaying. Can just as easily give a soft catch by jumping or letting some rope slide through the belay device in control before locking it down.
more rope in the system does give a softer catch in that there is more rope out to stretch when you fall (Taking a fall on a sport route with 60m of rope out is the most relaxing fall I've ever had!) though as you say, I think loops near to the floor is a bit ridiculous
Honestly when I tray belay people I'm far more worried about them hitting features, slabs etc on the way down
7
In reply to radddogg:
You are both correct but if the loop is almost touching the floor that sounds like a little too much and if you are below the third bolt there should hardly be any.
There is a video on Youtube showing a young climber being seriously hurt precisely because there is no slack in the system and the belayer has one foot braced hard against a rock therefore allowing for no movement at all. In circumstances like this the rope acts almost like a solid lever and slams the climber into the rock. Having a little slack allows for some vertical movement.
Al
You are both correct but if the loop is almost touching the floor that sounds like a little too much and if you are below the third bolt there should hardly be any.
There is a video on Youtube showing a young climber being seriously hurt precisely because there is no slack in the system and the belayer has one foot braced hard against a rock therefore allowing for no movement at all. In circumstances like this the rope acts almost like a solid lever and slams the climber into the rock. Having a little slack allows for some vertical movement.
Al
Post edited at 10:57
3
1
In reply to radddogg:
There's a trade off between the two, as there are two different risk factors you're trying to mitigate: the climber hitting something on the way down, and the climber hitting the wall as they swing in (to ignore forces on trad gear for the moment).
The consequences of hitting something on the way down are generally a bit higher than the consequences of hitting the wall, so guarding against that will take preference - near the ground, a ledge, or a change of angle from slabby to steep you would always want to keep the slack to a minimum.
If the fall is clean, you're on bolts, and you're well above the ground there's no danger from falling a little bit further, and a meter or two of slack in the system will help guard against an accidentally hard catch, so it's a bit safer to have that slack.
To take that a little bit further, if your climber puts his foot behind the rope and is at risk of inverting in a fall, the consequences of swinging into the rock suddenly become much higher, so the (rather counter-intuitive) safest thing to do at that point will often be to throw some more slack into the system.
Do you take many falls on his belay?
It's quite a complicated scenario - as you rightly say the climber will be moving faster and therefore falling with more energy to absorb if there's slack in the system. I would expect this to generally outweigh the effect of having a longer dynamic rope in play in terms of peak forces.
However, as you climb up to around your piece of gear a bit of slack does two things:
a) it gives the belayer a bit more time to react and give a soft catch
b) it changes the angle at which the rope starts to come tight - increasing the vertical component of the load on the gear and decreasing the horizontal component.
Both of which are likely to be more important than the extra metre of fall when it comes to minimising the load in unwanted directions.
TL;DR in moderation, a bit of slack as you're climbing past the pro is no bad thing
> When I belay I keep the slack to a minimum without hindering the leader as my opinion is the drop should be kept to a minimum.
> A regular partner pays out the slack without taking any in if for example you place gear above your head then climb up to it.
There's a trade off between the two, as there are two different risk factors you're trying to mitigate: the climber hitting something on the way down, and the climber hitting the wall as they swing in (to ignore forces on trad gear for the moment).
The consequences of hitting something on the way down are generally a bit higher than the consequences of hitting the wall, so guarding against that will take preference - near the ground, a ledge, or a change of angle from slabby to steep you would always want to keep the slack to a minimum.
If the fall is clean, you're on bolts, and you're well above the ground there's no danger from falling a little bit further, and a meter or two of slack in the system will help guard against an accidentally hard catch, so it's a bit safer to have that slack.
To take that a little bit further, if your climber puts his foot behind the rope and is at risk of inverting in a fall, the consequences of swinging into the rock suddenly become much higher, so the (rather counter-intuitive) safest thing to do at that point will often be to throw some more slack into the system.
> As a leader, looking down and seeing the rope looping down from the belay device near to the floor is quite disconcerting - for me anyway - and it has psyched me out on a few harder routes. I tried to tactfully raise this and he talked about giving me a "soft catch".
Do you take many falls on his belay?
> Another climber then backed him up talking about the fall factor. The theory was that the more rope in the system the more dynamic the catch and the less force on the anchors. I didn't understand this as I would expect the further you fall the faster you fall which increases the force on the anchors.
It's quite a complicated scenario - as you rightly say the climber will be moving faster and therefore falling with more energy to absorb if there's slack in the system. I would expect this to generally outweigh the effect of having a longer dynamic rope in play in terms of peak forces.
However, as you climb up to around your piece of gear a bit of slack does two things:
a) it gives the belayer a bit more time to react and give a soft catch
b) it changes the angle at which the rope starts to come tight - increasing the vertical component of the load on the gear and decreasing the horizontal component.
Both of which are likely to be more important than the extra metre of fall when it comes to minimising the load in unwanted directions.
TL;DR in moderation, a bit of slack as you're climbing past the pro is no bad thing
9
In reply to radddogg:
They do not understand fall factors. Extra slack in the system over and above the length of rope needed to reach from the belayer to the climber increases rather than decreases the forces in a fall. The argument for any such extra slack is to guard against the falling climber slamming into the rock (this mainly applies in sport climbing when there are no worries about the forces on runners and often nothing to hit in a longer fall)
> Another climber then backed him up talking about the fall factor. The theory was that the more rope in the system the more dynamic the catch and the less force on the anchors.
They do not understand fall factors. Extra slack in the system over and above the length of rope needed to reach from the belayer to the climber increases rather than decreases the forces in a fall. The argument for any such extra slack is to guard against the falling climber slamming into the rock (this mainly applies in sport climbing when there are no worries about the forces on runners and often nothing to hit in a longer fall)
18
In reply to radddogg:
It's a question of degree, of course. To avoid hampering the leader entails keeping slack (a bow) in the ropes; if the belayer is overly concerned about minimising slack, it's unlikely that the leader will always feel free to move (and clip). On the other hand, slack lying on the floor in front of the belayer is definitely overdoing it! Maybe the partner you mention is just plain lazy: it doesn't seem too much to ask of a belayer of a lead climber that they are prepared to take in (when appropriate) as well as pay out, and FWIW the "soft catch" explanation wouldn't convince me.
It's a question of degree, of course. To avoid hampering the leader entails keeping slack (a bow) in the ropes; if the belayer is overly concerned about minimising slack, it's unlikely that the leader will always feel free to move (and clip). On the other hand, slack lying on the floor in front of the belayer is definitely overdoing it! Maybe the partner you mention is just plain lazy: it doesn't seem too much to ask of a belayer of a lead climber that they are prepared to take in (when appropriate) as well as pay out, and FWIW the "soft catch" explanation wouldn't convince me.
1
1
2
In reply to Ciro:
Not really. In fact never that I can think. I've always backed off and asked him to take when I bottled it. More recently I've been climbing with someone else and I have felt more confident and actually taken a fall this week on my hardest ever onsight attempt. There may be other factors here; I've lost some weight, getting more experienced, improving technique. Maybe these have improved my confidence more than a change in belayer.
Anyway, I am not criticising anyone, I just wanted to understand the science and best practice. Sounds like somewhere between both styles is about right but obviously tuned to the situation.
> Do you take many falls on his belay?
Not really. In fact never that I can think. I've always backed off and asked him to take when I bottled it. More recently I've been climbing with someone else and I have felt more confident and actually taken a fall this week on my hardest ever onsight attempt. There may be other factors here; I've lost some weight, getting more experienced, improving technique. Maybe these have improved my confidence more than a change in belayer.
Anyway, I am not criticising anyone, I just wanted to understand the science and best practice. Sounds like somewhere between both styles is about right but obviously tuned to the situation.
3
In reply to alx:
I know more people that have broken ankles bouldering than climbers that have hurt themselves!
> Go bouldering!
I know more people that have broken ankles bouldering than climbers that have hurt themselves!
6
In reply to radddogg:
What's most important is how you feel about your belayer.
A major part of most people's climbing is psychological, if you don't trust your belayer this will have an adverse affect on both your performance and your enjoyment.
What's most important is how you feel about your belayer.
A major part of most people's climbing is psychological, if you don't trust your belayer this will have an adverse affect on both your performance and your enjoyment.
7
In reply to radddogg:
Yeah I get that, was just interested from the point of view of whether your fears had been realised in practice, as the perception can often be very different from the reality. It wasn't a suggesting you rush out and start falling on his belay... your perceptions may also be right!
> Anyway, I am not criticising anyone, I just wanted to understand the science and best practice.
Yeah I get that, was just interested from the point of view of whether your fears had been realised in practice, as the perception can often be very different from the reality. It wasn't a suggesting you rush out and start falling on his belay... your perceptions may also be right!
1
In reply to radddogg:
Were they using a Grigri by any chance? I've had a similar problem. Mainly with people who primarily climb indoors or sport outdoors. The rules and priorities definitely change depending whether dealing with overhangs, clean walls, or slabs, and whether bolts or marginal gear. Particularly when there are ledges involved that could meet with an ankle during a fall.
> A regular partner pays out the slack without taking any in if for example you place gear above your head then climb up to it. As a leader, looking down and seeing the rope looping down from the belay device near to the floor is quite disconcerting - for me anyway - and it has psyched me out on a few harder routes. I tried to tactfully raise this and he talked about giving me a "soft catch"
Were they using a Grigri by any chance? I've had a similar problem. Mainly with people who primarily climb indoors or sport outdoors. The rules and priorities definitely change depending whether dealing with overhangs, clean walls, or slabs, and whether bolts or marginal gear. Particularly when there are ledges involved that could meet with an ankle during a fall.
1
In reply to radddogg:
Your belayer is misinformed. An extra metre of rope out will have a negligible effect on the softness of the catch, while an extra metre of fall distance will cause a significant additional force to be held.
The whole concept of dynamic belaying is one of those things (like E grades) that's really quite straightforward but seems to be misunderstood bafflingly often. In essence, what you're usually trying to achieve is to soften the impact of the catch, not by giving more slack in advance, but by spreading the time taken to arrest the fall over a longer period. If you're sport belaying on flat ground this is easy to achieve by letting yourself be pulled a step or two towards the face by the force of the fall. In less mobile belaying situations it's still possible to let yourself be pulled upwards a little from a crouched position or to use a belay device that doesn't grab the rope so tightly, thereby letting up to a foot or so of rope pass through the device while bringing the fall to a stop. What you definitely shouldn't do - in all cases except where the fall risks being long enough to hit the ground or a ledge, is to take in rope during the fall and 'fight against' the fall, as this will shorten the catch duration and increase the impact forces.
Your belayer is misinformed. An extra metre of rope out will have a negligible effect on the softness of the catch, while an extra metre of fall distance will cause a significant additional force to be held.
The whole concept of dynamic belaying is one of those things (like E grades) that's really quite straightforward but seems to be misunderstood bafflingly often. In essence, what you're usually trying to achieve is to soften the impact of the catch, not by giving more slack in advance, but by spreading the time taken to arrest the fall over a longer period. If you're sport belaying on flat ground this is easy to achieve by letting yourself be pulled a step or two towards the face by the force of the fall. In less mobile belaying situations it's still possible to let yourself be pulled upwards a little from a crouched position or to use a belay device that doesn't grab the rope so tightly, thereby letting up to a foot or so of rope pass through the device while bringing the fall to a stop. What you definitely shouldn't do - in all cases except where the fall risks being long enough to hit the ground or a ledge, is to take in rope during the fall and 'fight against' the fall, as this will shorten the catch duration and increase the impact forces.
21
In reply to radddogg:
An attentive belayer will be able to see when the second is moving, or needs slack to clip an extender, then quickly push 2 lots through the belay device, which could easily be over a metre of rope in just a second or two. If too much was given, it's just as easy to shuffle a little bit back as you observe them climbing.
I would just politely communicate with your 2nd, 'take in a little', 'watch me' etc.. If they still don't learn time to expand your climbing circle of friends. The rights and wrongs of absorbing force, fall factors etc.. could be slightly relevant on more extreme routes or ground, but it's about you enjoying climbing with people you do it with that matters too.
An attentive belayer will be able to see when the second is moving, or needs slack to clip an extender, then quickly push 2 lots through the belay device, which could easily be over a metre of rope in just a second or two. If too much was given, it's just as easy to shuffle a little bit back as you observe them climbing.
I would just politely communicate with your 2nd, 'take in a little', 'watch me' etc.. If they still don't learn time to expand your climbing circle of friends. The rights and wrongs of absorbing force, fall factors etc.. could be slightly relevant on more extreme routes or ground, but it's about you enjoying climbing with people you do it with that matters too.
4
In reply to Mr. Lee:
Thinking about it, the times I've noticed it most have been indoors when it's more sterile so I am more at ease and able to look down. On indoor/outdoor sport he does use a grigri. Indoors the chance of decking is much higher which was when I noticed it and brought it up.
> Were they using a Grigri by any chance?
Thinking about it, the times I've noticed it most have been indoors when it's more sterile so I am more at ease and able to look down. On indoor/outdoor sport he does use a grigri. Indoors the chance of decking is much higher which was when I noticed it and brought it up.
1
1
In reply to john arran:
On the whole I agree, however it is a bit more complicated. The extra metre of slack will result in a lot more energy to be absorbed, but it will also reduce the pendulum effect, which can significantly lower the impact on the wall (despite increasing peak load on the top runner), all other things being equal. Particularly if theres a large weight discrepancy and the belayer isn't top notch at soft catches, or there's a lot of drag in the system.
For that reason I will sometimes ask a belayer to give me a lot of slack at a certain point on a sport route, where I know I'm likely to come off in unpredictable fashion.
On the whole I agree, however it is a bit more complicated. The extra metre of slack will result in a lot more energy to be absorbed, but it will also reduce the pendulum effect, which can significantly lower the impact on the wall (despite increasing peak load on the top runner), all other things being equal. Particularly if theres a large weight discrepancy and the belayer isn't top notch at soft catches, or there's a lot of drag in the system.
For that reason I will sometimes ask a belayer to give me a lot of slack at a certain point on a sport route, where I know I'm likely to come off in unpredictable fashion.
In reply to radddogg:
As others have already mentioned, this is complete bollocks. Soft catches involve the belayer allowing themselves to be pulled by the rope, or actively moving with it if heavier than the climber, which requires good timing, which requires practice. And have nothing to do with loops of slack. And are beside the point anyway if you have gear above you.
Sounds like your belayer is either misinformed or lazy, and can't be bothered to change his or her habits to make you feel more at ease. Making the leader feel at ease is an important part of the belayer's job (unless the leader wants something that is actually dangerous) so completely disregarding your expressed wishes is lazy and rude.
You need a new belayer.
You're right, he or she is wrong. Let's say you fall from two metres above a bolt at ten metres. You fall four metres on twelve metres of rope with a fall factor of 0.33. Now let's say Lazy Muppet has two metres of slack in the system: you fall six metres on fourteen metres of rope with a fall factor of 0.43. Plus stretch, plus belayer probably gets lifted a bit, plus your feet are a metre below your tie-in point - you could be surprisingly close to the floor at this point.
> I tried to tactfully raise this and he talked about giving me a "soft catch".
As others have already mentioned, this is complete bollocks. Soft catches involve the belayer allowing themselves to be pulled by the rope, or actively moving with it if heavier than the climber, which requires good timing, which requires practice. And have nothing to do with loops of slack. And are beside the point anyway if you have gear above you.
Sounds like your belayer is either misinformed or lazy, and can't be bothered to change his or her habits to make you feel more at ease. Making the leader feel at ease is an important part of the belayer's job (unless the leader wants something that is actually dangerous) so completely disregarding your expressed wishes is lazy and rude.
You need a new belayer.
> Another climber then backed him up talking about the fall factor. The theory was that the more rope in the system the more dynamic the catch and the less force on the anchors. I didn't understand this as I would expect the further you fall the faster you fall which increases the force on the anchors.
You're right, he or she is wrong. Let's say you fall from two metres above a bolt at ten metres. You fall four metres on twelve metres of rope with a fall factor of 0.33. Now let's say Lazy Muppet has two metres of slack in the system: you fall six metres on fourteen metres of rope with a fall factor of 0.43. Plus stretch, plus belayer probably gets lifted a bit, plus your feet are a metre below your tie-in point - you could be surprisingly close to the floor at this point.
12
In reply to radddogg:
Climb a little above him, clip the first bit of gear and look down, check he has given you plenty of slack, as you move up and he leaves the slack, jump off, land on his head and thank him for his 'soft catch'.
Climb a little above him, clip the first bit of gear and look down, check he has given you plenty of slack, as you move up and he leaves the slack, jump off, land on his head and thank him for his 'soft catch'.
9
1
In reply to DerwentDiluted:
I've done this with inattentive belayers in the past. As long as you don't hurt yourself it's quite effective
I've done this with inattentive belayers in the past. As long as you don't hurt yourself it's quite effective
1
In reply to AlanLittle:
Fall factors only apply when there is no excess slack in the system. Excess slack certainly increases forces, but not in proportion to the square root of the fall factor (as you have calculated it) in the way it does for situations with no excess slack (usual asumptions about friction, elasticity etc applying!).
> You're right, he or she is wrong. Let's say you fall from two metres above a bolt at ten metres. You fall four metres on twelve metres of rope with a fall factor of 0.33. Now let's say Lazy Muppet has two metres of slack in the system: you fall six metres on fourteen metres of rope with a fall factor of 0.43.
Fall factors only apply when there is no excess slack in the system. Excess slack certainly increases forces, but not in proportion to the square root of the fall factor (as you have calculated it) in the way it does for situations with no excess slack (usual asumptions about friction, elasticity etc applying!).
1
In reply to Robert Durran:
Yes, I was aware I was over-simplifying.
I presume the increase in force would actually be greater than the increase in "fall factor" would suggest? In my example the free-fall distance before any braking starts is increased by 50%
Yes, I was aware I was over-simplifying.
I presume the increase in force would actually be greater than the increase in "fall factor" would suggest? In my example the free-fall distance before any braking starts is increased by 50%
Post edited at 13:27
In reply to radddogg:
my understanding is that a "soft catch" involves absorbing force over a longer period eg by stepping forward when starting to take the load of a falling climber or letting the rope slip a bit through the belay device when load comes on it. Excessive amounts of slack is just bad belaying IMHO, I always aim to keep the rope with just enough slack for the leader to move freely, in return he rewards me with no slack when I'm seconding Might be a solution to reward the belayer with a similar degree of slack when following
my understanding is that a "soft catch" involves absorbing force over a longer period eg by stepping forward when starting to take the load of a falling climber or letting the rope slip a bit through the belay device when load comes on it. Excessive amounts of slack is just bad belaying IMHO, I always aim to keep the rope with just enough slack for the leader to move freely, in return he rewards me with no slack when I'm seconding Might be a solution to reward the belayer with a similar degree of slack when following
3
In reply to Ciro:
When pretty rare exceptions are brought into the discussion, that only apply to overhanging walls anyway, it's no wonder people with little experience get so confused!
> On the whole I agree, however it is a bit more complicated. The extra metre of slack will result in a lot more energy to be absorbed, but it will also reduce the pendulum effect, which can significantly lower the impact on the wall (despite increasing peak load on the top runner), all other things being equal. Particularly if theres a large weight discrepancy and the belayer isn't top notch at soft catches, or there's a lot of drag in the system.
> For that reason I will sometimes ask a belayer to give me a lot of slack at a certain point on a sport route, where I know I'm likely to come off in unpredictable fashion.
When pretty rare exceptions are brought into the discussion, that only apply to overhanging walls anyway, it's no wonder people with little experience get so confused!
In reply to Ciro:
If you take the, "I'd like an extra 2m of slack please" to it's logical conclusion... (assuming ledges aren't an issue) why not 5m or 10m or as much will just to say keep you off the ground? I'm in the minimal slack camp to minimise the length and momentum of initial fall then with good timing of movement, maximise the time taken to arrest the fall. My general tactic is to stand a good few meters out from the wall to allow a couple of quick paces towards in the event of a fall.
I can see there is something in the slamming pendulum effect but I'd like to see the maths which prove there is a sweet spot amount of slack rather than too much or too little...
If you take the, "I'd like an extra 2m of slack please" to it's logical conclusion... (assuming ledges aren't an issue) why not 5m or 10m or as much will just to say keep you off the ground? I'm in the minimal slack camp to minimise the length and momentum of initial fall then with good timing of movement, maximise the time taken to arrest the fall. My general tactic is to stand a good few meters out from the wall to allow a couple of quick paces towards in the event of a fall.
I can see there is something in the slamming pendulum effect but I'd like to see the maths which prove there is a sweet spot amount of slack rather than too much or too little...
1
In reply to Robert Durran:
Erm no, I think you'll find he's calculated it by dividing the distance fallen by the amount of rope in the system. No square roots involved.
> Fall factors only apply when there is no excess slack in the system. Excess slack certainly increases forces, but not in proportion to the square root of the fall factor (as you have calculated it) in the way it does for situations with no excess slack (usual asumptions about friction, elasticity etc applying!).
Erm no, I think you'll find he's calculated it by dividing the distance fallen by the amount of rope in the system. No square roots involved.
1
In reply to radddogg:
I think there is no need to be tactful! You're leading, it's your call. As others have said, increasing slack in the system increases the distance fallen and hence actually increases the fall factor.
> When I belay I keep the slack to a minimum without hindering the leader as my opinion is the drop should be kept to a minimum.
> A regular partner pays out the slack without taking any in if for example you place gear above your head then climb up to it. As a leader, looking down and seeing the rope looping down from the belay device near to the floor is quite disconcerting - for me anyway - and it has psyched me out on a few harder routes. I tried to tactfully raise this and he talked about giving me a "soft catch"
I think there is no need to be tactful! You're leading, it's your call. As others have said, increasing slack in the system increases the distance fallen and hence actually increases the fall factor.
1
In reply to Lion Bakes:
Yes, but it does not apply when there is excess slack in the system. For an elastic rope and no friction and with no excess slack, the maximum tension in the rope is proportional to the square root of the fall factor (no square roots are involved in working out the fall factor, just the maximum tension). Once there is excess slack, things become rather more complicated, though it is true that paying out extra slack while keeping other things the same will always increase the maximum tension. If I have time I'll do the maths later and try to see whether a higher 'fall factor' calculated with extra slack (as he did) can in fact result in a lower maximum tension.
> Erm no, I think you'll find he's calculated it by dividing the distance fallen by the amount of rope in the system. No square roots involved.
Yes, but it does not apply when there is excess slack in the system. For an elastic rope and no friction and with no excess slack, the maximum tension in the rope is proportional to the square root of the fall factor (no square roots are involved in working out the fall factor, just the maximum tension). Once there is excess slack, things become rather more complicated, though it is true that paying out extra slack while keeping other things the same will always increase the maximum tension. If I have time I'll do the maths later and try to see whether a higher 'fall factor' calculated with extra slack (as he did) can in fact result in a lower maximum tension.
Post edited at 14:09
In reply to Mark Kemball:
Is there a corresponding "dynamic factor" for the rope? I know diameter and brand affects stretch but is there a %/metre figure that can be used in conjunction with fall factor to calculate the force in correlation to the distance fallen?
> As others have said, increasing slack in the system increases the distance fallen and hence actually increases the fall factor.
Is there a corresponding "dynamic factor" for the rope? I know diameter and brand affects stretch but is there a %/metre figure that can be used in conjunction with fall factor to calculate the force in correlation to the distance fallen?
In reply to radddogg:
The more elastic the rope (generally that means thinner), the lower maximum tension will be.
> Is there a corresponding "dynamic factor" for the rope? I know diameter and brand affects stretch but is there a %/metre figure that can be used in conjunction with fall factor to calculate the force in correlation to the distance fallen?
The more elastic the rope (generally that means thinner), the lower maximum tension will be.
In reply to john arran:
On the other hand, the benefit of reducing the pendulum effect is probably most noticeable when a beginner moves from the extreme of having no slack in the system to allowing an appropriate amount of slack.
If the reasons behind their own observable outcomes are ignored from the discussion, it's no wonder they get confused.
> When pretty rare exceptions are brought into the discussion, that only apply to overhanging walls anyway, it's no wonder people with little experience get so confused!
On the other hand, the benefit of reducing the pendulum effect is probably most noticeable when a beginner moves from the extreme of having no slack in the system to allowing an appropriate amount of slack.
If the reasons behind their own observable outcomes are ignored from the discussion, it's no wonder they get confused.
In reply to JLS:
Indeed you can take it to that conclusion. The calculations are pretty complex, probably easier to just do the experiment when you're climbing
Indeed you can take it to that conclusion. The calculations are pretty complex, probably easier to just do the experiment when you're climbing
In reply to radddogg:
I wouldn't climb with them!
no excuse for that amount of slack especially with any groundfall potential...
unless you are a kangaroo about to commit to a spectacular dyno?
I wouldn't climb with them!
no excuse for that amount of slack especially with any groundfall potential...
unless you are a kangaroo about to commit to a spectacular dyno?
2
In reply to Ciro:
I think this is something i keep on seeing written down wrong, including in instructional books, + even more confusingly, + super stressfully, being shouted up to warn about (with good intention but incorrectly worded), when on routes outside + in.
You are at risk of inverting,
When your leg / foot is in front of the rope
= When the rope is behind your leg/foot
....... viewed from ground, behind the climber looking up = rope> leg/foot> rock
You are NOT at risk of inverting, + it is best to keep
your leg/foot behind the rope
= when the rope is in front of your leg/foot.
Viewed from ground looking up at climber =
Leg /foot > rope > Rock
The rope should be kept in front of yr leg /foot, between it and the rock
= your leg/foot should be kept behind the rope.
?
> To take that a little bit further, if your climber puts his foot behind the rope and is at risk of inverting in a fall, the consequences of swinging into the rock suddenly become much higher, so the (rather counter-intuitive) safest thing to do at that point will often be to throw some more slack into the system.
I think this is something i keep on seeing written down wrong, including in instructional books, + even more confusingly, + super stressfully, being shouted up to warn about (with good intention but incorrectly worded), when on routes outside + in.
You are at risk of inverting,
When your leg / foot is in front of the rope
= When the rope is behind your leg/foot
....... viewed from ground, behind the climber looking up = rope> leg/foot> rock
You are NOT at risk of inverting, + it is best to keep
your leg/foot behind the rope
= when the rope is in front of your leg/foot.
Viewed from ground looking up at climber =
Leg /foot > rope > Rock
The rope should be kept in front of yr leg /foot, between it and the rock
= your leg/foot should be kept behind the rope.
?
Post edited at 15:17
1
In reply to Rock to Fakey:
Sorry to be confusing, but I'm not sure how you get around that as it's more a matter of perspective than right or wrong.
When I'm climbing, the rope is in front of me and the rock is behind the rope, so putting my foot round the rope would be going behind.
Perhaps "between the rope and the rock" would be less confusing.
Sorry to be confusing, but I'm not sure how you get around that as it's more a matter of perspective than right or wrong.
When I'm climbing, the rope is in front of me and the rock is behind the rope, so putting my foot round the rope would be going behind.
Perhaps "between the rope and the rock" would be less confusing.
In reply to Ciro:
Surely if the rope is... In front of you
Then...
The rock must be.... in front of the rope?
unless you have the rock between you (your front) and the rope, which would be odd...
Surely if the rope is... In front of you
Then...
The rock must be.... in front of the rope?
unless you have the rock between you (your front) and the rope, which would be odd...
Post edited at 15:23
In reply to Rock to Fakey:
If you're standing in your front garden, your house is in front of you, is your back garden not behind your house?
If you're standing in your front garden, your house is in front of you, is your back garden not behind your house?
1
In reply to Robert Durran:
the square root of the fall factor (as you have calculated it)
He didn't calculate it that way, certainly not in the post you were replying to. Show me which reply he calculated a force as the square root of the fall factor.
> Yes, but it does not apply when there is excess slack in the system. For an elastic rope and no friction and with no excess slack, the maximum tension in the rope is proportional to the square root of the fall factor (no square roots are involved in working out the fall factor, just the maximum tension). Once there is excess slack, things become rather more complicated, though it is true that paying out extra slack while keeping other things the same will always increase the maximum tension. If I have time I'll do the maths later and try to see whether a higher 'fall factor' calculated with extra slack (as he did) can in fact result in a lower maximum tension.
>
the square root of the fall factor (as you have calculated it)
He didn't calculate it that way, certainly not in the post you were replying to. Show me which reply he calculated a force as the square root of the fall factor.
In reply to radddogg:
I suspect the belay doesn't really know what they are doing.
Think of it this way.. if you placed gear above your head and then climbed up until you harness actually passes the gear and if you had no slack out then you could just dangle on your gear without falling at all. Any extra slack out (and you need some just to move) will increase the load on your gear should you fall. Adding extra slack will increase the fall factor and not decrease it!
I suspect the belay doesn't really know what they are doing.
Think of it this way.. if you placed gear above your head and then climbed up until you harness actually passes the gear and if you had no slack out then you could just dangle on your gear without falling at all. Any extra slack out (and you need some just to move) will increase the load on your gear should you fall. Adding extra slack will increase the fall factor and not decrease it!
1
In reply to AlanLittle:
Is it as simple as that? Intuitively I'm not sure you can model all the rope that is out as a single 12m or 14m 'spring' absorbing the impact force because the rope is also bending round an anchor. Once the rope starts to come tight it is no longer able to move freely round the anchor so it is more like two springs with more impact force on the (short) spring between the climber and the anchor than on the (much longer) spring between anchor and belayer.
> You're right, he or she is wrong. Let's say you fall from two metres above a bolt at ten metres. You fall four metres on twelve metres of rope with a fall factor of 0.33. Now let's say Lazy Muppet has two metres of slack in the system: you fall six metres on fourteen metres of rope with a fall factor of 0.43.
Is it as simple as that? Intuitively I'm not sure you can model all the rope that is out as a single 12m or 14m 'spring' absorbing the impact force because the rope is also bending round an anchor. Once the rope starts to come tight it is no longer able to move freely round the anchor so it is more like two springs with more impact force on the (short) spring between the climber and the anchor than on the (much longer) spring between anchor and belayer.
In reply to Lion Bakes:
He didn't calculate any force. He just calculated a "fall factor" and asserted that a higher "fall factor" means higher forces (correctly in the situation described). To calculate forces from the fall factor requires a square root.
> Show me which reply he calculated a force as the square root of the fall factor.
He didn't calculate any force. He just calculated a "fall factor" and asserted that a higher "fall factor" means higher forces (correctly in the situation described). To calculate forces from the fall factor requires a square root.
In reply to tom_in_edinburgh:
Yes, as discussed above with Robert- I suspect the extra slack is actually substantially worse than "just" an increase in the fall factor, because all of it amounts to extra freefall & accumulated kinetic energy before the braking system starts to do anything. Not to mention being closer to the ground.
Yes, as discussed above with Robert- I suspect the extra slack is actually substantially worse than "just" an increase in the fall factor, because all of it amounts to extra freefall & accumulated kinetic energy before the braking system starts to do anything. Not to mention being closer to the ground.
In reply to AlanLittle:
If you consider that in the real world, the adjusted fall factor on the climbers side of the rope will be somewhere between the frictionless model (Fall length over total length of rope) and the infinite friction model (Fall length over the length of rope between the climber and the top runner) you'll see that your suspicions are undoubtedly correct.
If you consider that in the real world, the adjusted fall factor on the climbers side of the rope will be somewhere between the frictionless model (Fall length over total length of rope) and the infinite friction model (Fall length over the length of rope between the climber and the top runner) you'll see that your suspicions are undoubtedly correct.
1
In reply to radddogg:
For me (and obviously others on here) the answer is " don't climb with a belayer you don't trust ".
This is a regular issue at our club, we have a youth member who knows everything, but his belaying is at best inattentive. I won't climb with him and I advise my mates to do likewise.
Several of us have spoken to him and his father but they are not receptive.
For me (and obviously others on here) the answer is " don't climb with a belayer you don't trust ".
This is a regular issue at our club, we have a youth member who knows everything, but his belaying is at best inattentive. I won't climb with him and I advise my mates to do likewise.
Several of us have spoken to him and his father but they are not receptive.
2
1
In reply to Robert Durran:
So why did you say te calculated it as the square root when he quite clearly didn't ?
> He didn't calculate any force. He just calculated a "fall factor" and asserted that a higher "fall factor" means higher forces (correctly in the situation described). To calculate forces from the fall factor requires a square root.
So why did you say te calculated it as the square root when he quite clearly didn't ?
In reply to Lion Bakes:
I didn't say that!
> So why did you say te calculated it as the square root when he quite clearly didn't ?
I didn't say that!
In reply to Ciro:
Your back garden technically is such when u r in yr house looking out to the front of the house.
Normall/mostly we climb facing the rock, in which case things are positioned in front of us.
Technically your back garden is in front of you when u r looking at it from inside yr house, but has been called yr back garden to help you know front from back, + to help u go the right direction in the morning when u leave yr ouse, so's u don't trip over the fence or go fence hopping to get to the shops or work, + so u don't hurt yrself on yr way out to go climbing.
Front + back gardens technically just change name, (not position) , according to which way you are facing when in yr house, but various factors decide which is which over a reference period of 42 wks, in relation to which door you have decided to designate front or back. The maths side of it is beyond me, but i think i'm ok with spacey relationships.
Your back garden technically is such when u r in yr house looking out to the front of the house.
Normall/mostly we climb facing the rock, in which case things are positioned in front of us.
Technically your back garden is in front of you when u r looking at it from inside yr house, but has been called yr back garden to help you know front from back, + to help u go the right direction in the morning when u leave yr ouse, so's u don't trip over the fence or go fence hopping to get to the shops or work, + so u don't hurt yrself on yr way out to go climbing.
Front + back gardens technically just change name, (not position) , according to which way you are facing when in yr house, but various factors decide which is which over a reference period of 42 wks, in relation to which door you have decided to designate front or back. The maths side of it is beyond me, but i think i'm ok with spacey relationships.
Post edited at 21:19
1
In reply to radddogg:
Some general comments.
1. Adding slack to the system makes the fall factor approach 1. The added rope definitely "counts." So for fall factors less than 1 (this is the only case for one-pitch sport climbs), the fall factor goes up (since it gets closer to 1) and consequently the peak rope tension goes up as well. From the point of view of peak rope tension (and so maximum loads on gear and leader), adding slack means higher peak loads.
2. If the climb overhangs, there could be a reason to add slack, because that lengthens the pendulum arm, meaning the rock the leader will eventually hit gets further away, and once past the low point of the pendulum, the leader is heading up and so is losing velocity. Adding slack is a particularly good idea when the overhang is gentle and the leader is close to the pro---drop 'em so that the wall they'll hit is further away! Another reason to add slack is to make sure the leader fully clears the lip of a ceiling. In cases like these, the higher rope tension is far less important than the pendulum impact against the wall. On the other hand, added slack will make everything worse on a less than vertical wall---you get higher peak loads and bigger bigger pendulum impacts if something makes the climber fall away from the face. So the point is that decisions about adding slack are highly situational, and there is no valid argument for always leaving a lot of slack in the rope and many potentially bad outcomes if there are rock features for the leader to hit.
3. Soft catches occur because the belayer provides some way for the falling climber do to work that contributes to absorbing fall energy, leaving less fall energy for the rope to absorb by stretching and therefore lowering peak rope tension. The usual method is to allow the falling climber to do some work raising the belayer. The fact that this work takes time is often confused with the notion that the peak load can be reduced by "spreading the load out over time." The spread over time is an artifact of the additional work mechanism and not, in principle, a cause of lowered peak load, as the loading curve can be extended over time without reducing its peak(s) by narrowing the peaks and/or reducing the height of other portions. Since soft catches also add to the fall distance, they can also mitigate the effects of penduluming into an overhanging wall. For this reason, they are often confused with just leaving slack in the rope, even though the total results are different.
4. Belay techniques that are appropriate for overhanging sport climbs where the leader is in no danger of hitting anything other than the overhanging the wall itself are different from belay techniques for vertical or less than vertical pitches and for trad climbs in general, many of which have features a falling leader does not want to hit. Although general rules are to be avoided, I'd say that on most trad climbs the belayer should be leaving considerably less slack than for overhanging sport routes and should almost always be taking in slack when the leader makes a high clip and moves up.
Some general comments.
1. Adding slack to the system makes the fall factor approach 1. The added rope definitely "counts." So for fall factors less than 1 (this is the only case for one-pitch sport climbs), the fall factor goes up (since it gets closer to 1) and consequently the peak rope tension goes up as well. From the point of view of peak rope tension (and so maximum loads on gear and leader), adding slack means higher peak loads.
2. If the climb overhangs, there could be a reason to add slack, because that lengthens the pendulum arm, meaning the rock the leader will eventually hit gets further away, and once past the low point of the pendulum, the leader is heading up and so is losing velocity. Adding slack is a particularly good idea when the overhang is gentle and the leader is close to the pro---drop 'em so that the wall they'll hit is further away! Another reason to add slack is to make sure the leader fully clears the lip of a ceiling. In cases like these, the higher rope tension is far less important than the pendulum impact against the wall. On the other hand, added slack will make everything worse on a less than vertical wall---you get higher peak loads and bigger bigger pendulum impacts if something makes the climber fall away from the face. So the point is that decisions about adding slack are highly situational, and there is no valid argument for always leaving a lot of slack in the rope and many potentially bad outcomes if there are rock features for the leader to hit.
3. Soft catches occur because the belayer provides some way for the falling climber do to work that contributes to absorbing fall energy, leaving less fall energy for the rope to absorb by stretching and therefore lowering peak rope tension. The usual method is to allow the falling climber to do some work raising the belayer. The fact that this work takes time is often confused with the notion that the peak load can be reduced by "spreading the load out over time." The spread over time is an artifact of the additional work mechanism and not, in principle, a cause of lowered peak load, as the loading curve can be extended over time without reducing its peak(s) by narrowing the peaks and/or reducing the height of other portions. Since soft catches also add to the fall distance, they can also mitigate the effects of penduluming into an overhanging wall. For this reason, they are often confused with just leaving slack in the rope, even though the total results are different.
4. Belay techniques that are appropriate for overhanging sport climbs where the leader is in no danger of hitting anything other than the overhanging the wall itself are different from belay techniques for vertical or less than vertical pitches and for trad climbs in general, many of which have features a falling leader does not want to hit. Although general rules are to be avoided, I'd say that on most trad climbs the belayer should be leaving considerably less slack than for overhanging sport routes and should almost always be taking in slack when the leader makes a high clip and moves up.
12
1
In reply to rgold:
I forgot another item:
5. It is not true that the maximum rope tension is proportional to the square root of the fall factor. For example, if a climber just applies their weight to a rope, the maximum tension will be twice the climber's weight and the fall factor is zero. An account of the elementary math and physics can be found at http://4sport.ua/_upl/2/1404/StandardEqn.pdf.
I forgot another item:
5. It is not true that the maximum rope tension is proportional to the square root of the fall factor. For example, if a climber just applies their weight to a rope, the maximum tension will be twice the climber's weight and the fall factor is zero. An account of the elementary math and physics can be found at http://4sport.ua/_upl/2/1404/StandardEqn.pdf.
In reply to radddogg:
I should probably have expanded on the Grigri thing. I've seen a lot less dynamic belaying by some people who primarily use Grigris. Instead just leaving ample slack permanently in the system so that all they need to do is keep paying out the rope. It's possible to take in slack with a Grigri but for some it seems too much of a faff given the thumb needs to block the breaking mechanism to do this. The same goes for walking backwards and forwards. Maybe it's related to Grigris fully locking during a fall, thereby making users more aware of the whipping pendulum affect into the rock. I've seen this mainly with people who have learnt to climb indoors using a Grigri and have then taken this belay style outdoors. It's obviously not the case with all Grigri users but I am certainly more paranoid about all of the above given I've experienced it first hand quite a few times in recent years.
> Were they using a Grigri by any chance?
> Thinking about it, the times I've noticed it most have been indoors when it's more sterile so I am more at ease and able to look down. On indoor/outdoor sport he does use a grigri. Indoors the chance of decking is much higher which was when I noticed it and brought it up.
I should probably have expanded on the Grigri thing. I've seen a lot less dynamic belaying by some people who primarily use Grigris. Instead just leaving ample slack permanently in the system so that all they need to do is keep paying out the rope. It's possible to take in slack with a Grigri but for some it seems too much of a faff given the thumb needs to block the breaking mechanism to do this. The same goes for walking backwards and forwards. Maybe it's related to Grigris fully locking during a fall, thereby making users more aware of the whipping pendulum affect into the rock. I've seen this mainly with people who have learnt to climb indoors using a Grigri and have then taken this belay style outdoors. It's obviously not the case with all Grigri users but I am certainly more paranoid about all of the above given I've experienced it first hand quite a few times in recent years.
1
In reply to radddogg:
Any chance they've learnt to belay via sport climbing? Similar principles with trad but a completely different ball game with far more variables as others have pointed out (I'm not saying sport is completely safe btw)
Any chance they've learnt to belay via sport climbing? Similar principles with trad but a completely different ball game with far more variables as others have pointed out (I'm not saying sport is completely safe btw)
In reply to john arran:
Worth also mentioning that rope provides a fair amount of absorption in the system anyway. If I'm 30m up a pitch then the fall is always going to be pretty soft even if the belayer provides no dampening. Particularly with half ropes.
> In essence, what you're usually trying to achieve is to soften the impact of the catch, not by giving more slack in advance, but by spreading the time taken to arrest the fall over a longer period. If you're sport belaying on flat ground this is easy to achieve by letting yourself be pulled a step or two towards the face by the force of the fall. In less mobile belaying situations it's still possible to let yourself be pulled upwards a little from a crouched position or to use a belay device that doesn't grab the rope so tightly, thereby letting up to a foot or so of rope pass through the device while bringing the fall to a stop.
Worth also mentioning that rope provides a fair amount of absorption in the system anyway. If I'm 30m up a pitch then the fall is always going to be pretty soft even if the belayer provides no dampening. Particularly with half ropes.
In reply to rgold:
Sorry, I misremembered that and got it wrong. Done the maths again. It's more complicated and it does produce a modified a fall factor which includes the excess slack (so I got that wrong too....... ). If the fall factor calculated as if there were no excess slack is less than 1 then adding extra slack increases the max tension (and, as you said, this will always be the case on single pitch routes because you can't fall further than the length of rope out without hitting the ground). But if the fall factor is greater than 1 (so that you fall past the belay on a multi pitch routes) then extra slack will, perhaps counterintuitively, decrease the max tension.
> It is not true that the maximum rope tension is proportional to the square root of the fall factor.
Sorry, I misremembered that and got it wrong. Done the maths again. It's more complicated and it does produce a modified a fall factor which includes the excess slack (so I got that wrong too....... ). If the fall factor calculated as if there were no excess slack is less than 1 then adding extra slack increases the max tension (and, as you said, this will always be the case on single pitch routes because you can't fall further than the length of rope out without hitting the ground). But if the fall factor is greater than 1 (so that you fall past the belay on a multi pitch routes) then extra slack will, perhaps counterintuitively, decrease the max tension.
Post edited at 09:02
In reply to radddogg:
If the runner is above waist height then you are effectively on a top rope and there's no need to do anything to increase the dynamism of the belay. Rope stretch is enough. Extra slack, meaning extra fall distance, will just increase the force on the runner and thus increase the risk of it pulling out.
If the belayer doesn't want to look up to watch you climbing - for instance they don't want to see the moves because they want to onsight the same route - then having a loop of slack out is important to allow you to pull up rope quickly. I don't think many people do go to such lengths these days though. Having belay glasses greatly help focus attention on the lead climber at all times without stiff neck problems which means you can pay out rope at just the right moment.
One of the easiest ways to get soft falls is to use DMM roller biners.
If the runner is above waist height then you are effectively on a top rope and there's no need to do anything to increase the dynamism of the belay. Rope stretch is enough. Extra slack, meaning extra fall distance, will just increase the force on the runner and thus increase the risk of it pulling out.
If the belayer doesn't want to look up to watch you climbing - for instance they don't want to see the moves because they want to onsight the same route - then having a loop of slack out is important to allow you to pull up rope quickly. I don't think many people do go to such lengths these days though. Having belay glasses greatly help focus attention on the lead climber at all times without stiff neck problems which means you can pay out rope at just the right moment.
One of the easiest ways to get soft falls is to use DMM roller biners.
Post edited at 09:06
1
In reply to rgold:
>"Soft catches occur because the belayer provides some way for the falling climber do to work that contributes to absorbing fall energy, leaving less fall energy for the rope to absorb by stretching and therefore lowering peak rope tension. The usual method is to allow the falling climber to do some work raising the belayer. "
I'm surprised you think "spreading the load over time" is a red herring and it is the "work done" that's important. That would suggest that moving a half ton concrete block a few centimetres would give the same results as moving a 50kg bloke by 2m. I'd expect the light belayer to give a softer catch than the concrete.
>"Soft catches occur because the belayer provides some way for the falling climber do to work that contributes to absorbing fall energy, leaving less fall energy for the rope to absorb by stretching and therefore lowering peak rope tension. The usual method is to allow the falling climber to do some work raising the belayer. "
I'm surprised you think "spreading the load over time" is a red herring and it is the "work done" that's important. That would suggest that moving a half ton concrete block a few centimetres would give the same results as moving a 50kg bloke by 2m. I'd expect the light belayer to give a softer catch than the concrete.
In reply to radddogg:
It's very simple, the ONLY correct way to belay is exactly how the individual leader WANTS to be belayed. If someone won't belay you how you want, find another climbing partner.
How the belayer thinks they should belay you, how they have historically belayed and how they personally like to be belayed are irrelevant. If a leader is excessively paranoid and wants zero slack, you belay them that way. If they are a super chilled sport climber and insist on making fast clips and having a soft catch then you belay them really dynamically with lots of movement.
If your belayer isn't belaying you how you want, TELL THEM. Equally if you're not completely comfortable with giving a really dynamic belay then have an honest conversation with the leader.
The golden rule is never, ever take offense at having your belaying criticised. Leading is stressful and falling off even more so. Just roll with it and do your best. Anyone who does take offense is not someone I want to climb with. (One of my climbing partners is always shouting for me to have her tighter, another invariably criticises me for never being dynamic enough if she falls.)
Regardless of individual preferences there are still some good general principles:
Low down on routes, belay more statically; high up on routes belay more dynamically.
Adapt your belaying to how the leader is climbing - on crux moves belay extremely attentively; on easy ground concentrate on giving enough slack whilst always maintaining a proper grip on the dead rope.
Finally, as numerous other posters have already expounded upon at length, dynamic belaying has nothing to do with loads of slack and everything to do with the belayer MOVING lots. For a light belayer that may happen naturally, for a heavier belay more effort is required.
It's very simple, the ONLY correct way to belay is exactly how the individual leader WANTS to be belayed. If someone won't belay you how you want, find another climbing partner.
How the belayer thinks they should belay you, how they have historically belayed and how they personally like to be belayed are irrelevant. If a leader is excessively paranoid and wants zero slack, you belay them that way. If they are a super chilled sport climber and insist on making fast clips and having a soft catch then you belay them really dynamically with lots of movement.
If your belayer isn't belaying you how you want, TELL THEM. Equally if you're not completely comfortable with giving a really dynamic belay then have an honest conversation with the leader.
The golden rule is never, ever take offense at having your belaying criticised. Leading is stressful and falling off even more so. Just roll with it and do your best. Anyone who does take offense is not someone I want to climb with. (One of my climbing partners is always shouting for me to have her tighter, another invariably criticises me for never being dynamic enough if she falls.)
Regardless of individual preferences there are still some good general principles:
Low down on routes, belay more statically; high up on routes belay more dynamically.
Adapt your belaying to how the leader is climbing - on crux moves belay extremely attentively; on easy ground concentrate on giving enough slack whilst always maintaining a proper grip on the dead rope.
Finally, as numerous other posters have already expounded upon at length, dynamic belaying has nothing to do with loads of slack and everything to do with the belayer MOVING lots. For a light belayer that may happen naturally, for a heavier belay more effort is required.
10
In reply to rgold:
I think that might be the wrong link (or maybe my Russian just isn't up to scratch!)
Anyway the formula for max tension T is:
T = W + sqrt(W^2+2WkF) where W is the weight of the climber, k the stiffness of the rope (tension/fractional stretch) and F the fall factor taking into account excess slack (ie distance fallen before rope starts going tight/rope payed out including slack)
> An account of the elementary math and physics can be found at http://4sport.ua/_upl/2/1404/StandardEqn.pdf.
I think that might be the wrong link (or maybe my Russian just isn't up to scratch!)
Anyway the formula for max tension T is:
T = W + sqrt(W^2+2WkF) where W is the weight of the climber, k the stiffness of the rope (tension/fractional stretch) and F the fall factor taking into account excess slack (ie distance fallen before rope starts going tight/rope payed out including slack)
1
In reply to Robert Durran:
It's those Russian hackers, they're bored now that they got Trump elected. Actually, UKC behaves oddly (and unpredictably) if you give a link and terminate it with a period. I knew this but made the mistake anyway. Here's the same link with a space before the period; it should produce the account I mentioned, with the formula you quoted. http://4sport.ua/_upl/2/1404/StandardEqn.pdf .
> I think that might be the wrong link (or maybe my Russian just isn't up to scratch!)
It's those Russian hackers, they're bored now that they got Trump elected. Actually, UKC behaves oddly (and unpredictably) if you give a link and terminate it with a period. I knew this but made the mistake anyway. Here's the same link with a space before the period; it should produce the account I mentioned, with the formula you quoted. http://4sport.ua/_upl/2/1404/StandardEqn.pdf .
Post edited at 16:06
1
In reply to JLS:
It's not just the quantity of work done, it is the way in which the work is done, and I'm saying that in terms of the peak load at some instant, there is no direct mechanism in which the lengthening of the time of arrest necessarily lowers the peak load. Perhaps there is an unacknowledged shift of attention to the impulse rather than the peak load, together with an assumption that during the catch the arresting force is constant? (And in fact it may be, in terms of damage to the leader's body, that impulse is an important quantity, but that is a different question.)
> >"Soft catches occur because the belayer provides some way for the falling climber do to work that contributes to absorbing fall energy, leaving less fall energy for the rope to absorb by stretching and therefore lowering peak rope tension. The usual method is to allow the falling climber to do some work raising the belayer. "
> I'm surprised you think "spreading the load over time" is a red herring and it is the "work done" that's important. That would suggest that moving a half ton concrete block a few centimetres would give the same results as moving a 50kg bloke by 2m. I'd expect the light belayer to give a softer catch than the concrete.
It's not just the quantity of work done, it is the way in which the work is done, and I'm saying that in terms of the peak load at some instant, there is no direct mechanism in which the lengthening of the time of arrest necessarily lowers the peak load. Perhaps there is an unacknowledged shift of attention to the impulse rather than the peak load, together with an assumption that during the catch the arresting force is constant? (And in fact it may be, in terms of damage to the leader's body, that impulse is an important quantity, but that is a different question.)
In reply to radddogg:
Hopefully you've got enough ammo for a ukc sponsored witch hunt by now. I'm just curious if your slack mate does much leading or takes many falls?
Hopefully you've got enough ammo for a ukc sponsored witch hunt by now. I'm just curious if your slack mate does much leading or takes many falls?
In reply to stp:
I should hope not! A belayer who is more interested in their own onsight rather than my safety seems like a really bad person to have at the other end of the rope. That said, even if the belayer is willing, keeping the leader in sight isn't always possible. All the belayer has to watch is the rope right in front of them; its motions will tell them when to pump slack for a clip. This is especially important when managing half ropes, since it can be hard, even when watching the leader, to know which rope should be pumped out for the clip, but the rope motions right in front of the belayer immediately convey the correct information.
> If the belayer doesn't want to look up to watch you climbing - for instance they don't want to see the moves because they want to onsight the same route - then having a loop of slack out is important to allow you to pull up rope quickly. I don't think many people do go to such lengths these days though.
I should hope not! A belayer who is more interested in their own onsight rather than my safety seems like a really bad person to have at the other end of the rope. That said, even if the belayer is willing, keeping the leader in sight isn't always possible. All the belayer has to watch is the rope right in front of them; its motions will tell them when to pump slack for a clip. This is especially important when managing half ropes, since it can be hard, even when watching the leader, to know which rope should be pumped out for the clip, but the rope motions right in front of the belayer immediately convey the correct information.
4
In reply to steveriley:
As I've said before, I'm not criticising anyone, just disagreed with the method and sought the wisdom of the many.
He leads lots but doesn't take many falls.
As I've said before, I'm not criticising anyone, just disagreed with the method and sought the wisdom of the many.
He leads lots but doesn't take many falls.
1
Seen people doing this at the wall:
youtube.com/watch?v=KC3knap-cQs&
Don't rate it. The belayer ended up by the first bolt and nearly knocked me over in the process. On another occasion (different climbers) the belayer leapt in to the air and collided with the falling climber.
Only seen younger climbers doing it - probably after watching the video?
youtube.com/watch?v=KC3knap-cQs&
Don't rate it. The belayer ended up by the first bolt and nearly knocked me over in the process. On another occasion (different climbers) the belayer leapt in to the air and collided with the falling climber.
Only seen younger climbers doing it - probably after watching the video?
In reply to meggie:
No need for tons of slack except when you are certain a leader is going to clip a high piece in the next few seconds.A metre of slack will allow the leader to telegraph their intention,to start pulling rope,while you pay out any more slack they may need.One idiot at New Mills Torrs used the dynamic belaying excuse while belaying a leader on Mather Crack.This climb has a half metre wide ledge that one could in theory hit on a fall.The belayer had 2.5 metres of slack out,and the leader had no need of it.I told him about the ledge,but he said the leader would not fall any where near.This is not a call for the belayer.Idiot. The slack was extending a potential fall by 5 metres,plus a bit of stretch.The bigger the fall,the more the jolt on the leader's body and the more you trash the rope.They don't last for ever.If you sport climb and take lots of dobs,use a thick rope.Some people use two thin ones for sport.Extends rope life.You can indeed allow say up to a metre of rope to slip through the plate,to reduce the impact,but don't give tons of slack as a matter of course.
No need for tons of slack except when you are certain a leader is going to clip a high piece in the next few seconds.A metre of slack will allow the leader to telegraph their intention,to start pulling rope,while you pay out any more slack they may need.One idiot at New Mills Torrs used the dynamic belaying excuse while belaying a leader on Mather Crack.This climb has a half metre wide ledge that one could in theory hit on a fall.The belayer had 2.5 metres of slack out,and the leader had no need of it.I told him about the ledge,but he said the leader would not fall any where near.This is not a call for the belayer.Idiot. The slack was extending a potential fall by 5 metres,plus a bit of stretch.The bigger the fall,the more the jolt on the leader's body and the more you trash the rope.They don't last for ever.If you sport climb and take lots of dobs,use a thick rope.Some people use two thin ones for sport.Extends rope life.You can indeed allow say up to a metre of rope to slip through the plate,to reduce the impact,but don't give tons of slack as a matter of course.
2
In reply to radddogg:
The belayer is right in that more rope in the system will reduce the fall factor BUT ONLY IF THE LENGTH OF FALL DOESN'T INCREASE. So, assuming the first bit of gear won't rip they can simply stand further away from the base of the route with a tight rope. Giving slack allows the climber to fall further negating the effect of the extra rope.
The belayer is right in that more rope in the system will reduce the fall factor BUT ONLY IF THE LENGTH OF FALL DOESN'T INCREASE. So, assuming the first bit of gear won't rip they can simply stand further away from the base of the route with a tight rope. Giving slack allows the climber to fall further negating the effect of the extra rope.
In reply to Toerag:
This is true. I have seen the rope being run through a bombproof anchor at ground level with the belayer then positioned about 10m out from the rock to protect a crucial marginal top runner.
> The belayer is right in that more rope in the system will reduce the fall factor BUT ONLY IF THE LENGTH OF FALL DOESN'T INCREASE. So, assuming the first bit of gear won't rip they can simply stand further away from the base of the route with a tight rope. Giving slack allows the climber to fall further negating the effect of the extra rope.
This is true. I have seen the rope being run through a bombproof anchor at ground level with the belayer then positioned about 10m out from the rock to protect a crucial marginal top runner.
In reply to Robert Durran:
But the ground anchor does need to be absolutely bombproof. And perhaps we should make it clear when we're talking about esoteric special situations versus normal practice.
But the ground anchor does need to be absolutely bombproof. And perhaps we should make it clear when we're talking about esoteric special situations versus normal practice.
In reply to paul mitchell:
This^^
Slipping the rope it's not the same as having a lot of slack in the system, this is a case of a little knowledge wrongly applied causing dangerous situations.
Talk to your belayer, if they are a friend they belay how YOU want them to, I tend to alter my baleying technique depending on what the climber likes. Some people like a slack rope others like to feel the rope is ready to catch them.
The climber should be in charge of this.
> You can indeed allow say up to a metre of rope to slip through the plate,to reduce the impact,but don't give tons of slack as a matter of course.
This^^
Slipping the rope it's not the same as having a lot of slack in the system, this is a case of a little knowledge wrongly applied causing dangerous situations.
Talk to your belayer, if they are a friend they belay how YOU want them to, I tend to alter my baleying technique depending on what the climber likes. Some people like a slack rope others like to feel the rope is ready to catch them.
The climber should be in charge of this.
In reply to meggie:
Me neither. If there wasn't so much slack in the system the leader wouldn't be falling so far/fast generating more force catapulting the belayer up to the first bolt.
I wonder if this is where my belayer got his information from.
> Seen people doing this at the wall:
> Don't rate it.
Me neither. If there wasn't so much slack in the system the leader wouldn't be falling so far/fast generating more force catapulting the belayer up to the first bolt.
I wonder if this is where my belayer got his information from.
In reply to radddogg:
There's nothing much wrong with what's shown in that video clip. There's some slack in the system and the climber gets a soft catch. If you're not tethered down and the climber takes a reasonable fall there's a high likelyhood the belayer will end up in the air (and there's nothing wrong with that), unless he's significantly heavier than the climber, or there's a lot of rope drag -- I'm quite light and usually end up in the air if it's anything more than a slump. If you're belayed tight there's a risk of injury as you (the climber) swing in to the wall, which is even greater if you're climbing off to the side of the bolts with your body side on to the wall as you have less opportunity to protect yourself by using your feet to take the impact.
However, it is also correct to say that until you get to the third bolt+ the priority is one of preventing the climber hitting the ground which means belaying close in to the wall and paying close attention to mimimising slack -- not standing 6 foot out from it with the rope in a position to cause the climber a painful injury if he falls as is often seen indoors on an evening.
It's really all just commonsense, as is not climbing directly under other climbers and being aware of what's going on around you when belaying.
> Me neither. If there wasn't so much slack in the system the leader wouldn't be falling so far/fast generating more force catapulting the belayer up to the first bolt.
> I wonder if this is where my belayer got his information from.
There's nothing much wrong with what's shown in that video clip. There's some slack in the system and the climber gets a soft catch. If you're not tethered down and the climber takes a reasonable fall there's a high likelyhood the belayer will end up in the air (and there's nothing wrong with that), unless he's significantly heavier than the climber, or there's a lot of rope drag -- I'm quite light and usually end up in the air if it's anything more than a slump. If you're belayed tight there's a risk of injury as you (the climber) swing in to the wall, which is even greater if you're climbing off to the side of the bolts with your body side on to the wall as you have less opportunity to protect yourself by using your feet to take the impact.
However, it is also correct to say that until you get to the third bolt+ the priority is one of preventing the climber hitting the ground which means belaying close in to the wall and paying close attention to mimimising slack -- not standing 6 foot out from it with the rope in a position to cause the climber a painful injury if he falls as is often seen indoors on an evening.
It's really all just commonsense, as is not climbing directly under other climbers and being aware of what's going on around you when belaying.
In reply to radddogg:
I actually didn't think there was all that much slack by typical sport climbing standards (and I hate a lot of slack!). Maybe it's just that it was a relatively heavy climber and it was a substantial fall.
> Me neither. If there wasn't so much slack in the system the leader wouldn't be falling so far/fast generating more force catapulting the belayer up to the first bolt.
I actually didn't think there was all that much slack by typical sport climbing standards (and I hate a lot of slack!). Maybe it's just that it was a relatively heavy climber and it was a substantial fall.
Post edited at 19:48
2
In reply to wurzelinzummerset:
Yes, the classic is the potential fall straddling the rope, cheesewiring the bollocks and then flipping over smack head first onto the floor. See it regularly. Some people's lack of imagination is extraordinary.
> .........not standing 6 foot out from it with the rope in a position to cause the climber a painful injury if he falls as is often seen indoors on an evening.
Yes, the classic is the potential fall straddling the rope, cheesewiring the bollocks and then flipping over smack head first onto the floor. See it regularly. Some people's lack of imagination is extraordinary.
In reply to radddogg:
You're the leader, if you ask for slack to be taken in, the belayer has to take it in!
Yes it could increase the impact force but unless the gear is poor that's far less important than the risk of hitting the deck, unless you're fairly high up of course.
You're the leader, if you ask for slack to be taken in, the belayer has to take it in!
Yes it could increase the impact force but unless the gear is poor that's far less important than the risk of hitting the deck, unless you're fairly high up of course.
1
In reply to radddogg:
Here is the link to a video that shows a climber suffering injuries precisely because there was no slack in the system, at least as far as I understand it.
youtube.com/watch?v=hDGCZqryZlk&
I can't see any issues with the BMC belaying video, looks fine to me.
Al
Here is the link to a video that shows a climber suffering injuries precisely because there was no slack in the system, at least as far as I understand it.
youtube.com/watch?v=hDGCZqryZlk&
I can't see any issues with the BMC belaying video, looks fine to me.
Al
In reply to GridNorth:
The injuries in that film were caused because he got the rope between his legs which flipped him upside down (and possibly because he wasn't wearing a helmet) so he hit the rock badly and totally out of control.
With say another metre of slack, he'd have just fallen another metre before slamming into the rock out of control and injuring himself in the same way, possibly worse as he'd have been going slightly faster.
> Here is the link to a video that shows a climber suffering injuries precisely because there was no slack in the system, at least as far as I understand it.
The injuries in that film were caused because he got the rope between his legs which flipped him upside down (and possibly because he wasn't wearing a helmet) so he hit the rock badly and totally out of control.
With say another metre of slack, he'd have just fallen another metre before slamming into the rock out of control and injuring himself in the same way, possibly worse as he'd have been going slightly faster.
1
In reply to pec:
That's not what I was told and as far as I understand it he did not sustain any injuries to the head. I was sent this link by someone who was there to illustrate the tight rope and the fact that the belayer is braced against a rock. I don't think the position of the rope was bad when he first fell he didn't seem to invert until he was well down suggesting that he caught the rope lower down. Of course this contributed to his injuries.
Al
That's not what I was told and as far as I understand it he did not sustain any injuries to the head. I was sent this link by someone who was there to illustrate the tight rope and the fact that the belayer is braced against a rock. I don't think the position of the rope was bad when he first fell he didn't seem to invert until he was well down suggesting that he caught the rope lower down. Of course this contributed to his injuries.
Al
In reply to GridNorth:
What you say about the belayer may be true but you can't really tell from the video, the angle it's filmed from makes it difficult to tell where he would have landed with more slack but more slack wouldn't have stopped him being flipped and hitting the rock out of control.
If you look carefully you can see that the rope is between his legs right from the start, its under his right thigh and as it starts to come tight it flips him over causing him to hit the rock backwards and upside down which is the principal cause of any injuries he sustained.
I only suggested that he may have had head injuries, but being flipped whlist not wearing a helmet creates a high risk of it.
What you say about the belayer may be true but you can't really tell from the video, the angle it's filmed from makes it difficult to tell where he would have landed with more slack but more slack wouldn't have stopped him being flipped and hitting the rock out of control.
If you look carefully you can see that the rope is between his legs right from the start, its under his right thigh and as it starts to come tight it flips him over causing him to hit the rock backwards and upside down which is the principal cause of any injuries he sustained.
I only suggested that he may have had head injuries, but being flipped whlist not wearing a helmet creates a high risk of it.
1
In reply to pec:
It looked to me like more slack would have simply made him hit the rock harder lower down. It just looks like a badly bolted route (unless he had missed a clip), though I suppose the perspective might have been misleading
> The injuries in that film were caused because he got the rope between his legs which flipped him upside down (and possibly because he wasn't wearing a helmet) so he hit the rock badly and totally out of control.
It looked to me like more slack would have simply made him hit the rock harder lower down. It just looks like a badly bolted route (unless he had missed a clip), though I suppose the perspective might have been misleading
In reply to pec:
During the fall the belayer actually took in an armful of rope and locked the belay off tight - possibly the worst thing to have done in the circumstances. This would have substantially increased the speed of horizontal impact, as it's the exact opposite of a soft catch. It's actually a very good example of when a soft catch could have helped a lot, since with a soft catch much of the energy of the fall could have been absorbed relatively slowly, leaving relatively little to be translated into horizontal movement.
During the fall the belayer actually took in an armful of rope and locked the belay off tight - possibly the worst thing to have done in the circumstances. This would have substantially increased the speed of horizontal impact, as it's the exact opposite of a soft catch. It's actually a very good example of when a soft catch could have helped a lot, since with a soft catch much of the energy of the fall could have been absorbed relatively slowly, leaving relatively little to be translated into horizontal movement.
1
In reply to john arran:
That's the point I was making although I have no doubt the other factors mentioned all contributed. For me the video is far too blurry to be sure about those factors however although at one point it did look to me like he missed a clip.
Al
That's the point I was making although I have no doubt the other factors mentioned all contributed. For me the video is far too blurry to be sure about those factors however although at one point it did look to me like he missed a clip.
Al
Post edited at 22:08
In reply to john arran:
Its hard to tell exactly but yes, it does look a bit like the belayer takes in but from the angle its filmed at it's hard to tell where he would have landed otherwise.
What I still think is very clear however is that catching the rope under his thigh flipped him. Had this not happened he would have landed upright facing the rock and instinctively put his arms out to protect his torso and head and received less severe injuries.
Its hard to tell exactly but yes, it does look a bit like the belayer takes in but from the angle its filmed at it's hard to tell where he would have landed otherwise.
What I still think is very clear however is that catching the rope under his thigh flipped him. Had this not happened he would have landed upright facing the rock and instinctively put his arms out to protect his torso and head and received less severe injuries.
This topic has been archived, and won't accept reply postings.
Elsewhere on the site
Loading Notifications...