Clip first quick draw with both rope strands when using half rope technique

The topic started here in an other thread (“7.3mm...Grigri”) but because a separate thread may has build about it, I would like to move this topic to a new thread.

A few issues ago the trade magazine "bergundsteigen"  (the alpine association magazine of germany, austria, switzerland)  has done extensive tests on half rope technique braking force and has come to the conclusion that the first express should be double clipped even with (subsequent) half-rope technique. Contrary to previous fears, there is no danger of burning ropes with different loads in this case.

Direct link to the article (german language) here:
www.bergundsteigen.com/wp-content/uploads/2021/08/34-41halbe-sache-oder-optimal.pdf

Link to the issue:
www.bergundsteigen.com/ausgabe/114/
(scroll down to "34-41 halbe-sache-oder-optimal")

Sorry the article is in german  an I am not able to translate it but for those who are interested I am sure that several online translators could help to get the main statement.

Essence is:
1. A falling lead climber who has clipped the first quick draw (test setting was 1m above belay-station) with only one part of the half rope may not get caught by the belayer (e.g. with reverso 4) even with half ropes of larger diameters (8,9 cm when lead climber weight is 120 kg).See the tables for other settings - weight, diameter, belay devices…

2. Mixing single and double clipping does not harm the ropes (as long as they run parallel like in this scenario)

3. That is why you should double clip the first quick draw. (That is surprising but proven in the article.)

Kyle Tarry:
We should also take note that this isn't a unique phenomenon to half ropes; a single rope in the same size range is likely going to have the exact same issue (there are several popular 8.5-8.9mm single rated ropes these days). 

Yes and no...
The big difference is that when using thin single ropes, we al would use an appropriate belay device (e.g. I use the Micro Jul with the Opera 8.5) because the braking forces to be expected are relatively clear and there is no significant change in this between the first and second quick draw .

The situation is different with half ropes in strict half rope technique, beacuse the braking force in the tuber increases after the second strand of the rope has been clipped to an value that it is sufficient to be able to hold a fall.

Kyle Tarry:
Luckily, from those results it looks like the issues are mainly with heavy climbers (120 kg).

I was worried that this impression might appear, but - although the problem obviously increases with higher fall mass - it's not quite what I'd read.
In the tests they made a 90kg lead climber fall could no longer be catched (close no catch) with a Reverso 4 (specified for half ropes between 7.1 and 9.2 mm) and 7.1mm rope. Also close no catch with an ATC guide and a 7.9mm rope.  

True that a 120kg is quite heavy but as you see the problem also exists with an 90kg climber what (and more) can achieved very quickly. -> 85kg climber + clothing + helmet + gear + water (+ boots + crampons...)

 things to note

1. if any fall is agressive enough, it will overpower any belayer and the rope will slide or their hand be drawn into the plate

2. the weaker the hand of the belayer, or the wetter or icier the ropes, or the thinner the rope, the more easily this will happen

3. adding a second carabiner helps with all of number 2, above.

4. I can't read German, but I think in the measurements the force is greater than the weight of the belayer, so they would be lifted. This could make quite a difference. But maybe that is all discussed.

5. I've got a feeling (Jim might pop along and get this bit right), but is it also true that a hand holding a single strand of half rope is stronger than one holding both strands - if only one strand takes the force of the fall? I might have this completely wrong, and it does not feel like that when belaying, but I thought this was true?

6. The hand rig shown is I think an attempt to represent the strength of the fingers. It does not represent the arm. In my teaching in the climbing gym, the hand is not the weakest link. It is the arm. Do the following test. Stand with your belay arm down but bent and in the kind of position it might be when relaxed but belaying. Make a fist as though you were holding a rope. Now have a friend attempt to lift your hand up to waist level - i.e. into the imaginary plate. This is surprisingly easy on many people. The arm is often the weakest link. Again, maybe this is all discussed in the article.

Thanks for posting the article

5. I've got a feeling (Jim might pop along and get this bit right), but is it also true that a hand holding a single strand of half rope is stronger than one holding both strands - if only one strand takes the force of the fall? I might have this completely wrong, and it does not feel like that when belaying, but I thought this was true?

This is correct, the tests are posted on MP sonewhere.

Thanks for the participation David and Jim!

The article and the conclusion is all about: "Clip both ropes at the first quick draw – no risk of burning the ropes."
I found that extremely surprising because it differs from the previous doctrine (as far as I know) not to mix double and single technique.

David, the testsetting/assumption was a fixed point belay so weight of the belayer ist not relevant in this case. Apart from the fact that a strong arm is always a plus, I personally don't think that the triceps is  the weakest link here. The hand can move close to the tuber (of course not from above), which  sometimes of course is done intentionally.

Of course there are a lot of things that generally should be taken into account or can help creating more brake force (two carabiner also have been tested;-) but that was not the intention of the article.

Verti Cally wrote:

Thanks for the participation David and Jim!

The article and the conclusion is all about: "Clip both ropes at the first quick draw – no risk of burning the ropes."
I found that extremely surprising because it differs from the previous doctrine (as far as I know) not to mix double and single technique.

David, the testsetting/assumption was a fixed point belay so weight of the belayer ist not relevant in this case. Apart from the fact that a strong arm is always a plus, I personally don't think that the triceps is  the weakest link here. The hand can move close to the tuber (of course not from above), which  sometimes of course is done intentionally.

Of course there are a lot of things that generally should be taken into account or can help creating more brake force (two carabiner also have been tested;-) but that was not the intention of the article.

Yes, the no risk of burning was interesting. Many have thought this for a long time. The reason I think instructors don't recommend it is that it says not to in various bits of manufacturer's instructions and various books. Thus it is hard to recommend something different. And whilst some tests are good, they might not cover all strange possibilities. Hence we are a little bit stuck.

However there was more in the article than the burning issue. I was hampered by not reading German, but it seemed to also be saying that falls with a single strand might be impossible to hold. This might also be true, but to conclude that, one needs to do a realistic test. At the very minimum, if the force is great enough to lift the belayer, the "belayer" must be lifted.

I'm not sure you are right about the arm not being that important. If the arm moves, the rope slides, the peak force is reduced and possibly the fall held. Or if the hand moves far enough to reach the plate, the person is likely to let go, or at least greatly reduce their grip. I find when teaching that with unexpected falls (I teach such that the belayer does not know when the fall might happen, or even see the climber) the arm moves a lot and is the weakest point. Very little rope slides through the hand and the hand moves a lot more.

I would think it might be a good idea to try and repeat some of those falls down the climbing gym and see if you get anything close to the results in the table with respect to holding/not holding on one or two strands.

David Coley wrote:

Yes, the no risk of burning was interesting. Many have thought this for a long time. The reason I think instructors don't recommend it is that it says not to in various bits of manufacturer's instructions and various books. Thus it is hard to recommend something different. And whilst some tests are good, they might not cover all strange possibilities. Hence we are a little bit stuck.

However there was more in the article than the burning issue. I was hampered by not reading German, but it seemed to also be saying that falls with a single strand might be impossible to hold. This might also be true, but to conclude that, one needs to do a realistic test. At the very minimum, if the force is great enough to lift the belayer, the "belayer" must be lifted.

I'm not sure you are right about the arm not being that important. If the arm moves, the rope slides, the peak force is reduced and possibly the fall held. Or if the hand moves far enough to reach the plate, the person is likely to let go, or at least greatly reduce their grip. I find when teaching that with unexpected falls (I teach such that the belayer does not know when the fall might happen, or even see the climber) the arm moves a lot and is the weakest point. Very little rope slides through the hand and the hand moves a lot more.

I would think it might be a good idea to try and repeat some of those falls down the climbing gym and see if you get anything close to the results in the table with respect to holding/not holding on one or two strands.

So what’s the idea? The belayer should hold just the rope clipped to the last piece in event if a fall?

About the arm movement. The Italian Alpine Club found a long time ago that the braking force due to the acceleration of the arm is significant and has the advantage that (in an unexpected fall) it starts before human reflexes can kick in. The movement of the arm in such a fall is thus a benefit rather than a weak point. I attach an image from a power point presentation by CIA showing data with the arm acceleration (inertial), rope slippage through the hand, and no rope slippage phases demarcated.

Tradiban wrote:

So what’s the idea? The belayer should hold just the rope clipped to the last piece in event if a fall?

I theory, yes, if the fall was of such force than they might not otherwise be able to hold it. However this is silly as you will hold the wrong rope, or that piece will fail, and you will need to be holding the other rope.

The thing that is surprising to me is that holding 2 rope feels stronger in the hand, yet apparently isn't.

dave custer wrote:

About the arm movement. The Italian Alpine Club found a long time ago that the braking force due to the acceleration of the arm is significant and has the advantage that (in an unexpected fall) it starts before human reflexes can kick in. The movement of the arm in such a fall is thus a benefit rather than a weak point. I attach an image from a power point presentation by CIA showing data with the arm acceleration (inertial), rope slippage through the hand, and no rope slippage phases demarcated.

That graph is a thing of beauty. Sorry, I possibly gave the wrong impression with the word weak. What I meant is that I don't often see slippage through the hand without the arm moving; but I often see the arm moving, without slippage through the hand, it is in that sense the weaker point.

The graph shows a fall with large forces and is really interesting. The hand moves by around 0.5m? This must mean it went from full extent to right by the plate. I have twice removed someone's hand from the inside of a plate. I would suggest most people don't belay with the hand 0.5m from the plate, more often it is 20cm, or 10cm. Hence a real risk of their hand hitting the plate, at which point holding the fall might be questionable.

The guy was belaying with an HMS on a bolt actually above his head and wearing a thick leather glove, an unlikely scenario at least in my trad climbing circles!

David Coley wrote:

... one needs to do a realistic test. At the very minimum, if the force is great enough to lift the belayer, the "belayer" must be lifted.

No, the idea of fixed point belay is is of course that the belayer ist not lifted. That was the use case and that was checked. Of course you have to do other test setups if you want to test something different. 

David Coley wrote:
...I'm not sure you are right about the arm not being that important. If the arm moves, the rope slides, the peak force is reduced and possibly the fall held... 

Exacly what I said. I said it is not the weakest link and evenen "sometimes of course is done intentionally" (to reduce force of course). 

David Coley wrote:
I would think it might be a good idea to try and repeat some of those falls down the climbing gym and see if you get anything close to the results in the table with respect to holding/not holding on one or two strands.

It was done so.

Verti Cally wrote:

No, the idea of fixed point belay is is of course that the belayer ist not lifted. That was the use case and that was checked. Of course you have to do other test setups if you want to test something different. 

Thanks for that. Does that mean the other conclusions in the work might only be valid for a fixed point belay?

Verti Cally wrote: Yes David, more ore less. Sorry for the misunderstanding and that I have not mentioned the fixed point assumption. Yes the measurements and result values are valid for fixed point belay.

Thanks again. Shame about that, as that is almost never done in most of the world. It would be good to see the work done again with normal, off the harness, belaying, as half ropes are the norm in the UK and as the cliffs small, the ground is often close!

David Coley wrote:

Thanks again. Shame about that, as that is almost never done in most of the world. It would be good to see the work done again with normal, off the harness, belaying, as half ropes are the norm in the UK and as the cliffs small, the ground is often close!

But what is there to learn? Almost every scenario has already been tested and taking a high factor fall directly above a ledge is already known to be bad news. That the braking power is massively reduced when only one strand is loaded has been known for decades.

David Coley wrote:

I theory, yes, if the fall was of such force than they might not otherwise be able to hold it. However this is silly as you will hold the wrong rope, or that piece will fail, and you will need to be holding the other rope.

 I suppose In Theory it might be worth belaying on just the rope through the top runner  whenever the highest runner for the other rope was too low to arrest a fall before hitting the ground/ledge, and leaving one rope temporarily slack. That might be fairly common on single pitch climbs with widely spaced protection and always true before the second rope was clipped to anything.  And it would often be worth clipping both ropes if one thought it wouldn't result in much drag. In a party of three the leader would often be safer with a separate belayer on each rope as the braking force with one slack rope in hand < with both ropes taut in hand< with each strand belayed separately. It would be easier for people unused to handling half ropes too. :)

Note that the entire article is about using fixed-point belays with half ropes. As a more or less dedicated half-rope user, and one interested in the pros and cons of a direct belay off the anchor, I was interested enough in the Bergundsteigen paper to translate the whole thing.  I'm not a German speaker, but found Google Translate to be pretty effective, enough so that I could clean up the language and also rewrite some parts that lacked clarity.  I have an English .pdf version with all the original figures.  If anyone would like to see my English version, send me a DM and I'll email you a copy of what I've got.

rgold wrote:

Note that the entire article is about using fixed-point belays with half ropes. As a more or less dedicated half-rope user, and one interested in the pros and cons of a direct belay off the anchor, I was interested enough in the Bergundsteigen paper to translate the whole thing.  I'm not a German speaker, but found Google Translate to be pretty effective, enough so that I could clean up the language and also rewrite some parts that lacked clarity.  I have an English .pdf version with all the original figures.  If anyone would like to see my English version, send me a DM and I'll email you a copy of what I've got.

Could you post it here instead? That would be much more convenient for everybody, including you.

Jacob Posner wrote:

Could you post it here instead? That would be much more convenient for everybody, including you.

It's a .pdf and I don't have a website I could link from.  I perhaps could put it in a public file in dropbox.  I rather doubt there's going to be much interest, but if I'm inundated with requests maybe I'll do that.

Edit: here is a dropbox link https://www.dropbox.com/sh/oupxjbhn59ysz21/AAB-brfbGHFy3vlfeF5C8LW-a?dl=0 . Tried to make it public. LMK if it doesn't work.

RGold - file was successfully downloaded.

Thank you for this and all your other contributions.

I'd caution that anyone who wants to quote the article should say "as edited and translated by Richard Goldstone" in order not to attribute any infelicity I  (or Google Translate) may have added to the original document.