Belay practice

[sonnylawrence]

Last week we did a short belay workshop wherein 100 kg was dropped one meter. We used 11.6 mm low stretch and 8.5 mm dynamic (high stretch) rope. We used either a Munter or ATC as a belay device. We measured the forces the anchor saw with a dynamometer. A video is at

The Munter allowed very little rope to slip through the belay. The anchor saw a 3 kN load. With an ATC, the rope definitely slipped. Calius’ hand was pulled to the ATC and then rope continued to slip through her hand. The anchor saw 1.7 kN load in that case.

You may ask what relevance this discussion has to canyoneering. The whole concept of low vs. high stretch rope is important. It is relevant when discussing the material a personal tether is made out of. Also you may be tempted to use a canyoneering rope for climbing. In Imlay canyon there is a huge pothole. Some people get past it by climbing up and right. They go around the pothole. There are some anchors up high. Presumably the lead climber is roped up. It is very likely the only type of rope the group has is low stretch. If the lead climber should fall, the potential is present for him or the anchors to see huge forces that could result in a catastrophe. Once, when I climbed around this spot, I had my belayer float in the pool above. He had me on a very loose body belay. If I had fallen, I would have gotten scraped up. Hopefully the rope would have slipped around the belayer and his body would have moved through the water a few inches. Consequently the force of my fall would have been partially dissipated. At least so goes the theory.

I have a belay workshop scheduled for next week. We are rigging the system so the weight is 16 feet above the ground. We will be able to increase the amount of slack in the rope. We will be experiencing forces in the 5 to 8 kN range. If you are interested, go to http://www.meetup.com/ACA-Canyoneeri...ndar/15687436/ for more information.

[Brian in SLC]

The Munter allowed very little rope to slip through the belay. The anchor saw a 3 kN load. With an ATC, the rope definitely slipped. Calius’ hand was pulled to the ATC and then rope continued to slip through her hand. The anchor saw 1.7 kN load in that case.

Unclear what you did. Watched the video. Did you use both the 11.6mm rope and the 8.5mm rope together in the system, with the belayer only handling the 8.5mm rope?

Did the rope always slip with the ATC with everyone? Did everyone use gloves? Were there more than just two test results?

Good stuff, Sonny!

[sonnylawrence]

We were just testing the test gear. We only did a couple iterations. This weekend we will do a lot more runs. The main rope is 11.6 low stretch. We did a few drops with it using a Munter. We then tied a sheep shank with the 8.5 mm dynamic into the 11.6 just to test it on a Munter and ATC. I have done similar tests before with less weight. Results were similar. Munter is an amazing device. When it is all the way closed, virtually no rope slips through. The downside is that the anchor and/or belayer sees a lot of force. In the video of me, I experienced 1.9 kN. I felt it! Calius experienced 3 kN when it lifted her off the deck.

[Scott Card]

Waiting for more....

[ratagonia]

We were just testing the test gear. We only did a couple iterations. This weekend we will do a lot more runs. The main rope is 11.6 low stretch. We did a few drops with it using a Munter. We then tied a sheep shank with the 8.5 mm dynamic into the 11.6 just to test it on a Munter and ATC. I have done similar tests before with less weight. Results were similar. Munter is an amazing device. When it is all the way closed, virtually no rope slips through. The downside is that the anchor and/or belayer sees a lot of force. In the video of me, I experienced 1.9 kN. I felt it! Calius experienced 3 kN when it lifted her off the deck.

Do you get a force v. time graph with that, or only a peak load???

Tom

[sonnylawrence]

The device I have access to only does peak force. However Paul Stovall built a device to sample often and spit out force data over time. Perhaps we can use it in the future.

[Brian in SLC]

Calius experienced 3 kN when it lifted her off the deck.

Immediately following that, she also apparently got to experience a loud guffaw too!

Peak load is great. Be interesting to see a comparison with gloves, no gloves, ATC v ATC XP v ATC guide, maybe compare to a Petzl Reverso 3, etc.

Be great to see or experience. Dang, if I were close, I'd join ya.

[sonnylawrence]

I am not willing to offer my flesh to the belay gods. Been there, done that, got the scars to show. So I use leather gloves. The various devices are worthy of playing with. The primary focus of this workshop is for people to experience catching a fall. The secondary foci are using low vs. high stretch rope and various devices. We will see. I will put together a table of data next week.

[ratagonia]

I am not willing to offer my flesh to the belay gods. Been there, done that, got the scars to show. So I use leather gloves. The various devices are worthy of playing with. The primary focus of this workshop is for people to experience catching a fall. The secondary foci are using low vs. high stretch rope and various devices. We will see. I will put together a table of data next week.

When comparing belay devices, REI does not use a human holding the rope, but a "clamp" (two plates with springs and bolts and stuff) that provides 50 lbs resistance to the rope running through. REI is usually pretty good about sharing technical information. You or Paul might call their lab and see if you can get specs on this, and perhaps some of their data.

Tom

[sonnylawrence]

We held the belay workshop. The weight was 100 kg. The slack in the rope varied from zero to 2 meters. The release point was suspended 5 meters above the ground. We used 11 mm low stretch, 11 mm high stretch, 8.5 mm high stretch and 9 mm low stretch rope. We tried various devices to catch the fall including ATC, ATC XP, ATC guide, Reverso, Reverso 3, Trango Pyramid, Trango Jaws, Gri Gri, Gi Gi, Figure 8, Pirana, Tandem Triple Wrap Prusik (8 mm nylon), VTprusik, Purcell prusik (5 mm nylon), Jumar and Screamer. Typically the anchor experienced 3 to 5 kN peak load with a static system. Dynamic systems revealed peak loads 1.5 to 3 kN. Comments from some participants are listed below along with links to some representative videos.

1) The most important concept I walked away with was why belay technique so important. We are taught belay in TRBC, yet most of us will never experience a real scenario. One can never let their guard down when handling belay.
Use of ATC was also reiterated. Penelope

2) Most people have never experienced catching a full kN load on static rope. Getting hands on experience using various belay devices, or even body belaying is absolutely invaluable. I'll never forget the experience of catching a 1 kN load dropped from two meters on an ATC. Very eye-opening. I strongly suggest anyone who works with static rope, even very occasional, take the Belay Workshop. Dave

3) Sonny, your Belay Workshop Saturday was a real eye opener for me. I had given some, but admittedly little thought, to the impact forces in a belay on the anchor, the belayer, the rope and the person being belayed. I knew climbers used a dynamic rope and canyoneers employed a static or low stretch rope and that was about it.
It was definitely a learning experience to see first hand how the impact forces in a belay varied with how the belayer is anchored (if anchored at all), whether he is sitting or standing, the type of belay brake, the type (dynamic or low stretch) of and diameter of the rope and the amount of slack in the system all effect the outcome.
Additionally I was surprised that I had never thought of the Munter Hitch as a belay break. I knew how to tie a Munter and that it could be used for lowering a person.....and that was it. Also the fact that to lock the Munter one brings the break hand forward as opposed to tube & plate devices where the hand is back to lock off (yes I could of figured this out, but it much better to learn it in a controlled practice situation). Chip

4) Thank you Sonny for a great experience. The most important
thing I learned is the value of anchoring yourself when
belaying someone. I enjoyed hearing the force and distance
numbers and watching others try different techniques. It left
a lasting impression that the force of someone suddenly falling
is very hard to stop, most likely result in both the climber
and the belayer being injured or killed. Anchor, anchor,
anchor! Caryn

5) The most significant thing I got out of the belay workshop, is that
maybe our purcell prusiks don't perform as well as fall-arresters as
we've been led to believe. I'd like to try the same test with a 2-on-1
prusik, and see if it would slide enough to dissipate some energy, or
if it would just slam shut like the first test.
It was interesting to see the actual forces involved in the falls in
proportion to the reported strength of our gear.
The most useful lessons I learned were:
1. If possible, do not insert yourself into the system when belaying a load.
2. Although it will stop you, it won't absorb much energy, so don't
allow much slack when using a purcell prusik as a tether.
3. I wouldn't feel real comfortable belaying a heavy lead-climber on
9mm rope using the Reverso3. Trevor

6) Great learning day! I learned that when using a tandem triple wrap prussic the system is very reliable but not idiot proof. Things happen very quickly when the rope goes under tension. The tactile feel of the prusik should not be ignored and delays in reaction times are a critical consideration. As far as body belays are concerned, they are painful but incredibly enlightening as it brings into consciousness things that are not felt when using a belay device like direction of force and how friction is used to slow and stop a fall. I also have a better understanding of how to organize my belay stance to be safer and more effective. I saw how and gained a feel for how screamers could be used to minimize peak load. Purcell prusik need further investigation. Gloves- always always always wear gloves!!!

7) Knowing how you and your gear will react to a fall is key.
How different market products respond to different rope diameters, and stretches is astonishing. There's alot of gear out there, what really works.
How well a munter worked with smaller diameters than the ATCs was also astonishing.
Like you say when were in the canyons "think of the pull down" when belaying a leader "think of the fall".
What will create friction?
Where will I end up?direction of forces.
Can I create an anchor to better secure myself from a force? Justin

8) What we did on Friday night and what I saw on Saturday really opened my eyes to what can happen if minor changes are made in your rope system. John

http://vimeo.com/18935355
http://vimeo.com/18904344
http://vimeo.com/18904224
http://vimeo.com/18904134
http://vimeo.com/18904034

[Brian in SLC]

Wow, great stuff.

Interesting to hear the take aways. Especially the anchoring the belayer stuff. Anchor best be capable!

Really, in a canyon, especially with non-bolted anchors, how many rock stacks, chockstones, buried twigs, etc, would survive some of these peak loads? And, if folks think they need to be either belaying off the anchor, and/or, tied into it, then, that might be a scary situation.

Severe fall!

Did anyone attempt to hold the fall without being anchored? That would have been interesting.

I can't recall your test set up. Where was the force gage? At/behind the belayer or at the redirect off the weight? Dropping onto a pulley or through a carabiner?

Any attempts at a "soft catch" (ie, stepping forward to reduce peak load)?

Great stuff, Sonny!

[sonnylawrence]

The dynamometer was anchored to the ground. The belayer tied directly into it. An 11 mm low stretch rope ran up over a large pulley to the weight. The rope being tested was tied into the primary rope with a sheet bend. This would allow the experience of say, 8.5 mm high stretch rope with an ATC. It may have only been tried once. The purpose of the event was more for the sake of the individual experiencing a belay, not so much to test gear. There were some experiences worth noting. But keep in mind it takes many trials to have any statistical significance.

Yeap!! We tried not being anchored. John was 5 meters from the drop zone using 11 mm low stretch rope with 1 meter of slack. He simply wrapped the rope around his waist and sat down. I pulled the release cord. Immediately he was flying about 1 1/2 feet above the ground, horizontally. It was a race between him and the 100 kg weight. Just as the weight hit the ground, John slammed into it. He hit soft tissues on his right flank. It took him out of action for many days. He did not get medically examined. Close call for internal injuries. His was the last comment in the list of participants noted above. The next day we placed the belayer 20 meters away from the drop zone. Human anchors were used, they are dynamite. We added one 11 year old plus an adult to the belayer with a 1 meter slack. They did not move very far.
Some observations:
None of the metal devices held the 8.5 mm high stretch rope. (Keep in mind we were set for the best case scenario with the particular device in full friction mode.)
The Trango Jaws held the best of all the tube style devices.
A surprising amount of rope fed through the GriGri. But at least the belayer can let go of it and still have a belay.
The GiGi (not GriGri) was impressive. But one of the new Petzl lightweight Atache style biners took two chunks out of the brand new GiGi.
It was better (goes against intuition) to have a single strand of 8.5 mm high stretch than two strands in an ATC. [Keep in mind this was only tried once.]
Munter was always superior.
Reverso 3 was better than Reverso.
New ATC XP was better than a worn one.
Rich Carlson's VTprusik held the sudden loading with zero meter slack with only 2 cm movement. As the system settled, the anchor saw 1.79 kN. (I view this as pretty good.)
If a person was not tight against the anchor, he/she was jerked around noticeably. The anchor saw far less peak load, for example 1.9 instead of 3 kN. But of course that belayer then felt far more of the force.
With a body belay, belayer tied to the anchor, and zero meters slack in the system, it still hurt the belayer. He did not want to try any slack in the system. He claims in the future he will only use a metal device of some sort or Munter.
One Purcell prusik totally slipped and still resulted in high loads being applied to the anchor.
Two other Purcells did not slip at all with forces up to 4 kN.
Tandem Triple Wrap Prusiks used by SAR teams are very effective. Just don't get even a tiny bit of glove in the wraps.
If you use a tree wrap, bring the rope greater than 360 degrees around the tree and have your hands a meter away from the tree.
ATC guide, not worn, did not perform significantly better than ATC.
Trango Pyramid was fair.
Standard Figure 8 in standard mode was good. Well worth using in the canyon.
Pirana with one ear in use was fair.
We played with a single Screamer and then two in series. I screwed up the dynamometer. Not sure about the two in series. One by itself is not useful.