Is it safe to climb SRT on the Zig Zag with a rope wrench?

Is it safe to use the Petzl Zig Zag in an SRT setup with the Rope Wrench? What is the breaking strength of the Petzl Zig Zag and the Zag Wrench Tether? What forces are exerted on a rope and climber in different kinds of tree climbing accidents? How much force can the human body withstand? Watch this video and hopefully the tests and analyses shown here will help you make your own decisions.
Thanks to Kevin Bingham (www.singingtreedetroit.com) for providing the Rope Wrench used in the pull tests and to Richard Mumford (climbinginnovations.com) for performing the pull tests.
Results of the 7 stress tests shown in this video:
1. Zag Wrench Tether setup (SRT) on Blue Moon rope. ZZ slipped at 1237 pounds
2. Zig Zag in pure SRT setup on Blue Moon. ZZ slipped at 604 pounds
3. Zag Wrench Tether (SRT) setup on Marlow Vega rope. ZZ slipped at 1349 pounds
4. Zig Zag in standard DRT setup on Marlow Vega. ZZ skipped at 1496
5. Zag Wrench Tether (SRT) setup on Marlow Vega rope with alpine butterfly stopper knot. Rope broke at 4995 pounds
6. Zig Zag in standard DRT setup on Blue Moon with alpine butterfly stopper knot. Zig Zag broke apart at 4663 pounds
7. Straight pull test of the Zag Wrench Tether. Tether broke at 5505 pounds
Credits, References, and More information:
1. You can download the Zag Wrench Tether design file or find information on how to buy a Zag Wrench Tether at: www.tree-minded.com/p/tether....
2. The original video showing the Zag Wrench Tether is at: • Zag Wrench Tether
3. More on fall factor from Wikipedia: en.wikipedia.org/wiki/Fall_fa...
4. Richard Goldstone’s paper on deriving and explaining the impact force equation. Contact me for a copy or download the paper for free at: www.rockclimbing.com/cgi-bin/f...
5. Blue moon rope modulus: www.yalecordage.com/custom-and...
6. 67 page paper titled Survivable Impact Forces on Human Body by Harry Crawford. Contact me for a copy of download the paper for free at: www.hse.gov.uk/research/hsl_pd...
7. Pendulum equation derivation: • Horizontal Pendulum & ...
8. More on John Stapp • John Paul Stapp and So...
9. Another video about John Stapp: • MANNED ROCKET SLED RUN
10. Petzl ZigZag certification explanation: www.petzl.com/US/en/Professio...
11. Changes made between the 2013 and 2014 ZZ as a result of the recall: www.petzl.com/security/profes...
12. Johnny Pro's crane swing video: • Crane Swing
13. Results of side impact testing on the Zig Zag: www.petzl.com/US/en/Professio...

[@TreeCutterDoug]

Damn bro... You scienced the shit out of it.

[@remingtonsawdust8046]

This...is...gold!!! I can't be the only one who's been waiting to hear this stuff. Excellent presentation!

[@WestonDeutschlander]

Absolutely incredible, thank you so much for taking the time and effort to do all those tests, calculations and research. Bravo!

[@65BAJA]

Damn. That was ...Very informative. Thank you for all the work you put into this video.

[@skclimb]

Thank you Patrick for being so thorough and covering all of these scenarios. Great video!

[@phillipdolliverjr.8656]

This was an awesome video, thank you for putting all the time and products into it. I was stuck to it and watched the entire video start to finish.

[@willriseley]

Thanks guys for making that. Really put my mind at ease and great explanations of fall factors

[@psidvicious]

Very comprehensive testing. Nice work! 🤜🤛

[@Atimonster]

it's really amazing the amount of work you have put in to this. now i am even more excited to receive my tether.

[@gschgvt2956]

A HUGE thank you to you, Mumford, and Bingham for collaborating on this. I, like many others, have been waiting for something official like this for quite some time. I now feel even safer on my ZZ in either setup knowing it’ll most likely slip and not fail catastrophically as long as my TIP doesn’t break.

[@Brian-Outdoors]

This is a great video that I am sure required a great amount of your time to make. Thank you so much!

[@jolkraeremeark6949]

Great content, thanks for all you've done! I have not tried my zz yet, but will try double rope first and move on from there.

[@joshmullinnex5113]

I love the zig zag and have been hesitant to use SRS. Thanks for the detailed info!

[@Joesdifferent]

Every time I recommend your product my recommendation always comes from the exact thing you have just explained in this video. You are very educated on the background of every scenario in this video you have done the study time and I appreciate all of the time you have taken him have given back

[@tomplucknette5941]

Thank you for all of your research regarding these products as they pertain to SRT!

[@jonboy215]

Anyone can tell that lots of time, brain power, and effort went into the making of this video. Phenomenal job!!!

[@cbrackin531]

thanks for the info. This is very good info to know. thank you for putting out the effort to put out this video for us.

[@alltree78]

Thank you. This answered all questions that are in the back of every climbers mind. Not just about the zig zag but about rope and force and all kinds of stuff lol.

[@jodygucwa8892]

Great video. Very well done.

[@climbe4422]

Thank you for making this excellent video.

[@dmanstasiu]

Wow. Thank you for the amazing research, for your time preparing this video and for sacrificing beautiful gear in the name of science. I’m sharing your results with my colleagues hoping to stir some discussion.

[@victoriousvictor7978]

This is awesome. Thanks a billion for this video buddy. This almost fully convinces me to get a zag now.

[@proxy7863]

Do it Victor, they best device for srt and drt :-)

[@gregbrown9271]

Vic where you been and how the hell are yah man

[@kplandscapinglawncare563]

This was very informative thank you for putting this together.

[@Billster1955]

Wow! Now that was a thorough test. Thank you.

[@southerntasclimbers7271]

This was Bloody Awesome and Very educational.... a must watch.!!!

[@chrisgodinez2568]

Wow. That was very informative and puts to rest some of my concerns with the Petzl zigzag. Thank you.

[@delroybaggins8680]

I'm so glad to find this vid. Amazing information. Thanks

[@keithklassen5320]

I like what you're doing, and I'm even more convinced that the Zig-Zag/rope wrench combo is safe in SRT, BUT! I do disagree with your conclusion that during a bad fall, a shock load that would otherwise break the rope would instead be dissipated by the slippage of the Zig-Zag. Or rather, that may be true, but I don't think that your tests were sufficient to prove it. A load that is applied slowly and evenly, like in your test, is likely to provoke a very different reaction than the kind of dynamic shock load produced by a fall. In any case, this is great research and is much appreciated.

[@jeffweaver5728]

I agree with this thought, sudden intense force, could cause the zigzag to jam onto the rope, but it's hard to imagine it would exceed 12kn... More tests, more videos we will watch...

[@mickduprez9598]

@@jeffweaver5728 I think we also need to consider the elongation factor of the rope to dissipate some of the 'snap' shock load at which time the zz could start slipping(?)

[@GrouseHiker]

Good stuff Patrick! That was a pretty exhaustive study. Your explanation free-fall effects was very enlightening. Your Tether only sees the load taken by the Wrench (maybe 40%-60% of climber weight?), so it's VERY strong for this application.

[@Hp2G1]

Great video! You did an outstanding research and clear presentation job! As stated below, you answered many questions that are in the back of climbers mind. You convince me to buy a Zigzag. I have the first version of the Rope Wrench. I will check to see if it is compatible with the Zag Wrench Tether, and if it is, will order one. A HUGE thanks to you guys!

[@NHlocal]

Very well explained Patrick. I have a ZigZag and have been wanting to set it up in an SRT system but of course I'm concerned about safety. After watching the video how could anyone argue against using the ZigZag in an SRT system??? Thanks for all the time and effort you put into testing/proving what a lot of us already knew. Be safe! Randy

[@justinmcnulty601]

Wow that was crazy informative, good stuff!!

[@cannonball9478]

Thanks v much for doing this. Really appreciated

[@dqmc07]

And how right you are seeing Petzl came out with the chicane, and backed up all your evidence, well done. God bless.

[@mvblitzyo]

That was an amazing video thank you so much !! I purchase my zigzag tether a few years ago and my coworkers love it ! And yes it is paired A singing rope tree 😉

[@tomwilson8190]

Thanks for the effort put in for this video. Very clear and informative. Would be interesting to see the tests when using a stiff rope tethether.

[@sjbrandt5792]

Strong work man! Nice to see a fellow climber who's concerned about safety.

[@PatrickBrandt]

You crack me up, Sarah Joy :)

[@mreggbird]

This was very interesting! Thank you

[@brayanamador14]

This video is really awesome demonstrating these tests is inspiring for me to try the zigzag with a stiff Tether

[@eliseo3500]

Amazing data. Good job

[@mute7116]

Nicely done. Thank you.

[@Cholton327]

Awesome vid dude. Just awesome

[@johncitizen3227]

Awesomely done!🙌👍 great vid.

[@larryhill5649]

Absolutely awesome insights and info. Thx so much.

[@ALTN8NRG]

Great demo! I learned a lot.

[@tomjaworskininja]

One of the best videos on KZbin, supported by scientific proof not someone else feelings or believes. Thak you and keep UP good work with more videos like that one 👌👍

[@charliearbor3387]

Good stuff thanks for the info.

[@neightjay]

Nicely done. Thanks for the knowledge. 👍🏼🇨🇦

[@ryanward8117]

great analysis!

[@andrehak]

This is epic. Thanks man!

[@xxstreme]

very great information. thanks very much for this video

[@johnbray614]

that was an absolutely fantastic video... i wish i would have watched that before beginning climbing... i would have been way less worried about my equipment failing

[@tbowen83]

That's my photo of the 2019 Zigzag at the start of the video! Will give it a watch in full when the kids go to bed!

[@PatrickBrandt]

Nice. That photo was the first one I saw of the ZZ+. Have you climbed much on it?

[@tbowen83]

@@PatrickBrandt Not that version as it was being shown off at a trade show. Climbed a bit on the Old Zigzag

[@sampatterson7749]

Great presentation

[@derek5463]

Love the video. Glad to see the science explained behind the theory. The human body will fail long before our equipment.

[@1underwaterant]

Fantastic explanation. From a Mechanical Engineering perspective, I'm impressed. Guys, remember that the Yield point of a rope is the point that it has lost it's Elasticity and cannot keep it's Strength. After it goes past it's Yield point ( The Point of No Return), it will gradually keep stretching until Failure at it's Breaking point.

[@plmengineer9238]

To reiterate what others have said, thank you so much for making this video. Clears up the functional and safety concerns regarding the Zig Zag plus in an SRT configuration and your scientific assessments leave no stone unturned. Wouldn't surprise me if Petzl proffered this video in promotion of the Zig Zag. Wish videos with this level of detail existed for many other arb products. Many thanks again 👏👍

[@Rucksack57]

I love my Zigag I use a little foot locking on the way down if I feel the need. The only thing I don't like is that it is not mid line attachable. I have recently bought the Unicender which I attached Richard Mumford"s drum to It makes the Unicender a great tool. I have put my order in for the Akimbo. all great products. Petzel has done a great job. I do like my Zigzag and the Petzel Products. Thank you ever one for your hard work making rope climbing safe.

[@crowtjenr1]

Thanks for crunching the numbers! Glad to see the ZigZag will start to slip to prevent any serious structural damage. And that it can exceed it's limit of 15KN, with a whopping 7,4KN before breaking in the second test at 5,5KN above it's limit! A bit bummed though to see a climbing line which should handle 24KN, break already at 22,4KN that should well be within it's limit!

[@1bottlefed]

Great vid....Thanks, to you Patrick as well as the rest of the group. Super generous of Kevin to supply the ZZ and Richard to supply the time on his test bench as he so often does with random peoples splices. PS, Would love to see a follow up with some static drops of 180 lb rounds to see if the ZZ tether RR combo dissipates force at the same rate when stopping a high speed drop as it does under a steady state hydraulic pull

[@PatrickBrandt]

That would be a nice test, but it is not in the plans right now. I agree that it would be good to see how far the ZZ actually slides under various fall factor scenarios.

[@LifeOnLine40]

Who in their right mind put a thumbs down to this video? That has got to be the best work I've seen to Answer so many unanswered questions!

[@eudesmatos4417]

Excelente trabalho de conscientização gostei muito obrigado

[@Rucksack57]

thank you for all your time and hard work. My 190 lbs should be fine on my Zigazag. I am not paying $200 more dollars for the aluminum tether.

[@PatrickBrandt]

The tether isn't $200 - it's $74 - but there are lots of ways to climb without buying an aluminum tether if its not your thing.

[@michaelalter2912]

I find it absolutely Ludicrous to charge $200+ for an aluminum tether as others are asking! I Love my tree-minded tether! Thank you Patrick!

[@PatrickBrandt]

My pleasure. I'm glad you are enjoying it!

[@larryd3403]

great video, thank you!

[@2-4outdooradventure53]

great video!

[@Ithzzz]

First off really good video and you made some really interesting points about how and when a potentially deadly force would be applied to the climber. I recently started climbing SRT with the ZigZag and Chicane thou I did not know about this device before I got the chicane thou it dose not flop around at all as you assum in the video. I put up a video on my channel to demonstrate.

[@mayconflores2430]

Good information

[@IgorLukyanov]

Great study. Very useful. Тhank!

[@fustratedfisher]

I have used my zig zag 4_5 times a week for the last two years and it's still going strong. Never slips And I climb in the rain wich I have confidence in all my gear. No worries it's a great addition to a climbers gear bag. The singing tree is a great piece of gear for srt also

[@seamuspurcell5065]

good work

[@Rucksack57]

When you are up a pitchy tree like a pine you will love the Zigzag and the Zillon lanyard prusic. When it comes clean up time they are easy. When your prusic becomes glued to your lanyard or rope then you will realize the that mecanicle prusic's work in the pine trees.

[@danhenderson783]

West Coast True firs ( White, Red etc.) can be extremely sticky when it's warm. Prusik hitches become useless when they sick to the rope

[@turtlezed]

Very interesting post....Its reassuring to know the zigzag by design slippage is helping to lessen the shock......with the ball swivel breaking away, it definitely reasserts the instruction to scrap your kit after a big overload event........cos how many would say' hmmm it looks ok, I might just keep using it' ...?1?

[@davyoh8986]

A thousand thank you's..

[@sionwright3570]

you are assuming that the slippage would be the same in a shock load scenario as to when force is gradually applied like in the test. very good video!

[@keevinrassi7010]

How about a uni and various prusik knot configurations? Can we get a full comparison of a variety of the different options that are available? This is great info and would like to see more :)

[@lucfournier3939]

Great explaination thanks for effort put in the content

[@aliray1165]

17:27 this happened to me two weeks ago. I fell 30ft vertical drop until my rope tightened up from the 15ft difference. Scared the shit out of me but I hit the ground so lightly with the stretch in the rope I was unhurt. Total lucky escape!

[@mohdtamizi9832]

Very nice and power tq

[@callummackenzie9040]

Have sat and watched a 2019 zig zag 9.5 inch tethered rope wrench combo, with 11.8mm drenaline, lower me like a figure 8 ... still use it ... best combo.

[@sawdogluke9636]

This is such an awesome video thank you man! My paranoia gets crazy at times and I often think “how strong is my zig zag really” “will this mechanical man made device fail me” haha This video gives me some reassurance!!... just a little lol thanks again!

[@Rucksack57]

Just bought the Petzel Zillon for my landyard because of the sap from pine trees. My Prusics kept locking up due to the pitch or sap of the pine trees.

[@BTrout150]

I love the research done! My only question I felt was missed was the strengh of the zig zag if side loaded.. The only reason I have yet to purchase a zig zag is due to this reason. I fell like this is a very possible thing to do on a natural redirect, a swing back into the side of a limb due to a slip fall etc. Even leaning around a large spar pushing/pulling against a old wound, previous collar cut, etc. to maintain good body position to make a nice collar cut on a large limb. Whats your thoughts or feelings on this?

[@PatrickBrandt]

Thanks BTrout. Petzl did some tests related to a side impact swing. They showed that the links held a force of 8kN in a side loaded setup and did not break. They did a simulated swinging impact with a 100kg weight smashing into a steel beam. The zig zag links did not break under that force either. Maybe you've already seen the technical notice, but if not you can read about it at: www.petzl.com/US/en/Professional/Torsion-on-the-ZIGZAG-and-ZILLON-chain

[@jbcardin]

Great video. Thanks! I went to your site and it seems you're no longer making the zagwrench. Why did you choose to not make any more? Thanks again.

[@jackberdine]

Thanks ! Awesome to know that my zig zag won’t break my rope and won’t break unless I do something very wrong.

[@slmlawncare7077]

Scienced the $@$@? Out of it but thanks answered alot of questions ans helped make mind up for srt setup 👍💪💪💯

[@carlosperez4032]

Thanks for your valuable info..where did you get your aluminum tether for zig zag

[@vipero00]

13:12 use "k" on your pc keyboard to stop/start and use "," and "." to step frame by frame. Amazing

[@kodyray6077]

Patric any way you could do similar testing in popular unicender set ups please ?

[@jasonblanton7185]

I sure wish someone would send me a zigzag and a rope wrench, Im restricted to just using a friction hitch by itself simply because I can't aford to purchase the proper equipment ,but hey at least I dont let that stop me ,,its just not as easy and not as fun ,and alot more dangerous.....anyway I love the video ,I am sure it has eased alot of minds in the field and its very important to be able to know you can trust your equipment ,and this video has assured me that my rope isnt going to break on me ... thanks.. Also it looks like it is easier to climb with that type equipment, I have to use spikes because it's very hard to climb for me with just a simple friction presic without using the spikes,, wonder why that is ..

[@ArboristUk]

Petzl reps are the worst, no product familiarity. No you cannot use the Chicane with the 2014 zig zag. The new zig zag, has a stronger swivel, thicker side plates, stronger links, repositioned links offset of the pulley to improve rope angle in single leg configuration. Regardless the original 2014 zigzag is still fit for use in single leg work positioning in my opinion. Great video by the way, nicely presented.

[@PatrickBrandt]

This rep seems pretty in the know, but I have talked to a few others that gave contradicting information. If Petzl sells the Chicane separately what is stopping a climber from using it on the 2014 version? Have you heard that Petzl is going to advise against using the Chicane with the 2014 ZZ?

[@ArboristUk]

Patrick Brandt yes it is specifically designed in conjunction with the new zigzag, you also mention it is floppy indicating it will pivot around the attachment holes on the handle and zigzag respectively this is also not the case it is rigid and designed to work with only two carabiners, the OK and AM’d another reason why it will not be compatible due to the design of the attachment hole on the zigzag itself..

[@obamagaming5754]

Does anyone have any idea if a rope wrench with a ART lockjack for SRT would work? Thanks for the great video!!

[@parrishcooper2818]

Great video. Could the climber not reach a fall factor 2 though if they canopy anchored, climbed one metre above tie in point and then fell? 2/1 = ff2

[@PatrickBrandt]

Great point. Yes you are right - that would also be a fall factor of 2. Thanks for the comment.

[@jsherwood4665]

I would love to see the same test hooked to a live tree limb as the anchor point to see what fails first lol

[@Treeesmith]

I like that it slips and doesn't just bind and break

[@br-dj2ti]

Hey buddy another question for you I have the older style zigzag I think I bought it in 2016 I didn't use it too much now I have the 2000 I believe 20 the bigger one that came out recently do you think if my one from 2016 sat for two or three years and I didn't use it do you think it's safe to use if I start using it now

[@andersprytz8119]

Great video! Do you think the zigzag would act differently than slipping, if the force applied is "shock loaded" i.e. a free falling climber, instead of a consistent pull, like Richards machine?

[@PatrickBrandt]

That's a good question. Here's my opinion for whatever it's worth. There is enough stretch even in arborist ropes that the rope stretch would dissipate a lot of the immediate shock load of a falling climber. After the rope stretches, my prediction is that the ZZ links will slip at about the same force seen in the lab testing with Richard's machine.

[@andersprytz8119]

Thank you for answering. Yeah that was my thought too. Just wondering if you had tested that scenario. I guess the human body would give up before the gear anyway?

[@br-dj2ti]

I think it was one of your videos you said you had diagrams for the rope wrench to be made if so can you please tell me where to get them diagrams at

[@PatrickBrandt]

You can download the tether design file from my website: www.tree-minded.com/p/tether.html

[@billbliss2500]

I'd like to know how you climbed that rope so fast?

[@adamcastro8497]

Patrick are u still climbing on this system? How long has it been now on the same zig zag with zag wrench tether ?

[@jeffweaver5728]

Is there a video comparing different composition hitch cords and different hitches tied on different ropes? If not I might've just gotten some youtuber a million views... I wiild be interested to see that..