Does PURCELL PRUSSIK save you If you fall on an ASCENDER???

Does a purcell prusik shock absorb enough as a personal lanyard to prevent an ascender from desheathing a climbing rope if you were to take a short fall while passing an obstacle? A little is the answer but 1/2" ropes are so burly that they won't desheath even with a static sling in our tests. However, your spine may not appreciate 5kN+ so just don't fall.
1/2" rope with purcell - 4.10kN - Did NOT desheath - purcell slipped half way
1/2" rope with purcell - 5.18kN - Did NOT desheath - purcell slipped half way
8mm rope with purcell - 5.36kN - Did NOT desheath - purcell slipped a little
8mm rope with dyneema sling - 5.69kN - Rope Desheathed!
1/2" rope with dyneema sling - 5.8kN - Did NOT desheath
Our guest: Matt O’Donnell from Ebbetts Pass Fire District - [e-mail]
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Intro
02:32 Example of concern
07:07 1st Test
09:24 - 2nd Test
09:55 - 3rd Test
12:08 - 4th Test
13:08 - 5th Test

[@HowNOT2]

You can get the SPLAT shirt that Decker is wearing at www.hownot2.com/swag Check out our new store! hownot2.store/

[@tehrater480]

Looks like Bobby let the Mythbusters influence shine through at 5:48 ! Calling him Buster instead of Decker, I love that

[@HowNOT2]

Wow, i missed that and i've watched this at least 12x

[@plastikmaiden]

Thanks for all the testing!

[@Michaelzehr]

I am well past my climbing (or rescue) days, but have been enjoying your channel and all the tests you do - thanks for all the info you put out to the community.

[@Dexter_Morgan.]

I always love seeing your break testing videos keep up the awesome work guys 👍

[@panubrodkin7107]

It would be interesting to see other adjustable lanyards, such as Petzl Adjust, Camp Swing, CT Tuner and Gong Slyde etc., tested as well.

[@HowNOT2]

Yea, I want to test all personal anchors and lanyards apples for apples

[@skylarmerritt3590]

Matt is awesome! One of the best instructors I've ever had!

[@no1EvilMinion]

Yesss i wanted to know this for ageeees. Cool video, thanks ryan.

[@cmeister1265]

heard someone talking about this in a background video a while ago, glad to see it

[@zacharyh.4892]

Thank you for doing what you do!

[@dirtydogvideo]

good stuff. it would be cool to see the breaking strength of the ropes that were damaged.

[@feluver]

One more data point would be very useful: compare with a fall onto a full strength piece of dynamic rope (8.9-9.2mm). Most of my team runs dynamic cowtails (like a caver's setup) and it would be awesome to see the comparison of absorption between the Purcell and the dynamic landyard. I see another comment that seems to be asking about making a Purcell from dynamic cordage, but I have never seen that in the wild.

[@feluver]

The dynamic cord should protect your pelvis, but will it protect the sheath?

[@HowNOT2]

Testing dynamic cows tails vs other lanyards is a good idea

[@mattodonnell3571]

The Dynamic lanyards seem like a good idea and I would love to see a side-by-side test. We use them on the top ascender to make adjustments between individuals easy. That said, based upon their length, the overall load limiting on them should be pretty minimal compared to a purcell slipping over a longer length, which is why we use the purcells on the lower. I'll bring both next time Ryan and we can find out!

[@timonix2]

I have seen enough ropes being de-sheathed on youtube that I buy unicore ropes now. It just seems spooky to me that I could hit the ground on a fall as low as 3kn because the rope failed.

[@shoqed]

Lol you can still desheathe a unicore rope, it only eliminates sheath slippage

[@BatmanProject777]

Crossloading a carabiner can happen way too easily for how little talk about it there seems to be....and is something that can break a binder and drop ya, where a damaged sheath may not be as quick of a full on disaster, by comparison anyway.

[@ClimbingEasy]

5:50 I see bobby is a fan of the myth busters as well 😏

[@juanmckelvey]

Love the rescue content!

[@effyoo6081]

112k. creeping up slowly. wish u had a million

[@HowNOT2]

Growth slowed way down. I think the big wall course will help though.

[@tommasomainiero2538]

super cool video!!! i'm really curious to know how to rescue him easily with this distance between him and the toothed device. I think it will be probably more difficult than the usual method. thanks a lot for yuor work and for the passion you put in it

[@HomeDepotJunkies]

Hi! I’ve been watching your videos for about a year and a half now. I don’t even climb (yet) but I just love the content and breaking things + numbers comparisons is just cool. I have a request, in the military we are issued rigger belts similar to the Wolf tactical belts. I have been trained multiple times that in a pinch you can use just your belt to repel or hook into a safety device in lieu of a harness, which is why we are issued them. I have seen videos also demonstrating that they can be used to repel if need be. After watching enough of your vids I am very aware that everything has a breaking point, and trusting a manufacturer isn’t always enough to keep you alive. I’d love to send you a couple of the ones we get issued and have you try break test them and see if they are indeed suitable. The military uses many rope systems and slings, there might be another area for you to expand into! I hope to see them on your channel soon!

[@JZ909]

I was issued a heavy duty belt like that too, complete with a metal piece that you could attach a carabineer to. I always felt that if you used one of those for rappelling, you would get the world's biggest wedgie, your pants would rip, and then the belt would go up to your armpits. I live in the Seattle area and would be willing to sacrifice my old military belt if you want to do some testing.

[@timeorspace]

While shopping for gear I've often seen purcell prussiks and I finally know why they exist. Thank You!

[@timeorspace]

Also, I'm tinkering with arborist gear in my garage and just obtained my first set of ascenders this month, so I appreciate the image of a stripped sheath that is now burned into my memory.

[@adamreynolds3863]

Very cool and interesting video! i love these experiments on the drop tower. it "feels" more intuitive when you can actually see what is happening and where. keep up the awesome content guys

[@leviy.3578]

This was a very cool video. Being a part of a rescue organization stuff has to be NFPA certified and we cant budge from that or else its opening up a can of worms. It makes the equipment we are allowed to ascend/descend with very limited. Very interesting content. Thanks!

[@radostwaszkiewicz4982]

I'm a caver an when we put a knot-pass we make a loop hanging from the knot so that you can clip into it with a lanyard when transferring across the knot.

[@HowNOT2]

Yea, I was at risk of falling on ascenders when i was caving and passing Y hang or J hang rebelays.

[@M1American]

Thats one method of many, of course. But with speed in mind the hand ascender moves over faster then tying a knot in. Although I do see your method used at times.

[@radostwaszkiewicz4982]

@@M1American I think, I must've explained it badly. The initial rigger (who decided that knot-pass is necessary) puts in a knot like in this figure: verticalsection.caves.org/nh/46/srt-knot.jpg. Everyone else just clips in when passing it - the extra time is really minimal, but it allows for resting and we avoid having single attachment point very hard.

[@radostwaszkiewicz4982]

@@HowNOT2 It sometimes happens in sloppy 'expedition' rigging :( What makes the biggest difference for me is using fusion knot Y-hangs instead of the more popular fig8 + alpine butterfly Y-hangs. With fusion continuation above starts right at the knot making transitions faster and safer.

[@ThorLarsen]

I would think that even a Purcell Prussik on a bigger rope would be a throw away... as the heat in the coils will always increase, as it is sliding down the rope that only seen transient heat. I'm surprised that it doesn't melt even more. Thank you for the great tests (as always).

[@kmacdough]

Why not just use a screamer if it's sacrificial anyway? They have much more reliable/consistent force distribution than any friction knot.

[@mischavanengelen5343]

So, in stead of a ascender, what if you would use a petzl shunt as a capture/load limiter? It sort of acts as a ascender, but works with a cam (almost like a grigri), in stead of teeth. Keep up the great work educating the community!

[@Papershields001]

I’ve always wondered what the shock load conditions of a fall on Everest would be. Those guys will fall onto Jumars and that always seemed a little sketchy to me.

[@xamtest3366]

It would be awesome to see rope solo systems shock loaded on the drop tower. I use a locker draw connected to my harness with a micro traction on top and then a rope man on the bottom so it’s somewhat redundant. But it’s likely to take a small top rope whip that could de sheath the rope and that worries me a lot when I rope solo

[@JoshBrown-nt1xn]

Would love to see you test the limitations of various rope solo set ups!

[@HowNOT2]

It will happen. We did try to desheath a micro traxion with my body. My body said nope after 4.5kn so I'll have to use decker to finish that episode

[@tehrater480]

@@HowNOT2 Can't wait for this!!!

[@teddyruxpin3811]

Hey Ryan, you should do a collab with the "primitive technology" youtube channel and break test some of his primitively made ropes. He makes some weird rope from bark, just like ancient cultures used to do. Probably not practical for anything but it would be interesting and entertaining nonetheless.

[@kolinpauli5862]

I wonder when ascenders start to slip on Unicore rope since the sheath is bonded to the core, would like to see a test!

[@paddymalley8077]

Have you ever tested falls on a petzl shunt and its effect on the rope ?

[@xxstreme]

7:40 hello can you gave me brand or type or series for machine use with pulling rope up

[@n0pe213]

Awesome Ryan thank you! I use a petzl ascension and a micro traxion as my Top rope solo setup like petzl recommends. Did not realize it could desheath as low as 2kn (I use each device on a separate line). Would love to see some TRS setups tested as there are many different methods with little actual research. Last night I was TRS when I took a fall and the Biner on my micro cross loaded the screw gate went into the the hole separating the orange metal plate of the micro, my secondary (ascension) caught me. Would really love to know how close I am to 2kn on that. Are clamp style devices safer?

[@HowNOT2]

wow, that's crazy. I took a 20 foot whipper on a 40 foot piece of rope (0.5ff) on a micro traxion installed at anchor like a top rope belay device simulating someone not belaying tight or slack in a simul scenario. Did not desheath my rope at 4.5kn. I'll have to use decker to figure it out as my body doesn't want to do that test again :)

[@tehrater480]

Thats crazy! You should post some pictures and a detailed explanation somewhere so toher TR Soloers can learn from that!

[@n0pe213]

@@tehrater480 definitely gave me some willies. I’ll try to recreate what happened so I can show, shoulda taken pics when it happened. I was using a Petzl OK biner from the micro to a sling on my hard points. Then a sling around my neck attached by a non locker to the OK biner. I had been noticing it was cross loading when climbing but didn’t think I was gonna put 7kn on it so wasn’t super worried. Everything would have been fine if it wasn’t the actual screw part of the locker that got ripped through the micro, the screw is what popped the orange plate apart. I’m gonna try using a gridlock with the small side on the micro to keep it aligned.

[@randomizednamme]

I have basically the same setup but I use the ascension as the primary. What carabiner were you using on the microtrax? I’ve found that if you don’t pick the right one it can jam (the carabiner not the cam) while cross loaded.

[@n0pe213]

@@HowNOT2 that’s good info thank you! I think what happened with me was a bit of an anomaly since if it wasn’t the screw gate side that got ripped through the micro everything would have been fine. I’m gonna try using a grid lock with the micro on the small side to keep everything aligned. I hope my description is enough to picture what happened, and any advice would be appreciated! I could imagine like a factor 1.5 fall onto your backup but thankfully my backup was pretty taught

[@JZ909]

It may not be entirely necessary for this application, but different material for that purcell may be worth considering if melting is a concern. Even if I'm not planning on taking a fall, I'd rather have a system where I can take a fall and be able to descend rather than take a fall and be stuck in my harness at height because of some melted rope. There are plenty of ropes that are nigh unmeltable and relatively cheap, at least when you're talking about just a handful of feet of rope.

[@AnonymousOtters]

It would be cool to see a similar setup with a follower belayed from the top on a Micro-Traxion. I keep seeing this pop up with mostly new climbers on multi-pitchs and it looks scary AF. Petzl says it can de-sheath the rope with as little as a 1m fall, with anything bigger causing core damage. Confirm?

[@thelast929]

What type/brand is that 1/2” orange line? It looks just like the Teufelberger KM III that I use.

[@danp2509]

Could you guys test mammut's integrated harness climbing shorts Vs a normal harness

[@ASR_385]

As Matt mentioned, the assumption is the fire fighters are heavy, especially with all the crazy equipment they carry around. 150lbs seems a bit on the light side for testing this given the subjects might be 200lbs to start, and have 50lbs+ of gear. Is the increase in weight something that you all thought would not significantly change the results? Maybe you need a "double decker"

[@HowNOT2]

Future tests I will consider adding more weight. 300lbs is what i want but moving it around is very difficult and way more aggressive in the falling and landing. Basically it's like slack snapping things above 90kn... it becomes 10x harder to 2x the force or the weight in this case, but yea... i'll explore more sustainably heavier dummy

[@ASR_385]

@@HowNOT2 I saw "Rescue Randy Large Body Manikin (250 Lb.)" on Amazon. Wow is it expensive. Supersack with Sand seems more viable. Maybe triple layered to keep it from ripping. Perhaps a swinging boom/builders hoist mounted up high with a remote controlled winch would simplify things. Although again, expensive. Thanks for all the work!

[@TheRopeAccessChannel]

Awesome video and exactly the stuff I am interested in. Except for the 12mm rope part, thats a bit too burly for my line or work😉😉. If you get the chance using 11 or 10,5 would be great for rope access tests. And by all means, plug away! Like you say, free content is not free to make👍🏻

[@HowNOT2]

This could be worth doing again and doing 6mm all the way back up to 12mm but actually desheath it and see what each one takes

[@TheRopeAccessChannel]

@@HowNOT2 To make it more challenging add different ascenders to the mix as well... Not all teeth are created equal. Some brands have "sharper" teeth than others. That should also make a difference. I mean, you probably don't have enough time already so why not triple or quadruple the number of tests with 3 or 4 different ascenders 😜😜😂👊🏻

[@drthik1]

Would be interesting to see how much gforce is generated in these drop tests, perhaps that could be another data point to add to future tests

[@geoninja8971]

F=ma..... the strain gauges are measuring force (F), just divide by the mass being dropped - this gives the acceleration, which is what g-forces refer to...

[@cohesive3482]

Any chance you can help me choosing the right prusik length for my system? I SRT climb for saddle hunting and want to add a little redundancy with this setup. Im trying to figure how long of a loop to get to end up with the system being 12" long when fully collapsed and ready to use. Any longer and I feel there would be too much slack in the system. Im using a 12" nylon sling now, but really like the slipping feature of this setup.

[@NPC-fl3gq]

What about using a Kong Kisa instead!? It's probably be more consistent.

[@Alvinyokatori]

Well it does seem effective

[@Smile-hp1xg]

Have y’all seen a rope runner pro or a akimbo? Look into tree trimming gear some

[@dragade101]

Its why you want and need backups. Say never to fall on your ascender / how to fall 'safer' on your ascender

[@MrBlablubb33]

Could you do a reaction video to this one, explaining all the potential forces and breaking points? kzbin.info/www/bejne/jmTJq2mHiph8Z5I There's so much sketchy stuff going on I stopped counting. Bonus factor >2 fall on slings included.

[@dodsg]

What's the foot loop chain on the lower ascender? Looks more versatile than the single end loop straps I'm used to.

[@WranglerTJ24]

It's an etrier (pronounced aye-tree-aye). Popular in rope access and rescue. Just extra flexibility, like a little webbing ladder.

[@angrybirder9983]

If the Purcell gets welded together after a fall anyway, couldn't you use a webbing energy absorber (like those on modern via ferrata sets)? Sure, that's more expensive, but via ferrata equipment has moved away from rope friction based shock absorbers for a reason.

[@andrewhunter6536]

Would the intermediate 2kn stitching on a normal daisy chain also absorb shock like that? Assuming you don’t clip the daisy in the way you can die

[@HowNOT2]

I definitely want to test that. Just put it on the list.

[@davit1]

I might have missed it. But size cord was the Purcell Prusik that was drop tested?

[@HowNOT2]

6mm static accessory cord

[@piman3072]

I assume it was static cord on the purcell? Have you tested static vs dynamic, 7 vs 8mm cord for the lanyard?

[@HowNOT2]

Yes, 6mm static accessory cord. I have not done too many other lanyard tests

[@grigorypostnikov9319]

Good idea! The system should be even more safe with dynamic cord.

[@piman3072]

@@HowNOT2 I think there's a lot more value in testing those homebrew systems like DIY lanyards and the splice tests you did recently, and gear being used "incorrectly," like the carabineer over the edge tests, than another carabineer chain link showdown. Tied my own Purcell after being disillusioned with every store made lanyard 😂

[@M1American]

@@HowNOT2 you sure it was 6mm on that purcell not 8mm?

[@wakinguptooearly]

7:35 - "Man, Decker, you really carry a lot!! 😏" \*zooms in, scene cuts\* Edit: on another note, thank you for these videos. I think everyone has those questions of "whatifs", and so definitely appreciate you doing these empirical tests haha

[@Alvinyokatori]

Why not just use a shock absorbing lanyard or dynamic rope tied into a loop

[@yair3k]

What size snap shackle did you use I have seen some on Amazon but look to small for a carabiner was wondering what size you have?

[@bobbyhutton1989]

It is a Wichard quick release. They make a variety of sizes. Just check the dimensions and load rating before you order.

[@mattbaker1683]

Get a skydiving 3 ring system for the release, so much better for this kind of thing.

[@timkirkpatrick9155]

And that is why arborists use a prussik with ascenders on SRS.

[@sstorholm]

I wonder if a dyneema Purcell would perform better, the line itself would be very static, but it has better heat performance and less friction so it’s less likely to melt together.

[@HowNOT2]

Dyneema has a lower melting point but it's so slippery that it doesn't generate the heat like you said so it probably would melt but its so slippery im wondering if it would hold at all.

[@sstorholm]

@@HowNOT2 oh, I thought it was higher since you can’t melt the ends like with for instance polypropylene. Still would make for an interesting experiment as the nylon version didn’t seem to do much to the peak force.

[@wb2242]

Now you just have to find a fireman that only weighs 150lb....

[@maxm10081]

Have you tried the same but with a nylon daisy? If I had infinite money, I'd have a couple petzl connects... But I don't

[@HowNOT2]

Super similar enough, they just aren't adjustable

[@maxm10081]

@@HowNOT2 super similar enough to dynema you mean? I really wanna believe in the slight dynamic properties of nylon

[@mitchellan-ebbott7408]

Great stuff. What was the Purcell made from? I made mine with dynamic accessory cord, curious to know if that’s necessary.

[@M1American]

I believe it was made from 8mm (CMC?) static cord.

[@ShurikB93]

Are 7mm prucell prusik good for via ferata in that case?

[@gruboziarnisty]

If I remember correctly, friction based ferrata kits aren't used anymore, because they are unreliable and unpredictable

[@DaOndee]

*Prusik (Karl Prusik's last name is spelled with one s) 👍

[@richardsmith9918]

Wonder if it was 230lb

[@karlarvidson9616]

Is that a graveyard?

[@marcushill78]

What about using a screamer instead of the Purcell?

[@HowNOT2]

The Purcell serves the primary function of being very adjustable.

[@davidseslar5798]

@@HowNOT2 Only problem is, the seat/safety sling to the lower/foot ascender for a 'Texas' ascending system is where one *doesn't* want a long adjustable sling. If this is too long, the force when one drops onto it is greatly increased, as demonstrated here in your tests. Matt's sling lengths are wretchedly inefficient, both for climbing and for clipping over anchors, lips, etc., They put both ascenders over one's head, requiring the person using them to push them up by straightening their arms, and they put the upper/sit ascender at a very awkward visual angle overhead for reclipping the rope when crossing knots. It is much more efficient and ergonomic to have the top of the upper/sit ascender at one's chin-to-eye-level, allowing the ascender to be raised by pulling it up with a flexing arm motion (curl). The lower/foot ascender foot slings should be just long enough to allow a maximum step when it contacts the upper ascender. The safety/seat sling should be just long enough to reach from seat link to ascender link when standing on the lower ascender on-rope. This should still be short enough to keep this ascender below the top of one's head when falling onto it due to a missed rope clip or upper/seat sling failure, and will minimize impact forces.

[@edwardlewis6352]

Ask any arborist and that prussik is just broken in with that glaze!

[@adventureswithfrodo2721]

If the Purcell is dynemoa this is bad.

[@Rufeo0]

you should increase the weight in increments until it de-sheathes

[@HowNOT2]

Yea, i plan on doing heavier drops when I iron out the logistics of that. It takes a bit of getting use to dropping just these weights

[@grosminetytp5520]

It's too complicated anyway to use a prussik in this situation

[@HowNOT2]

I find I like petzl connect adjust but this isn't that bad