Knee Ascender/Stairwalking SRT

[sam1991]

Out of interest, has anyone here had any experience of trying a knee ascender/stairwalking SRT technique?
I recently bought Alpine Caving Techniques which mentioned the French using a bungee cord to position a hand jammer at knee height and a pantin on the other foot, which allowed them to effectively ‘walk’ up ropes with both hands kept free, but still be very easy to detach at a rebelay/pitch head (unlike the American method).
After a bit of research and asking around clubs, I’ve yet to find anyone that’s actually tried doing it, though seems like it is very common in rope access roles. Also noticed that Petzl have actually released a package kit exactly for this purpose. I’m keen to try it out but can’t help but think there is a reason this isn’t a ‘thing’ in caving (otherwise surely someone in the UK would be doing it already, especially if it is as rapid and less tiring as Marbach says)?

 

[snebbit]

@flashheart has tried this with some disappointment a couple of times I think

 

[Brains]

Decades ago you could get a kit of bits from "Caving Supplies" and they had a good diagram and set of instructions on how to set it up. I recall asking at the time why no one tried it, and a few in the club I was in said they had tried it but it was too much of a faff, referring it to it derogatively as an "elastico-fantastico" system or method and I should stick with frog. This was not long after SRT had seen the demise of ladders, and many different systems were being tried and advocated as the best thing ever. Over the years since I think the addition of a pantin type jammer is a good supplement, but frog is still the basic to work with... Give it a go and let us know

 

[cavemanmike]

I attached a basic hand jammer to a wide sling which I also stitched in a bungee cord inside with a foot loop on the end.works fine

 

[sam1991]

Decades ago you could get a kit of bits from "Caving Supplies" and they had a good diagram and set of instructions on how to set it up. I recall asking at the time why no one tried it, and a few in the club I was in said they had tried it but it was too much of a faff, referring it to it derogatively as an "elastico-fantastico" system or method and I should stick with frog. This was not long after SRT had seen the demise of ladders, and many different systems were being tried and advocated as the best thing ever. Over the years since I think the addition of a pantin type jammer is a good supplement, but frog is still the basic to work with... Give it a go and let us know

That was rather similar to the response I got from friends that I mentioned it to 😂. I’ve been researching it for a few months and found relatively little.
While perusing a tree surgeon/rope access retailer I found a whole section of knee ascenders and discovered hundreds of arborist videos on YouTube on set-up, techniques etc, and from the videos it really does look quite impressive, so I shall give it a go in the next few weeks and report back.

Slightly aside from that; I just realised Petzl sell a safety catch for the Pantin that prevents the rope from unintentionally flicking out… it’s only £4 so definitely going to try that out

 

[MarkS]

I tried it a while back, and concluded it wasn't really worthwhile. You can't really do it with a chest ascender attached in the usual way because there just isn't space on the rope. You then start looking at attaching the chest ascender higher up, so you end up modifying everything and getting into the realms of chest rollers etc. to hold you close to the rope. It might be be just about manageable for rebelays, but I'd love to see someone using it to negotiate a deviation above a rebelay.

My memory is that for straight prussiking I could get something to work that felt fairly efficient, but the lack of versatility and the faff with any obstacles meant I never bothered pursuing it. It's always worth people exploring these things and I'd absolutely recommend giving it a go - techniques will never progress without people experimenting - but personally I'd be surprised if you find it a significant improvement over rope-walking using a pantin with a standard frog system.

 

[pwhole]

I think a chest roller is almost mandatory for this system to work properly, and rebelays then make it a serious pain - I believe it was developed in the US where they don't do rebelays, and just add thicker rope until it rubs the rock smooth. Speaking of rope access, I've never heard of this system being used - in fact even a foot-ascender is seen as something akin to black magic, such is the average rope-technician's aversion to prussicking - or 'jugging', as they call it. I once put a Pantin on for a job and I thought the level 3 was going to faint with shock as I rope-walked past him - he'd literally never even heard of one. And he still hasn't bought one, four years later.

I used a motorised rope-climber for the first time ever two weeks ago, and felt really guilty, even though I could see the logic of multiple 50m climbs a day - it still felt wrong. Though only took two minutes

 

[topcat]

Frog plus pantin : if it ain't broke, don't fix it.

 

[sam1991]

I tried it a while back, and concluded it wasn't really worthwhile. You can't really do it with a chest ascender attached in the usual way because there just isn't space on the rope. You then start looking at attaching the chest ascender higher up, so you end up modifying everything and getting into the realms of chest rollers etc. to hold you close to the rope. It might be be just about manageable for rebelays, but I'd love to see someone using it to negotiate a deviation above a rebelay.

My memory is that for straight prussiking I could get something to work that felt fairly efficient, but the lack of versatility and the faff with any obstacles meant I never bothered pursuing it. It's always worth people exploring these things and I'd absolutely recommend giving it a go - techniques will never progress without people experimenting - but personally I'd be surprised if you find it a significant improvement over rope-walking using a pantin with a standard frog system.

So the original reason I assumed it wasn’t going to work was because of the chest roller too; I’ve read about the American system quite a lot and it seemed like a faff.
However the authors insist that they have made it work using only a chest jammer with the repositioned hand jammer, and therefore it doesn’t need a roller system. We did try it at Whitewalls about a month ago and the concept worked but we had forgotten to bring the bungee cord. Just seemed like an interesting concept to me as he claims rebelays etc are very straightforward. Hard to tell until put into practice though!

 

[sam1991]

I think a chest roller is almost mandatory for this system to work properly, and rebelays then make it a serious pain - I believe it was developed in the US where they don't do rebelays, and just add thicker rope until it rubs the rock smooth. Speaking of rope access, I've never heard of this system being used - in fact even a foot-ascender is seen as something akin to black magic, such is the average rope-technician's aversion to prussicking - or 'jugging', as they call it. I once put a Pantin on for a job and I thought the level 3 was going to faint with shock as I rope-walked past him - he'd literally never even heard of one. And he still hasn't bought one, four years later.

I used a motorised rope-climber for the first time ever two weeks ago, and felt really guilty, even though I could see the logic of multiple 50m climbs a day - it still felt wrong. Though only took two minutes

See for yourself 😉

 

[CalT]

Out of interest, has anyone here had any experience of trying a knee ascender/stairwalking SRT technique?
I recently bought Alpine Caving Techniques which mentioned the French using a bungee cord to position a hand jammer at knee height and a pantin on the other foot, which allowed them to effectively ‘walk’ up ropes with both hands kept free, but still be very easy to detach at a rebelay/pitch head (unlike the American method).
After a bit of research and asking around clubs, I’ve yet to find anyone that’s actually tried doing it, though seems like it is very common in rope access roles. Also noticed that Petzl have actually released a package kit exactly for this purpose. I’m keen to try it out but can’t help but think there is a reason this isn’t a ‘thing’ in caving (otherwise surely someone in the UK would be doing it already, especially if it is as rapid and less tiring as Marbach says)?

The first time i used rope ascension kit was for lead climb soloing and i was sold a set up at caving supplies in buxon. It's super fast using the rope walk system and now ive started caving ive been experimenting with my set up it for achieving fast rebelays.

After a trip last weekend ive realised whats causing me issues and this is my system....

I have a pulley at my chest (pulley is held on to chest harness by a very simple hook for easy removal) and a hand ascender above it attached to a cowstails (hand ascender can be clipped into pulley for hands free operation). Then the knee ascender is the same as i was taught at caving supplies with a bungee going to the back of my harness, another cowstail and footloop to stand in. And of course a pantin.
Going to try out my revised setup tomorrow so ill soon know if its feasible.

 

[MarkS]

So the original reason I assumed it wasn’t going to work was because of the chest roller too; I’ve read about the American system quite a lot and it seemed like a faff.
However the authors insist that they have made it work using only a chest jammer with the repositioned hand jammer, and therefore it doesn’t need a roller system. We did try it at Whitewalls about a month ago and the concept worked but we had forgotten to bring the bungee cord. Just seemed like an interesting concept to me as he claims rebelays etc are very straightforward. Hard to tell until put into practice though!

Interesting! Give it a go, and let us know how you get on

 

[pwhole]

See for yourself 😉

I noticed that guy has his rope tied off tight at the bottom, which would make all of this far easier. Unlikely to be used in caving though, unless you're climbing an aven rather than exiting the cave/mine. A heavy tackle-bag always helps, or a friendly last colleague, who won't benefit from the help themselves. But that does look interesting. I always use my free hand to grip the rope above when rope-walking, so wondered whether two hand-jammers might help with that, but I suspect they'd just end up smashing into each other a lot.

 

[wellyjen]

I did briefly try this system around 1990, if I remember right. I got it to work and found it could be very fast for rope walking, but got so out of breath that I had to rest a couple of times on the ascent till my heart and lungs had caught up. The resulting total ascent time ended up being about the same as using frog, timed over the same pitch. For some one much fitter than I then was, it might have worked better. The pantin, or other third foot mounted jammer has been really the only major improvement/addition to the basic frog set up that I've yet seen.

 

[christopher]

I think a chest roller is almost mandatory for this system to work properly, and rebelays then make it a serious pain - I believe it was developed in the US where they don't do rebelays, and just add thicker rope until it rubs the rock smooth. Speaking of rope access, I've never heard of this system being used - in fact even a foot-ascender is seen as something akin to black magic, such is the average rope-technician's aversion to prussicking - or 'jugging', as they call it. I once put a Pantin on for a job and I thought the level 3 was going to faint with shock as I rope-walked past him - he'd literally never even heard of one. And he still hasn't bought one, four years later.

I used a motorised rope-climber for the first time ever two weeks ago, and felt really guilty, even though I could see the logic of multiple 50m climbs a day - it still felt wrong. Though only took two minutes

The lengths that some techs go to in order to avoid jugging is staggering -)

 

[sam1991]

I did briefly try this system around 1990, if I remember right. I got it to work and found it could be very fast for rope walking, but got so out of breath that I had to rest a couple of times on the ascent till my heart and lungs had caught up. The resulting total ascent time ended up being about the same as using frog, timed over the same pitch. For some one much fitter than I then was, it might have worked better. The pantin, or other third foot mounted jammer has been really the only major improvement/addition to the basic frog set up that I've yet seen.

Yeah I did wonder how much energy it would actually save over a proper long pitch; in terms of speed it makes sense, but in comparison it’s basically squats versus walking up stairs isn’t it?
Maybe when I test it I’ll do the same pitch twice with frog and stair-walking with a stopwatch, and see which one wins them over 😂 either way, seems like an interesting concept. My thinking is there must be a reason it never caught on, just a shame no one really seems to have recorded why!

 

[David Rose]

The best way to minimise effort climbing ropes I find is to use a bra-style chest harness with frog set-up adjusted so that it sits high on the chest (ie shorten the shoulder straps), and therefore it holds your upper body in close to the rope. A Pantin also helps, of course. I just don't believe that ropewalker systems with bungees etc will ever be as easy and slick at rebelays.

 

[wellyjen]

Yeah I did wonder how much energy it would actually save over a proper long pitch; in terms of speed it makes sense, but in comparison it’s basically squats versus walking up stairs isn’t it?
Maybe when I test it I’ll do the same pitch twice with frog and stair-walking with a stopwatch, and see which one wins them over 😂 either way, seems like an interesting concept. My thinking is there must be a reason it never caught on, just a shame no one really seems to have recorded why!

One of the problems I found was that the recommended method of attaching the foot jammer wasn't too comfortable. It tried to twist your ankle. No Pantins with their optimised strap system back then, remember. At the time it was being promoted, you could add the bits needed to an existing frog rig pretty easily and cheaply. An extra jammer and a bit of bungee and tape, so it seemed worth trying. I found it not worth the faff in the end and stopped using it after a couple of trips. It was a long time ago and I'm trying to drag up the details from my memories long term storage, so more may surface later.

 

[wellyjen]

Some more memories of my trial of this system, over thirty years ago.
I can't remember where I read about it. Either a Descent article, or a page in the Caving Supplies catalogue. Possibly both? The idea was that it extended the Frog system, with a few extra components and you could flip from Frog to rope walking and back as you climbed. You could rope walk for speed, or use frog to pass rebelays, or other tricky bits.

The loop of the foot loop was tied at such a length that when the top jammer krab was clipped in to the loop itself, the jammer was at knee height. When you changed back to frog, you moved the jammer krab back to the top end knot of the foot loop.

The 4mm or so diameter bungee was clipped, or tied to the back of the harness, came over one shoulder, then was clipped to the top of the hand jammer, an old style Petzl Basic. When in frog mode, the bungee had no tension on it, so could be left in place, or unclipped. When in rope walker mode, it towed the hand jammer up the rope when you stood up on the foot jammer.

The foot jammer was another Petzl basic. I can't remember the details of how it was attached to the foot, but it ended up somewhat higher on the boot than the ankle height of a modern Pantin. I think it may have used something like a 25mm tape waist belt to tie it to the welly boot.

Disadvantages I found:

• There was a risk of the bungeee either getting caught in the Croll jammer, or possibly disconnecting the safety catch and opening the Croll. I did get the bungee caught once. Fortunately, I managed to free it, but there was a good chance of getting badly hung up mid-rope. The Croll design of the time had a safety catch that was easier to accidentally get caught and opened than the modern versions. This never happened to me, but I didn't like the risk. If the croll became disconnected, you could put a potentially high fall factor on the knee mounted Basic's cam teeth, via the dynamic rope safety cord, that could damage, or cut the rope.
• When in Frog mode, the bungee cord was either slack and still attached to the top jammer, or disconnected. There was a risk of it getting caught on cave features in either case and stretched taught, before being noticed.
• Using the old Petzl Basic as a foot jammer wasn't ideal. The strong cam spring made it difficult to get it to run freely, when starting a pitch. The method of attaching to the boot was uncomfortable and tried to twist the ankle. The safety catch meant you had to be sure to be able to reach the catch to release the foot jammer. Not always possible at a constricted rebelay. The modern Pantin was designed to get round all these problems, with a weaker cam spring, proper strap system and initially no (later optional) safety catch.
• Unless you had a very good power to weight ratio, then the extra effort of lifting your weight with one leg, rather than two, got you more knackered more quickly. This was worse when hauling tackle bags, or being knackered. Derigging the upper pitches of a deep and difficult cave of course combines both carrying tackle bags and being knackered!

I found that the extra faff meant that once I'd switched to Frog for some reason, I'd stay in Frog mode. The trial only lasted a few trips and I abandoned it. I only next went beyond basic Frog, when I tried an early Kong foot jammer in around '97. This used one of their Basic knock off jammers, with a better strap system. It had a safety catch. I abandoned it as I couldn't get it to run up the rope reliably. I then started using a Pantin in the early naughties. Recently I found the old Kong foot jammer in the back of the caving cupboard, after losing a Pantin and am using it again after drilling out the safety catch. With this modification, it now works well and I'll probably carry on with it till it wears out. Not PPE, so I'm happy using it.

On a modern version of this knee walking system, a Pantin, or other modern foot jammer gets round the problems I had using an old Basic in this role. You might be able to get round the Croll jamming risk with a different bungee material, like Cavemanmike describes above, or routing. Modern Crolls are less prone to accidental unclipping. The other problems still remain.

 

[sam1991]

Some more memories of my trial of this system, over thirty years ago.
I can't remember where I read about it. Either a Descent article, or a page in the Caving Supplies catalogue. Possibly both? The idea was that it extended the Frog system, with a few extra components and you could flip from Frog to rope walking and back as you climbed. You could rope walk for speed, or use frog to pass rebelays, or other tricky bits.

The loop of the foot loop was tied at such a length that when the top jammer krab was clipped in to the loop itself, the jammer was at knee height. When you changed back to frog, you moved the jammer krab back to the top end knot of the foot loop.

The 4mm or so diameter bungee was clipped, or tied to the back of the harness, came over one shoulder, then was clipped to the top of the hand jammer, an old style Petzl Basic. When in frog mode, the bungee had no tension on it, so could be left in place, or unclipped. When in rope walker mode, it towed the hand jammer up the rope when you stood up on the foot jammer.

The foot jammer was another Petzl basic. I can't remember the details of how it was attached to the foot, but it ended up somewhat higher on the boot than the ankle height of a modern Pantin. I think it may have used something like a 25mm tape waist belt to tie it to the welly boot.

Disadvantages I found:

• There was a risk of the bungeee either getting caught in the Croll jammer, or possibly disconnecting the safety catch and opening the Croll. I did get the bungee caught once. Fortunately, I managed to free it, but there was a good chance of getting badly hung up mid-rope. The Croll design of the time had a safety catch that was easier to accidentally get caught and opened than the modern versions. This never happened to me, but I didn't like the risk. If the croll became disconnected, you could put a potentially high fall factor on the knee mounted Basic's cam teeth, via the dynamic rope safety cord, that could damage, or cut the rope.
• When in Frog mode, the bungee cord was either slack and still attached to the top jammer, or disconnected. There was a risk of it getting caught on cave features in either case and stretched taught, before being noticed.
• Using the old Petzl Basic as a foot jammer wasn't ideal. The strong cam spring made it difficult to get it to run freely, when starting a pitch. The method of attaching to the boot was uncomfortable and tried to twist the ankle. The safety catch meant you had to be sure to be able to reach the catch to release the foot jammer. Not always possible at a constricted rebelay. The modern Pantin was designed to get round all these problems, with a weaker cam spring, proper strap system and initially no (later optional) safety catch.
• Unless you had a very good power to weight ratio, then the extra effort of lifting your weight with one leg, rather than two, got you more knackered more quickly. This was worse when hauling tackle bags, or being knackered. Derigging the upper pitches of a deep and difficult cave of course combines both carrying tackle bags and being knackered!

I found that the extra faff meant that once I'd switched to Frog for some reason, I'd stay in Frog mode. The trial only lasted a few trips and I abandoned it. I only next went beyond basic Frog, when I tried an early Kong foot jammer in around '97. This used one of their Basic knock off jammers, with a better strap system. It had a safety catch. I abandoned it as I couldn't get it to run up the rope reliably. I then started using a Pantin in the early naughties. Recently I found the old Kong foot jammer in the back of the caving cupboard, after losing a Pantin and am using it again after drilling out the safety catch. With this modification, it now works well and I'll probably carry on with it till it wears out. Not PPE, so I'm happy using it.

On a modern version of this knee walking system, a Pantin, or other modern foot jammer gets round the problems I had using an old Basic in this role. You might be able to get round the Croll jamming risk with a different bungee material, like Cavemanmike describes above, or routing. Modern Crolls are less prone to accidental unclipping. The other problems still remain.

Brilliant, that’s some great advice, thank you! I think we’re going to pop over to Hunter’s Hole for a trial at some point in the next few weeks so I’ll remember the disadvantages you mentioned and see if the modern gear designs might have rectified any of the issues you had. Whether or not Petzl’s own bungee harness strap design might offset the bungee enough to reduce the snag issue could be interesting. I shall report back with some snaps and let you guys know the outcome!