New Ascender / Descender Device Design: Input Needed!

[UCR SeniorDesign]

Hello,

My name is Jared Ayers, and I am a senior in the Mechanical Engineering program at University of California in Riverisde, CA. My Senior Design team and I have been contracted to come up with a design for a device which would allow ease of ascent and descent on a rope, with an easy interchange between the two. It would be for used primarily in caving, but would have applications in rock climbing and rescue, as well. We are in the research stage currently, and are looking for input on preferences of what would be desired in such a device. We are posting on a few forums in an aim to get as much information and input as we can, and every bit is greatly appreciated.
If possible, please take a few minutes to look at the following questions, and let me know of any questions, comments, and advice that you may have.
On behalf of my team, I want to thank you all for taking the time to read this and for lending your expertice and suggestions.


1. What kind of climbing do you do?
a. Spelunking/caving
b. Rock climbing
c. Canyoneering
d. Other _____________________________________

2. Why do you climb?
a. For fun
b. For work (guide/instructor/search & rescue)
c. Other _____________________________________

3. What climbing skill/experience would you consider yourself?
a. Amateur
b. Professional
c. Intermediate
d. Other _____________________________________

4. What equipment do you currently use to ascend?

5. What equipment do you currently use to descend?

6. What techniques for ascending do you like the best?

7. What techniques for descending do you like the best?

8. What size, type and brand of rope do you use?

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?)

12. How much would you be willing to spend on a device like this?

13. i) How do you typically buy your equipment?
a. Online
b. Directly from a manufacturer
c. From a magazine
d. Other _____________________________________

13. ii) Where?

[Ralph E. Powers]

No offense but it seems that Petzl has made a great design that'd be hard to improve upon for an ascender. It's been imitated many times to be sure. Right now the only peeve I have with it when they "upgraded" their design was the removal of the small hole to the side of the large one on top.
The bottom two holes (for the hand ascenders) could be a tad larger to accommodate larger screw links.

Other than that...

[Wayne Harrison]

Admin note: Since people can't type on the blank lines and the long blank lines in the original post were messing up the formatting of the page, forcing it to the far right, I removed them because they were unnecessary.

[mgmills]

Maybe I'm missing something but why do you think there is a need for a device to both ascend and descend?

Seems to me that to have a device which would do both it would be more complex and therefore more likely to have problems occur. But then I'm a nurse not a mechanical engineer.

I've logged many miles on rope on my trusty rack (actually I have two types of racks) and my petzl ascenders and I'm very happy with both.

Regarding equipment failure - many moons ago I had a spring break on my old jumar when I was half way up an ~ 160 foot pitch. The ascender still worked (sort of) . . . I just had to be careful not to bump it.

I've had several interesting experiences on rope but they were user error not equipment failure.

[brrrdog]

Common folks, a student has asked some very simple questions for his research. Perhaps his sponsor specifically asked for a device that goes in both directions. But in any case, who are we to question the value or method of his research? Frankly, starting from the beginning is a great way revolutionize vs evolutionize an idea. But even if that's not the case, the simple answers my help him refine or change his focus.

1. What kind of climbing do you do?
a. Spelunking/caving

2. Why do you climb?
a. For fun

3. What climbing skill/experience would you consider yourself?
c. Intermediate

4. What equipment do you currently use to ascend?
Petzl "Ascender", "Croll"

5. What equipment do you currently use to descend?
Petzl "Rack"

6. What techniques for ascending do you like the best?
Frog

7. What techniques for descending do you like the best?
Rack with a "French Wrap"

8. What size, type and brand of rope do you use?
Not sure, I'm always using somebody else ;)

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?
If you're asking if a combo ascender/decender would be desireable I'd say yes, but in caving, only if it could do both jobs at least as good as two systems. To my knowledge a changeover on a single pitch is rare and is only needed when something "out of the norm" is encountered.

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?
No

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?)
I'm not sure if I care about weight - but that long rack sure doesn't fit too well in a bag.

12. How much would you be willing to spend on a device like this?
Assuming two asenders and a rack will set you back about 180 bucks, I might pay that same amout.

13. i) How do you typically buy your equipment?
a. Online
d. Other: Local climbing gym

13. ii) Where?
a. KarstSports, REI

[Dwight Livingston]

1. What kind of climbing do you do?
Caving

2. Why do you climb?
Project caving, survey, to find new cave.

3. What climbing skill/experience would you consider yourself?
Intermediate

4. What equipment do you currently use to ascend?
Petzl Basic and Croll

5. What equipment do you currently use to descend?
Long microrack

6. What techniques for ascending do you like the best?
Frog

7. What techniques for descending do you like the best?
Microrack

8. What size, type and brand of rope do you use?
PMI and other, 9mm to 11mm.

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?
Compared to what I use now, if it were smaller, not much heavier, and able cross rebelays as easily, then I'd consider paying more than what I use now if I tried it and liked it.

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?
No.

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?)
Much of the weight and size of my kit is the harness and cowstail, which I do not see replacing. You're left with the Croll, Basic, a 6mm piece of cord for a foot loop and a piece of webbing for a chest harness.

12. How much would you be willing to spend on a device like this?
I might go $200 if it were small and wonderful.

13. i) How do you typically buy your equipment?
Online
At caving events.

13. ii) Where?
a. IMO, On Rope, KarstSports, Mountain Gear

[Andy Shoun]

1. What kind of climbing do you do?
a. Spelunking/caving , b. Rock climbing, d. Other _Tree__

2. Why do you climb? a. For fun

3. What climbing skill/experience would you consider yourself?
a. Amateur

4. What equipment do you currently use to ascend? petzel croll n basic

5. What equipment do you currently use to descend? figure 8 or hitch

6. What techniques for ascending do you like the best? frog, (double rope prussick and foot loop for tree climbing)

7. What techniques for descending do you like the best?

8. What size, type and brand of rope do you use? 11mm petzel, 11mm bluewater, 7/16 New England Fly

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it? yes

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions? n/a

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?) don't know how much it weighs, but low weight is important to me.

12. How much would you be willing to spend on a device like this? depends on precived reliability and convience, $100-150

13. i) How do you typically buy your equipment?
a. Online, directly and at caver specific events

13. ii) Where? WesSpur, REI, Inner Mountain Outfitters, On Rope, Sunrift Adventures

[Komebeaux]

1. What kind of climbing do you do?
a. Spelunking/caving

2. Why do you climb?
a. For fun

3. What climbing skill/experience would you consider yourself?
a. Amateur

4. What equipment do you currently use to ascend?
Frog System with Petzl Croll, haven't purchased a hand ascender yet, but have used Petzl and will probably purchase a petzl or the like.

5. What equipment do you currently use to descend?
Don't own one yet, but plan to purchase a rack with hyperbar.

6. What techniques for ascending do you like the best?
Prefer a frog, but a ropewalker is great too, just more expensive.

7. What techniques for descending do you like the best?
I don't have enough experience to have an opinion.

8. What size, type and brand of rope do you use?


9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?
Yes.

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?
No

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?)
Not sure of the weight of a frog, but if the combo ascender/descender weighed less, then it would be a huge advantage.

12. How much would you be willing to spend on a device like this?
If it made being on rope considerably easier and safer, then I could definitely see paying something comparable to a Frog or Ropewalker plus rack.


13. i) How do you typically buy your equipment?
a. Online

13. ii) Where?
Karstsports, Bob & Bob.

[UCR SeniorDesign]

To all, thanks for the replies and keep the feedback comming..... It is a great help!
Now, to answer back to some of your responses:

Ralph: True, Petzl has designed a great ascender, and we are using their designs as a jumping off point for concepts....not copying them, but rather seeing the technology that they use. Our device would ideally give ease to ascending and descending, in one package, for ease of use. Thanks for the note about the hole sizes...I've noted that as an item to be looked at for our design.

Wayne: Thanks for moving this to a more appropriate board, also for the re-format. The help is much appreciated!

mgmills: You are correct that by combining the two devices, there stands the potential to over-complicate a simple concept. This is exactly what we are trying to avoid, and we believe that the more simple the design, the better it will ultimately function. We are siming for functionality and simplicity, minimalizing moving parts, etc.
Also, thanks for the note on equipment failure. Its nice to hear the malfunctions tend to be rare

brrrdog: Thanks for answering the questionairre, and for breaking the ice on our purpose in asking what we ask. You are correct in that our sponsor (the University) has specified that the device must be able to aid in ascending and descending, hence why we are going this route.
When talking about the desirability of a combo unit, you said that a changeover is typically only used when something "out of the norm happens"....what, in your opinion, would be something "out of the norm", and what is the norm? I ask so that we can design for the right conditions, and also to be prepared for the right circumstances.

Dwight: Thanks very much for your input on the questionairre. You mentioned re-belays....how often in general caving do you come across rebelays? I have heard that this is important from a couple individuals now, so I figured Id ask.

Andy: Thanks for your answers. In ascending, what is a "frog"?


Again, thank you to all for taking the time to answer the questions posted. I will be on here continuously for the next 8 months asking more and updating you all on our design status. Please feel free to keep the questions, comments, and input comming

-Jared

[NZcaver]

OK, I'll play your game...


1. What kind of climbing do you do?

a. caving (NOT spelunking)

2. Why do you climb?

Mostly a. For fun; sometimes b. For work (usually volunteer, occasionally paid/compensated)

3. What climbing skill/experience would you consider yourself?

c. Intermediate-ish...

4. What equipment do you currently use to ascend?

Frog System with Petzl Ascension/Croll

5. What equipment do you currently use to descend?

Mostly my Petzl Stop

6. What techniques for ascending do you like the best?

Frog, sometimes with added Petzl Pantin foot ascender

7. What techniques for descending do you like the best?

Autostop bobbin with braking carabiner

8. What size, type and brand of rope do you use?

Mostly 11mm low-stretch, currently use PMI and Sterling

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?

Yes - pending assessment/trials of the device

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?

Technically, no

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit?

Frog system (including seat/chest harnesses and emergency Prusik/mini pulley/carabiner/spare maillon, minus optional third ascender and Pantin) 2.1kg (4 lbs 10 oz). The weight of just my descender and two ascenders is 765g (1 lb 11 oz).

12. How much would you be willing to spend on a device like this?

At current prices, an "average" descender and 2 ascenders will set you back about US$200 total. Ascenders are usually ~$50-70 each, and caving descenders (racks/bobbins) vary from ~60-$100+. I don't think I've ever paid more than about $100 for any one ascender or descender... but I'll keep an open mind.

13. i) How do you typically buy your equipment?

Both a. Online; and d. From outdoor/caving stores/vendors

13. ii) Where?

eBay (online), Inner Mountain Outfitters/Howies/etc (online and at caving events), Eastern Mountain Sports (store)


Good luck getting straight answers from cavers about vertical caving! But I hope this helps.

Now a question for you. When you say "a device which would allow ease of ascent and descent on a rope" - that seems to imply a single device for moving up or down. As you may have noticed, we all refer to our ascenders in pairs (or three's). Body mechanics and gravity being what they are, I assume you know why multiple ascenders are used in virtually every rope climbing system? Unless... perhaps you are thinking of designing a powered/motorized ascender that can double as a descender??

If not, a second ascender (or more) will be required. As you may know, there are already a number of devices out there that can function as combination descender/belay device/ascenders (assuming there is a second ascender to make up the other half of the climbing system). One of these devices is the Petzl I'D, which is mostly used by the rope access industry and costs about $185.

[subter]

Good luck

1. What kind of climbing do you do?
a. Spelunking/caving

2. Why do you climb?
a. For fun

3. What climbing skill/experience would you consider yourself?
a. Amateur

4. What equipment do you currently use to ascend?
Petzl B17

5. What equipment do you currently use to descend?
SMC Stainless Steel 6 bar Rack $81.95

6. What techniques for ascending do you like the best?
I'm only familiar w/ Frog

7. What techniques for descending do you like the best?
I've only used a rack

8. What size, type and brand of rope do you use?
House rope

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?
Heck yes. You know, I think if the device is really great the price will become less important. you have people who pay over $300 for headlamps known as gear whores, they will do anything for the best equipment.. build it well and they will come.

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions?
Nothing like that... thank goodness.

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?) I'm not sure on the weight but of course you would like for the device to be as light as the material/design allows. I DO know that I hate lugging that SS rack around a cave... but I respect the design and durability. Hope that helps.

12. How much would you be willing to spend on a device like this?
cavers are cheap.. but not stupid. You charge what you must but I would expect to start around $200.

13. i) How do you typically buy your equipment?
a. Online

13. ii) Where?
KarstSports, OnRope1, InnerMountain Outfitters.

I'm not sure how deep you are into this but an additional feature (as if you're not taking on enough already) would be to have some sort of Rappell safety in the device. Have a look at the Petzl ASAP. The general consensus right now is that it is not durable or light enough for a wet, muddy caving environment... and I agree. Also see the Petzl shunt and read up on the french wrap.

Like I said, best of luck. I really hope that you will take the time to come back and share your development progress with this community.

[NZcaver]

how often in general caving do you come across rebelays?

This depends mostly on where people are caving... different regions of the world and regions of the US tend to differ a little or a lot in rigging trends/practices/philosophies. TAG (TN, AL, GA) cavers probably don't rig too many rebelays on a regular basis, whereas cavers in alpine areas often take the European approach and add rebelays. Caving around the US, I've rigged/used rebelays only occasionally to moderately depending on the region/cave/cavers I'm with. By contrast, in NZ rebelays are a little more common.

In ascending, what is a "frog"?

Frog System

(Sorry to jump the gun and answer for other people they'll probably have more to add anyway.)

[fuzzy-hair-man]

1. What kind of climbing do you do? a. caving

2. Why do you climb? a. For fun

3. What climbing skill/experience would you consider yourself? a. Amateur to Intermediate

4. What equipment do you currently use to ascend? Petzl Ascension, Petzl Croll, sometimes a Pantin

5. What equipment do you currently use to descend? Petzl Simple

6. What techniques for ascending do you like the best? Frog

7. What techniques for descending do you like the best? Bobbin and brake carabiner

8. What size, type and brand of rope do you use? mostly Mammut 10mm or 10.5mm

9. Do you think that a device like this would be helpful and if it was reasonably priced would you use it?
It depends greatly on the design, multiple purpose gear is great but caving gear generally needs to be fairly mechanically simple otherwise mud, wear, bumps etc will cause it to break or stuff up.

10. Have you ever had any equipment failures? If so, what kind of equipment were you using at the time? What were the conditions? Not that I recall.

11. How much does the climbing kit you usually use weigh and if you were to use this device instead of multiple other devices, do you think you would benefit? (How should we word this?)
Asecenders and descenders only not harness and connecting hardware etc.
Ascension: 188 grams
Croll: 133 grams
Pantin (occasionally use): 81 grams
Simple: 237 grams
Total: 639 grams.

It depends on the design if the ascending / descending device is complex odds are it will be heavier than the seperate ascenders and descender.

12. How much would you be willing to spend on a device like this?
Depends on how well it does the job and it's advantages over the current system, if I hadn't already got my gear and your device performed as well then about the same as the price of the components listed above.
In my opinion you should be aware that it you replace multiple devices with a single device it may make it harder for cavers to cope with a failure, for example if an ascender fails we generally have a spare and we still have another working ascender and descender, if a descender fails we can down prussik on our ascenders or use crossed carabiners. In other words I think a single device makes the caver more vulnerable to failures in the device and may reduce safety for this reason.

13. i) How do you typically buy your equipment? Online (ebay, inner mountain outfitters, REI) and at a local outdoors store (Canberra, Australia)

If your interested herre is a device that tried to combine the roles of ascender and descender:
http://storrick.cnchost.com/VerticalDevicesPage/Rappel/BobbinPages/SBobbin452.html
Gary's webpage will show a lot of the devices people talk about here and is a great place to research past and present vertical devices.
http://storrick.cnchost.com/VerticalDevicesPage/VerticalHome.shtml

[Squirrel Girl]

Hi Jared, I just glanced at this thread. You won't find many (maybe not any) spelunkers here. Just cavers. Most spelunkers don't know how to climb ropes, and when they do, they commonly need cavers to rescue them. We had a thread about such an example from a week or two ago.

I'm gonna guess I speak for a bunch of cavers where when I post this. We probably all wish you well, but it's a little puzzling to us. You post up about being a design engineer and that you're going to design an improved device, but you don't seem to know much about the subject at hand if you don't know what a frog is.

Perhaps you need to read a book like "On Rope." And find a local caving club (Grotto) and have some of them teach you about ropewalkers and frogs, maybe a Mitchell and Texas, Gibbs, racks, mini-racks, bobbins, etc.

Good luck to you.

[fuzzy-hair-man]

Perhaps you need to read a book like "On Rope." And find a local caving club (Grotto) and have some of them teach you about ropewalkers and frogs, maybe a Mitchell and Texas, Gibbs, racks, mini-racks, bobbins, etc.

It would probably be worth your while trying to get along to a SRT(ropes) practice and trying out as many devices as possible (find a gear junky and get them to bring along thier collection), it's not until you try manouvers like changeovers and knot crossings (in particular) that you find the deficentcies in current devices.

One point I might suggest is that longer descending devices tend to make change overs and knot crossings and tight rebelays harder so the shorter your device the better. On and off rope times are important particularly if there are lot's of rebelays, your device should also be able to be removed from the rope without having to be removed from the caver's harness (figure eights are an example of a device that doesn't do this). Also your device would be good if it provides a good heatsink to dissipate heat although this conflicts the weight issue and the desender length issue.

Adjustable friction is also a good descender trait so you can more easily adjust the descender to different rope conditions (mud water rope diameter etc)