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27-Dec-2011 6:14:01 PM
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Hi,
I'm not a climber as such, but I have a related problem to solve that I figured a climbing community might be able to help me solve.
I have been recently employed to perform fire spotting duties atop a 30 meter fire tower.
Apart from some very basic equipment, I have to hoist everything up by rope.
This creates two problems.
First and most importantly, My gear is expensive and not exactly shock proof, so I am looking for a way to prevent accidental slipping, and of course the ensuing mayhem at ground level.
The other half of this is getting it down again. I noticed some carbiner rappel methods listed on this site somewhere that looked like a contender.
The solution needs to be simple and small, as I'm climbing up caged ladders that were not designe for someone with shoulders as wide as mine.
My second issue is less important. How to get multiple loads of gear up the tower without climbing back down again. My curent contingency is to string each load 30meters apart and pull it up one after the other.
Any ideas welcome, or if this is one of these anal retentive forums where I'll get abused for not being aware of the rightful place for this post, I hope admin will be patient.
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27-Dec-2011 6:17:48 PM
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rock exotica wall hauler or petzl pro traxion or equivilent, i.e. any self jaming pulley should do the trick. how much gear, you should be abvle to do 40kg in one go without too much of a problem.
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27-Dec-2011 6:20:25 PM
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looking at about 10kg a load. Thanks heaps I'll look them up.
"self jamming pulley" was the terminology I was looking for.
I should be able to engineer something that approximates that.
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27-Dec-2011 9:26:25 PM
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I have drawn up designs for a custom size "shunt" to suit my weight and rope size.
I'll get it cut out of stainless when I visit a mate with a CNC plasma cutter tomorrow.
This seems to be the best option and I just need some emergency protection in case i slip with the rope.
I have also made a large radius cam so that I can ue it as a descender and adjust the downrate with a carbiner clip on the back of the cam.
Thanks Paul for sending me down the right track.
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28-Dec-2011 8:18:02 PM
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Well it's complete.
Finally worked out that a "Shunt" was what I was after.
Paid a visit to a friend with a computer controlled plasma cutter, and here is the result:
I can supply the CAD file for anyone else who wants to make one.
Keep in mind this is NOT rated for human use, Gear bag only, though it holds 150kg's overnight without slipping.
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28-Dec-2011 9:17:16 PM
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That is impressively scary. $1.75 for a biner is cheap as too.
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29-Dec-2011 12:00:24 AM
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Yeah I know. Design load was 10 kg with room for mistake. This is high tensile stainless and the clip is the same. Not something I will trust my life too, but a backup to save my gear from smashing at the base of the tower. Got orders for a dozen of these already for light duty applications.
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29-Dec-2011 1:04:17 AM
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On 27/12/2011 Dranoweb wrote:
>
>I have also made a large radius cam so that I can ue it as a descender
>and adjust the downrate with a carbiner clip on the back of the cam.
>
Got a photo of this too? I'm intrigued.
Also, have u ordered 12 of ya shunty things or 12 $1.75 crabs? U may as well get fully rated ones for $7.
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29-Dec-2011 9:16:12 AM
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do be careful hauling lots of stuff on skinny ropes. its not an uncommon thing to hear people getting really sore hand from trying to grip such small diameters(up to 11mm)
cool looking new toy tho!! i wanna come play at making stuff.
make a shunt type device that you can rate for two person use and you'll solve current IRATA woes too!!!
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29-Dec-2011 11:06:21 AM
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"Large Raduius cam" referred to the existing one fitted to my shunt design.
It has a gentle angle that allows for partial release of tesion so that I can lower my gear at a comfortable rate.
As for sore hands, I just wear riggers gloves. save rope burn, and adds a little extra diameter to anything I need to hang on to.
As for orders, I have been making these myself on a plasma cutter. As of this morning, 15 people want a prototypes.
The carbs are available at my local hardware store, and are of a design that doesn't open up when overloaded. Entirely suitable for the task at hand.
As these are to be left on the tower, and there is a high risk of vandalism and theft, therefore buying fully rated carbs is probably not worth my time.
EG: I can throw away $28 worth of carbs, or I can throw away $5 worth.
since a few people seem interested, I'm heading out there shortly to test the rig, I'll take a few photos and show you what I'm up against.
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29-Dec-2011 11:12:33 PM
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A few pics for those interested.
The rig works well, but I need to shave a little off the cam to compensate for rope size, but aside from that it does what it's meant to, and holds my gear bag ok.
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30-Dec-2011 5:40:06 PM
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I know its a toothed device but i use a ASAP with the higher rated absorbica suitable for use with 2 people and find it very usable. I am a level 2 ARAA operator so im not sure if IRATA has different rules concerning ASAP's but if you can get get around one.
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30-Dec-2011 8:33:16 PM
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Hmm, it appears I have some homework to do. Did I mention that I'm not a climber, and am unfamiliar with the acronyms and terminology. Hence the original post?
Also, I can climb up a ladder, I'm not required to ascend or descend the rope.
so a google search or two later and I'm at this stage:
ASAP? some kind of fall protection device, that's easily confused with the common acronym "as swiftly as possible"
Absorbica: Massive overkill for my task, the nichrome steel bar that the pulley is attached to is more than springy enough to absorb some of the shock loading, as it the tower itself. A 10kg pack makes the entire structure shake considerably.
IRAA and IRATA are probably not going to have much to say about this, as again, I'm not required to descend the rope. It's purely to haul my gear up down the tower.
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30-Dec-2011 10:01:07 PM
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sorry mate i was referring to the post by sliamese: "i wanna come play at making stuff. make a shunt type device that you can rate for two person use and you'll solve current IRATA woes too!!!"
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31-Dec-2011 9:02:00 PM
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Fair enough. Understand the confusion now.
As another question, are there any accepted practices for hauling multiple loads up a wall?
EG: I haul one 10kg pack, and then need to get another separate one up in a second haul.
At present I plan to join a 30m rope between packs and loop over the pulley at the top. The only hitch here is that I have to re-thread my shunt each time, which is a bit of a pain considering it's design.
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1-Jan-2012 6:04:54 PM
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On 30/12/2011 Dranoweb wrote:
>ASAP?
Petzl Asap:
http://www.petzl.com/en/pro/verticality/mobile-fall-arrest-device/mobile-fall-arrest-device-rope/asap
As you say, far beyond anything you would need.
As far as having to rethread your device, could you modify to have a removable pin; like this only less complicated:
http://www.petzl.com/en/pro/rope-clamps-hauling-and-lifting/microcender
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1-Jan-2012 10:37:34 PM
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Had another sesion on the CNC plasma cutter today with some 3mm aluminium.
Have added a few features like some locking holes and have changed the dimensions a little.
I have found cheap spring clips that should work as a removable pin as you suggest.
Current design below, not much different to look at, but much better to use as it flows over the rope far more easily, and can be locked in position.
I have my first shift up the tower tomorrow so it will be interesting to see how this all comes together.
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15-Jan-2013 11:02:45 PM
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I know this forum is an old one by now, but thought I would follow up with a bit of video of the system in action.
http://www.youtube.com/watch?v=-Ad-H8IQyKw&feature=share&list=UUE1JvruiummI5uv3GUbtTnQ
I would also like to say thanks for all the advice and suggestions - they were very helpful.
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15-Jan-2013 11:40:14 PM
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Where abouts is this fire-tower you work in? I know some folks who work the towers down Lakes way see..
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16-Jan-2013 9:21:25 PM
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As a matter of interest, are you using something better than Bunnings $10 rope on the tower? I'm sure you could find much safer ropes in various Chockstoners cupboards, or your local-ish climbing gym's retired section.
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