jsb
Trad climber
Bay area
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Jan 24, 2008 - 04:23pm PT
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uhhhh... you know that trees fall over in ice storms, right?
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jsb
Trad climber
Bay area
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Jan 24, 2008 - 04:26pm PT
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Actually... just an order of magnitude calculation here for ya.
Let's say you want some ice that's 5 inches thick, and your sheet is about 15ft x 50ft. The total weight of the ice on your rig is gonna be about 20,000 lbs.
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WBraun
climber
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Jan 24, 2008 - 04:32pm PT
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Pretty cool, hope it works for you.
Good luck ....
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Prod
Social climber
Charlevoix, MI
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Topic Author's Reply - Jan 24, 2008 - 04:35pm PT
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Hi JSB,
Now tell me the vertical compression strength of a 2x4. Added to the fact that we are counting on, and building toward, a heafty load bearing base, along with guy wires and triangulation bracing to other trees. Above all of that I really hope you're wrong and it does not fall down.
Prod.
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Dingus Milktoast
climber
NorCal
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Jan 24, 2008 - 04:35pm PT
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Have you seen how they build that self supporting ice tower thing in Alaska each year? They pay a lot of attention to the base, making it strong and broad.
Yours doesn't appear to have a base.
Cheers
DMT
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divad
Trad climber
wmass
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Jan 24, 2008 - 04:41pm PT
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Well, has there been a first ascent yet?
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Prod
Social climber
Charlevoix, MI
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Topic Author's Reply - Jan 24, 2008 - 04:42pm PT
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Thanks DMT,
We are working on that and have found that by blowing light snow on the ice the snow combines with the tower to get some mass. For sure we are working toward a heafty base. Currently it is way more bomber that one would expect. We considered topping the maples to cut down on the wind effect but have decided that the set up we have is adequate? We'll see????
Prod.
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Tarbuster
climber
right here, right now
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Jan 24, 2008 - 04:47pm PT
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Uh, human fly swatter?
For the love of God: get outa' there Prod.
I got my rope stacked for you.
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jsb
Trad climber
Bay area
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Jan 24, 2008 - 05:00pm PT
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hmmm, yeah... i guess i didn't realize that you were hoping for the structure to support itself. that'll be awesome if it works.
i'd love to see more photos as this thing comes along.
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O.D.
Trad climber
LA LA Land
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Jan 24, 2008 - 05:00pm PT
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Hmmmm....those trees look kinda slender with respect to the load they'll be carrying.
With water ice weighing in at about 57-lb/cu.ft., when the ice has built up to a thickness of 6 inches (maybe the thickness before a supporting pedestal starts to form at the base of the sheet) the total ice load will be about 7.5 tons. When the ice gets to 8 inches in thickness (maybe a minimum for climbing in this situation?) the total ice weight will be about 11.5 tons; some of that weight may be supported by the sheet itself as it makes contact with the ground. Just looking at the photo, it's difficult to see how the top of the fence is keyed into the tree branches -- but however the fence is fixed to the trees, each attachment point has to be capable of sustaining several tons of force.
And, it looks like the ice sheet will function like a great big sail in the wind. Add a nice cantilever load to the trees in addition to the vertical load from the ice, and you may see the supporting trees turn to splinters in the blink of an eye.
A couple of suggestions: never undercut the base of the sheet (thereby removing its ability to support itself), and I wouldn't go near the sheet when there is anything more than a gentle breeze blowing. No helmet in the world will protect you from 10 tons of ice falling down on you.
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Russ Walling
Social climber
Out on the sand.... man.....
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Jan 24, 2008 - 05:04pm PT
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Tar is on to something....
Got to say it Prod.....
YER GONNA DIE!!!!!!!!!!!!!!!!!!!!!!!!!!!!1111111
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paganmonkeyboy
climber
mars...it's near nevada...
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Jan 24, 2008 - 05:05pm PT
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I wonder if you might want to throw an intermittent support across the back - put up a 4x4 on either side and a cap across to support some of the weight, and just ice it in with the rest ? say 10-15 up ? might take some of the stress off the trees...
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graniteclimber
Trad climber
Nowhere
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Jan 24, 2008 - 05:06pm PT
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"Now tell me the vertical compression strength of a 2x4."
I wouldn't expect vertical compression to be the primary failure mode. That thing looks like it wants to fall over sidways. I really hope I am wrong.
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goatboy smellz
climber
colorado
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Jan 24, 2008 - 05:12pm PT
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Holy piss and cheerios Guyman!
That's a Wile E Coyote disaster waiting to happen.
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Jaybro
Social climber
The West
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Jan 24, 2008 - 05:23pm PT
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Now DMT, we all know, since 1957 (59?, 72?), that the summit ice shroom don't mean sheeit!
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Dingus Milktoast
climber
NorCal
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Jan 24, 2008 - 05:26pm PT
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They left the water pump just hanging there. Someone tried to chop it down last year I heard.
Cook claimed the FA.
DMT
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Tarbuster
climber
right here, right now
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Jan 24, 2008 - 05:28pm PT
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Nothin' to be alramed about folks.
Read careful like upthread, at what Prod wrote.
Prod's boss, an architekt, designded & built this thing.
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O.D.
Trad climber
LA LA Land
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Jan 24, 2008 - 05:28pm PT
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Yeah, affirming what DMT said -- looking at the photos on the Alaska Alpine Club site, it seems that if some kind of flaring structure were tacked right away onto the base of the sheet, you'd get a supporting pedestal built up fairly quickly. This thing could really work! Good luck!
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