snow pickets

[drl]

I want to make some tubular snow pickets with an inside diameter of about 5/8". Can anybody tell me what wall thickness I should use? Should that be 6061 T6 aluminum?

[jaee]

Disclaimer: I'm probably full of crap, so you're on your own if you take my advice

Your choice of material is not bad, but with an ID of 5/8" there's not much material left if you put a hole thru it for webbing or biner.

 

5/8 id wouldn't really be stiff enough for a safe picket in snow. You'd be better off with a bigger tube with a thinner wall. I think you'd need around 1-1/4 OD. I'd have to run the numbers to optimize the thickness, but any wall thickness over .100 would be probably be a safe starting point.

 

Any particular reason you're reinventing the wheel?

[cj001f]

5/8" ID is just a long ice screw.

[ken4ord]

I would tend to think that a tubular picket would be hard to clean out and not hold as well. I have never used them, anybody have any experience with them?

[selkirk]

Used one of the ones that Pro Mountain caries in hard snow this season. They drive real well in consolidated snow so long as you have a hammer on your ice tool, but if it's at all loose i think they would pull out too easily. It's more like a giant snarg (?) that doesn't screw out. Ok to clean though. You ought to take a look at those and model after them. Less of a picket more a snow piton it seemed like.

[Jedi]

The one's like Petzl makes are basically a handle of an ice axe. There is a hole for to tieing or girth hitching webbing too. They are light for a picket at around 9.5oz.

Not sure what the I.D. is. It is ovel.

At the same weight, I think the Yates pickets would have more surface area. The MSR's seem to have even more surface area but are heavier.

 

I wish someone would do some side by side comparisons to see how the 3 different designs compare in strength and sheering.

 

Logically, in loose snow, it seems the picket with biggest suface area would hold the best and be more forgiving if not placed ideally.

 

Jedi

[Big_Sky_Ry]

Yates expeditions are 10 oz. The tubes used over in Europe (more than here) run 8 to 9 and don't work at all in anything but pretty hard snow - something about that aerodynamic surface area that makes a cylinder a poor anchor. The Yates pickets are excellent. I've been really happy with them.

 

I took a leader fall above a belay anchor that consisted of a tubular picket in hard snow, an MSR Blizzard stake in hard snow (don't ask), and a screw in ice. The anchor was equalized among all three and the picket was the one that pulled.

 

RJ

[bigwalling]

snow pickets are aid

[RuMR]

Yes...i agree...i typically grab a "bigwalling" and pound his dumb arse into the snow and clip his sumbitch ass off and go...werx like a charm...

[drl]

Thanks for the replies guys.

I am making something that rquires tubing and the size is determined by other factors. I thouht if the part could double as a picket, it would be a bonus. 5/8" ID with thick enough wall should be strong. THe small ID may limit the type of snow where it would work. I don't know.

[cj001f]

THe small ID may limit the type of snow where it would work. I don't know.

Pull out strength is going to be proportional to the OD/external dimensions for any deadman/picket type anchor.