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Snow pickets

10:36 p.m. on December 13, 2001 (EST)
(Guest)

Expert advice needed...

I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

The v-section is 5cm either side and 3mm thick as recommended.

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Opinions welcomed!

Cheers,
Alan.

1:47 a.m. on December 14, 2001 (EST)
(Guest)

Quote:

Expert advice needed...

Who's a snow picket expert anyway??? FWIW:

Quote:

I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

I'd go w/ T section, holes are mostly to reduce weight and provide clip in access near the surface or dead man clips.

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The v-section is 5cm either side and 3mm thick as recommended.

OK. I'm no mettalugist, I'll spend the under 20 bucks, save the time and the risk.

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Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

A not so sharp spiked end makes a nice start for when you are really starting to whack/stomping on it. Why not at least a bit of a bevel? Can't hurt.

Quote:

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

I don't really trust pickets as deadman. They just provide a basic anchor and don't dig in like a real shovel type deadman. I just solo at that point. When I do use a picket, I girth a runner through the hole closest to the surface, reduces a biner.

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Opinions welcomed!

Good luck, have fun, be safe.

Quote:

Cheers,
Alan.


Cheers,
Christian :?)

9:53 a.m. on December 14, 2001 (EST)
(Guest)

I know a lot of guys who use homeade pickets and they seem to be no different from the manufactured ones. I would just mimic the design of one of the current model for the # and spacing of holes etc. I use a double sewn runner girth hitched through the centre hole. This way its ready to use as a deadman and can be threaded through a higher hole for conventional use (a cable is more of a nuisance to handle) I use pickets mostly in deadman mode. If the snow has a frozen layer deeper in the pack and the deadman hits it, it can deflect and fly right back up to the surface. A picket can be better in this situation. If you want to test this safely, place a picket or deadman on a flat snowfield as you would normally. Attach one end of the rope through the anchor and then three or four guys tied in along the rope leaving some slack. Then get the guys to run in unison to simulate a large force on the anchor. If there is a frozen layer in the snowpack the deadman may deflect off it and fly out to the surface.

I dont know if manufactured pickets are even tested like ice screws are so if you use good quality aluminum I dont see a big difference. Maybe someone else can confirm or deny this.

 


Quote:

Expert advice needed...

I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

The v-section is 5cm either side and 3mm thick as recommended.

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Opinions welcomed!

Cheers,
Alan.

11:12 a.m. on December 14, 2001 (EST)
0 reviewer rep
408 forum posts

Quote:

Quote:

I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

Since your makin' 'em, you "should" know about min. edge distance to maintain min strength. If you don't, then, I'd suggest not makin' em.

That said, go to a shop and measure a 24" MSR picket and copy the hole spacing and diameter. Or, just buy one...

Quote:

Quote:

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

A not so sharp spiked end makes a nice start for when you are really starting to whack/stomping on it. Why not at least a bit of a bevel? Can't hurt.

I'd bevel.

Quote:

Quote:

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Funky load path. I wouldn't attach cable.

Quote:

I don't really trust pickets as deadman. They just provide a basic anchor and don't dig in like a real shovel type deadman. I just solo at that point. When I do use a picket, I girth a runner through the hole closest to the surface, reduces a biner.

I trust pickets way more than deadman since I can never tell when a deadman is gonna dive down then bounce off a rock or ice chunk and become useless...etc etc...also, havin' to get the angle of the wire just right, I much prefer pickets. Haven't bothered carrying deadman in years...

Never rapped off a wired in place self diggin' deadman. Rapped off many pickets....

Personal preference...

Brian in SLC

12:33 p.m. on December 14, 2001 (EST)
(Guest)

pickets

Quote:

Expert advice needed...

The v-section is 5cm either side and 3mm thick as recommended.

I am no expert.

But a V shaped section is probably not the best shape to use. It only gives a small surface area against the shearing force through the snow.


chris

2:26 p.m. on December 14, 2001 (EST)
TOP 10 REVIEWER REVIEW CORPS
2,219 reviewer rep
5,180 forum posts

Not sure the real experts (i.e. the guys at the manufacturers) will dispense advice for free to a potential competitor. So you will have to make do with us opinionated am'churs.

As others have said, T-section is pretty much standard for pickets. I can see where angle would have problems in the snow.

I have made my own from T-section and then just basically copied what's out there in simplest form. Seems to work just fine. Use tubular webbing, not cables. I think your cable has too many potential problems, as Brian already said.

Have to agree about potential problems of a fluke, although I haven't had any problems with one when I put it in properly. Sometimes I put a picket in by just sticking it vertically into the snow (well, at the proper angle), but most of the time, if I had time, I set it in as a deadman. That is, trench in the snow, lay it horizontally, girth hitch at the middle.

Sounds like you come from a rock background and don't have experience on snow. I suggest that before you start making pickets that are so different from accepted practice, you climb a bit with some experienced snow and ice folks, or take a course on snow and ice, to see how pickets, flukes, ice screws, etc are really used. It's easy to get it wrong, and a wrongly placed picket can pull out very easily just when you want it.

6:30 p.m. on December 14, 2001 (EST)
(Guest)

a.k.a. Karl

I've made some pickets out of "L" bent alu and they work fine, but they are a little heavier than purchases ones. Also, when you clip in a biner in one flange, the strength is fine and it puts a torque and twisting force on the picket, but from testing, it didn't make any difference in the holding power. Put holes every 6 inches or so. Make sure you keep the holes as far away from the flange edge as you can and still get a biner to clip into it and rotate around. I beveled the bottom to a "point." My metal was free, otherwise I wouldn't bother making them. I like my bought ones better.

My big question is why don't they design an ice axe that allows pounding in of pickets in harder snow without either messing up the axe head or mushing out the top of the picket?

Karl

 


My metal


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I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

Since your makin' 'em, you "should" know about min. edge distance to maintain min strength. If you don't, then, I'd suggest not makin' em.

That said, go to a shop and measure a 24" MSR picket and copy the hole spacing and diameter. Or, just buy one...

Quote:

Quote:

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

A not so sharp spiked end makes a nice start for when you are really starting to whack/stomping on it. Why not at least a bit of a bevel? Can't hurt.

I'd bevel.

Quote:

Quote:

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Funky load path. I wouldn't attach cable.

Quote:

I don't really trust pickets as deadman. They just provide a basic anchor and don't dig in like a real shovel type deadman. I just solo at that point. When I do use a picket, I girth a runner through the hole closest to the surface, reduces a biner.

I trust pickets way more than deadman since I can never tell when a deadman is gonna dive down then bounce off a rock or ice chunk and become useless...etc etc...also, havin' to get the angle of the wire just right, I much prefer pickets. Haven't bothered carrying deadman in years...

Never rapped off a wired in place self diggin' deadman. Rapped off many pickets....

Personal preference...

Brian in SLC

8:44 p.m. on December 14, 2001 (EST)
(Guest)

Thanks for all the replies folks!

A couple of things as best I can work out...

A T-section picket uses the same amount of metal as a v-section one of the same section width (hence they are of the same weight), except it has less holding power than the V-section because the width resisting the load is only one section (e.g. 5cm) across. Also, the v-section acts as a wedge, it compacts the snow across its front surface, loading the back edges of the sections which are made up by the triangle of the V.

If using it as a standard picket, the v-section on the back also holds snow like a shovel, which resists the tendency of the picket to flip over and out when loaded from the top holes at the snow surface. (Not a problem in hard snow where you need to whack 'em in... certainly a problem in soft spring snow around here)

Yes, I know about having the cabled snowpigs catapult out... it has happened to me a couple of times when I've put 'em in and tested them prior to depending on them for holding a fall. If the snow is not right for it, yeah, just bury them horizontally.

Still, I reckon a self-burying deadman/snowpig is more trustworthy than a standard picket... I guess it depends on the snow. That has been my experience around here anyway.

I agree the cable is a pain to handle... I was worried that a sling or accessory cord would cut on the edge... but yes, a guy I was with this winter (Australian winter) had his set up with 6mm access. cord and we had no problems so maybe I'll ditch the cable idea and smooth the edges of the hole.

Re: hole diameter... well, I decided to go with 3/4 of an inch. I can't just copy the MSR ones b/c they use a different kind of aluminium (a Magnesium alloy?) than the stuff you get at the hardware store... I believe its a bit harder than mine. That's why I was asking about the hole size. I've erred on the side of caution and put in less holes and of narrow diameter to preserve the strength.

Yep, bevelling is a good idea... doing that too, tah.

Oh, and BTW... down here in Oz, an MSR coyote is around $50... too much for me to afford to buy a few and throw them away on rap's. Hence my eagerness to make them myself.

Never know... I could go into business with my own design... or then again, I could just go climbing :-)

Cheers,
Alan.

7:10 a.m. on December 15, 2001 (EST)
(Guest)

Having worked on and around aircraft structures (aluminum) for many years I wouldn

2:30 p.m. on December 15, 2001 (EST)
(Guest)

I ain't no picket expert, and did you posted similar questions last year?

Quote:

I'm making up some v-section snow pickets

>V-section gives a slicing edge if you go off-path or if loading your picket away from your fallline . Think about it... a T-section will still give a right-angled V-surface for force distribution during lateral loading. Don't you think there is a bit more safety margin for T than a V?

Quote:

To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner

>I agree with Brian in SLC. This is funky force loading. Your anchor point is still at the middle of the picket and yet you direct the load up the length and redirect it at "right-angle" thru a top hole. Something ain't right in this loading.

Base on the thinking process that arrives at the above 2 designs (sorry, I'm just guessing here), I suggest you don't make your own picket at all. Happy Holidays. :-)

9:12 p.m. on December 15, 2001 (EST)
(Guest)

Quote:

Having worked on and around aircraft structures (aluminum) for many years I wouldn

11:05 p.m. on December 15, 2001 (EST)
(Guest)

Re: NZ Snow pickets

I've done this to create so called NZ pickets.

Used pictures I got off the Yates site (no problems there - they have obviously ripped this design off some NZ guide or other). Did up a quick CAD drawing and made up out of 10cm Al angle. Two end holes for sling(s) lightening holes at 50-60mm offsets centres along length. Swallowtail end. Did up in red two part enamel paint for vis. Don't believe those Seppos that tell you that you have to have T sections - snow/ice will give first anyway!

In short: 0.5 and 0.66m l3lengths. Cost me $A14 each to make including getting the cable swaging professionally done.

Email for more info paul@asott.nsw.edu.au.nospam (remove nospam)

Cheers,

Macca

2:53 a.m. on December 17, 2001 (EST)
(Guest)

NZ cable pickets....

Can be rigged in either configuratuon. End attachment as picket, side cable attachment as pig.

Macca

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I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

Since your makin' 'em, you "should" know about min. edge distance to maintain min strength. If you don't, then, I'd suggest not makin' em.

That said, go to a shop and measure a 24" MSR picket and copy the hole spacing and diameter. Or, just buy one...

Quote:

Quote:

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

A not so sharp spiked end makes a nice start for when you are really starting to whack/stomping on it. Why not at least a bit of a bevel? Can't hurt.

I'd bevel.

Quote:

Quote:

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Funky load path. I wouldn't attach cable.

Quote:

I don't really trust pickets as deadman. They just provide a basic anchor and don't dig in like a real shovel type deadman. I just solo at that point. When I do use a picket, I girth a runner through the hole closest to the surface, reduces a biner.

I trust pickets way more than deadman since I can never tell when a deadman is gonna dive down then bounce off a rock or ice chunk and become useless...etc etc...also, havin' to get the angle of the wire just right, I much prefer pickets. Haven't bothered carrying deadman in years...

Never rapped off a wired in place self diggin' deadman. Rapped off many pickets....

Personal preference...

Brian in SLC

11:49 a.m. on December 17, 2001 (EST)
(Guest)

V vs. T ??

Quote:

A T-section picket uses the same amount of metal as a v-section one of the same section width (hence they are of the same weight), except it has less holding power than the V-section because the width resisting the load is only one section (e.g. 5cm) across. Also, the v-section acts as a wedge, it compacts the snow across its front surface, loading the back edges of the sections which are made up by the triangle of the V.


This the part that loses me.


chris

5:38 p.m. on December 17, 2001 (EST)
(Guest)

The temper is your biggest variable now that you

3:22 p.m. on December 18, 2001 (EST)
(Guest)

a.k.a. Karl

Well, we've beat this one to death!! All good thoughts. Just one more for the road: I doubt the engineering aspects of the metallurgy and shape even come close in importance to the skill in setting the anchor--at least in less than hard glacier snow. I've experimented with test falls in various picket placements and found that in snow that is not solid (you don't have to pound the picket in) that you MUST try a hard jerk or test fall on them to be sure they will hold. I have pulled steady as hard as I could against some placements and thought they were solid, but a test fall proved me wrong. The test jerk is critical.

Karl

Quote:

Expert advice needed...
I'm making up some v-section snow pickets from extruded aluminium. They'll be 24" (60cm) long. I'm wondering, besides the holes in the middle, and ones at either end, how many holes ought I drill along their length, and what diameter should these holes be?

The v-section is 5cm either side and 3mm thick as recommended.

Also, I'm thinking of leaving the ends smoothed over but flat... like the MSR coyote's rather than spiking one end. What do folks here think?

Last question... to use these as snow pigs I plan on attaching cables through the centre holes. To use them as conventional stakes, I can then thread the cable up thru the top holes and clip in a biner... or should I just clip in a quickdraw thru the top holes and forget the cable?

Opinions welcomed!

Cheers,
Alan.

7:48 p.m. on December 28, 2001 (EST)
(Guest)

It sounds like you are basing your design on the specs in 'mountaincraft'. I made a couple of stakes on this design earlier in the year (I was the poster who asked a similar question a year or so ago) and tested them in the snowies over winter. They seemed to stand up well, although I didn't use cables or use them as pigs. For a 60 cm stake I drilled 5-6 18mm holes. This seemed right, from memory, and from a picture of commercially available ones online:

http://www.outdoorstore.co.nz/snow_stakes.htm

They aren't all that expensive in NZ. I remember them for sale in Christchurch for the Aus equivalent of $20-25, so it's worth considering buying them there, if that's where you're headed.

Andrew

April 16, 2014
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