I am digging for ideas for a UL above tree-line, winter shelter.

Examples of two pole shelter:
>MSR twin sisters
>Golite Shangrila 2
>BD

Examples of single pole pyramid/half-pyramid:
>Oware pyramid
>Oware alphamid
>Golite hex/shangrila 3
>MLD mid
>BD

my question is does two pole twin sister design sheds wind and snow better then a pyramid/half pyramid when both properly pitched? Does the lower profile offer any advantage?

A one-pole shelter (e.g. teepee) properly staked down and guyed out is going to be pretty darn secure against wind and snow. Some winter tents come in this configuration.

I don't recall seeing a "twin peak" configuration winter tent. As you might picture, they won't shed snow as well.

But two poles can also make a dome. This is good enough for most 3-season use, but for serious winter or mountaineering, even dome tents will often come in 3 or more pole configurations. Increasing the number of poles and intersection points provide increased structuring / load bearing strength.

Edited by ben2world on 05/01/2008 00:38:16 MDT.

Ben, you may get surprised but MSR rates its twin sister tent as an 'expedition tent'.

If you are after a minimalist, ultralite, above tree line shelter, I doubt that you can go past a tipi type design.

Franco

There are several two pole shaped tarps used four season
1. MSR twin peaks
2. MSR twin sisters
3. BD betamid
4. BD beta light
5. Golite shangrila 2, 6, 8
6. MLD superfly (could be)

Edited by jshann on 05/01/2008 09:09:23 MDT.

I think the lower profile of the Twin Peaks has some advantages in the wind. This benefit is probably offsest by the extra width of the teepee though. Any side panel deflection due to wind is going to intrude in the useable space easier on the Twin Peaks than a larger Teepee.

The more important wind related thing may be the pole. If you strap two treking poles together with a 8-12" overlap to use as the center pole of the teepee, it will probably be much wobblier than using 1 trekking pole per peak in the Twin Peak type tent.

Also, the steeper sides of the Twin Peaks means you don't have to beat the sides as often to keep snow from building up during storms.

On the other hand, the extra room to move around in a teepee sure is nice when snow camping...

"Does the lower profile offer any advantage?"

If you can reduce your exposed area, you will gain advantage. Wind at ground-level is less than wind 5 feet above. Wind at altitude is fierce everywhere.

A tepee requires a tall pole to provide usable volume, so unless you're capping a snow pit with a 'mid top you'll have more exposure. Walls would help.

I had a sectional, 6' tall, 1.5" diameter aluminum (6061T6) pole fold due to wind while in an 'mid above treeline.

I favor low profile.

I was also wondering about that, especially for a winter shelter ... any experts to chime in? SMD? MLD?
Sven

On a recent winter trip I had my two pole MSR Twin Sister set up next to a Mountain Hardware Kiva tepee style single pole shelter. With very strong winds and hard blowing snow the MSR two pole design handled the conditions better requiring less attention after set up. This was likely due in large part to the lower profile. The single pole did provided greater head room and a larger foot print. With the MSR, and similer shelters, being floorless a user can dig down (in snow) to provide greater head room if pole length is planned for.

John, Greg, Thom good points.

I really dont need (or want) the space hex/tipee offers. It poses a problem of finding a large clearing and more guyout and stakes.

My sub-2 pound tent plans were going fine but Mike Hinsley pushed me to consider tipee design. I spent last few days digging tipee, hex, four side pyramids, alphamid, and then two pole tarp shelters. From reviews/comments I have read and from my own understanding a properly pitched twin pole design should work better. Actually it could be seen as two short but steep pyramids connected together.

Thom, your comparison comfirms that.

Hi,
Mids, hex and alphamids all have flat panels and are less aerodynamic then a tipi. The Titanium Goat is a true tipi design and is far more aerodynamic then the above mentioned designs. I have used mine in a variety of above tree line applications and never had a problem. It spills wind easily and I have never had a blow down in some pretty knarly winds. The Ti-Goat has 11 stake out points which is either a blessing or a curse. You have to find open ground for 11 stakes, but this offers a lot of ground holding capability. if you are on snow and using snow anchors then you should be fine. If you want it for winter camping and don't mind a little extra weight, then they can custom build one out of Epic. The canopy for the standard syl nylon, 2 person model weighs 21 oz. It is super well made and strong and shows no wear.

Geometrically, the conical teepee will deflect winds and snow better than the more complicated shapes of twin peaks.

>Geometrically, the conical teepee will deflect winds and snow better than the more complicated shapes of twin peaks.

oops. I think I generalised a teepee as a hex/pyramid design with a pointed center.

Ben, you are right. A conical teepee should shed wind better then twin peaks or pyramids.

I had in mind the TiGoat Vertex 5 when I suggested a tipi(teepee), but thinking about what you are trying to accomplish a two pole A frame design may be better.
Franco

Edited by Franco on 05/02/2008 02:48:34 MDT.

A small conical pyramid with enough place for two people to sit/eat/play and you sleep outside with only your head in the pyramid?

If you take a look at many arctic and antarctic tents you
will find a lot of pyramids. The hold up extremely well in
high winds. I have had mids set up in eastern oregon that
survived wind gusts that crumpled and broke poles on a
4 person Northface expedition dome.

The issue with teepees is the internal space is less usable
with its circular floor than a square or rectangle. You
end up having to make the shelter larger, which defeats
the purpose of less surface area and weight.

In heavy snow, a tall mid will do better than a shorter
2 pole design, given a strong enough pole. Same for
condensation.

A pyramid wouldn't be my first choice on Everest (too
much floor space) but they've been there.

Thanks for the comments.

David, its assuring to know that pyramids have been used on everest and are still used in arctic and antarctic.

Some days back I read the thread about henry shires new tarptent. It uses a inverted 'V' pole configuration. I think it may just be the ticket for more usable space and wind stabilty. A hex/tipi using two ski/trekking poles I can have just enough space to sit/eat and my gear or (may be) for two people to sit/eat. For sleeping only a part of the upper body stays inside while rest of the body is outside. Best thing is that I dont even need a bivy since I will be using a inflatable waterproof DAM and overquilt. I think it is an improvement over a hooped bivy idea.

Any comments on this idea?

Edited by huzefa on 05/02/2008 13:12:28 MDT.

I have been playing with the V-pole configuartion. I drew some sketches of diamond shaped shelter but even though its very aerodynamic it is longish and I suspect the ends wont hold up in snow.

I find hex shape to be the best design. The key is to keep it as short as possible.

Shorter lenght = steeper ends = better snow shedding

Edited by huzefa on 05/05/2008 09:51:34 MDT.

Hey Huzefa,

Your design is very similar to the SMD Oasis other than it being a single pole.
I'm sure you could go off of a modified form of it.

http://www.sixmoondesigns.com/shop/shopexd.asp?id=48

There are a few other crazy but due able things you can do to make any tarp/tent type of shelter a 4 season shelter.

My input to make your shelter multiply in strength by 10 fold (?) would be to get a spool of 500# test strength.

http://www.kitebuilder.com/catalog/index.php/cPath/30_75?osCsid=061963412f010c14ec44635cd3b85fe8

All you would have to do with it is to sew it in loose along your lateral lines that would go all the way from the top to bottom and would act as your tie out lines as well.
You could also sew it in half way up the side of the opening door side(s) to the corner of them for extra strength.

The spectra will hold up to anything and now all you would need is to just be able to have the fabric hold up in between. This will cut out the flapping you would have from the wind big time.
You would just have to use a very strong fabric where the Spectra would be sewn in so it doesn't tear.
I use this (the 200# test weight) on a few home-made tarp/ tents I have made and it works excellent.

I was thinking that the V-pole was your sub-2 4 season hense the strength issue on this, but you could utilize it in the 4 season as well.

Edited by awsorensen on 05/10/2008 15:51:43 MDT.

I recently switched from a Golite Hex 3 to a Shangri-La 2 and am very happy I did. It is easier to set up, has a lower profile, and since there are two apexes, in some ways it feels larger, or at least less confining, than the Hex 3 with all sides sloping to a point.

Best of all, I can set up both my wife and my hiking poles as inverted Vs, so we have a completely pole-free interior! This also puts the poles right up against the side walls, which keeps wind deflection to a minimum. If you think about it, Native American tipis were sucessful, but they had wooden poles supporting each fabric segment. My inverted-V Shangri-La 2 setup is closer in spirit to that than a pyramid tarp with only the single pole in the middle. I was never comfortable with the amount of bend my poles did holding up the Hex 3.

Finally, a Golie rep told me that in January 2010 they will release an updated version that is the same dimensions but is 5oz lighter thanks to a "lighter and stronger" fabric and will have larger peak vents. Since my Shangri-La 2 is 22.4oz, that should bring this down to a 1 lb, 4 season tarp.

>> Best of all, I can set up both my wife and my hiking poles as inverted Vs, so we have a completely pole-free interior!

Doesn't she get fatiged? But, wow, talk about multi-use gear! How much does she weigh?

Fatigue shouldn't be a problem if she's done enough down dogs in yoga.

And as I've mentioned before, ALL wives are LW. Disagree at your own peril, and I call first dibs on your gear.

I have to admit that was really funny. Poor choice of syntax on my part... I never thought about using one's bones as UL poles before...