3+ season Tent Design

[Nia Schmald]

I've been looking for a 2-person shelter suitable for 3+ season use in the sierras. The best option seems like the mid style tents (betamid, shangri-la, superfly) or the tube tents. The mids don't have much in the way of headroom and I don't like the idea of having poles between me and my companion. The tubes are quite heavy with the support poles. My thought is to combine the two by using the mid design and putting two small 30" fibraplex spreader poles perpendicular to the trekking pole supports. These would be inserted under stress to create a supported peak.

The result would look something like this except that a used a straight line rather than an arch (can't figure out how to do that in sketchup) to approximate the curve of the spreader poles.

It will use about 8.5 yards of fabric and can be made with 4 pieces of spinnaker which should yield a fairly low weight.

Is there any rule of thumb as to how much additional weight is added with seams, tie out points, zippers, etc?

Has anyone tried anything similar? Will the flatter top collect snow if there is any significant snow fall? Any other critiques and criticisms?

Thanks for looking.

Edit: Sorry for the lack of pretty colors.

[David Passey]

I have spent a bit of time working on a similar design, but lacked the time/motivation to carry it through to completion. My design is very similar to yours, except I had the back dropping to allow rain to run off the ridge and reduce the weight. The nice thing about the mid is that the fabric that would otherwise serve as a "beak" (e.g., tarptent) is used for a zipped panel. The drawback is no vestibule space.

[Nia Schmald]

Hi David,

Yeah I thought about dropping the back down as well, but with my pathetic cad skills I couldn't make it look right. I like that idea though as it should deal better with wind and rain and I could potentially move the rear pole to the outside connected with a guy line to the peak, freeing up interior space.

One advantage of being only 5'8" is that I don't need to use the space under the entry way for sleep space so that can serve as a small vestibule. It's tight at only 2' at ground level, but it would probably be enough space to cook in in an emergency. If I added a floor it would start after the pole.

[Greg Mihalik]

This may give you some insight…

Posted by Roger Caffin, in Editor's Roundtable, on 12/05/07

More details at
http://www.bushwalking.org.au/FAQ/DIY_RNCTents.htm
http://www.bushwalking.org.au/FAQ/DIY_RNCSummer.htm
http://www.bushwalking.org.au/FAQ/DIY_RNCWinter.htm

[Devin Montgomery]

Hi Nia,
I recently spent more time than I care to think about trying to get a handle on sketchup, and I also had no CAD experience. From engineering pals of mine, I understand that it's a lot easier than true CAD, but the simplicity and debatably "intuitive interface" do have their drawbacks.

Anyway, if you use the arc tool, you can make an arch as steep as a half circle (half as tall as it is wide). Any taller than that it starts to bulge more than an arch would. If you want something with more height relative to its width, the best I've found is that you can create a steep pointed arch by making an a-frame with the arc tool, and just having each side slightly bulge. I hope that helps, and I have found the online tutorials offered can be helpful if you have the patience to sit through them.

Good luck!

[Author]

Posts