4 Yard Tarp Challenge w/ Side Entry & 2 Stake Set-Up

Just came up with this idea.

Trying to come up with a simple side entry tarp design that only requires 2 stakes to set it up.

I have to reverse engineer the L out of it to get everything to line up.

Figured I would throw the challenge up to see if anyone else can come up with something better.

I’ll get some photos up as soon as I get the design squared away.

Is that 4 roll yards, or square yards?  How ’bout poles?

This is 5 sq yd of fabric.  Trekking poles set to 52″ in an A-frame, 48″ wide at the base.  Over all length is 9′.  Short, horizontal rods at the ends are 18″ and 30″, 7′ apart.  The apex is dead center.  For entry, you either put a zipper up the side, or cut one side high.

4 roll yards.

Assuming a single straight pole, and no attachments to trees and what-not, then it cannot be done.
Three stakes are needed to define a plane. On that plane you can mount a pole for the fourth point (or 3rd dimension.) This is sample of a minimal configuration:
Using an offset pole for sleeping space, this leaves one corner for gear storage, assuming a 48″ high shelter and side walls about 96″-102″ long.

Agreed. James’ tetrahedron is the simplest 3-dimensional shape possible.

However, you could stretch it to create more options.

Of course.

You have to use 2 poles.  Everything I’ve been doing lately is off a diamond shape.

This one will be a little different.  It will curve around the rear pole to assist in having the sleeping area centred.

I’ll be using the 4 yards with only 2 cuts in the fabric and they will be moved to the front and sewn back on to complete the shape.

And there is already a tent that can be pitched, and is actually quite stable, with only 2 stakes: The Lightheart Gear Solo, so you could model a tarp with that arrangement.

If there is adequate tension along the ridge line, the side poles can be held quite firmly to the ground.

Hey Bob,

I’ve been using that design for about 10 years no.  Much more than 4 yards though.

For the tarp you’re proposing now, is one side open?

The stretched tetrahedron is about as efficient as you can get… it’s essentially half of a flying diamond.

I’m very interested to see what you’ve come up with!

You don’t always have to have a closed end.  As long as the angles are the same, the 3 ends can be held with 1 stake.

You don’t always have to have a closed end.  As long as the angles are the same, the 3 ends can be held with 1 stake.

OK, so you must be thinking of an enlongated half diamond(??) This is still a tetrahedron, albeit with 2 open planes. This could be pinned with 2 stakes using tension and friction to hold down the pole tips, and a string or strip of material between the pole tips to maintain the distance between them.

In lieu of further speculation, I await your photos!  :^)

Yeah, like bob says, it is still basically a tetrahedron. In lieu of a third stake, you use a second pole. I think a stake is lighter.

For example: You could lay the triangular shaped poles sideways. Ie, one pole laid down and one offset pole to hold up. Of course then you need the two stakes to hold the pole from flopping one way or the other. But you cannot cheat physics. 4 points must be stable to create a tetrahedron. The first and simplest of a geometric structure. This can be made from a simple square tarp. Anchor the center and one of the far corners. Insert a hiking staff and pull the other far corner out and anchor it. Done.

Of course, using a flexible pole or two you can actually create a freestanding tent or tarp frame. This doesn’t require ANY stakes. With no definition on the number and type of poles, you can literally do anything. But, I don’t thing this is what you are after.

If my 150 kb photo would load (this site thinks it’s over 1mb), I would update what I have so far.

jpeg?

You can also copy/paste an image directly in to the editor.

This is a mock up sketch from a full width, 4 yard piece of fabric.
There are 2 cuts that are made and sewn back on the tarp shown with the black dotted lines.
The red lines are the ridge lines.
The purple lines are where it would be cut and it comes together to form the 2 halves of the front, with the door being #1.

None of these lines are correct to allow this to be set up with 2 stakes yet. It takes some reverse engineering to make that happen.

Yeah, you need 1 pole and 6 stakes the way it is drawn.

Or 2 hiking poles and 2 stakes.

There’s only 1 at the foot end.  The ridge lines just have to line up for 3 lines to come together and be staked out with 1 stake.

Hmm… I’m not visualizing that. A photo or an isometric drawing would help.

My first model wanted 13′ on a roll.  Here’s one in 4yds, any width, 3 cuts, 4 seams.

Shown here using 54″ (DCF) roll width.  Trekking poles pin down front corners.  Tent length is ~10.5′, 14′ stake to stake (guy line at 45d); 43″ tall (not accounting for hem losses).  If you don’t like the sloping front end (poles lean away from guy lines), flip the main triangles before sewing to make it vertical – this loses about a foot of length and makes it a bit taller.

Here’s a side door cut out, 30″ tall, 6′ long, w/ a bivy foot print (84″, 30″/18″) and center line inside.  Bivy doesn’t get rained on when open.  7′ from the front end, it’s 18″ wide and 16″ tall – laying on your back, your feet will probably be pressing against the side walls.

This actually isn’t all that bad.  I’ve never taken this close a look at this paradigm due to the the cramped foot space and long foot print.  6 sq yd of fabric, and a yard of zipper.

This is looking better and looks to be usable.

I believe there was a 4 yd challenge for a tarp some time ago. But, this was not side entry. And it required a minimum of 6 stakes and two poles. Note that my pack also uses 16″ stays. So, I just clip these together (after some mods) to make a 30-1/2″ rear tent pole. My front pole is my 45″ hiking staff. The main body was from the 4 yd challenge. Roughly, laid out like this:

There are multiple erection options with only a single 7′ pole and some long lines at the front/side staking points, and the back tied off to a lean-to, it can stretch over the fireplace in rainy/cold weather.