+1 on Just Bill's analysis. We got us another bridge hammock engineer. We'll have to out shug shug and make up some T-shirts.

Shortly (really!) I'll be pushing a video on the design of the 'Ariel'. w.r.t. this discussion here it is ballpack Just Bill's numbers.
36" spreader bar, 46" hammock width at head and foot, 7" cut in the middle, which gives me 32" in the mid-section.
The spreaders are recessed to be 5'6" apart, which helps both with making that 7" cut "do more" and flatten things out a bit more
near the shoulders. The tricky bit, at least from a design point of view, is cutting the fabric beyond the spreader bars because that piece
will be support some of the head (almost) and the feet.

My earliest bridge hammocks were bathtubs, coffins almost. Narrower for flatness is the name of my game these days.


Quote Originally Posted by Just Bill View Post
Did I read that wrong? You are going 58" wide as the head and foot base width?

If so, that is your problem, not your spreader bar. 90" long? Those are gathered end dims, not bridge dims.

I hope I'm not giving any big secret away here- but in doing bridges myself I started looking for some common math and came up with a formula that roughly works/fits most bridges.

As far as the body/spreader bar- a good ratio to start with is 4/3.
So a 36" bar multiplied by 4/3= 48"
If you look at the picture- you'll see that this results in a curve a bit over 10" deep. You'll also see if I put a 20" wide (1'8") person in there you are relatively close to the top. The shape will deform a bit in real life though so you are looking for a balance of shallow enough but still supportive. In a bit of an extreme example- I took the same fabric size and made a V (in yellow)
If you look at the first curve (4/3 ratio) you'll see the two lines cross the 20" wide line about the same. In your 36 bar-58" fabric shape- you can see it's much too deep and the crossover point is much higher (more squeeze).

In reality the shape is more of an ellipse but that gets a bit messy to express and is for Professors in hammocking to do. But your bar size to fabric is way too far out to be flat enough.

As far as the cat cut- roughly speaking two things happen:

If you stick with the roughly standard 80-84" length (plenty for 6' tall folks) then a good starter is to make the center of the bridge the same width as your spreader bar. (48" head/foot- 36" bar= 12"/2= 6" cat cuts)

As you go longer with the bridge- the cat cuts need to get deeper and deeper to "pop" the center of the bridge up. So longer doesn't help you much- it actually hurts you in a bridge. You want to stick with the bare minimum length or you're cat cuts will need to be so deep that you lose too much width to be comfy in the middle. Or, if not made deeper, you'll fold up and feel like a banana.

If you are heavier (say above 180ish) you may need an extra inch of cut vs somebody Grizz's size as well to help counteract your fat *** (I'm 220+). If you are lighter you may find the center has too much pop, so you might want to go with an 1" or so less cut.

My personal opinion- if you go much past 36"- you have to go with the heavier (.75" vs .625" poles) if you are above 180 or so. Which adds a good bit of weight all around if you care.

If your shoulders are extra wide- or you just want more hammock...
Then go with the bigger bars- but keep the ratio about right and fine tune from there.
42" bar= 56" of fabric and would probably give you a good 25" of fairly flatish sleep space (at the bottom of the ellipse.)

That's a big bridge- I can pretty easily use my wife's monster car camping pad into a 36" bar/48" 7 ish foot long bridge-
https://www.rei.com/product/870757/r...00873461&lsft=

That said- next bridge I will work on is a 1.5 person for me and my kid using this pad- Pretty sure I can work it out with a 36" bar, but may have to bump to a 40"
https://www.rei.com/product/896427/e...o-sleeping-pad


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