Bridge Hammock Woes

[smalls]

I'm working on building my bridge hammock based on the dimensions Dutch gives for his Gearskin 3. I like the shallow lay and reduced constriction it seems to offer compared to some other bridge designs. I'm having some issues with it though.

I cut the curve in the fabric without any trouble, and I'm using nylon tow strap type material for the webbing along the sides. When I attached the webbing to the fabric, it seemed to eliminate the curve. The fabric tended to bunch in some areas, or remain loose in others and the width at the ends is just sort of 'absorbed' for lack of a better word.

Is this more of an illusion, or should the curve still be quite prominent with the webbing attached?

I'm considering making an attempt at using amsteel or similar for the supporting lines, but I've read that cord/rope is more difficult to work with in a bridge hammock. Can anyone maybe offer some additional info on that?

-Smalls

[GrizzlyAdams]

I know the kind of bunching you're talking about. It's due to geometry of rolling the webbing...the wider the webbing and the more you roll it the greater the potential.

The way I minimize the risk is (1) use 1/2" wide webbing, rolled twice, (2) pin pin pin pin.

At every point in the curve you want to roll perpendicular to the the curve at that point. Since the curve moves, so does the "roll angle" for lack of a better non-calculus word. If you remember calculus you want to roll in the direction of the normal vector. So after putting the webbing in place along the curve using a basting stitch I move along the webbing every 2 or 3 inches, rolling twice in the direction of the normal, getting the fabric tucked well in, and then pin it ON THE UNDERSIDE because otherwise the position of the fabric on the webbing can move. This is a lesson learned and the picture in my tutorial on this point (where the pins are on top) is out of date.

Then when laying down the stitches I am careful to let the feeder dogs do the pulling. Not only does this reduce the risk of hairball thread punches on the bottom, it helps to keep the fabric in place.

with nylon webbing you're going to get stretching...hope the fabric stretches along with it... I use polyester webbing to reduce the risk of that.

[smalls]

Grizz, thanks for the advice. I did pin along the top, but I used iron-on seam adhesive rather than pins, which worked fairly well. I didn't use it along the bottom though, and that might have been my mistake.

I just did a bit of reading here to positively identify the webbing I'm using. I don't think its nylon. It's a rather tight weave, kind of shiny, and doesn't have that standard nylon stink when burned. It's gotta be either Polypro or Polyester.

I guess I'll make another attempt today. At least it was a cheap learning experience. $8 or so I think, and I'm much more familiar with the sewing machine's little quirks now.

-Smalls

[smalls]

Just wanted to say I took your advice Grizz, used the seam tape the entire length of all my seams before sewing (Nylon is rolled twice, giving 3 layers of fabric stitched to the webbing), and had some good success for a first attempt.

I attached a photo. The spreader bars are just 2"x2" boards because its what I had handy. It is very light Wally World bargain bin ripstop (0.8oz? 1.1oz maybe?), but its holding up just fine. I've got what I think is Polypro tow-strap webbing, and the webbing is brought together in a double figure-8 on a bight, hooked to a couple ratchet straps for a make-shift suspension.

After a little tinkering, It is fantastically comfortable. I'm completely smitten. I could easily sleep on my side, though not my stomach.

I cut it too short, so this one will become my nephew's new hammock for Boy Scout outings. I'll be starting a new one tomorrow, made of slightly heavier fabric (though I think I might miss some of the stretch the light fabric gives), more careful sewing techniques, and a few other tweaks (carbon fiber spreaders, etc). I've already got my tarp figured out, so I think I'm in good shape to be ready to hang inside 2 weeks!

-Smalls

[Timberrr]

Beautiful job!

An idea for your consideration... Looking at the photo, you coud sew a piece of fabric about two to two and a half feet long (the same ripstop nylon) on each end with channels on the ends that are away from the hammock. You could then gather it through the channel and attach the gathered point to the point where your suspension lines come together. Then you would have gear storage inside the hammock. The Chrysalis bridge hammock uses this concept.

PS. What are those blue rocks in the back ground?

[smalls]

Timberrr, I had considered something much like that, in place of the more typical Grizz Bridge style end caps. Those will simplify my weather proofing and bug proofing too, at least a bit.

The blue rock looking things are actually bits of a blue tarp left over from last year's firewood splitting efforts, mostly buried under the leaves.

-Smalls

[GrizzlyAdams]

hey smalls, you sure look comfortable! good job.

I find I can sleep on my stomach so long as I have a pillow with enough bulk to get my face up out of the fabric, and my arms are straight down at my sides, or even I lay on them. Arms as a pillow don't work because my elbows ride up the sides of the hammock.