Backpacking Hammock

c.d. pritchard 11/02. tweaked 6/03 In Use (by my better half, sans sleeping bag):

I sleep much better in a hammock than on a pad on the ground. Surprisingly, I can sleep on my side in this one. The problem with hammocks is that you lower side gets COLD since the sleeping bag is compressed beneath you. My first try at insulation was simply to place a 3/8" thick foam sleeping pad in the bottom of a hammock. It kinda crimped up around me but was workable- what wasn't was that I woke up the next morning with the bottom of the sleeping bag soaked. Condensation had formed on the pad since mosture from my body could not pass through it... Next stab was punching 3/8" holes in the sleeping pad pad. No condensation but still a bit on the cool side. Final step was to add 1.5" of polyester fiber insulation below the hammock.

The hammock is made of 1.1 oz breathable ripstop nylon (a tip: cut the fabric with a soldering iron- it'll seal the cut edge and help prevent unraveling). I weight about 140 pounds, if you are heavier, you might want to use 1.9 oz. ripstop for the hammock body and 1.1 oz. for the sleeping pad pocket and over the insulation. The hammock itself weights 19 oz. The ropes to tie it to a tree add another 5 oz. I don't count the foam pad because I'd pack it anyway.

Drawing:



Note in the detail how the holes for the support strings are formed. A text description: First hem the long edges. Make a 2" fold in the short edge and stitch the free end to make a simple hem. Stitch 18 evenly spaced button holes in the center of the 2" hem. Stitch alot around the button holes. Cut slits in the fabric in the center of the button holes. Fold the 2" hemmed end over lenghtwise so the button holes are centered in the fold and double or tripple stitch along the edge of the fabric. A 6' lenght of ~1/16" diameter twisted nylon twine (a.k.a. trot line) is snaked through two adjacent button holes (or the end and one button hole at the edges). The ends of each loop of twine are fastened together with a square knot. Melt the ends of twine after tying knot to secure the knot. Push the knot through the button hole so it's concealed in fabric.

The sleeping pad pocket keeps the pad in place and prevents it from curling or crimping when you lay in the hammock. It is formed from two pieces of ripstop which overlap. The overlap helps keep the edges of the pad from crimping when you get in. The pocket is a tad bigger than the pad so the hammock and not the pocket fabric is under load when you get in. The edges were turned under before stiching it to the hammock. The pad is removed for packing. To ease inserting the pad, kinda fold it a bit lengthwise first.

The bottom insulation isn't shown in the drawing but does show on the first photo. It was rather tedious to make. First, 3 layers of 1/2" thick polyester fiberfill were cut about the same size as the foam pad. It was basted by hand laterally every foot or so to a piece of ripstop about 2-3" larger all around than than the insulation. Next, I got in the hammock and the better half pinned the thing to the underside of the hammock so that the top of the insulation was just barely in contact with the bottom of the hammock. Next came the tedious part- the edge of the ripstop was turned under to conceal it and it was stitched to the hammock. What was tedious was doing the gathers so that it looked decent.

Detail of end showing buttonholes:



This shows the twine loops and the button holes they run through. One of the square knots was pulled out for viewing.

Sleeping pad:



The pad is a cheap one from Wal-Mart. The holes were punched with a piece of 3/8" thin-wall brass tube- sharpen the business end and twist it as the holes are punched. The holes are on a staggered 1-1/8" grid. The better half says it looks like an ironing board.

End of hammock showing pocket for sleeping pad:



The sleeping pad is shown stuffed into its pocket. Note overlap on pocket opening in center of photo. This keeps the edges of the pad relatively straight when you lie in the hammock.

Loop at the end of strings:



The loop was stiched from heavy 3/4" wide nylon webbing. A simple hitch secures the loops of twine from the hammock.

Thing over strings:



This thing is unfurled over the hammock strings before packing the hammock in it's stuff sack. It prevents string tangles.

Use:

I hang the hammock using 3/8" polyester rope. It's ligher than nylon and doesn't stretch as much. I currently hang a 10' x 12' tarp made from 1.1 oz. silicon coated ripstop over the hammock when it looks like rain or a heavy frost or dew.