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Kelli Wise Hennesy Hammock Underquilt Experiment

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Hennessy Underquilt Pattern
by Kelli Wise
This is the pattern I based my trial underquilt on.  I did not make the center slit for the HH.  Instead, I get into the hammock by pushing the underquilt aside.  I made my underquilt from an old nylon sleeping bag, to which I added new insulation.  Frankly, it doesn't seem to come up as far on the sides of the hammock as I would have liked.  See photos. 
Test #1.  11/18/05.  Hung the HH with underquilt under the deck at home.  Equipment used:  HH hammock, Kelli's underquilt, REI zero degree synthetic sleeping bag, Pickup truck windshield reflector placed between the quilt and the hammock, silver side up.  Wore midweight fleece pants, and expedition weight thermal top.  Light fleece balaclava.  Low temp of 30 degrees.  Wind of 0-5 mph.  Slept warm.  Slightly less warm at my one calf - legs were pointed in the direction of the wind.  If I leaned against the upper sides of the hammock, they were cold above the underquilt level.  Future underquilts should rise higher along the sides of the hammock.


Side view of underquilt

End view of underquilt

Further experiments with winter hammocks
I made a quick hammock from some $1/yard ripstop nylon from Walmart based on the method of Risk's test hammock  http://www.imrisk.com/testhammock/testhammock.htm.
I took the underquilt from the Hennessy as shown above and used it on the test hammock.  It worked well, being able to wrap more around my body and providing more wind block.  Happy with the insulation results, I stitched the underquilt to the hammock with large quilting stitches spaces about 6 - 8 inches apart down both sides, leaving the ends unsewn, but tightenable by the drawstrings.  I did most of the sewing while laying in the hammock so that I could make sure that I would not over tension the underquilt and compress the insulation too much.  This worked well.  I am also able to insert an inflatable pad or foam pad between the hammock and the underquilt through the ends of the hammock to add additional insulation. 
1/31/06 I slept in the hammock in 38 degree F 20% humidity with winds 10-15 mph.  I had inserted a 3/8 inch CCF pad between the hammock and the underquilt in the area of my butt and lower back.  I used my 15 degree F rated down bag as a top quilt, wore a poly pro top and a fleece cap and was overly warm all night. 
I would guess the weight at about 3-4 lbs for the hammock, pad, webbing, and underquilt.

 2/4/06 Spent the weekend backpacking at Assateague.  I slept in the cold weather hammock and 15 degree bag with fleece clothing.  Had the 1/2 length CCF 1/4 inch pad under my butt and lower back between the hammock and insulation.  Low of 43 with 20 knot winds that shifted around and spent the night blowing right through the open ends of the tarp.  I felt like I was sticking my head out of a car moving about 20-30 mph - I woke up with my eyes tearing, but plenty warm.  Slept with the bag one third open for most of the night with my arms out.   Set up the tarp on seperate lines from the hammock, and tried the method of tying the tarp lines lower than the hammock lines to get the tarp down around the hammock more.  This caused some problems in that the hammock lines, if I hung the hammock with enough slack for a sweet spot, interfered with the 8 x 10 tarp.  My trees were only about 14 feet apart.


The above photo is the cold weather hammock under an 8 ft x 10 ft silnylon tarp on Assateague Island.