View Full Version : hammock bivy

03-17-2003, 10:00
My latest project, which I finished yesterday, is a bivy sack that can be used around a hammock (not a Hennessey, though). It's Goretex on top and coated ripstop on the bottom, with a half length zipper and 12 inch strips of velcro on each end for the hammock straps to run through. I had to make the head end longer than necessary to clear the end of the hammock. Seems to add quite a bit of warmth to the hammock, and one could stuff clothing or other insulators into the bottom half underneath the hammock. Currently it hangs too loosely around the head opening, but that could be fixed with a drawcord on each side of the opening to cinch it around the hammock.

03-20-2003, 10:19
I added the side drawstrings to the hammock bivy and slept outside in it last night. The completed bivy weights 20 oz. Pictures in the gallery at:


Overnight temperature 25F. I used a bag which keeps me warm to about 30 under the stars. The bivy definitely added at least 5 degrees, probably more. I put a summer polarguard bag in the bottom of the bivy under the hammock for extra insulation there (clothing would have worked as well). A single 1/2 inch thick, 20 inch wide foam pad inside the hammock. I was perfectly warm on the bottom side. The top of my shoulders got chilly near the opening of the bivy, so I slid deeper inside during the night. My feet and everything well inside the bivy stayed quite warm. In the morning I found frost on the outside of the bivy top and condensation (some of it frozen) on the inside of the bivy top. So my bag got a lilttle damp. I'll have to remember to use a VBL next time as condensation inside a bivy in those conditions is almost unavoidable.