bivy/hammock....

[mike!]

hmmm, being that this forum has a collection of hammocking fans i thought i would ask a question. I haven't really thought of the specifics of this idea yet, so please feel free to brainstorm or shoot me down. im going to hike the AT next year if all goes well, and i plan on using a poncho tarp for versatility. i also plan on using a bivy sack for under the poncho and in shelters. now my question is, would it be possible to make a bivy sack that would be able to transform into a hammock? this would be the ultimate in versatility imho, being able to sleep anywhere and not limiting your choices. now i've never made a hammock nor slept in a non-backyard hammock, so thats why im woundering how this idea could come into life. the bivy bottom needs to be pretty water resistant, yet the top should offer some light protection when in ground mode. i would imagine you would have to run a good sized zipper for ease of hammock entry. maybe have a heavier sil-nylon or coated nylon floor, with a 1.1 dwr top and some bug netting.
any comments/suggestions?
mike!

[hammock engineer]

Check out the the HH at www.hennessyhamocks.com (I think) or at www.hikinghq.net . They have a pic of SGT Rock using his hammock as a bivy. It is not free standing, but uses hiking pole.

I am not that experienced with bivy's. The enterance would have to be moved to the side to allow both hanging and ground entrance. I would also put a ridgeline of sorts in to hold up the bivy celling when it is in hammock mode.

Not a fan of poncho's, but that is just me.

[Seeker]

i'd go the other way with it... why sleep on the ground if you don't have to? find a hammock you're comfortable using as a bivy, not make a bivy that doubles as a hammock... if you made the poncho with an extra flap on the front and back that tucks up out of the way, you might be able to use it over the hammock...

and remember the under-insulation issue... quilt is easier/more expensive, ccf pad is harder to stay on/cheaper... if you plan to use the bivy mode a lot, a ccf pad may be the way to go... but i don't like shelters and don't stay in them unless i have to...

[DebW]

I designed and built a hammock bivy a couple years ago. Picture here

http://www.whiteblaze.net/gallery/sh...ppuser/37/sl/d

Your idea sounds like a good way to save weight and be flexible at the same time, but the reality is a little different. You don't want a hammock made of waterproof fabric on the bottom - you would get too wet and uncomfortable from sweat, yet a bivy needs to be waterproof on the bottom. My hammock bivy was actually a normal bivy with some extra length and openings in both ends so a hammock could be used inside it with the straps passing through velcro openings. I had a waterproof bottom and goretex top. Condensation proved to be a problem, and the hammock is extra weight over ground sleeping. My best suggestion now is a simple nylon sleeve enclosing the hammock for additional warmth and windproofness, made of breathable nylon with DWR, plus a 2-3 oz grondcloth of waterproof nylon or plastic for the ground bivy situation. You could consider a Speer type hammock with a top cover velcroed to its edges to make an enclosed sleeping area for ground or air use for less weight penalty.

[mike!]

thanks guys for the replies! ya your right seeker, that opposite view might be better, and i deffinitly plan on using the poncho above the hammock. Debw, ya thats the picture that came into my head! i just dont remember where i saw it. i agree with the sweat problems, but how about this.... (mind you ive never made a hammock) just picture a square peice of waterproof fabric about 30- 35" wide and i dunno 100" long. at both narrow ends (30/35" wide ends) have a nylon sleeve to hold 1 trekking pole in each sleeve. (acting like spread bars/attachment points) and then attach some rope to the trekking poles. i think this setup would minmize the waterproof fabric rapping around my sides like a coccon. i currently weigh 150 pounds, and im 6 feet tall. my trekking poles are pretty sturdy carbon fiber poles, and since they dont need to extend much to reach 35" i think they will be sturdy enough (i cant flex them applying weight when hiking) for the top of the bivy, just have some light weight 1.1 oz dwr and a vent in the footbox. have a generious proportion zipper for venting/ease of entry, and a no-seeum area for the face. what kind of fabric would everyone recomend for the bottom? sil-nylon stretches to much correct? would a 70 denier urathane coated be fine or a little exessive? i plan on hiking the trail for 4 months or so, and i wont be spending every night hanging. maybe 1/3 or so? geuss it depends on how comfortable it is...
comments/suggestions?
thanks!
mike!