Bridge Hammock

[GrizzlyAdams]

I 'think' I understand what your doing grizz.
Do you think you need two sidewalls?
I think you might be able to save some weight, time and complexity by just sewing one on and leave the other side for adjusting.
If I understand the 'railroad' dohicky correctly that seems like a lot of magic.
Are you running that many strips along the whole length of the sidewall?

I'm concerned about compression at the corners, and so will sew
the coverpiece to have "bent" at the corner already (just a stitch along side the velcro). And I want the ability to take the sidewalls off altogether, when I'm using only pad with the underbody.

I can focus the velcro only on the points where it might be used. Long strips will take less time though.


Grizz

[slowhike]

I was talking to Scott who knows what it is, and forgot there is an Internet-wide community of eavesdroppers. Well you, anyway, and Cannibal.
Grizz

hey... i'm eavesdropping too (using my speed reading skills<g>)

[GrizzlyAdams]

Finished the underbody sketched in this post.

To recap, the objective is to make an underbody that comes up tight against the bottom of the hammock when occupied, and has a compartment hanging from it that contains a quilt (which is then assured to be flush with the hammock body).

So I started with a piece that before cutting a 3" deep parabolic curve, and applying bias tape edging was 82" x 44". Make of no-see-um mesh from Ed Speer, weighs about 1 oz / sq yard. Put strips of FreeMagic velcro in the long direction, separated by 36", centered. Small D rings at the corners.

Seen here.

This same piece can be used to support pads under the hammock. I made some lightweight accessories to hold a Thermarest in place (along with a pair of 20" wide Gossamer Thinpads, which overlap under the Thermarest. The four pieces all attach to the velcro strip, the end pieces are 1.1 oz, the "straps" are bias tape with some velcro at the ends. I'll be adding seams to the end pieces to keep the pad from moving side to side.

On to the quilt.

I have 5" tall sidewalls (made of 1.1 oz nylon) that attach to the underbody's velcro strips. The vertical strips are spaced 12" apart, and will serve to hold a cover. The 48" wide quilt is easily puffed up a bit to fit in a 36" wide space. See that the sidewall is still quite a bit taller than the quilt. A couple of particular things to notice in this picture...the gross grain tab with biner from the quilt corner comes through the vecro mating to the outside. From there a short piece of shock cord connects the biner and the D ring in the underbody. This ensures that the quilt is pulled up to the edge of the underbody, and stretched in the long direction (to avoid sliding to the middle of the underbody container. About 18 " to the right of the biner you can see another gross grain tab---again from the quilt, again passed through the vecro mating, again to help discourage the quilt from sliding to the middle when it's hung.

In a long view you see that there's lots of loft, but also a lot of sidewall left to use. I have fitted another 2.5" loft quilt (the JRB Stealth) on top of the Nest. For the HF winter campout if it happens at Mt. Rogers .

The cover is an 82" x 36" piece of 1.1 oz nylon, with FreeMagic velcro all along its long edges. There are also 20" pieces of velcro on at the head and foot (centered) that mate with similarly sided velcro strips on the underbody.

Here's the underbody/quilt in action, with my beautiful and talented wife in the hammock. You can tell from the tautness of the edge of the underbody that the underbody is pulled up under the hammock as desired.

The space available to the quilt can be adjusted even when in use by adjusting where the edge of the cover attaches to the vertical strips.

Since a JRB quilt can be hung from a bridge without all this fuss, why then all this fuss? In addition to the snug fit of the quilt with hammock bottom, I have covered the bottom part of my hammock from the suspension lines down with another layer of 1.1 oz DWR nylon, containing still and heated air. This is almost a complete weather cover for the bottom, although I want to add something at the ends as well, for wind-blown rain coming in from the open ends of the tarp.

The same underbody and cover work as a weather cover in more temperate conditions by leaving out the quilt (e.g., use pads, and the sidewalls+cover to create more wind block and dead air.) The underbody makes a convenient place also to attach the lower edge of an overbody, which is still in the contemplation stage, but I'll be doing soon.

[EDIT 10/28 8 a.m. Slept out last night, low temp hit 32 degrees, 15 mph winds. I was in long johns, wool socks, wool hat, and lightweight fleece top. Used a Wiggy's bag 0 degree bag as a top quilt, stayed toasty all night. Except for the mineral re-introduction projects for the trees, but warmed up quickly after that. ]

Grizz

[Oms]

Anyone know where I can find carbon fiber rod/tubes? In other words, I trying find light weight dowels.

Thttp://www.fibraplex.com/tentpoles.htmry this place

[Oms]

Messed that up http://www.fibraplex.com/tentpoles.htm

[Rapt]

Slick Griz...

I like too how the outer cover allows you to use a range of thicknesses without having excess space or bagginess in there if you go with a thinner quilt for milder temperatures.

Personally I think I'd have opted to try and skip the pad retaining system and just make sure the quilt retainer would do up tight enough to retain pads if so desired... But I suspect you intend yours to allow the use of both quilt and pad if so desired.

[schrochem]

Well done Grizz.
The only question I had was in regard to getting the body snug up against the hammock. I don't think you mentioned it...
Did you just make it snug without anyone in it?

[GrizzlyAdams]

Rapt- yes, I'm looking to be able to use pads + quilt if need be. I'm still experimenting with how all that can work together. The weather forecast suggests it will be at least another week before night-time lows get into the interesting-for-hammock-experiments range, e.g., near 0 C.


Scott- Yep, the lengths of the sides of the underbody are just about exactly the length of the distance between the rings from which they hang. So I pull it all taut while on the outside, and when I get in the underbody is tight up against the hammock body.

On a separate note I'm back to using a ridgeline. There was too much fussing about when I was doing the hanging between near trees, and then back out to hanging between distant trees. So I've shortened the suspension triangle to be 36" spreader bar, with 50" sides, and put a biner at the top of the triangle. Then I have one piece of suspension line with SMC rings larked on with a gap of about 14'. The ends of this line go to the trees, the hammock is clipped onto the rings. Not my own design, others have floated the idea in HF. Makes setup very simple. Further, I can bring a spare SMC ring along so that if I can't find trees 15 or 16 feet apart, I can do the close tree hanging drill as shown before (provided I bring the extra gear for that).

Grizz

[Rapt]

Last night was -4C here... Haven't had a chance to try out anything in that temperature... (I still consider that relatively mild camping weather, fall camping.)

[GrizzlyAdams]

This over-cover designed evolved as I tried one thing, and then another. Little bits of abandoned design are to be found throughout.

My original idea was to have an over-cover, and let my quilt suspension cover serve as as the underbody. This overcover was cut from 1.1 oz ripstop, 60" wide and 80" long. To fasten it to the under-cover I put tabs of same-side velcro (referred to hereafter by its brand-name FreeMagic) on the edges---lots of strips of that on the under-cover. 80" length was chosen, because its the distance between my poles....the 60" width is not wide enough to cover the ends of the pole and descend far enough to attach to the under-body. So the design had to have 3 pieces---the main rectangle in the middle, and end-pieces. The end-cap and main piece meet the main piece at the poles, and go around the pole tips and handle. I put a strip of grosgrain ribbon along the center of the main piece, with a series of loops so that I could raise the roof a bit.


I figured I'd try the waterproofed camo rip-stop I got a while ago for the ends. It's pretty heavy, but it's just the end-caps. I sewed the foot-end end-cap to the main piece, and put a two-tabbed zipper between the head-end end-cap and the main piece. The idea there was to allow me to open an air vent near my head from inside. I put a strip of grosgrain ribbon along the center of the main piece

I spent one night out in this; 25 degree low, pretty stiff wind---25 mph is what was reported later. The orientation of my tarp was exactly wrong...the wind came straight at the open end. In the under-body I had a Thermarest Prolite 4, and below that a JRB Nest. From below I was Not Warm. Not quite up to Cold, but with all that insulation I would have expected warm.

I came to realize the now-obvious....that there really isn't much more dead air in the underbody other than what the quilt itself provides. Because the nylon cover for the under-body is supporting the quilt, there isn't much more dead air. I also saw that the camo waterproof end-caps were pretty dang heavy relative to the main body.

Onto plan B then. I would need to add an underbody. Fortunately I had more of the 1.1 oz ripstop for that, and so cut a piece to match the upper portion, only narrower : 39" x 80". This piece is sewed to the overbody along one side, and attached by a zipper on the other side (which by accident is just about exactly the right length to join these.) I ripped out the zipper+camo-head-cap, and made one of silnylon. That piece is sewed to the underbody, and attaches to the overbody using FreeMagic. I can open that connection as needed to get more air inside. There are a bunch of FreeMagic tabs that connect the end-cap to the underbody, and tuck its odd ends away.

The camo end-cap was well-sewn to the overbody and I didn't want to rip that out and risk tearing up the edge of the main piece. So I left enough of it attached to serve as an attachment point to bring up the bottom edge of the underbody, attached again with FreeMagic.

Lesson learned...If I'd known up-front that I was going to enclose the hammock top-and-bottom I would have made the over and under bodies longer to completely cover the pole ends. Working around the exposed end of the head pole creates more complication than is really needed. On the other hand, the gaps around the pole ends create vents. In any case, the thing is done, and I hope useable.

A couple of more pictures

Another view from the side, buttoned up

Zipper open, quilt suspension inside

Grizz