Bridge Hammock

[GrizzlyAdams]

Great to know this, thanks for the effort.

Grizz

[schrochem]

Thanks for the update Walking Bear.
I think I'd be hesitant to sew the two layers together perpendicular to the load.
The JRB hammock does that but it's a double up seam. If it's just a simple row of stitching it may not hold....
I hear ya about the CCF and breathing.
You can get better breathability with and inflatable.
This winter I plan to use an underquilt and when it gets really cold (cough, cough), I will insert my BA insulated air mat.
We'll see how it goes....

[Walking Bear]

schrochem

Thanks for the update Walking Bear.
I think I'd be hesitant to sew the two layers together perpendicular to the load.

Both layers are stiched to the side webbing and wrapped around the webbing just like I did with a one layer hammock. Two or three rows of stiching on finnal wrap. I'm confident in that part of the hammock. What was a concern was one layerof fabric taking all of the load. And the load is greater than it should be at about 230 lbs. With the strech of the fabric and how it was made I don't think that will be a problem.

[schrochem]

Yes, I agree.
I forgot to stipulate the part I was talking about.
I mentioned that in regard to sewing in that pocket to hold up the wings.

[warbonnetguy]

yes, i would leave the extra pad pocket stitches out too. get yourself a wider pad and give it a mummy cut. that way the single pad is wide enough at the shoulders. you don't want that inch gap at the seam, and it would likely interfere with the nice even loading you seem to have going on.

i used a single layer of 1.9 for my bridge, i think you would be fine with 2 layers of 1.1. if i were making a double layer bridge this is the way i would go.

[GrizzlyAdams]

in our last episode of "As the Grizz Bridge Turns", I'd shown that a piece of fabric sized to a pad could hold it to conform to the occupant. Since then I experimented with some lightweight polyester mesh with 1/2" squares to replace the fabric; the mesh's normal use is to protect plants from birds. It turns out that the mesh weighs 1 oz / sq yd, does not compact as nicely as fabric, and pads slide right off it if they are not secured to it. So I scrubbed that idea and will stick with fabric, 1.1 oz the next time I make the piece.

I also realized that I should be hanging the piece from the furthest rings out at the head, not the ones with the pole. This stretches it out very nicely to conform to the occupant. In the picture below there is a Thermarest Prolite 4 pad, partially inflated. The underbody is wide enough so that it would support some CCF wings, which as you can see would be brought up along the sides of the hammock.



Next I worked on hanging a JRB Nest. This has corner-to-corner shockcord at the ends, with minibiners, which lends itself very nicely to threading the shockcord through the rings. Pictures of the JRB BMBH show this. My hammock is wider than the BMBH, and so out of concern for pulling the underquilt up too far, and having it be compressed, I added length to the shockcords. This was done by taking a length of a few inches of my own shockcord, threading it through a terminating loop in the Nest's shock cord, then securing the two ends of my shockcord with a toggle. Moving the toggle changes the added length.

I hung it black-side out so as to avoid litigation from the neighborhood association. In the photo below, HLH is inside.



Now the underquilt hangs straight from the corners of the hammock. But the sides of a bridge curve in toward the center. So there are air gaps on the sides, maybe an inch or so.



This may be particular to my DIY flavor of the bridge. The JRB BMBH is narrower to begin with, and is reported to have a much shallower cut than I do. This will make its sides flatter, and any air gaps smaller. But for me, I need to close that up (confirmed experimentally the other night once the temps dropped below 50). This can be done with a couple of cheap plastic clips and some stretch cord.



The sides are high enough that I don't anticipate that this will interfer with my quilt or sleeping bag. I'll just have to remember that it's there on my 2 a.m. and 5 a.m. irrigation projects. With a pad system strapped up first, then an underquilt, the lot covered by under/over - cover (in the contemplation stage at present), I should be set for as cold as I'm likely to encounter this winter in mid-land America.

In other news, I lengthened the head pole to a 39" spread from 36", reflected in the photos above. Also I weighed v0.2, hammock body and suspension (excluding tree hugger straps and their biners). 18.4 oz.

Taking it into the woods tomorrow night.

Grizz

[Rapt]

Looking really good... That's quite the system you're building...

When you get the pad support finalized are you going to give dimensions/side cut info?

[schrochem]

Interesting to see what you've been up to. It won't be cold enough down here for awhile....
I had a thought about the separation in the middle.
I'm not sure how this will pan out but I'll probably find out down the line.
After seeing your camo underbelly I started wondering about attachment points etc.
As you know I currently have a full sized under piece. I tried some strange things that didn't work and went back to this. Something I do is run the support line the entire length of the edge. I was starting to think I could just get away with attaching to the corners like you did.
But now I wonder if running the whole length will aid in keeping the middle in close. Here is my original underthingy's midsection. I know it works well with thin stuff but don't know about a full underquilt.
I always wondered why the JRB underquilts ran the baffles horiz. I always thought lengthwise made more sense for an underquilt. The snugfit definitely benefits there.
BTW, what are using for a pillow?
Have a nice trip!

[Rapt]

I always wondered why the JRB underquilts ran the baffles horiz. I always thought lengthwise made more sense for an underquilt.

Me too.... I was just thinking about this the other night. Its a departure from sleeping bags though.

[GrizzlyAdams]

Looking really good... That's quite the system you're building...

When you get the pad support finalized are you going to give dimensions/side cut info?

I'm happy with what I have now. Before the cut the underpiece is 80" long and 38" wide. It has a 3 inch cut. When I redo with 1.1 oz I may extend the width to 40" to accommodate two 20" width Gossamer Gear pads that are (rather, will be) adjoined side-by-side.

Scott, I think the underpiece does already (by design) have the effect of suspension lines, through the bias tape on the edge. I saw what you'd done, and wondered if I could get the same effect but on a smaller piece. On the long sides I cut the tape to extend past the end of the fabric by 3 inches, sewed the extended pieces to fold over like they do when edging, and then brought the end back to the fabric and sewed on to form a loop that when pulled might transfer its force along the bias tape (just as does a gross grain tape along the edge of a cat cut tarp). Equivalent to a suspension line.

What I think you're saying is that if the underpiece were as large as the body itself, then it might close that air gap by the "outside" suspension line. Yes, but. The reason the normal suspension webbing pulls in at the middle is because of the weight of the occupant pulling the center of the hammock down, away from the corners. For the "outside" line to likewise pull in, the weight of the occupant would likewise need to be pulling down on the outside underpiece. But that necessitates my butt pushing down on the outer piece with enough force to pull in the sides---which will compress the down.

When I get to an over/under shell, the under shell will have to hang loosely enough not to compress a down underquilt, and so won't be closing the gap either. But perhaps with the enclosed space that won't matter so much, or maybe I just have to live with the clips. It's that, or put something like omnitape on the inside (not the edge!) of the underquilt to get it to attach to the hammock body, and I'd really rather not go there.

Nothing rugged this weekend, I'm bringing my wife and 6-year-old out into the woods for a family camping experience.

Grizz