Bridge Hammock

[schrochem]

Do you mean like the one gunn parker described here?

Yep, that's exactly what I mean!
I would most likely just use speer mode for lounging (I much prefer it to being flat) and switch to bridge to actually sleep.
So, in my head right now I have a hammock that merges TB's, Grizz latest, and Gunn's cat speer.
It would be cut with cat cuts, narrow at the foot, and have the end caps like TB's. The foot cap could be made like Grizz' but I like TBs because of the ease of bugnet adding Oh, and I'd want a double layer!
The other details would be how long, depth of curve and where to put the poles.
TB, what's the distance between whippings in your bananna? how long is that ridgeline?
It would be great if that maxxed out at 10' for tarp reasons.....

[Walking Bear]

No. The lines are carrying all the weight and they just collapse in on you. But with the spreader bar in I can recline with my head raised enough to read by scooting back and getting my shoulders and head up onto the very end of the head part. I've got the spreader bar right in front of my face though, but I can position my book around that.

Grizz

I'm looking for the photos of the intergrated spreader bar with book rest The second verson of the intergrated spreader bar with book rest can have an auto page trun feature and built in light.

[turkeyboy]

TB, what's the distance between whippings in your bananna? how long is that ridgeline?

Good question . . . . I'll check it out, but I think it is less than 10'. My next version will be even shorter because I think I have at least 18" wasted fabric length.

[schrochem]

If the intent of using speer syle is just for lounging, I think some more streamlining could be done. I mentioned earlier putting a dart at the end like an M. Effectively you could hang it like TBs and sew where the red line is and remove the waste. (see attached).
I'm not sure how that would hang though.....

[schrochem]

I'll try again...
I was gonna search the thread but the site is REALLY sloooooww......
Grizz, I recall some of your earlier experiments with making the bridge narrow.
What's the difference between a 60" wide with 12" curve and a 54" with a 6"? Is it just less of chasm and same mid width?
I'm tempted to start cutting the next bridge and was gonna go with 80" long with 54" wide at the head, 6" curve to 44" wide at the foot end. Then each end would extend an extra 20" to make ends/speer style.

[schrochem]

I'll try again...
I was gonna search the thread but the site is REALLY sloooooww......
Grizz, I recall some of your earlier experiments with making the bridge narrow.
What's the difference between a 60" wide with 12" curve and a 54" with a 6"? Is it just less of chasm and same mid width?
I'm tempted to start cutting the next bridge and was gonna go with 80" long with 54" wide at the head, 6" curve to 44" wide at the foot end. Then each end would extend an extra 20" to make ends/speer style.

[GrizzlyAdams]

I'll try again...
I was gonna search the thread but the site is REALLY sloooooww......
Grizz, I recall some of your earlier experiments with making the bridge narrow.
What's the difference between a 60" wide with 12" curve and a 54" with a 6"? Is it just less of chasm and same mid width?
I'm tempted to start cutting the next bridge and was gonna go with 80" long with 54" wide at the head, 6" curve to 44" wide at the foot end. Then each end would extend an extra 20" to make ends/speer style.

The shallower cut you describe will of course give you the same width at the mid-point, and make the hammock 6" shorter. For a given spreader bar length it will also make the hammock "flatter" up by your shoulders : the angle that the fabric takes going the last last it touches your shoulders is shallower, and the last place it touches your shoulders is lower down. I'm beginning to suspect that for a given hammock length, one with a shallower suspension cut has to have the suspension triangle pulled flatter to get a flat lay in the hammock. Have not quantified this yet though. Makes sense though because the angle that the suspension cut leaves the hammock is flatter with a shallow suspension cut. Grizz

[schrochem]

I'm glad you brought that last bit up about the flatter suspension triangle.
This past week I've been sleeping in the bridge with different spreader lengths.
It's hung on a vario stand with the ends 12' apart.
I left the suspension triangles the same length (like 30" on both ends).
Changing from a 40" head spreader to a 36" length dropped the hammock (head end).
The foot spreader was 30" and I put in a 18" and that dropped as well.
I slept with various combinations of the lengths above with keeping the suspension triangles the same and it does change the lay.
Last night I left the head end the same 36" spreader, 30" suspension triangle and put an 18" spreader on the foot. It was hanging too low (kind of hitting the stand itself) so I reduced the triangle on the foot end. I just eyeballed it but it's about 24." That lifted the whole hammock but after sleeping in it, that was a bit high on the foot end.
Anyway....
This was done with an imaginary ridgeline of 12'
As you said, it might be true that the shallower the curve the longer the ridgeline has to be to get the same lay. However, that might only hold if the fabric width stays the same but be offset if reduced with the shallower curve....like going from 60" and 12"curve to 54" and 6"
Another twist in all this is having a shorter spreader bar will reduce the suspension triangle. As well as cutting the fabric accordingly to maintain the parabola height for head and foot end for their given spreaders. It's not a big deal when the head is 36 and foot 30, but 36 and 18 are significantly different looking parabolas.
I'm also very comfortable with an 18" footer for any and all advantages it may have. I've probably had 3 nights with the footer at that length. In between those I switched it back to 30 and while it was a little nicer while I was awake, it didn't change comfort while sleeping....

[schrochem]

BTW Grizz, I'd be up for some more math on how to compute 'equivalent parabolas for head and foot with different spreaders.
I kind of did it the ol fashioned way and measured. So I think a head spread of 36" and 54" fabric would be the same 'depth' as the foot with 18" spread and 44" fabric.

[GrizzlyAdams]

BTW Grizz, I'd be up for some more math on how to compute 'equivalent parabolas for head and foot with different spreaders.
I kind of did it the ol fashioned way and measured. So I think a head spread of 36" and 54" fabric would be the same 'depth' as the foot with 18" spread and 44" fabric.

That's really close according to my calculations. I'm far more likely to screw up on the line integral you solve to get arc length than I am to screw up a simple program, so I write Perl scripts to estimate arc length as a sum of short linear segments, each over a change in x of 0.05 inches. The one quoted below accepts the height that you want common at the head and foot, then computes the arc length of the parabolas that achieve that height with a spreader distance of 36", and 18". So poking around a bit it looks like a height of 18.7 inches corresponds to a 54" at the head and 43" at the foot.

Grizz

$dx = 0.05;
while(1) {
 print "enter height ";
 $h = <STDIN>;
 chomp $h;

 $w = 18;
 $a = $h/($w*$w);
 $ox = $oy = 0.0;
 $L1 = 0;
 for($x=$dx; $x<=$w; $x+=$dx) {
   $y = $a*$x*$x;
   $L1 += sqrt( ($x-$ox)*($x-$ox)+($y-$oy)*($y-$oy));
   $oy = $y; $ox = $x;
 }
 $L1 *= 2;

 $w = 9;
 $a = $h/($w*$w);
 $ox = $oy = 0.0;
 $L2 = 0;
 for($x=$dx; $x<=$w; $x+=$dx) {
   $y = $a*$x*$x;
   $L2 += sqrt( ($x-$ox)*($x-$ox)+($y-$oy)*($y-$oy));
   $oy = $y; $ox = $x;
 }
 $L2 *= 2;
 print "$h\t$L1\t$L2\n";
}