Amsteel Experts' Advice Needed!

[SteelToe]

So,
I'm working on getting my bridge hammock project up to load bearing status, but first I need to figure out the best way to attach some tie-outs.

It's a bit of an unorthodox design, but here's a diagram of what I'm trying to achieve:


I have a taffeta fabric panel that tapers to a point, and the edges are reinforced with polyester webbing. My intention is for the webbing to take the bulk of the tension load, while the panel carries the distributed load of my upper back. It's basically like a tarp tie-out, but needs to be far stronger--probably about half as strong as the attachment at the end of a gathered end hammock.

I believe it can be done by sewing or tying the 1/4" Amsteel to the ~3" tag-ends of the webbing extending past the fabric, but I don't have the experience with this cable to simply improvise something.

Any suggestions? Something other than crimping a steel cable splice over all three?

TCB

[mrmike65]

That looks like an interesting project. Here is what I would try: Sew the webbing onto a aluminum descender ring. Use the Amsteel to make a whoopie sling terminated with a buried loop, then use a Lark's Head knot to attach the buried loop to the descender ring.

[MotoHanger]

Based on your diagram it is probably too late for this, but if the webbing was "continuous"...meaning the ends terminated on the side (vs the end) they would form a loop of sorts that you could larks head the Amsteel to it (whoopie sling fashion).

I am not sure I would trust the strength of sewing the ends together to get the loop, so I would follow the approach of sewing on rings (maybe some dutch ware?) then attaching the amsteel.

[krugd]

I have used Amsteel instead of the webbing. But you can finish it much the same: Attach a single steel ring to the webbing. (Form loops on both ends.) Then run the Amsteel through the ring as well and bury the Amsteel back into itself.

Also, make sure the lengths of webbing on either side are exactly the same length or the hammock will not hang right. Trust me - I know !

[SteelToe]

whoopie sling terminated with a buried loop

Crazy hammock jargon... ...Do you mean an eye-splice on the end that's larks-headed to the ring, with the other end run out to the attachment point?

My current plan (emphasis; current) is to run this cable through the support point, and then back across to form the structural ridgeline. There's one of these attachments at both ends of the hammock, and it seemed like rolling them into the same suspension element could reduce complexity a bit.

It sounds like a hardware solution is what's needed here...darn. I was hoping a direct attachment could be made somehow, because it'd be much more compact, but I do have some super-light aluminum 2"x3/8" rings scavenged from my previous hammock suspension. Those might work nicely, and they weigh nothing. The two straps actually run back along the "floor" of the torso-section of the hammock about 3ft, which is why I found it much easier to attach them separately. Since Amsteel can apparently be larksheaded to webbing, I'd probably make a point to put a closed/reinforced loop there on the next go-around.

Thanks for the tips, any reccomendations on how much overlap on the straps I should sew through? (I'm guessing ~1" --half what I do for tree-straps)

TCB

[SteelToe]

I have a new course of action I'm gonna try, and fall back to the descending ring option as a backup in the event my head hits the floor:

The two straps on the perimeter of the fabric meet at about a 20deg angle, so there is about 3" where they basically overlap (shallower angle than depicted in the drawing). I will attach a short length (~1ft) of tubular webbing between the straps with a 3" lap joint with lots of lines of stitches, and sew a loop into the end of that for larks-heading to the Dyneema. That would load all stitched connections "ideally" in simple shear, meaning they could be made strong enough with ample stitching

Ideally, I'd have had the foresight to give myself a bit longer tag ends, but my initial intention was to use webbing for the suspension and attach it this way (found my 2 year old notes on the subject ). Now, I'll simply splice that webbing suspension into a Dyneema cord setup after a short distance. If this setup fails, it will be because the stitching gives, so I'd still be able to rip it all out and try again with the descender ring option.

Would ya'll suggest a simple bend for the webbing loop, or would a folded/twisted loop work better? Is a cord/strap larkshead as simple as I'm picturing to be, or do the different materials require something different?

TCB

[Mouseskowitz]

I think you're on the right track with adding a piece of webbing. My thought would be to make a loop instead of sowing a ring in, less hardware. Check out this thread specifically post #22 too see what kind of loop I'm thinking of. Then go down to post #29 and look at the article on sowing webbing.

[SteelToe]

What's the advantage of loops like that? (other than that they look awesome ) Do they make for a wider bend radius in the Dyneema when looped through it? I do like that concept; seems neater than the simple turned-over straps I've done before for my tree-straps and whatall. Another plus for the two-part webbing/cord connection is it allows for adjustability potential as I zero in on a preferred geometry.

TCB

[Mouseskowitz]

From my understanding it is done to reduce the stress and wear on the edge of the webbing. I think that will be even more so the case in your application. In and of its self I don't think it will change your bend radius much. But that question got me thinking. If you want to something about the radius add a couple of wraps of extra webbing to the loop. Securing it will be the hard part. My three thoughts would be a lock stitch like with spicing, whipping, or the handy man's helper duct tape.

[SteelToe]

reduce the stress and wear on the edge of the webbing

Ah, now I see the light! The edge is where the webbing will let go first, and a flat-to-round connection will put much more stress at the edge of the webbing. This folded solution turns it into something more resembling the cable it's mated up against.

What if I run a U-shaped section of tubular webbing to each of the tag ends (all four ends overlapping--my machine can take it! ) and put some sort of round filler material in the webbing to create a round profile. Maybe a short chunk of thick rope, or something? I've seen backpack handles that have a foam piece inserted and then sewn in place. I suppose I could just wrap the webbing around a chunk of singed Dyneema before sewing, as well.

I think the loop shown in the link will look cooler though, and will probably work better as well. Once I get this loop business sorted out I'll have the torso section of the hammock ready for testing!

TCB