Australian Standards, Synthetic Ropes & accessories.

[clubagreenie]

Further to the details I posted in the plasma v steel thread, I have been looking at the (recent?) development of the Dyneema soft shackles. A simple device, can be opened to thread through closed eyes in straps or recovery points and lock by cinching down on themselves using the load itself to grip on itself.

http://www.lucky8llc.com/ImageUploads/ProductID7209ImageID6027.JPG
Commercially available 12 strand soft shackle. Notice the large crown at the tail end that prevents the end slipping through the loop. The loop end is created by passing the tail of the bight back into the centre of the braid. To date I haven't found one that is sewn to prevent the internal end from slipping out. Opening is achieved by slipping the outer to allow the inner to pull out some, opening the loop and allowing the crown to pass through. I have found access to a local manufacturing facility that will sew the tail into the outer without loss of integrity.

I picked up 4m of 12mm winch rope and have made a test shackle (easiest/best min length for test bed is 1m). Will post some figures on breaking numbers when to hand. Whats everyones opinions of these, and having a locally made/supplied option at about 1/2 to 2/3rd's the price?

[Redback]

Depends on how much they are in relation to tyres needed;)

Baz.

[Blknight.aus]

I had a play with a couple of these.

for joining onto rope eyes a rounded recovery point, shackle or hook, go for it but I wouldn't use it to hook up to the eye of a strap if the strap wasnt setup with suitably re-enforced eyes. Once you apply the tension to the strap the rope shackle closes up and compresses the material of the loop its in.

[clubagreenie]

Cam anyone ID the stopped knot/braid/splice on the end of the sliding end of the sling? have been playing for a few days with a variety of knots but am yet to find something I'm happy with in terms of compactness and having a good flat underside to stop against the loop.

Also it appears (to me) that the working end of the loop (end passed back inside the hollow of the rope) runs all the way back to the end f the standing part and then it's tied/braided/spliced together. More research has shown these have been used for many years on lightweight sailing skiffs (by ultra weight savers) and also racing yachts as they don't damage deck surfaces. In these apps they are tied slightly differently, with a fixed loop created to pass back on itself to fix the shackle to a sail etc and the shackle end to allow it to be joined to a sheet. In these cases it seems that the working end stops short of the working end without sacrificing strength. I may run it this way but have the working end stitched inside the outer to prevent it coming undone and also reduce the size of the stopper from being potentially ridiculously large.

BK, when you say you wouldn't use for attaching to a non reinforced eye strap, do you mean a strap without eyes, with eyes but without an additional liner material covering the weight bearing material of the strap or simply on a SWR strap?

[isuzutoo-eh]

Have a read:
The Project Gutenberg E-text of Knots, Bends, Splices by J. Netherclift Jutsum (http://www.gutenberg.org/dirs/3/0/9/8/30983/30983-h/30983-h.htm)

My 'Knotting And Splicing Ropes And Cordage' book was also published in 1914!

[Tank]

Have a read:
The Project Gutenberg E-text of Knots, Bends, Splices by J. Netherclift Jutsum (http://www.gutenberg.org/dirs/3/0/9/8/30983/30983-h/30983-h.htm)

My 'Knotting And Splicing Ropes And Cordage' book was also published in 1914!
Mark, very good handbook, lot's of info for 4WD recovery using snatch/blocks re: mechanical advantage, anyone contemplating winch/snatch/block recoveries should read, Regards Frank.

[clubagreenie]

I found the same link on google but it won't open here but your link will on both phone and linux....

Pretty much confirms that I want to try the Mathew Walker knot or an immediate derivative. But need to adapt for use with 12 strand single braid.

I remember in the 70's (before we worried about security) spending time down at Garden Island while my father was diving (docking ships) and watching the old guys sitting around making up new ropes of all sorts. Then compared to yesterday when I spent the day back at TAFE to finish off 2 additional days to get an additional qualification for free (one course requires you enrol and pay for another course, some subjects of which cross over, so do 2 more days you've paid for anyway and get 2 certs). So we're doing berthing and knots & splices. 2 hours of berthing and I'm the only one who didn't get fingers jammed in the bollards. Another 6 hours to demonstrate/teach/practice 5 knots (clove hitch/reef/bowline/round turn-half hitch/sheet bend) and an eye splice. You realise where the skills this country used to have, have gone.

[chazza]

One thing alarms me - but perhaps I have misunderstood how this soft-shackle is used - rope-on-rope, or rope-on-sling, will create friction and synthetic ropes/slings will cut through each other very quickly, especially under load :eek:

I have always been taught to join slings and rope to anchors, using metal shackles,

Cheers Charlie

[Hymie]

I'd like to be able to buy them from an Australian source, don't get me wrong, the Lucky 8 guys are great to deal with.
For me, as I use them in a Commercial application, I'd need to be able to buy them with a Standards Tag to prove its SWL rating for Insurance purposes.
I've only used mine for testing the proof of concept but not on customers vehicles.

[Blknight.aus]

that only applies to moving connections. for a straight line pull you're fine with the exception of joining disimilar diameter lines.

A thin line will cut into the thicker line and may cut or cause crush damage under tension. The same applies to a web strap, they should only ever be pulled at the center by a wide bow shackle or the appropriate strap runners. Putting a line over the center of a web strap then pulling will cause the strap to fold and be damaged at the crease.

[chazza]

that only applies to moving connections. for a straight line pull you're fine with the exception of joining disimilar diameter lines.

A thin line will cut into the thicker line and may cut or cause crush damage under tension. The same applies to a web strap, they should only ever be pulled at the center by a wide bow shackle or the appropriate strap runners. Putting a line over the center of a web strap then pulling will cause the strap to fold and be damaged at the crease.

Agreed!

So what is the soft shackle for then; if not a moving connection?

For a straight line pull, a Follow-Through Figure-Eight knot could be tied through a recovery shackle, or eye,

Cheers Charlie

[clubagreenie]

It's simply an option for a lighter version of a shackle (instead of steel). They can be opened to be put through a recovery point (if rounded enough) or tree protector etc. I've made a few 1m loops for testing purposes and all of them weigh probably as much as one pin.

[chazza]

It's simply an option for a lighter version of a shackle (instead of steel). They can be opened to be put through a recovery point (if rounded enough) or tree protector etc. I've made a few 1m loops for testing purposes and all of them weigh probably as much as one pin.

If you put them through a tree-protector, then I say beware, because synthetic rubbing on synthetic, will cause catastrophic failure very quickly :eek:

Cheers Charlie

[Blknight.aus]

Agreed!

So what is the soft shackle for then; if not a moving connection?

For a straight line pull, a Follow-Through Figure-Eight knot could be tied through a recovery shackle, or eye,

Cheers Charlie

for joining the standing end of a line onto an object.

just to grab an example...

you would use one to join 2 ropes together for an extended single line pull

you wouldnt use one to setup the connection points on a vehicle that had to move across the line of pull (2 winches one pulling forwards and one pulling sideways) where the angle at the join can change.

I have heard that the shackles generally test out to something like 90% of the strenght of the rope they are constructed from and the usual failure point is the base of the "crown" or the end of the eye.

Me, I think they look cool and If I ever get a good source of the rope for the right price I'll probably learn how to tie them just for the hell of it and use them for something mundane like setting up tarps or jackstays.

[chazza]

for joining the standing end of a line onto an object.

just to grab an example...

you would use one to join 2 ropes together for an extended single line pull



The example you give is much like the one you gave earlier, where it would be a bad thing to to attach a soft-shackle across a sling.

Forget about different diameters - the dangerous thing is friction between two synthetic ropes. Even though it may be a straight-line-pull they will rub on each other and cause failure and it will be quicker the higher the load is - sometimes a matter of seconds.

If I had to join two ropes together to extend them, I would use a karabiner, or shackle, using Figure-Eight-on-the-Bight to form loops in the ends to be joined; or a knot, such as a Double-Fisherman's, on rope of the same diameter; or a Double-Sheet-Bend for ropes of unequal thickness,

Cheers Charlie

[isuzutoo-eh]

At least any damage would be visible on one of these, whereas a cracked cast shackle isn't immediately obvious. A throwaway item perhaps, just like a snatch strap.

[clubagreenie]

Thats what I'm thinking. Make them cheap enough to be just that. For ~$15- who'd care.

[Blknight.aus]

The example you give is much like the one you gave earlier, where it would be a bad thing to to attach a soft-shackle across a sling.

Forget about different diameters - the dangerous thing is friction between two synthetic ropes. Even though it may be a straight-line-pull they will rub on each other and cause failure and it will be quicker the higher the load is - sometimes a matter of seconds.

If I had to join two ropes together to extend them, I would use a karabiner, or shackle, using Figure-Eight-on-the-Bight to form loops in the ends to be joined; or a knot, such as a Double-Fisherman's, on rope of the same diameter; or a Double-Sheet-Bend for ropes of unequal thickness,

Cheers Charlie


thats assuming that your ropes dont have joiners in the end of them, Given the forces that can be involved I wouldn't be doing recovery work without properly rated and protected eyes. (hence the comment about using the rope shackles for tarp ties)

[clubagreenie]

Also after speaking to a friend that used to be at standards aust and searching their website I can't find a reference for recovery equipment of any type. Equipment for lifting purposes yes, but anything for horizontal, pulling/dragging uses there doesn't seen to be a referral to. Correct me i fI'm wrong with a number, and I'll dig it up.

[roverrescue]

Spliced eyes as used on these have been used with dacron and hollow braid for years.
Stitching them is a bad idea. They work by contracting upon each other, there is movement btwn each leg of the loop. Stopping this movement with stitching will most likely just tear the stitching, or the spectra fibres? Think chinese finger trap, tighter you pull, tighter it grips.

Steve

[chazza]

At least any damage would be visible on one of these, whereas a cracked cast shackle isn't immediately obvious.

Internal damage, or damage by chemical action, or UV isn't always obvious.
To help overcome this in the SES we keep rope log-books and anything old; suspect; or in anyway damaged, is chopped into small pieces and destroyed or buried at the tip.

Most steel shackles are not cast and can put up with a hard life, as can steel karabiners. Aluminium karabiners can be damaged by dropping, or scratching so I wouldn't use them for vehicle recovery,

Cheers Charlie

[clubagreenie]

The stitching was never to hold the eye. The eye is formed as you say. The tail is loped back into the core and passed back along the full length of the standing part of the rope, just short of the end where the stopper knot is placed. It's only to prevent someone from pulling the tail back out of the core which isn't too hard to put back but if it's something for sale then I'd rather not have people send them back for a warranty claim because they're pulling them apart.

[roverrescue]

i reckon the stitching will still tear.
Instead splice the tail along the standing line, just before the end of yourtail, weave it out and back into the centre of the standing line.

S

[clubagreenie]

How good are you at adapting hawse laid stopper knots to 12 straid braids then?