Dyneema soft shackles

[SimonM]

Hi all,

Here is a link to a video on soft shackles made out of Amsteel Blue.

Amsteel Blue soft shackle

I am making these out of a smaller diameter Australian made Hi Spec 3000 rope for hammock suspension connections but what are your thoughts on use in 4wd winching applications? Could they replace the dreaded metal shackle? If they did you would have to be careful not to wrap them around something sharp or with too great a bend.

Thoughts?

[101RRS]

This topic on the Real 4x4 Forum has some relevance - should not need to register to read.

The Portal Hub: All things Pinzgauer, Haflinger, Volvo 303 and more. - View topic - Rope Shackles (http://real4x4forums.com/PinzgauerBBS/viewtopic.php?f=18&t=8367)

[goingbush]

would like to see it work in a kinetic demonstration, but would certainly be handy in the recovery kit.

[Tank]

Fibre ropes can not be shock loaded (as in snatch strap type recoveries), a shock loaded Dyneema rope (shackle) will lose it's WLL if shock loaded and will break without any signs of damage at well below it's WLL, any rope that has been shock loaded should be discarded. These shackles (soft) will always break at the knot as the knot reduces it's GBS by 50%.
So a soft shackle that has rope rated at 10 tonne GBS is now reduced to 5 tonne GBS with a WLL of 1 Tonne, a correctly used metal shackle will never break if limits and loading alignments are followed, but misuse a shackle and it will become the weakest link. Soft shackles have the advantage of light weight so should not become a deadly missile if used incorrectly.
Remember that the strength of dyneema rope is reduced greatly by the spliced eye so any breaking strains for your diameter rope should include the fact that it has an eye splice and not the breaking strain of an eyeless piece of rope, Regards Frank.

[SimonM]

Hey Frank,

You have more experience in this filed than me, but :). Samson rate the plain bury at 90 to 100% of the breaking strain of the rope.

The diamond knot used in the video also is estimated to retain 60% of the break strength of the rope I am led to believe, but due to the way a soft shackle is made you have 2 layers of rope, one inside the other, so the rating is effectively doubled.

Tests have shown that soft shackles often break at a higher load rating than the actual rope due to this doubling up.

Soft shackle destruction test (http://l-36.com/soft_shackle_testing_3.php)

[Tank]

I think the idea is that soft shackles would be safer (as a flying object) than a heavy steel shackle.
If you read the post you put up with the video on syn. rope you will read that this type of rope will not take shock loads, as produced in snatching and with no visible sign of damage. This rope has a memory of shock loads and will fail if subjected to shock loads again.
Also I reckon that where the knot and spliced eye are will fuse together with repeated use, rope has it's advantages, but wire rope will outlast it and doesn't require babying like rope does, to each his own, but I have more faith in wire rope, Regards Frank.

[Tank]

I think you will find that Samson rate the breaking strain of their rope with a spliced eye, because rating just a length of rope with no eye/s does not give their customers the right info on their ropes in real world use i.e. with a spliced eye (or two), Regards Frank.

[Hymie]

I use the ones I bought from Lucky8 LLC (http://www.lucky8llc.com/default.aspx).
Love them, best thing going around in winch recovery terminal tackle.
Rated at 12000 Lb, which I worked out to 5.4 Tonnes and weighing sod all it is easy to stuff 6or so in your pocket when carting your Recovery gear out.

[Tank]

Don't use them in a snatch recovery though, Regards Frank.

[NavyDiver]

thanks for posting. Metal breaks just like rope given the right load or stresses.

Knots, splicing and breaking them are all of interest. http://www.bethandevans.com/pdf/8_strength.pdf or here chatting about splices Efficiencies of Splices, Knots, Bends and Hitches (http://catalog.mazzellalifting.com/Indexes/Cordage/Page474.aspx)

I agree about snatch loads between 2 3 tonne trucks like ours being dangerous to almost everything:D Snatch straps are clearly different.

Fishing tackle knots, bends, plats and splices are for the same reason. Shock load a 200kg fish on 15kg line and test is very entertaining.

Whenever I can skip using a heavy shackle I do. Saw several broken bones seen from broken rope while in the navy. Flying shackles would not be nice!

Might try below for a platt on some rope. That would give some shock absorbance but still not for a snatch which IMO should be a last resort after every other option has been tried.

IFISHTV - How to Plait a double in your fishing line - YouTube

Unlike knots, Platting line does not introduce a weakness in my braided fishing lines as my lost fish seem to break off at other parts:(.

[Tank]

You may note that a lot of fishing Knots used on nylon (brand name) require you to moisten (bit of spit) the knot before pulling up tight. This is because Synthetic lines/rope create heat when subjected to friction, why you need to spit on your knot before cinching up tight, regards Frank.