tech 12 rope shackles

Conachair

Conachair

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A friend jsut gave me some offcuts of 9mm tech 12 rope, the stunt riggers for film & tv don't really use steel wire rope any more, it's all technora or dynex.
http://www.samsonrope.com/index.cfm?rope=200
Amazing stuff, light as a feather and stronger than steel. Might make some shackles out of it but google didn't come up with any info on how to splice them, slicing the rope is easy but nothing on creating a shackle. Anyone know of any links?

Or anyone using synthetic rigging? Chafe would worry me a bit though it does seem sturdy stuff. Might be nice to have couple of shrouds made up as spares for offshore, much easier to work with.
 
IMG00035-20101218-1304.jpg


1st attempt.
 
You should look at splices for Amsteel or Dyneema. I think your splice is too short. This rope is very slippery and your splice will probably work apart.

Your thimble looks way too small for the size of rope too.
 
Conachair said:
.....google didn't come up with any info on how to splice them, slicing the rope is easy but nothing on creating a shackle. Anyone know of any links?
Click to expand...

I agree, this stuff is significant.

There are multiple YouTube videos and 'how to do it' documents on line. Maybe a short course on search terms might be useful to many of us oldsters....?

Really must try harder :D


Er, documents and vids on RHS of linked Colligo page above...
 
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Lady Campanula said:
I agree, this stuff is significant.

There are multiple YouTube videos and 'how to do it' documents on line. Maybe a short course on search terms might be useful to many of us oldsters....?

Really must try harder :D


Er, documents and vids on RHS of linked Colligo page above...
Click to expand...

Why try harder when others will do it for you :p

Thank you very much your ladyship. :cool: That stopper knot was the bit needed, stainless nut on the first attempt wasn't really the way forward.

IMG00039-20101218-1703.jpg


I've got access to a test bed so will stick a couple of tonnes on that next week and see what happens.
Only took a few minutes, rope was free - perfect present for aunties and uncles :)
 
Conachair said:
Why try harder when others will do it for you :p

Thank you very much your ladyship. :cool: That stopper knot was the bit needed, stainless nut on the first attempt wasn't really the way forward.

IMG00039-20101218-1703.jpg


I've got access to a test bed so will stick a couple of tonnes on that next week and see what happens.
Only took a few minutes, rope was free - perfect present for aunties and uncles :)
Click to expand...

Kidding apart, I'd be very interested in what your test bed tells you. As I understand it from the Colligo vids, the effectiveness of that knot is crucial to the SoftShackle remaining together, and the Colligo guys pre-load their commercial product on a hydraulic 'puller' - which I don't have.

Perhaps there's another way.... :confused:
 
Lady Campanula said:
Kidding apart, I'd be very interested in what your test bed tells you. As I understand it from the Colligo vids, the effectiveness of that knot is crucial to the SoftShackle remaining together, and the Colligo guys pre-load their commercial product on a hydraulic 'puller' - which I don't have.

Perhaps there's another way.... :confused:
Click to expand...

I took it from the vids that preloading tightened up the stopper knot, if you couldn't preload then leave the tails a bit longer and real world loading will do the same.

I can get to play with 3t lever hoists but the load cell only goes up to 2.5t. I could double reeve a bit of tech 12 taking the load upon the shackle to 5t before friction. 5t on something which may well break right next to you, well that should get the heart rate up!!! Interestingly from 4 x 4 sites where they use it as a winch cable they say that when an exotic like tech 12 goes it doesn't have the leg cutting off recoil of steel wire rope but just falls to the ground. I'll take their word on that:)
 
I'm interested in inter alia using loops of this stuff as so-called 'fuses' in running rigging, IF the loops' breaking strains can be predicted reasonably closely, so as to carry away when overloaded and thus protect e.g. the clews of sails.

This is an old idea from the days of working sail which is used, I believe, in racing circles today - but not, seemingly, in other sailing activities.

D'you think you can - or the manufacturer can - test then predict UTS for a single-loop, a doubled-loop, a tripled-loop....?

:cool:
 
Lady Campanula said:
I'm interested in inter alia using loops of this stuff as so-called 'fuses' in running rigging, IF the loops' breaking strains can be predicted reasonably closely, so as to carry away when overloaded and thus protect e.g. the clews of sails.

This is an old idea from the days of working sail which is used, I believe, in racing circles today - but not, seemingly, in other sailing activities.

D'you think you can - or the manufacturer can - test then predict UTS for a single-loop, a doubled-loop, a tripled-loop....?

:cool:
Click to expand...

Well i wouldn't use a 9mm loop as a weak link. Theoretical strength would be 16 tonnes. :eek: I didn't have access to a load cell today but had a 2t turnbuckle attached to the soft shackle, cranked it up as tight as I could and it held fine, must easily have been over a tonne, the rope felt like a piece of solid bar.
IMG00041-20101221-1347.jpg
 
IMG00049-20110121-1608.jpg


Finally got access to a load cell today. 2.5 tonnes. It was bar tight, the knot now feels like a nut. It did creep a bit, the load would decrease maybe 100Kg over a minute or so as i cranked it up over 1/2t increments so there was a bit of stretch in there, maybe the knot bedding in?.

Above the load cell is a 3t leverhoist, I was trying to hide behind an rsj collumn while cranking the handle just in case it went bang....


Now considering that a couple of back stay insulators could easily set you back close 500 quid, any reason not to put a length of something like dynex dux top and bottom of the backstay to insulate it for an ssb aerial?
 
Hi Padz.

Not too sure what its insulating properties would be when its wet ?

But it could be used with the old style aerial 'pot' insulators, google for egg insulators, no idea of what the working load of them would be, but they do fail safe.

Certainly cheaper than the normal backstay insulators.
 
SSB backstay aerial

Rather than use a rope shackle it is far better to use the dynex for the whole backstay. Pass the dynex through heat shrink tubing and then add copper wire of appropriate length. This way while you are still using dynex for insulator, insulation can be around 1 metre long at top and bottom. The copper wire at the bottom is led away from the backstay to a feed through the deck. So no join in the wire.
Salt and moisture will collect in the rope so reducing insulation resistance so a rope shackle may end up low resistance. olewill
 
William_H said:
Rather than use a rope shackle it is far better to use the dynex for the whole backstay. Pass the dynex through heat shrink tubing and then add copper wire of appropriate length. This way while you are still using dynex for insulator, insulation can be around 1 metre long at top and bottom. The copper wire at the bottom is led away from the backstay to a feed through the deck. So no join in the wire.
Salt and moisture will collect in the rope so reducing insulation resistance so a rope shackle may end up low resistance. olewill
Click to expand...

That's a good idea, or why not insert some insulated wire all the way up the centre of the rope, wouldn't be too difficult with the constructiuon.
I was initially thinking of having a spliced 3' or so length of rope top and bottom of the stay and using the stainless swr as the aerial.

It would certainly be a talking point if nothing alse :)
 
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