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Dyneema rope VS steel

Can’t speak about industrial uses of dyneema, but am a happy user of it for climbing. Way lighter and less bulky than nylon slings, doesn’t absorb water so doesn’t freeze solid, but isn’t as durable and on loading tends to melt as opposed to stretching. I know the industrial access boys use it, but still keep nylon and metal for certain uses.

Would be very interested in learning about industrial uses of dyneema.

L7
 
Can’t speak about industrial uses of dyneema, but am a happy user of it for climbing. Way lighter and less bulky than nylon slings, doesn’t absorb water so doesn’t freeze solid, but isn’t as durable and on loading tends to melt as opposed to stretching. I know the industrial access boys use it, but still keep nylon and metal for certain uses.

Would be very interested in learning about industrial uses of dyneema.

L7

light duty logging has it's advocates. I have not seen it on skidders in our area yet, but it is fairly common of "new" tractor mounted winch set ups. Progressive operators....;-)
 
light duty logging has it's advocates. I have not seen it on skidders in our area yet, but it is fairly common of "new" tractor mounted winch set ups. Progressive operators....;-)


What happens when it let's go ?
Is there much stretch ?
 
What happens when it let's go ?
Is there much stretch ?


never used it myself. The advertising indicates low stretch. but what does that mean? I've seen it laid over it's self on the drum so tight it had to be pulled off with the tractor. There was no way to walk it back out for a second pull.
 
Last I read about such products, they were vulnerable to UV damage, and had to be shielded in some way if used for long periods outdoors. But the material (or a proprietary variant) is used for the wheel tethers on racing cars (keeps the wheels/uprights from flying off in an accident), "bullet-proof" vests and body armor, etc.

And to think it's just a version of polyethylene...

Ultra-high-molecular-weight polyethylene - Wikipedia

[Going through the Wiki article, it says it is resistant to UV radiation, which is contrary to what I'd read previously. I'd want to get confirmation on that before I planned to use it with exposure]

[Yeah, further down the page it says this: "One notable drawback of Dyneema rope is its susceptibility to UV damage". WTF, Wiki?]
 
It's the way of the future on larger cranes especially. When you get into larger cranes with big blocks, it takes away a lot of the crane capacity just for the weight of the cable. Most people haven't made the swap though, because it wears out faster, cost a lot more, and most cranes get exposed to a lot of UV rays.
 
That seems to be an unfair test with all those cable clamps on one end of the steel cable and a nice crinp on the other. Like Cal said above, no surprise it broke there. Probably broke early also. No clamps on the dyneema. The cable should have been spliced like the dyneema or crimped on both ends, or one end wrapped around a spool as it would be on a winch.

I have heard from some old 4x4 buddies that that stuff is easily cut through if you need to run the winch cable over a rock. So easy to cut through it is almost guaranteed it will break (if run across rocks)
 
We are using a version of dyneema rope called Masterpull for tendons on some of our larger robots. It has a sheath of spectra, Making it more heat and abrasion resistant. they take a three-quarter inch piece of dyneema rope and heat it and stretch it so it ends up at 3/8 diameter once the spectra sheath is applied. It ends up as a very hard, steel cable like product. Not squishy like dyneema rope. The breaking strength on 3/8” is 28,000 pounds And it floats on water. It’s quite abrasion resistant. We have it going through titanium bushings under a lot of load and we are getting a pretty good lifetime out of it so far. Was originally developed as a steel cable replacement for the military. Terminating it is pretty tricky, we use a sefac Spiked type termination with an adhesive made by 3M on the fibers.
 
What happens when it let's go ?
Is there much stretch ?

Very minimal stretch and shorter lengths just drop to ground when it fails under load. Unlike steel cable that whips and cuts off someones head.
Downside of minimal stretch is that it sucks with shock loads.
 
Dyneema is a product from DSM A dutch compagnie Some 20 years ago I did work on machines to crossply dyneema
That is to make a fabric where the fibers are not woven but lay side by side in layers and each layer at a 90Dgr angle All bonded with a latex like glue Rather complex to make
It was mainly for balistic purposes Sold a machine to Israel to make lightweight cararmor for private use Also to the US to make helmets out of the material Nowadays it is also used on cockpitdoors I heard
It is very slippery so hard to put a nut in it Also hard to cut the yarn And even a single yarn cuts your finger off if it gets cought in the machine

Peter
 
I use quite a bit of spectra/ dynema for running rigging on sailboats. It’s low stretch characteristics are very important. Modern boats are loaded quite high. We’ll tie a spectra sheet onto a sail and load it to tons a second later. Modern sailing is more of contorting sails with high force than just letting them fly freely.
If there is stretch in the lines or sails that energy does not move the boat forward.
So the modern low stretch lines have helped sailing out quite a bit. We used to use wire sheets and guys, you had to use gloves as inevitably you’d get cut from a meat hook (fray)

We typically eye splice our terminations to metal bits. One nice thing is the termination is not permanent so you can adjust it a bit.
We are now moving on to heat treated lines with very low stretch for certain applications on the boat.
Cool technology that has trickled down. The only industrial application I have used is using an old spectra sheet (rope) around the shop.
 
I bought out a winch manufacturers entire Dyneema product line. Ended up with a couple semi trailer loads of the stuff.

I've sold most of it. Given my situation I used it for a lot of things one wouldn't normally use a $150 rope for.

UV kills it quick. A week outside and it is fading color. a Summer outside and it's garbage.

Abrasion resistant my ass. There's no abrasion resistance whatsoever unless you get the fancy stuff with a woven outer jacket.

In that test, that 3/8 cable must be pretty shitty to break at 14k pounds. Decent 3/8" wire rope shouldn't fail under 20K lbs.

It is super light, has no detectable stretch and is way stronger than you would expect. I have done some serious tugging with a 25K lb dozer and it didn't phase 8mm Dyneema.

If you actually use a winch or a steel cable frequently like search and rescue, tow company, or absolutely anything to do on water than Synthetic line is what you should have. One guy can pull 150 feet of 1/2" Dyneema TIGHT. Think about that. Consider what 1/2" steel cable weighs in comparison.

If it just sits around outside on a winch drum for 5 years at a time than synthetic line is not for you. It will be shit when you go to use it.

If anyone wants to try some good stuff out I have about a hundred 50 foot top quality made in UK 3/8" Dyneema winch lines that are slow moving. If there's interest I could throw an ad up in the sale section.
 
Heres what our terminations look like. A threaded bar with tapered hole and a matching cone. Strip the spectra cover back and fray the fiber out. Using 3M 8010 adhesive (with a working time of about 3 min so you have to get it applied to the fibers fast), we use an electric hair trimmer held crosswise to the rope, and a # 3 guard that get thrown away afterwards, comb the 8010 through the fibers. Pull the rope back into the tapered hole, center and insert the cone, and move to a press fixture and apply 3 tons to the cone. When cured, drill and pin. For testing we used a hollow enerpac ram and a pipe spacer between two terminations, rope breaks before the termination pulls out.

This is the old system, we use threaded caps now with a fine thread setscrew pressing onto the cone.
 

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Very minimal stretch and shorter lengths just drop to ground when it fails under load. Unlike steel cable that whips and cuts off someones head.
Downside of minimal stretch is that it sucks with shock loads.

Thank you for that bit of info.

Now when it does fail, how does it go ?
Steel cable sort of gradually let's down as it rips (sort of, slower than a chain breaking)
 








 
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