Line types...Vectran, Dacron, Spectra?

[lifewithoutanet 0]

Did a search on this already, but came up w/ some conflicting information, or at least information I'd like clarified. Could someone weigh in on the following and provide more info or corrections?

Dacron lines will stretch, but return to their original state and rarely go out of trim. As such, they're well-suited for BASE canopies in shock absorbtion, and in keeping their trim, help to prevent gear-influenced off-heading openings.

Spectra lines wear well, will not stretch, and to the contrary, will actually shrink over time.

Vectran lines will hold their trim, but don't wear as well as Spectra and tend to 'fuzz out' more rapidly.

Even with the differences, the 'lifespan' of Spectra and Vectran between relines is roughly equivalent.

How much of what I wrote above is accurate? What is a typical 'lifespan' (# of jumps) for each type of line? I'm sure many factors play into this, but the more qualifying info, the better. What other line types have I overlooked?

Much appreciated.
-C.

[GeeeeeeFly 0]

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Spectra lines wear well, will not stretch, and to the contrary, will actually shrink over time.

Spectra actually will stretch and it does shrink as well. This is what manufaturers call "creep". It goes out of trim after 500 or so jumps depending on the use and exposure to the elements.

Vectran has little to no "creep" it is a little stronger than spectra but has it fall backs when UV light is put into the equation.

As for the "fuzz" Spectra usually shows better signs of this than Vectran. It is the one signs of wear that is indigenous of spectra that lets the user know it is time to change the line set.
Vectran shows a little of this but it becomes very dark and gray in color. It tends to break down and turn into soft yarn as it gets older with use. Vectran has a tendency to break unsuspectedly, that is why it is good o check out lines made of this regularly, as it is good to check spectra too but the wear is more noticeable on spectra.

As for Dacron your info seems pretty much right on.

There is another type of line out there that you have missed it's called High Modulus Aramid (HMA). This is a relatively new line and has been used in the past 4-5 years with some research. It also goes by the trade name Technora.
It is a very strong line with similar characteristics of Vectran but it is has a smaller diameter, making for less drag.

~G~

"The edge ... there is no honest way to explain it because the only people who know where it is are those that have gone over"

[lifewithoutanet 0]

Thanks for the clarification and additional info on HMA.
-C.

[PhreeZone 15]

Dacron has a very large pack volume so if you have a canopy lined with this you need to take the increased volume into consideration also for packing.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[alain 0]

Had a new vectran lineset on my Safire after 500ish jumps. The old lines looked dark and 'fuzzed out' but the trim was still like new.
I understand that the darkness or 'fuzz out' factor are not the main concern with vectran's lines but they can snap without prior notice if you use them for too long. I did not play that game thoug and I could not say if 500ish jumps is a reasonable figure or if you can go further at no risk...
Just my experience, get in touch with people at www.wara-concepts.com : they reline vectran canopies all the time

[FrogNog 1]

Where is our info source that Vectran lines can snap without prior notice?

Someone at my DZ told me this entire story came from one incident where someone used understrength Vectran brake lines (and probably died when a brake line snapped during a swoop). The implication was there isn't a body of evidence saying Vectran are no-warning-snappy, there was one incident.

Does anyone have anything real on this? Know what forum search I would do? (If I searched now with what I know, I expect I would find 100 people quoting the person before them that "Everyone knows"...)

-=-=-=-=-
Pull.

[ianmdrennan 2]

IMO Vectran most definately shows signs of wear, it gets EXTREMLY fuzzy. HMA on the other hand is much, much harder to detect wear on.

Blues,
Ian

Performance Designs Factory Team

[alain 0]

true, I don't have any first hand reliable evidence or source on that point, that's only what I've read and heard many times.
once again, people really concerned with Vectran lifespan should get in touch with experts like para-concepts...

[masterrigger1 2]

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Dacron lines will stretch, but return to their original state and rarely go out of trim.

Dacron does go out of trim... it stretches mostly at the brake lines and at the center cell region most!

The rest of the info is pretty good.

BS,
MEL

Skyworks Parachute Service, LLC
www.Skyworksparachuteservice.com

[jerm 0]

indeed... HMA can have a couple hundres jumps on it, look like brand new, and snap. This has been shown repeatedly in labratory line-wear tests and i've heard of incident such as this in the field.

Landing without injury is not necessarily evidence that you didn't fuck up... it just means you got away with it this time

[alan 1]

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HMA can have a couple hundres jumps on it, look like brand new, and snap. This has been shown repeatedly in labratory line-wear tests

There must be a link to this somewhere, if there is, could you post it? Maybe just provide what labs did the testing and we can look it up for ourselves.

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and i've heard of incident such as this in the field.

Yes, many of us have heard about this and even a few have seen it first hand. I've seen dacron, spectra and the old kevlar do it as well.

alan

[masher 1]

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HMA can have a couple hundres jumps on it, look like brand new, and snap. This has been shown repeatedly in labratory line-wear tests

There must be a link to this somewhere, if there is, could you post it? Maybe just provide what labs did the testing and we can look it up for ourselves.

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and i've heard of incident such as this in the field.

Yes, many of us have heard about this and even a few have seen it first hand. I've seen dacron, spectra and the old kevlar do it as well.

In response to your last statement. Did the dacron, spectra and the old kevlar look brand new too? This is just a question, not confronting you...

I've heard the same about HMA (that it looks brand new and then snaps).

--
Arching is overrated - Marlies

[alan 1]

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In response to your last statement. Did the dacron, spectra and the old kevlar look brand new too?

The dacron looked a little used but not as if it should have failed. Several new looking spectra lines. By that, I mean that I know they had less than 100 jumps on them.

The old kevlar fell out of use for a reason. It was prone to breaking. It didn't take many jumps on it before it got a used look, kinda like Vectran, but they weren't old enough to be obviously worn out. I even had to replace a pc kill-line that was made of kevlar that had broken.

In most of the cases it seemed to me as if an odd occurance of uneven loading was probably the main culprit. Like one line that the loop had worked its' way over the barrel on a french link and hung up there while the others remained up on the bend.

alan