Reserve Line Types....

[udder 0]

Reading through previous posts a few people noted that an increase in the number of reserves blowing up coincided with people loading them above 1. Would this also be the result of using microline over dacron?

Also, would less reinforcing be required to have the same failure point if you used dacron line instead of spectra? For example, would the same design would be able to withstand greater shock loading (like premature head down) with dacron lines?

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[RMURRAY 1]

I don't know but I was thinking the same thing except having to do with tension knots. Are larger Dacon lines less likely to result in a tension knot? If yes then maybe we should be considering ordering Dacron on reserves.

rm

[riggerrob 558]

My experience is that Dacron is more likely to suffer tension knots. The older Dacron gets ... the fuzzier ... the dirtier ... the more likely Dacron will suffer tension knots.
Spectra usually has latex (?) coatings that allow knots to slip out more easily.

[linestretch 0]

But Rob, these would be on a reserve.....so HOPEFULLY they won't be getting fuzzy from being used.

I would think the larger dacron would GREATLY increase the packing volume.

my pics & stuff!

[billvon 2,400]

>Would this also be the result of using microline over dacron?

Possibly. Anecdotal evidence points to a reduction in slammer openings in regular mains when dacron is used.

>Also, would less reinforcing be required to have the same failure point
>if you used dacron line instead of spectra?

I doubt that any reserve manufacturer would weaken their canopy to accomplish such a goal, especially since the cost would be a requirement to use bulky dacron lines (which more than make up for the additional bulk of, say, reinforcing tape.)

You might accomplish a similar goal through the use of a load limiter sewn into the harness. (A load limiter is a device sometimes used by climbers that essentially sacrifices stitching to reduce ultimate loads on the harness.) However, since it would almost be guaranteed that one riser/side would yield more than the other, you'd need a large reserve so that the differential loading did not cause too many problems - and again you're back to a larger, more bulky reserve.

[udder 0]

Thanks billvon. I didn't take into account the buliker lines, so any reduction in reinforcement tape is more than made up for by the lines.

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[fcajump 153]

Quote

Reading through previous posts a few people noted that an increase in the number of reserves blowing up coincided with people loading them above 1. Would this also be the result of using microline over dacron?

Also, would less reinforcing be required to have the same failure point if you used dacron line instead of spectra? For example, would the same design would be able to withstand greater shock loading (like premature head down) with dacron lines?

Ah... but any implementation in this direction would violate one of B.Booths fundimental laws... (paraphrased "Skydivers will always choose smaller/faster/lighter over safety.")

For myself, the coated dacron lines on my reserve have yet to show any fuzz, wear or dirt... and they don't tend to snag on the freebag velcro.
And I am looking into going back to Dacron when my main is up for reline. (no decision on that... yet...)

Jim

Always remember that some clouds are harder than others...

[udder 0]

coated dacron? Did you do this yourself or is it the way they're made? I only know there are two types, one rater for more load than the other. Also how much did dacron increase your main packing volume? Is a one size increase a good approximation?

"In one way or the other, I'm a bad brother. Word to the motherf**ker." Eazy-E

[fcajump 153]

Quote

coated dacron? Did you do this yourself or is it the way they're made? I only know there are two types, one rater for more load than the other. Also how much did dacron increase your main packing volume? Is a one size increase a good approximation?

Coated - the way they came (Fury reserve 1991)
It does increase the pack volume, but how that translates into sizing... I would refer that to the container mfg.
As to changing my lines on my main, the advantage I have is that my container was originally bought for a 9-cell 260 w/ Dacron. The current canopy is a 7-cell 230, so the increase should not be a problem for me. If considering it for your own gear, this is an evaluation I would recommend you discuss in depth with the rigger who knows your particular gear combination and volumes.

BTW - Coated lines is not ALWAYS a good thing. While I prefer them, a recent one-on-one discussion with a mfg that uses uncoated lines on their reserve informed me of environmental conditions in which coated lines might cause issues (usually extreme temps). This is NOT a one-size-fits-all industry. Keep learning, keep asking questions.

Jim

Jim

Always remember that some clouds are harder than others...

[RMURRAY 1]

Quote

coated dacron? Did you do this yourself or is it the way they're made? I only know there are two types, one rater for more load than the other. Also how much did dacron increase your main packing volume? Is a one size increase a good approximation?

you need to consult the container manufacturer. Here is some info from jumpshack. The PD160R with dacron is about 8% larger in pack volume...

rm

[riggerrob 558]

Yes, Strong Enterprises has issued a couple of service bulletins (1979 and circa 2000) about reserves with to much latex on their suspension lines.
It turns out that the cordage mill applied too much latex to the lines. Under certain temperature and humidity conditions, the lines might stick together.
The first SB (1979) merely required washing the lines.

[riggermick 6]

You might accomplish a similar goal through the use of a load limiter sewn into the harness. (A load limiter is a device sometimes used by climbers that essentially sacrifices stitching to reduce ultimate loads on the harness.)



Bill, back in the eighties when they first came out, attenuaters were called "zingers" and consisted basicly of a long length of nylon webbing (aprox 2500 lb strength) with structural loops at each end. The main body of the webbing, sometimes up to two feet in length was s folded in to lengths of about six inches and bartacked with COTTON thread. This provided a sturdy but "fusable" link that wouldn't destroy the sturctural integrety of the webbing.


The basic premise is: As a load is placed on the "zinger" the bartacks will fail one after another slowing the velocity of the climber by way of momentaraly hanging up before failing on each bartack. the overall effect is to reduce the velocity of the fall and thus the load on the point(s) of protection placed in the wall. Never had to use one, but kept a few with me when I was an active climber. The tests we performed in the loft were quite remarkable, they actually worked!! Don't know if it's workable for a skydiving harness though, as you pointed out, risers generally tend to load assemetricly.

Mick.

[fcajump 153]

Quote

You might accomplish a similar goal through the use of a load limiter sewn into the harness. (A load limiter is a device sometimes used by climbers that essentially sacrifices stitching to reduce ultimate loads on the harness.)



Bill, back in the eighties when they first came out, attenuaters were called "zingers" and consisted basicly of a long length of nylon webbing (aprox 2500 lb strength) with structural loops at each end. The main body of the webbing, sometimes up to two feet in length was s folded in to lengths of about six inches and bartacked with COTTON thread. This provided a sturdy but "fusable" link that wouldn't destroy the sturctural integrety of the webbing.


The basic premise is: As a load is placed on the "zinger" the bartacks will fail one after another slowing the velocity of the climber by way of momentaraly hanging up before failing on each bartack. the overall effect is to reduce the velocity of the fall and thus the load on the point(s) of protection placed in the wall. Never had to use one, but kept a few with me when I was an active climber. The tests we performed in the loft were quite remarkable, they actually worked!! Don't know if it's workable for a skydiving harness though, as you pointed out, risers generally tend to load assemetricly.

Mick.

Implemented differently, but the concept is used by Butler in their higher speed PEP pilot chute bridles... really cool concept.

JW

Always remember that some clouds are harder than others...