Rig "failsafes"?

[AggieDave 6]

I had always been under the impression that certain items on our rig's main canopy system were designed to fail in the event of a very very hard opening, breaking so to keep from breaking the jumper.

Items like links on the risers, the risers, lines on the canopy, etc.

Could someone prove or bust that "myth" for me? Hard data from experienced riggers would be nice.

Thank you.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[mjosparky 4]

I have never heard of any being "designed" that way. Some designs end up with weak links either by accident or due to the choice of materials for various components.
Sparky

My idea of a fair fight is clubbing baby seals

[hookitt 1]

That's tough to say Dave. When risers were made from type 8, they just didn't break. It wasn't until type 17 risers came onto the scene that risers began to break on occasion.

Parachutes had Dacron lines, big fat risers and large 3 rings (once they were invented). Mjo states that the weak link was an accident. I'd tend to agree. Microline and ZP came into play, as well as parachutes that slammed the heck out of you. Something was bound to break.

I remember quite well when a couple lines on a falcon 215 broke. Little stars and tweety birds circled my head. Add another 60 or so pounds of weight to my frame and I wonder what else would have broke.

I'd say weak links are by accident. Keep in mind that the weak link is pretty damn strong.

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[Praetorian 1]

cant bust the myth but I've been told that risers are the weak link, that they could be made stornger, but there really is not the point in USAF studies it has been shown that the human body can survive short duration shocks of some huge number of Gs like 50+ now if the shock makes be break my neck thats one thing, but I cant imagine any riser which could take 200lbs *50G for 10000lbs aparent force what about 70 or 80G, now in the study the harnes was more complete then a skydiving harnes so you probably wouldn't die technically from the G load but from your ribs being broken and severing your lungs and heart.

Good Judgment comes from experience...a lot of experience comes from bad
judgment.

[Unstable 9]

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I'd say weak links are by accident. Keep in mind that the weak link is pretty damn strong.

Isn't your body the weak link??

=========Shaun ==========

[mjosparky 4]

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cant bust the myth but I've been told that risers are the weak link, that they could be made stornger, but there really is not the point in USAF studies it has been shown that the human body can survive short duration shocks of some huge number of Gs like 50+ now if the shock makes be break my neck thats one thing, but I cant imagine any riser which could take 200lbs *50G for 10000lbs aparent force what about 70 or 80G, now in the study the harnes was more complete then a skydiving harnes so you probably wouldn't die technically from the G load but from your ribs being broken and severing your lungs and heart.

Up until the introduction of Type 17 risers the weakest link on a sport harness was the hardware. Most of the hardware used is rated at 2500 pounds, while the webbing is from around 4000 pounds, Type VIII, to around 7000 pounds, Type XIII.
I have taken 3600 pounds per side, just under 36 G's total, on opening and it hurt like hell but did not break anything. It was considered a "non test" because I would not repeat it.
Sparky

My idea of a fair fight is clubbing baby seals

[696GrocuttT 0]

Check out http://www.relativeworkshop.com/support/tech_risers.html

Although it doesn't mention anything breaking before you get broken. It does say the risers are designed to break before the harness is damaged.

[Staso 0]

i would expect that canopy fabric will give up first on high speed deployment. and maybe couple of lines. Craig Poxon (cpoxon) has a slide show about speed skydiving and one of the slides is the pcitures of the rig after premature deployment during speed skydiving. it didin't look very good.

stan.

--
it's not about defying gravity; it's how hard you can abuse it. speed skydiving it is ...
Speed Skydiving Forum

[jmfreefly 0]

Exactly. The point is that risers are easy to replace, while harness is not.

Has nothing to do with reducing forces on the body.

j

[696GrocuttT 0]

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Exactly. The point is that risers are easy to replace, while harness is not.

Personally I'm not that bothered about how much it costs to get things fixed. However I would be pissed if a hard as hell opening cause damage that meant that the harness wasn't landable instead of just the main/main risers not being landable.

[jmfreefly 0]

I'd concur with that also.

j