Bridle length for static line jumps

[guest]

Just wondering the pros and cons of using the normal 9ft. bridle on static line jumps. Using a shorter bridle might help for faster deployments on LOW stuff where it is impossible to get someone to Dbag.What about using NO bridle? I realize that if the break cord "breaks" prematurely you will have a pilot chute trailing behind you in the burble. Any thoughts on this will be appreciated. CYA Jason

[guest]

The problem with using a static line that is very long is it increases the snatch force on the break cord. What you want is for the static line to load up early (before you are going very fast) and just have a nice steady strain on it right up until the point the breakcord fails.

With a longer bridle, the static line will lay at rest until you start pulling on it, but at that point the snatch force may have built up to the point where the breakcord fails at the onset of the snatch and not at the completion of line stretch like you want.

In this case hopefully you are using a pilot chute as well. (Never tie the S/L breakcord to the pilot chute)!

This may be a good time to remind everyone about Teresa Tran and how she died doing a static line jump a few years ago. She is the 2nd and last jumper off a low cliff. The first jumps and lands unevenfully. At this point, alone on top, Teresa changes the plan and places her pilot chute (that is already connected by its bridle to the static line) into her BOC about a third of the way in.

The static line is not too long, but when she jumped the part of the pilot chute inside the BOC, the part that had to make a 90 degree turn out of the pouch applied enough extra momentary resistance to the breakcord that it failed. It left the pilot chute in the pouch. A few seconds later she is dead. (This cliff is low enough that by the time you realize it isn't happening, it's all over).

Experiment with extreme caution . . .

Nick_BR

[Keith]

I thought that we developed the direct bag as a fix for the inherent obvoious problems that we were having with the static line/break cord/pilot chute assist deployment systems. Aren't we taking a step backwards and taking unneccessary risks when we use them? Personally, if I can't DB on a low site, then I'd rather watch TV.

[guest]

Keith,

You are not paying attention. He's a BASE jumper. You need trustworthy friends in order to jump direct bag http://www.baselogic.com/forum/images/happy.gif

I've not a big fan of static line BASE jumps, but I must admit after watching Simon Jakeman bang them out over the last few years (I believe he's gone over 300, just in S/L jumps alone) I know it works if you are hip to the way of it.

Some advantages over direct bag are you can do it alone, or if in a group, you're not leaving a bag holder behind. (Bag holders have the worst lot, they have none of the fun, and stand the largest risk of capture). You also get more freefall (not technically correct, but you know what I mean) and you're also a bit further away from the object on opening with static line.

My largest gripe about static line is I've always thought there's a bigger chance of an off-heading opening because of the pivot point caused by the static line. However, I've changed my view on this, not through personal experience, but just through the fact, I don't see or hear of it happening more than would be considered normal, i.e. from packing, body position, crosswinds, etc.

Rigging is more complicated with static line, but there are problems with direct bag too. We have seen every mistake you can imagine. You can put the bag on the canopy upside down, the bag holder can twist the bag when removing it from the container (while you of course are looking the other way) and it's also possible for the holder to drop the bag as you launch.

Better techniques and advancements in direct bag design have made it harder but not completely impossible to goof these up.

There was a time when direct bags (just regular skydiving bags) had no handles, the holder just tightly gripped the corners (I get the shudders just thinking we actually did that) but we did have the good sense to tie the bags to the object for just that reason. That way, no matter what, you'd get some lift. How much lift and which way it's going however is another thing entirely . . .

Keith alludes to another blast from BASE jumping's past with the big debate on freefall Vs D/B that concluded with (Rick Payne's?) famous quote, "I rather watch TV then DB!"

Another thing is people always wonder why early BASE jumpers counted down their launches, you know, the 3,2,1, C-ya, bit. I believe this comes from the historical fact that a whole generation started with direct bag as it was considered the safest way for a person to make a first BASE jump. It's a timing thing between bag holder and jumper, and the habit just stuck.

Okay, there is also the ham factor, if there's a camera around. http://www.baselogic.com/forum/images/happy.gif

Nick_BR

[guest]

Short bridle

When we need faster deployement during SL jumps, we sometimes tie the bridle to the object (with the breakcord) not at the end of the bridle (on the pilot chute side) but closer to the canopy. I have a built in loop on my 9ft bridle about 2ft from the canopy. If you don't have such a loop, you can use a second shorter bridle.

This way, you have a faster deployment and keep the advantage of a long bridle for the PC in case of breakcord malfunction.
Beware, short bridle use must be compatible with the object shape.

[chris]

I've made a "few" static line jumps and this is what I do..

Make bridle long enough for a good launch.
(what's 2' compared to 6')
Attach break cord as close to canopy as possible.
(snatch force)
Pilot chutes.. love to flop, drag,wrap,dance,stay where you don't wan't em..
(Don't attach!!!!)
If you don't trust the break cord..
DON'T USE IT !!!! DON'T JUMP FROM AN OBJECT THAT LOW... D-BAG.....

Static line jumps are low....

Keep it simple.
I do, And I enjoy!

[bps]

Hi Chris -

Do you rely solely on the break-cord? I realize that PCs could hang up etc. but it seems unlikely with a little thought and planning. And if the break-cord fails before extraction your day is going to deteriate rapidly!

But hey, what works for one, may not be ideal for another.

Happy Groundrush,

Bryan

[guest]

Have you heard about the electrical tape thing? Check it out. It's very simple and easy.

Oh no....don't expect to learn it from me here! Go find an Australian-they love that shite. ;-}

cya pr

[guest]

I just did a poll of everyone in the shop (that does S/L) and it's split about evenly between those who use a pilot chute and those who don't.

I really can't see a reason not to use one, except it takes a bit more rigging and thought.

But hey, I'm a certified weenie, I even experimented with stuffing pilot chutes inside direct bags as a back-up. Now, that's really being paranoid . . .

Nick
BR

[Yuri]

Yo !

While the break force for electrical tape isn't as predictable, it has a definite advantage over a regular break cord: plastic will stretch quite a bit before it breaks, thus reducing the danger of S/L breaking prematurely due to the snatch force. Watch out for low temperatures, though - it won't be as elastic.

The pilot chute issue is simple - it will still give you an open canopy at altitudes quite a bit below your regular freefall treshold. You may not have enough time to flare, but a broken leg is preferrable to becoming a road pizza when S/L fails on 150' jump. USE IT !!!

bsbd!

Yuri.

http://www.maxho.com/base

[imported_Tom Aiello]

Hey,

Aussies aren't the only ones who use that shite.

I love electrical tape.

--Tom Aiello

[bps]

For those who have never met Tom...

He may be American - but once you jump with him - you'd swear he's got some Australian blood in him!
http://www.baselogic.com/forum/images/wink.gif

Go Hard,

Bryan