Basejumper.com - archive

Exactly as the title says. Although I respect the leaps in rigging that the Manufacturers have made in BASE. Center Cell Strip, heretofore abbreviated as "CCS" is very OK IMHO. Center cell inflates first. What is the problem? Check out the BFL. How many died from CCS? None that we know of.
PCAs done 1000's of times. a classic example of CCS.
CCS is BS. I do appreciate the Manufacture's trying to make things better. My Student who is doing Low pull demos is using a 46" PC for jumps from 1sec to terminal and he has had no problem with heading or malfunctions in a few hundred jumps.
Inflates from the center out. What is the problem? I ain't exactly inexperienced on this matter.
This is my take on this.
Take care,
space

i might be way off track here but...why would you use a 46 for terminal jumps? that's seems like you're inviting gear failure; that seems to be a much larger problem than an off heading or a line over. i mean, if your gear fails entirely, what difference does it make that you're still on heading when you impact the ground? Maslow's hierarchy of needs says it best. basic needs would be your gear not failing; self-actualization would be perfect on heading and stand up landing. am i off subject?

Gee, Space, your lucky Mark Hewitt dropped out of the scene or I'm sure he'd be flying to Germany to kick your ass . . .

Anyway, you tend to get CCS more on high speed jumps where there's more snatch force involved. On PCAs, if done right the holder lets go when the container opens. And it's all low speed from there.

On nobody being on the BFL because of CCS, who really knows. There's a lot of people on there whose demise began with an off heading opening, and we haven't really proved CCSs relationship to bad openings one way or the other, so in that case it makes sense to avoid it.

I think Yuri's idea of pre-strip is all right, but only because the rest of his pack job is tight and spot on. When his canopy lifts off his back it all stays together. It's the newbies with fluff and stuff pack jobs that are at risk, if there is one. I've seen very slow mo video of center cells stripped out to the point the top skins of the remaining cells are pointed downward or 180 degrees away. I can't see how that's good. And Yuri's pack job isn't going to do that.

As long as we've been doing BASE there are still gray areas, and CCS is one of them. It's easy to dismiss CCS because there's not been any definitive answers. But if I don't feel I understand some aspect of BASE 100 percent then I treat it like a hand grenade. So until someone proves CCS is a good thing, I don't want anything to do with it . . .

NickD

That's not what I consider a PCA done right, but that another topic altogether.

Well, of course it depends on the object height, but if it's freefallable I don't like hanging on too long. Back in the day when we first started doing PCA we were hanging on to the bridle basically as long as we could. And I've always thought that contributed to the death of my friend Dick Pedley.

He had an off heading on a building on a PCA and might still have been all right, but he hit a cable running down the side of the structure that snagged one his brake lines. And it just turned into a horror show after that.

In my head I've always thought there was more chance for a canopy to begin turning, or pivot, around while being held more or less stationary in the air while the lines play out of the tail pocket. Now sure, I know folks do plenty of static line jumps, and lots of PCAs but I very infrequently do. As I never liked either method.

So it's more or less just me, but without explaining it, you wouldn't know that . . . and I probably shouldn't have worded the line the way I did.

NickD

on kinda the same note, I think center cell 'stripping' is a good thing for heading performance.

for the reason Yuri and I pack the way he showed pics of, with the 'pre' stripped center cell, it cuts the packjob in half, the way the center cell would be stripped in the event of extraction.

just my thought...

the most important thing you can do to a packjob is center or pre-strip the center cell bridal attatchment. if this is symmetrical, I think most other 'obsessive symmetry goons' are nullified. (of course, basic symmetry is good no matter what)

The reason why: He is a demo slut.
He is getting paid to perform these jumps (low pull demos) and due to cloud cover he may and has had to exit sub 100m (Heli jumps). He says he with this setup he is prepared for any altitude (1800-100m) and can deliver the goods. He also works out 3 times a week to stay in shape for the hard openings.

Over stressed PC attachment point would not be an issue as the canopy would have reached line stretch when the failure occurred. Total gear failure is not going to happen as a result of an over stressed PC attachment point . You cannot impact without an open canopy and be on heading anyway.

That being said. I would NEVER do as he has done.
I like being conscious under canopy. I do not want to get knocked out from opening and I do not want to work out at the Gym 3 times a week to prevent the "unconsciousness from opening" scenario. I prefer to modify my deployment method rather than my body.
Hope this helps.
Take care,
space

You know Mark well. I wish he would come over and kick my ass and then we could get down to jumping and reminiscing about "back in the day". I have a rig for him to jump too.


I think the opposite. Exchange the word "good" for "bad" in your above quote.

It brings to mind a quote by Samuel Langhorne Clemens. "The radical of one century is the conservative of the next"
Take care,
space

Hey..ask him to remove the slider? then he deploy even lower lol

>>You know Mark well.<<

I actually did see him about 2 years ago . . .

It was a nice evening and I was sitting on my porch in the Perris Ghetto enjoying a beer. I then see this figure walking toward me in the dark and I didn't recognize the walk or the body type. My internal "Stranger in the Ghetto" alarm went off but as he got closer, and said, "Hey, Nick!" I recognized him. Mark Hewitt!

I actually got up from my chair and took a step back in case he took a poke at me. You never know with him.

But we did as you said. Had a few brews and laughed our way through the old days. He reminded me of a lot of stuff I'd forgotten and clued me to some things I never knew. He looked good and appeared healthy, and I think he's doing some kind of construction work nowadays.

Oh, and we talked about you too. He asked if you were still around and I said you were, and still jumping, except you reverse-immigrated back to the old country . . .

NickD

Hmm... maybe we should pre-do-something to the side cells as well? Calvin19, what do you think?

Ears are nothing but top skins. When we flake and roll them, we are creating two bundles of free-hanging fabric that are yanked by inertia during extraction in one direction (down) and hit by relative wind in the opposite direction (up), often making them asymmetrical by the time the canopy reaches linestretch. What if we could stow them in such a way that their CG is lower and they are hidden from the relative wind?

I have an unpacked rig, and a feeling of unconditional, unearthly love to packing suddenly overwhelmed my heart . . .

isn't that exactly what the "g" final folding method we use does? I can see what you mean by the relative wind blowing it around, but it seems like that is negated by making the extraction stripping symmetrical.

Agree with Mr. #283 100%!
The one and only way to avoid 100%% the CCS is to make equal number of lines which hold the canopy top skin at the same spot like suspension lines hold the bottom skin. Those ''top skin'' lines than should be tight together w the bridle...
Now when canopy goes out, there is no way that any part of the canopy would left behind!
As that is very complicated and stupid to really make , question is:What is the point than to have the system which ''prevent'' the CCS?!

Also,
If the body position is wrong, the system actually making the of heading even worst..than there is the complexity...packing error etc...

This thread is fairly interesting and I wish I had more than a few moments to discuss it. So with CCS, the canopy presents itself like a round canopy, inflating from the top down, with the center cell at the top and the tail hopefully restricted through some sort of tailgate like device, even slider up. I do not necessarily agree with Space on this issue but hopefully we can explore it carefully and scientifically so I can (hey, I'm the one jumping my gear of choice) jump with what I think is the best choice. I like certain concepts of the multi, paritcularly the specific attachment to lift the heavy tailpocket full of lines. I have jumped a multi on about 200 jumps mesh slider up with delays from 3 seconds to >10 seconds and have had maybe 5 to 10 severe off heading openings, far better than any other canopy. Interestingly, the openings even feel different than with a single attachment point. Talk to you later and hopefully we can explore this concept.

 
CCS is just a sort of ' boogie-man' concept for base, something to provoke thought and arouse respect for the activity. We need something mysterious, scary, and difficult to get a handle on to scare some respect into jumpers that normally think they're invincible. So we use CCS: we warn the newbs that CCS is bad juju and how we need to fight against CCS with various precautions. I take it a bit further and warn them not to pull low, do solos, or get complacent because CCS happens alot more often in those situations.

take your video camera, place it so to shoot up and you'll have evidence of what I am talking, also you'll be surprised w what you will see :O))

is this an example of center cell strip?
http://www.basejumper.com/photos/Span/Troy_RG_513.html

http://www.basejumper.com/...pan/Troy_RG_513.html

Would you mind posting a video of this Robert? I don't have a video camera, a belly mount for a camera, and since all my jumps are illegal, I cannot jump in the daytime in the vicinity where I jump. This would greatly appreciated for my own education and food for thought for the rest of the jumper community! Thanks!

No, that is of a normal deployment. Everything looks in order to me.
Take care,
space

So I guess I am having trouble picturing what center cell strip is. Does anyone have any pictures of it actually happening?

Dude you don't need a picture ? Just do a bunch of static lines or PCA's and you will see them.
Man, really (imho) . 'Centercell Strip' gets it beginnings from PCA's from JM's doing skydive students and that carried into BASE and PCA's on objects there. BASE and Centercell Strip and being JM on static-lines Skydiving are one in the same. From tying-off a container with to much with Break Cord on a PCA to a skydive student. So that the Cessna drags and Stretches the Bridal and Centercell of canopy way to hard or holding-on to long when giving a PCA or tying-off yourself to a object with too much hold-time on a Static Line jump .
Centercell Strip is the extreme latter end. It's the over done result of a PCA and the bridal being held for to long on a PCA.. The term 'Centercell Strip'. carried into Hypothesis of BASE openings and bad off-headings when using larger PC's than necessary in proper airspeed on deployments.
A lot of AFF and Tandem progression skydive Teaching/Learning going on these days and not a whole lot of Main-Stream student skydive PCA's going on. So If you do or have tied-off and given a lot of PCA's from a Cessna or PCA'ed a lot of people off BASE objects. You know exactly what I am talking about. You can over-do the hold-time past line stretch. That also translates to a, over the top Snatch Force in the canopy extraction to line-stretch in high speed openings with too big a PC in freefall also.

So I guess what I am saying. "I am a firm believer in Centercell Strip". and do believe that it will give off-headings to the BASE jumper.
Giving a PCA just right is when just @ Line-Stretch there is good firm line from the jumpers, Open container, Risers, Line-set, his stretched-out canopy, Bridal and to your hand-hold. Then, "you Let Go".
If your a JM doing students or PCAing in BASE. To short/Little length of time on the hold and let-go is called, 'Short-Lineing' . That's 'Letting-Go to fast' before the firm strait line is made from risers and all to your hand-hold to Bridal.
Then when taking the Bridal hold to far on the end of the spectrum, When the container is open and @ end of Line-stretch when all it taunt and stretched out and the PCA is still on the hold. It's a Centercell Strip.
Just Ask yourself. If your exiting and someone is giving you a PCA off a short cliff or building. Do you want to be given a Short-Line ? or a Centercell Strip ? I for one want it done Just Right. Weather I am the jumper or I am giving the PCA. If you say to yourself. " I want it done just right". then you believe in Centercell Strip. ...
.

It is "center cell primary tensioning". Ha! CCPT. Why would one not want this? A Cessna flying at 70mph SL.. hmm I will think about the math involved.
But spot on.
take care,
space

With BD allowing 38” PC’s this year, is there anyway we can use this opportunity to learn something about CCS? Not sure how we would do that but, I know that there are always some pretty hefty delays with (what should have been 42”) PC’s at BD historically. Or is there enough of a difference between 38” and 42” to be significant at this height in terms of CCS? There is no lack of video at this event, so maybe we can use this opportunity somehow.

The PC/bridle is attached to the center cell. It extracts the canopy from the container, always stripping the center cell from the packjob in the process. PC Size doesn't affect the dynamics of the forces' vectors.
Some one can chime in and correct me.
Take care,
space