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Packing question: Tight or loose stows?

 

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Telek  (B 5564)

Apr 18, 2008, 1:18 PM
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Packing question: Tight or loose stows? Can't Post

I have a specific question about packing: Do the stows need to be really tight? Is double wrapping a good or bad thing?

The argument comes down to this: stows that are too tight can cause bag delay or (worst case) bag lock with subterminal deployment. I have been told that line dump is so incredibly rare that as long as the stows are organized and at least loosely held by the elastics then there is no problem. Tight stows also cause more rocking of the bag which can lead to twisting and line twists on deployment.

This is of course excluding the locking stows which should be tight but never double stowed. The pressure due to keeping the canopy in the bag should be more than sufficient to keep the locking stows tight.

What do you guys think?


Premier skydiverek  (C License)

Apr 18, 2008, 1:21 PM
Post #2 of 30 (3449 views)
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

1. According to PD, it should take 12 to 14 pounds of force to release the lines.

2. Baglock is better than line dump... Pirate.


(This post was edited by skydiverek on Apr 18, 2008, 1:21 PM)


philly51  (D 25269)

Apr 18, 2008, 1:58 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

Like the previous statement, it should take between 12-14 lbs to unstow the lines from the bands. Small rubber bands should never be double stowed. The large rubber bands should be. Trust me when I tell you, LINE DUMP HURTS!!!!!!!!


DocPop  (C License)

Apr 18, 2008, 2:12 PM
Post #4 of 30 (3405 views)
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Re: [philly51] Packing question: Tight or loose stows? [In reply to] Can't Post

I found that the small rubber bands were still too loose on the lines below the cascade, but I solved this by double wrapping them where they attach to the d-bag, to avoid having to double stow the lines.


mdrejhon  (C 3268)

Apr 18, 2008, 2:14 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

In reply to:
I have a specific question about packing: Do the stows need to be really tight? Is double wrapping a good or bad thing?
For my rig I found I liked it best with small bands on the outside loops and tandem bands on the two innnermost loops, since I don't use any of the thin line technologies. It's definitely much more than 12 to 14 pounds if I use small bands in the middle loops, and I keep breaking the small bands all the time and the openings are sometimes worse -- In fact I can lift my whole rig off the floor easily if I use the small bands for the centers. Even with tandem bands, the two inside loops still tighter than the last loops, as it holds more lines (cascaded) than the outer bands... Not a swooper here (yet?) so the lines are fairly thick and plain jane standard compared to many I've seen (except CRW) -- Basically I have the same kind of lines they use on student chutes.

I don't think it's always a recommended practice, but my lines were sufficiently thick to require that. And packers say it's fine the way it is.

May need to do a line force measurement sometime -- but with 99% excellent openings (I now currently ONLY get slammers if I open in a TRACK), I'm loathe to change my packing method...


(This post was edited by mdrejhon on Apr 18, 2008, 2:24 PM)


Martini  (D 23756)

Apr 18, 2008, 4:33 PM
Post #6 of 30 (3339 views)
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

This has been discussed to death here. It is essential to have tight stows. That's why reserves and BASE rigs don't use them. Unimpressed


Telek  (B 5564)

Apr 18, 2008, 6:41 PM
Post #7 of 30 (3305 views)
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Re: [Martini] Packing question: Tight or loose stows? [In reply to] Can't Post

Here's what I'm not understanding, and I did search and didn't find anything that really explained it.

Most people say tight stows to avoid line/bag dump openings, however that should only really relate to the locking stows and not all of the stows.

Also since reserves and base rigs don't use them (thus the lines are just routed in the tray to keep them neat) isn't that more in support of not needing tight stows than needing tight stows? If tight stows are very important than how can reserve and base rigs do without them?

Additionally since there are designs out there that don't even have stows (except for locking ones) again isn that in support that the non-locking stows are only used to keep the lines neat?


(This post was edited by Telek on Apr 18, 2008, 6:47 PM)


diablopilot  (D License)

Apr 18, 2008, 7:02 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

Bingo! Kudos to you for being a thinking skydiver!Smile


Martini  (D 23756)

Apr 18, 2008, 7:21 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

I was being sarcastic (as usual), lack of BASE and reserve line stows should make it plain that the necessity of tight stows is a myth. All that is required is that the lines are straight before the canopy opens and that the lines don't entangle. Many people are using "stowless" d-bags, naturally the bag must have a closing mechanism at the mouth. BTW BASE rigs and reserves typically don't route the lines in the tray, they're usually s-folded in the d-bag (reserve) or tailpocket (BASE). My wingsuit rig has very loose stows, I throw in full flight, jump a Sabre-1 and have great openings. Of course not everyone agrees with this, like PD for instance. I get to express my opinion about this here about three times a year, so far nobody has come up with a reasonable rebuttal.


Skydivesg  (D 10938)

Apr 18, 2008, 8:51 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

It sounds like your mind is already made up.

but just in case:

I use large bands and double wrap them.
It's faster to pack that way which helps if you're making 8-10 jumps a day and packing for yourself.

I also don't like the way the bottom lines of each stow can easily by pulled out or work their way out with out much tension on single wrap stows.

This is because the bands make a V where they are attatched to the bag making it quite easy to have the lines closest to the bag slid out.

I also use the standard small lines and an eliptcal canopy so I don't want an out of sequence opening.

Just MHO.


(This post was edited by Skydivesg on Apr 18, 2008, 8:51 PM)


hackish  (No License)

Apr 20, 2008, 11:12 AM
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Re: Packing question: Tight or loose stows? [In reply to] Can't Post

There have been many opinions stated at different DZ's. You should always do X or you should never do Y. When I visited the jumpshack they had an excellent high speed photo of a d-bag lifting out of the container. I'm sure the elastics were stretched a good 6" so I am of the opinion that it's not quite as important as some people believe. I'll go along with the recommendations that PD publishes but also say that most jumpers have significantly less than that.

-Michael


peek  (D 8884)

Apr 20, 2008, 6:43 PM
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Re: [philly51] Packing question: Tight or loose stows? [In reply to] Can't Post

In reply to:
Like the previous statement, it should take between 12-14 lbs to unstow the lines from the bands. Small rubber bands should never be double stowed. The large rubber bands should be. Trust me when I tell you, LINE DUMP HURTS!!!!!!!!

So you are saying that you have definitely experienced "line dump"? You realize this is very unlikely? Do you have video?

(You may want to read other threads about this.)


mjosparky  (D 5476)

Apr 20, 2008, 10:06 PM
Post #13 of 30 (3004 views)
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

I have over 1,000 jumps on the bag is the attached photos. No one problem with deployment. Nothing that happens while the canopy is still in the bag affects what the canopy does after leaving the bag. This is fact not fiction.

The use of stow bands causes bag whip and tight stows cause extreme bag whip. The purpose of the bag is to stage the deployment not to reef the opening.

Sparky
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Premier billvon  (D 16479)
Moderator
Apr 21, 2008, 9:47 AM
Post #14 of 30 (2945 views)
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Re: [Martini] Packing question: Tight or loose stows? [In reply to] Can't Post

>lack of BASE and reserve line stows should make it plain that the
>necessity of tight stows is a myth.

I think there may be some confusion here. BASE gear and freebags do not use stows at all; they use a different line stowage system that works completely differently. It's like saying maintaining your car's engine isn't important because bicycles don't have them.

The objective of line stows, as you mention, is to ensure orderly deployment of lines without a lot of slack (which can lead to tension knots.) Reserves and BASE canopies accomplish this via a velcroed pocket that pays lines out during deployment. Line stows on main bags must be tight enough to prevent premature release of lines.


packing_jarrett  (D License)

Apr 21, 2008, 2:09 PM
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Re: [mjosparky] Packing question: Tight or loose stows? [In reply to] Can't Post

I basically have the same setup. The only things I do differently is that I don't have velcro securing the pocket. I feel that its unnecessary and the velcro makes stowing way more difficult. I also have the stabilizer mod so that the bridle pulls equally from both sides of the bag.

I like it because it almost eliminates line twists, the ease of stowing lines, and you don't have to replace as much rubberbands.
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brianfry713  (D 28665)

Apr 21, 2008, 5:28 PM
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Re: [billvon] Packing question: Tight or loose stows? [In reply to] Can't Post

Every BASE canopy or tail pocket I've seen is usually packed first with a primary stow - one rubber band containing all the lines.

Every reserve I've seen so far uses a safety stow, so there is one elastic stow that captures two locking bights of lines.

The rest of the lines on both systems are stowed in a Velcro pouch.

It is incorrect to say that BASE gear and reserve freebags do not have any stows, they just don't have as many as a typical skydiving main.

As for the original question, just pack it so the line stows are moderately tight, use tan elastics (not the black death ones) - so they can break if needed, make your line stows neat and correct, replace worn rubber bands, and it'll open. Packing is religion not science.


mjosparky  (D 5476)

Apr 21, 2008, 7:03 PM
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Re: [packing_jarrett] Packing question: Tight or loose stows? [In reply to] Can't Post

The triangular extension going from the top of the bag and tapering to the bridle was first used by Hank Ascuitto on the main bag of his StreamLite container. Without digging out the data sheets I seem to remember that it worked great and reducing or eliminating bag spin during line deployment.

Sparky


Martini  (D 23756)

Apr 21, 2008, 7:16 PM
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Re: [billvon] Packing question: Tight or loose stows? [In reply to] Can't Post

Hmmmm, I don't think confusion exists about this. The point is that the line release system on BASE and reserve canopies doesn't require TIGHT (like 12 lbs) line containment; tailpocket line release is more like ounces, "stowless" d-bag tension is also very light and reserve line release from what I've seen is also pretty light. Your statement about tight enough to prevent premature release hits the nail on the head, unfortunately that tightness remains an elusive quantity. 12 lbs. works fine, so does 1 lb. as far as I can tell. That's about the release tension on both of my rigs or on my BASE canopy. Really tight stows, within reason of course, don't appear harmful, neither do they seem necessary.


riggerrob  (D 14840)

Apr 25, 2008, 8:21 PM
Post #19 of 30 (2644 views)
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

This is of course excluding the locking stows which should be tight but never double stowed.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Funny!
Strong encourages packers to double-stow locking stows on tandems.
I have double-stowed hundreds ... thousands of rubber bands on a bewildering array of rigs and cannot remember the last time I packed a bag-lock????


riggerrob  (D 14840)

Apr 25, 2008, 8:24 PM
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Re: [Telek] Packing question: Tight or loose stows? [In reply to] Can't Post

Loose stows only work consistently when they are "balanced."
Safety stows are balanced because the weight of suspension lines outboard of the locking stows is about the same weight as the amount of line suspension line between the stows.
The best example of balanced line stows is the Speed Bag installed on newer Racers. All the stows are lockng stows and they are all balanced.


riggerrob  (D 14840)

Apr 25, 2008, 8:30 PM
Post #21 of 30 (2638 views)
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Re: [Martini] Packing question: Tight or loose stows? [In reply to] Can't Post

In reply to:
This has been discussed to death here. It is essential to have tight stows. That's why reserves and BASE rigs don't use them. Unimpressed

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Nice attempt at humor.

Whether you use loose or tight stows and how many you use depends upon whether you are planning to deploy at the low-speed or high-speed edge of the envelope.
If you only deploy at the low-speed edge of the envelope, you can get away with a lot of sloppiness.

OTOH you need to very very careful at the heavy-weight, high -speed edge of the envelope. For example, all the tandem manufactures have had to modify their main deployment bags to prevent line dump. RWS(UPT, CPS or whatever they call themselves this week) use extra-wide rubber bands.
Strong uses an extra flap and tight bungees.
Eclipse used an extra row of rubber bands.
Racers use Speed Bags where very rubber band is a locking stow and every stow is balanced.


Martini  (D 23756)

Apr 25, 2008, 8:58 PM
Post #22 of 30 (2629 views)
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Re: [riggerrob] Packing question: Tight or loose stows? [In reply to] Can't Post

The OP wanted to know if stows needed to be "really tight". Presumably he's talking about ordinary skydiving gear not tandem rigs or special cases . FWIW I use what would be considered to be loose stows and deploy with minimal flaring from any jump and in full flight wingsuiting. I'm still sticking by my not-so-humble opinion that the main stows need minimal grip, the locking stows do the essential job of keeping the canopy from opening before linestretch. Come to think of it didn't you, in the distant past, used to freestow your lines?


riggerrob  (D 14840)

Apr 25, 2008, 9:33 PM
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Re: [Martini] Packing question: Tight or loose stows? [In reply to] Can't Post

I used to have a line stow pockets (similar to BASE or free-bag line stow pockets) sewn on the d-bags of my Mirage and Eze-Flyers.
They still had two or three rubber bands locking them closed.


Premier billvon  (D 16479)
Moderator
Apr 25, 2008, 9:46 PM
Post #24 of 30 (2618 views)
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Re: [Martini] Packing question: Tight or loose stows? [In reply to] Can't Post

>The point is that the line release system on BASE and reserve
>canopies doesn't require TIGHT (like 12 lbs) line containment . . .

Correct. No deployment system requires line containment; indeed, good line containment equals a bag lock. The requirement is for controlled payout of lines. Elastic stows accomplish this by a) friction and b) weight. Tail pockets accomplish this by a 'metered' opening that does not pass more than a single series of lines at a time. They are different systems designed for different environments.

Well-balanced stows can indeed take the place of friction, but I prefer to take advantage of both.


Martini  (D 23756)

Apr 25, 2008, 11:09 PM
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Re: [billvon] Packing question: Tight or loose stows? [In reply to] Can't Post

Well-balanced stows can indeed take the place of friction, but I prefer to take advantage of both.
In reply to:

That reminds me of another point against tight stows. The tighter the stows are the more the bag can rock even with balanced stow tension. In particular small, lightweight canopies would seem to be destabilized by very tight stows while looser stows would have relatively less effect on the bagged canopy. Again, I'm not recommending that lines should be stowed with no tension, freestowing increases the likelihood of tension knots and entanglements. Rather I'm suggesting that the prevailing 12 lb. standard is unnecessarily high. BTW I'm basing my view not just on theory but from experience, being a lazy packer has left me critical of only my locking stows.


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