Tube Stows

[phoenixlpr 0]

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>Tube stoes break a 25 pounds of force. Pilot chute averages
>90 pounds of force. Easy math.

DSE's didn't break. Your math is right, but your starting assumptions may be wrong.

What can you do if people does not read the (f) manual?
Making a tube stow tighter is not about double wrap it.....

We got a recommendation here for our student gear. Do not double wrap the locking stows. There are only rubber bands on student gear.

[dorbie 0]

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So she forgot to cock her pilot chute and because that didn't catch enough wind to pull the main canopy out it is the stows' fault?

Am I understanding this correctly.

I use rubber bands but you have got to be kidding me.

Jeff

It's not the strongest indictment, but it's part of a chain of events. No single factor would have led to the fatality, break the chain and you prevent the undesirable outcome. The investigator listed it as a factor. Her bag came out, and it highlights that the momentum of the bag and drag has the potential to reach line stretch with the correctly rigged stows even if your pilot chute is not correctly rigged, there's even video of a successful deployment with this error (after getting the bag out). It's not just about the force imparted by a correctly cocked and functioning pilot chute, these are not black & white systems, all sorts of crap might happen or go wrong that you'd preffer to survive.

However there are other instances of bag locks due to the stows on otherwise good gear, you don't have to rest the case on that single incident, but we're retreading the same ground, there's no utility in repeating it.

[SimonBones 1]

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However there are other instances of bag locks due to the stows on otherwise good gear, you don't have to rest the case on that single incident, but we're retreading the same ground, there's no utility in repeating it.

Again, nothing in that chain had anything to do with tube stoes. Nothing in that chain provides any evidence that the myth of tube stoes causing baglocks even when used properly has any truth to it. The entire incident you posted is completely irrelevant to the original point of this thread. Tube stoes were in no way involved or relevant. To refresh your memory:

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Does anyone know of any documented incidents where using tube stows instead of rubber bands actually caused a bag lock or any other problems? Any info or opinions are welcome concerning tube stows.

Go back and read through every post. You will not find one with evidence to say that simply having tube stoes will cause a baglock, where a rubber band could not have, even if used correctly.

Most people use rubber bands. Most baglocks occur with rubber bands. Some people use tube stoes, some people have had a baglock using tube stoes.

Using tube stoes will not increase your chances of having a baglock. In my opinion, using them properly will even decrease those chances.

108 way head down world record!!!
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[ufk22 32]

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I've used nothing but tube-stoes for the last 10+ years and never had a problem. I use the smaller version, made for microline, and double knot them per the instructions in the tube-stoe bag, then no need to double stow with microline.

A statistical sample of one careful jumper does not inform anyone about the risk from their use.

A statistical sample of one not-careful jumper does not inform anyone about the risk of their use.

This is the paradox of skydiving. We do something very dangerous, expose ourselves to a totally unnecesary risk, and then spend our time trying to make it safer.

[darthur2000 0]

I'm a little confused. The fatality report uses the term "stowage bands" and previous posts in this thread about the fatality are using that to mean tube stows but in this quote "stow bands" is used to mean rubber bands.

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"Consider this; Parachute "system" designers develop components based upon the characteristics of the stow band. This is a fact. I know, as that is what I do for a living, and have been doing it for over 30 years. I strongly advise all parachutists to use only Mil Spec. Rubber Stow Bands. To use anything else can and will compromise your system." - John Sherman

So is "stowage bands" actually another term for tube stows and "stow bands" another term for rubber bands?

And in regards to baglocks, mine came on rubber bands and yes, it was due to a packing error.

[erikph 0]

http://vimeo.com/6180054

footage of a baglock

The lines were sucked into the grommet. I don't know if it was caused by the tube-stows or by the velcro slit on the deployment bag. Or maybe a combination of both?

blue skies,

http://myjumps.blogspot.com/

[timmyfitz 0]

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http://vimeo.com/6180054

footage of a baglock

The lines were sucked into the grommet. I don't know if it was caused by the tube-stows or by the velcro slit on the deployment bag. Or maybe a combination of both?

Or maybe because the line stows were to long?

[JerryBaumchen 1,050]

Hi erik,

IMO, those grommets are way too large.

I would attribute that to the baglock and not the line retainers.

JerryBaumchen

[dorbie 0]

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Go back and read through every post. You will not find one with evidence to say that simply having tube stoes will cause a baglock, where a rubber band could not have, even if used correctly.

You're still ignoring DSE's incident. His packer packs all day long with no problems putting double wraps on bands then he does it to tube stows and it locks.

But according to your assumptions they should just break, realize there are the same number of connections to the D-bag on a double wrapped stow and a single one, so one might conclude according to your earlier math it should just have broken. Now if that locks so readily (and you know it does because you and other advocates have told everyone not to double wrap tube stows), there are a few other scenarios that can cause a lock that have nothing to do with double wraps.

Citing a precautionary safety advisory on select student gear about double wrapping bands does not equate to the well known risk associated with double wrapping tubes, our everyday experience as skydivers makes that clear.

DSE's bag lock was caused by tube stows and the advice given to avoid that obviously and trivially undermines other claims made for tube stows.

Something stinks here and it's due to the advocacy of a piece of gear some are determined to use.

P.S. you don't get to isolate every mal involving tubes and say it wasn't the tube it was the packer, or it wasn't the tube it was the grommet. These things are intrinsically linked, taking every tube baglock and saying it could have been avoided if something else had been done right is a seriously flawed way of evaluating their safety.

[dorbie 0]

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Hi erik,

IMO, those grommets are way too large.

I would attribute that to the baglock and not the line retainers.

JerryBaumchen

I was gonna ask about that, I think my slider has smaller grommets :-).

[strop45 0]

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Something stinks here and it's due to the advocacy of a piece of gear some are determined to use.

So anyone who doesn't agree with you and the points you make is smelly??

Stay with the facts, the PAs just indicate that even you think you are losing the argument.

The difference between stupidity and genius is that genius has its limits." -- Albert Einstein

[mjosparky 3]

First of all I think the argument on both side is just silly. You have people on both sides parroting what they have heard from others without any real knowledge of the subject of their own. But then as always that is just my opinion.

Just for the hell of it here is a copy of Mil-R-1832D for your reading pleasure.

Sparky

My idea of a fair fight is clubbing baby seals

[SimonBones 1]

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But according to your assumptions they should just break, realize there are the same number of connections to the D-bag on a double wrapped stow and a single one, so one might conclude according to your earlier math it should just have broken.

I disagree. As I've cited numerous times, when a bag locks with rubber bands, the rubber bands do not break even though they have a lower break force. According to your reason for using rubber bands (lower break force), one might conclude to your math that rubber bands should break. But as the skydiving world knows, they don't.

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DSE's bag lock was caused by tube stows and the advice given to avoid that obviously and trivially undermines other claims made for tube stows.

I disagree. It was caused by improper packing and improper use of a system component. Double stowing tube stoes eliminates their ability to roll and defeats the purpose of using them (see attached). The instructions that come with tube stoes have clear instructions on how to attach them to the bag so that they will be tighter.

Saying that the baglock was the fault of tube stoes is like saying that it's a sliders fault if the packer doesn't uncollapse it. It's like saying that it's a pilot chutes failure for a container lock if the packer doesn't cock the pilot chute.

Should we advise everyone to not using collapsible sliders collapsible pilot chutes because improper usage can create problems?

The truth is that if you improperly use tube stoes it can lead to problems. This is true for every part of your gear. You can run into problems with improper use of rubber bands too! Would that make it the rubber bands fault?

I'm not going to condemn tube stoes because some packer out there packed with them improperly.

Just like all gear components, if you use it right, it will should work just fine. You're not going to get a baglock from tube stoes if you use them right just because you're using tube stoes. They themselves do not cause baglocks.

I don't use packers. I always pack my own gear. I choose to use tube stoes because I respect my gear and am willing to pay a few extra bucks for their benefits.

108 way head down world record!!!
http://www.simonbones.com
Hit me up on Facebook

[dorbie 0]

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Something stinks here and it's due to the advocacy of a piece of gear some are determined to use.

So anyone who doesn't agree with you and the points you make is smelly??

Stay with the facts, the PAs just indicate that even you think you are losing the argument.

That wasn't a PA, not even close. Nice attempt at a distraction.

[dorbie 0]

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the rubber bands do not break even though they have a lower break force.

So you agree they have a lower break force.

Bag locks are caused by more than just double wraps.

Dismissing the threshold or likelihood of an event ignores a key part of the risk.

[SimonBones 1]

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So you agree they have a lower break force.

Never disagreed, in fact this is what I said in post #43 of this thread:

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Tube stoes are safer to use than rubber bands. The geometry of the stoe is more important for safety than the slightly lower break force. Rounded is safer than flat.

And here in Post #45:

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Your argument about the lower break force of a rubber band does not make sense because as seen over and over again, rubber bands do not break during a baglock. While a rubber band may have a slightly lower break force, it has a lesser ability to release lines.

You are just not reading the arguments. Instead you keep bashing tube stoes with no further argument than the one which has been disproven (A rubber band WILL break) by every baglock involving a rubber band.

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Bag locks are caused by more than just double wraps.

Finally! Something I can agree with! Pretty much every baglock I've seen involved either lines getting pulled into the grommets, or flat rubber bands laying flat against the lines and locking the stoe.

When lines get sucked into the grommet, it's usually because part of the canopy started coming out of the bag prematurely and wedged part of the lines into the grommet.

Neither of these things are caused specifically by having tube stoes.

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Dismissing the threshold or likelihood of an event ignores a key part of the risk.

And as I've repeated again and again, that likelihood of an event (baglock) does not increase because of using tube stoes, it lowers it, assuming people use their gear correctly. I'd explain the reasoning, but I'd just be repeating something I've explained more than once in this thread. I'm sure you didn't read it. And I'm sure there is no more point in trying to explain it to you, as you won't listen.

108 way head down world record!!!
http://www.simonbones.com
Hit me up on Facebook

[dorbie 0]

I've said that bag locks are caused by more than just double wraps (or similar) in about 5 posts, you must have missed that (although I had other failures in mind and mentioned it in several posts). I did read your posts on the geometry of the stows etc, and never entirely discounted it but I disagree with your final conclusions. Breaking strength is critical. This has become to and fro advocacy on an issue of judgement so I don't think we'll come to an agreement.

[phoenixlpr 0]

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Phoenixlpr,

Where do you get the tubing to make the tube stows and what size is it (inside diameter and outside diameter)? I would like to try and make some of my own to try.

Thanks

For locking stows: 5x8(mm inner x mm outer), 4x6 for the rest. The material is silicon tube. They get a bit softer after use and I sometimes break them using a pull-up cord.

[SimonBones 1]

I ordered some silicon tubing once in order to try and make my own. The product I got was too firm and inelastic for practical use, even though I bought the "softest" tubing I could find. Since brand name tube stoes are made from rubber, don't you think it makes more sense to by rubber tubing?

108 way head down world record!!!
http://www.simonbones.com
Hit me up on Facebook

[phoenixlpr 0]

I've tried. I could not find proper rubber tube for that.

I've found a silicon stuff manufacturer. They produce silicon tubes in all kind of properties. I've browsed their samples and pick what I find the most useful.

[sundevil777 93]

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Tube stows are expensive and may or may not break when needed.

I make them for myself, they are cheap too.
I can make them on proper size.

There is no need for the glue if you put the "joint" at the base of the larkshead.

I think tube stows are important for the critical 2 locking stows. I like knowing they are strong and unlikely to break when they are under so much tension - as the bag is being lifted off. There is a lot of stress on the middle locking stows at that time, and you definitely do not want any kind of stow to break at that time. The result can be canopy dump with violent opening shock.

Regular rubber bands will often tear the very first time they are used. Once they are slightly torn, they will break with very little tension. Tube stows will retain a lot of strength even after they have started to tear.

The advise to not mix types of stows is largely bogus. It is worthwhile to seek an even force for each L/R stow pair, but there is no reason to not have, as I do, tube stows on the locking, regular bands for the non-locking stows. The ability to have non-symmetric forces for the stows releasing is possible even if you use all rubber bands.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[sundevil777 93]

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I ordered some silicon tubing once in order to try and make my own. The product I got was too firm and inelastic for practical use, even though I bought the "softest" tubing I could find. Since brand name tube stoes are made from rubber, don't you think it makes more sense to by rubber tubing?

I buy the tubing that fishermen use, available in many sporting goods stores, very cheap. I don't know why they use it, but that is a good source.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[phoenixlpr 0]

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The advise to not mix types of stows is largely bogus. It is worthwhile to seek an even force for each L/R stow pair, but there is no reason to not have, as I do, tube stows on the locking, regular bands for the non-locking stows. The ability to have non-symmetric forces for the stows releasing is possible even if you use all rubber bands.

I used them mixed with rubber bands for locking stows for some time. I have not noticed any unusual.

[fcajump 153]

If anyone on this thread has not yet seen it, there is an associated Poll at:
http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3687456#3687456

JW

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

[mjosparky 3]

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I like knowing they are strong and unlikely to break when they are under so much tension - as the bag is being lifted off. There is a lot of stress on the middle locking stows at that time, and you definitely do not want any kind of stow to break at that time.

There is not stress on the locking stows until the other stows have released.

Sparky

My idea of a fair fight is clubbing baby seals