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Skydive_Gregor

Dangerous stowless bag from Seamless Rigging !!!

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I bought stowless bag from Seamless Rigging Brad Barnett

https://www.facebook.com/SeamlessRigging/

Look what me happened to me on video:

https://www.youtube.com/watch?v=C75zeWPgpQ8&t=0s


That's what I wrote to him:

""Hi, I have jumped with this bag around 30 jumps. In last one I have got premature opening in sitfly. This magnets didn't keep canopy inside bag, parachute exploded and melted the slider.
My thighs are all sine and back ache today. I got sick from work for a month. Well I was already in belly position because I could have twisted spine and even killed.
If the bag would be at least two rubber bands that it did not happen.
I think this bag is dangerous.
I want sent you this bag back and get my money back because I need buy new slider."

Now, he delete my post from his wall on facebook, he didn't respond to my messages and finally he blocked me on fb.

That's how he treats customer.

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Your main problem is not your POD but that you managed to pack yourself a premature deployment with brand new equipment.
Prematures have destroyed rigs and canopies long before magnetic bags came into fashion. Of course, it doesn't help in such a situation to basically have a freepacked canopy opening but at freefly speeds it would have been a nasty opening anyway with possible damage to your equipment no matter the POD closing method.

in my rather short time as a packer I've seen a couple of different styles (including SR) of magnetic bags and didn't like any of them. Used within reasonable parameters they all provided rather good results, though.
So to call them inherently dangerous is wrong IMHO. Rather an inferior design.
Sorry to hear of your bad experience with SR. But maybe you shouldn't try to hold them accountable for your mistakes.
-------------------------------------------------------

To absent friends

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Like others have said, premature deployment in freefly is always nasty business no matter what kind of d-bag you have... A friend of mine had similar situation with normal d-bag and he ended up with split canopy and had the canopy not split he would have broken his spine definitely...

So, dont blame the D-bag for this...

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Well, don't want to sound like an ass but you are the one that made a decision to buy and use a fully stowless bag that was not approved by the manufacturer of your container. You should take responsibility for making informed decision when buying stuff. The fact that he blocked you on Facebook is a different story...
Every time I packed a fully stowless bag I thought it was a very bad idea[:/]

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As far as aftermarket gear goes, you and only you are the responsible party and end user to determine if its worth the risk to jump. I've been saying these look sketchy to begin with... being able to shake the parachute out of the bag on the ground is a huge red flag. Im sure at normal pull speed, the magnets work just well enough to keep it closed until line stretch, but if you think about it, with magnets as a closing device, you have a very small speed window that it will operate properly in. Too slow and its essentially a bag lock, and too fast and it could strip as you experience. Rubber bands however, slide out of a loop and are not directly used to pry the bag open. Hope that makes sense. Youve got the equivalent of maybe 20lbs of magnets, plus friction holding it closed. Parachute is roughly 7 lets say, so if you get an acceleration of 3gs or more on that bag, its going to strip. Now i dont know the exact figures, but im sure theyre close to that.. one Rubber band, on the other hand takes 40lbs to break, and about 10 to release the lines from the stow at a right angle. So, if in sequence, its less force needed to open, but more force needed to strip it. Roughly 6 g's to break one rubber band... Again, all rough estimates. but basically it takes the same force to deploy normally as it does to prematurely strip the stowless magnet only bags... And thats if you have a perfect fit for your parachute, which lets be honest... almost nobody has a "perfect" fit.
Not that you knew any better when getting it, but it really is all on you. You need to ask questions and research everything you can before hooking something up and jumping out of a plane with it.
Many people have said it before, but the issue is less the bag, but rather the fact that somehow you packed a premature opening into a brand new system... you most likely would have had some damage either way. I would also send in your main and have the manufacturer look at it. You could have small tears in ribs that will only get worse.
The bottom line is take responsibility for your own actions and decisions. Remember that one line in the tandem video we all watched at some point about parachute assemblies sometimes malfunction even when packed and maintained properly? yeah shit happens. You're jumping out of a damn airplane. Cant take the risks or responsibility for your own ass? you might want to take up tennis or golf...
I was that kid jumping out if his tree house with a bed sheet. My dad wouldn't let me use the ladder to try the roof...

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Alexg3265

Parachute is roughly 7 lets say, so if you get an acceleration of 3gs or more on that bag, its going to strip.



I'd just add that depending on the flap configuration, there's likely also some lever effect adding to the resistance. Eg, a flap with magnets over on one side (and a stitched seam on the other) has a 2:1 ratio for a canopy evenly loaded on the flap. So magnets good for 10 lbs would hold 20.

But the overall idea still holds as you put it.

The incident was a good example of something that works in normal conditions but got dangerous more quickly than someone expected in an unusual situation.

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There is some leverage, yes, but with soft flaps, its negligible and turns more into friction as the 2 flaps slide past eachother until the magnets break free... I'd be curious to find out the actual numbers and if maybe stiffeners could help the leverage... maybe if i get some spare time haha ill mock it up and see what kind of forces each takes.... could be fun
I was that kid jumping out if his tree house with a bed sheet. My dad wouldn't let me use the ladder to try the roof...

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I asked Brad to explain how the stowless bags compare to rubberband stows and how it could provide the line tension to avoid line dump. I'm a double wrap on all stows kinda guy (250lbs door weight). roughly 12 lbs of tension per stow. I was told it's like comparing apples to oranges. The design works by controlling the bulk of the line. He was very responsive and friendly, however my mind has not grasped how this can work and still be safe. I'm curious to read other's posts on this.
Whale oil beef hooked

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Just watched your first video.
Your problem started when your pilot-chute got loose at faster-than-normal airspeeds. Deploying any parachute faster than it was designed for is asking for trouble in the form of hard openings, out-of-sequence openings, torn fabric, torn muscles, etc.
Start by reviewing your packing techniques to reduce the risk of pre-mature pilot-chute deployments.

Amusing how you "table totaled" the Seamless D-bag by demonstrating an out-of-sequence deployment (on the ground).
Any rig can be "table-totalled" by bored skydivers, but not all those "table totals" can be repeated in the air.
I have never packed a Seamless bag, but it looks like a two stacks (left and right) of 3 magnets each holds the mouth of the bag closed: line stow pocket magnet, closing flap magnet and bag magnet all working together to hold the d-bag closed until line-stretch.
When you peel pocket magnets (before line stretch) you reduce the number of magnets and deploy the canopy out-of-sequence.
Since pocket magnets never need to open (to deploy lines) they should help hold the mouth of the bag closed until line stretch. Then you should still have 6 magnets holding the d-bag closed.

Also consider that magnets work opposite of Velcro. While Velcro is strong in shear and weak in peel, magnets are the opposite: strong in peel and weak in shear, so magnetic bags need different configurations than Velcro bags or bags held closed by rubber bands.

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It is true that for line stows only, it's comparing apples to oranges. The confusion comes from the fact that stows have a double role on traditional d-bags:

  • Staging line release
  • Keeping canopy in the bag

  • In a (semi-)stowless bag, the first one is handled by the line pouch. Since the line pouch encloses all line and is pressed against by the bulk of the canopy to keep it tight, it has no trouble accelerating all the line material off the jumpers back, without spilling it. Only once line stretch is reached, does the line get pulled out of the pouch, maintaining the tension throughout. The danger that exists in line stows, ie. that the line in the bight is too heavy to be lifted by the rubber bands and falls out as the bag is accelerated by the PC, does not exist in the same form in a properly sized (semi-)stowless bag.

    However, the other role, of keeping the canopy in the bag until all the line is at stretch, is now delegated to some other mechanism. In semi-stowless bags, this continues to be the locking stows, and thus all the wisdom of conventional d-bags applies. In a fully stowless bag, you need to invent another method of keeping the canopy in the bag through the peak force caused by the acceleration of the bag. If you don't, your risk the canopy spilling out, at which point the lines are no longer contained and also spill out, and you end up with the shitshow experienced by the OP. The danger of a fully magnetic solution is that magnets are OK for a regular deployment, but cannot sustain the higher peak forces generated in an abnormal one, and amplify the problems by turning an already bad high-speed deployment into a high-speed line dump.
    "Skydivers are highly emotional people. They get all excited about their magical black box full of mysterious life saving forces."

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    tsalnukt

    I'm not sure you can blame the premature deployment on your d-bag. Might want to look into your BOC/bridle protection/closing loop area first.



    I don't blame premature opening on d-bag.
    I blame d-bag (magnets) that it didn't keep canopy inside bag when PC take it from container.

    if the process of opening were normal, links would be tightened and there would be a normal process of opening a parachute.

    It didn't happen and all lines and canopy were on my back and legs, canopy just blow up, slider does not slow down the opening.

    BOC/bridle protection/closing loop - everything was ok, checked on the ground by me and my friend, before exit i have checked hackey. BOC is in very good condition (DOM 07.2015).

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    Skydive_Gregor

    ***I suspect the canopy is too heavy for those magnets. How many magnets are there?



    2 for closing main bag nad 2 for closing lines.

    Mine has 4 on the closing flap and 4 on the lines flap (and the 4 in the bag where the closing flap is attached). 2 is definitely not enough.

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    Am I the only one here is not enthused over the design of the bag itself? Feels like some very basic principles of staging an opening were forgotten. When you look at the "stowless" bags big companies are using they tend to still have at least some positive staging mechanism.

    -Michael

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    Am I the only person who sees that although the canopy and lines were dumped out of the bag right away, the canopy didn't start expanding until linestrech, and the slider was still all the way up ?

    In other words, I doubt that a regular d-bag would have created a much better outcome. (i.e. you would have still had a bruiser of an opening).

    Anyone ?

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    It does not appear to be a “premature deployment”. It was a fast deployment by to initiated it. At 0.23 in the video you come out of what looks like a sit fly and about 3 seconds later, 0.26 on the video you are deploying you had deploy. Your speed is probably still up around 160+. Your pilot chute appears to be 30 or 32 inches which is probably too much snatch for your canopy.

    These are so things you might want to look at before blaming the gear.

    Back in the day when it was the “cool” thing to do I made about 500 jumps on a trash pack. This is where you pull all the lines taught, rap the tail around the canopy and put it in the container. No bag or stows. Never had a hard opening.
    My idea of a fair fight is clubbing baby seals

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