Avalanche Flotation safety device prototypes

**jtwassoc** · 01-19-2007, 10:53 AM

Hopefully this is a link to a video of the deployment of a head placed lift bag system:

http://www.avalanche-research.com/si...E.flv&logID=11

Its called the PUFF system...........

**jtwassoc** · 01-26-2007, 04:20 PM

Testing week has finally arrived and tomorrow morning Adam and Eve start the long drive to British Columbia. There should be avalanches rolling over them by Wednesday.

**jtwassoc** · 01-26-2007, 04:21 PM

Here is the finished prototype device.............

(Just a hair over three pounds.)

**Cyber Cop** · 01-26-2007, 04:23 PM

You should develop a float that stows on a snowboard to combat the anchor effect. Then send me royalties. cheers.

**JTWASSOC at Squaw** · 02-07-2007, 11:16 PM

Testing is complete in Revelstoke, British Columbia. We are back in the Squaw Valley, California office examining our film and data. Bottom line, lift bags tend to become completely exposed on top of the avalanche after it has stopped moving. You definately want to be attached to a lift bag if you find yourself in an avalanche. Lift bags work.

Very cool pictures to come.......

**wanghoeby** · 02-08-2007, 12:05 AM

Looks great!

A few posts ago you were discussing how buoyant the balloon is. Do you think that this will cause such an effect that the user will find it hard to stay in the upright position on the way down? With the use of actual moving limbs in a real human do you think that one might be able to position themselves so that they would be face up even if it was just before they stopped moving?

Will there be actual human guinea pigs making a trial run before it goes out to the testers?

Can't wait to see the photos.

**summit** · 02-08-2007, 12:06 AM

cool!!!!

**Jer** · 02-08-2007, 12:20 AM

... does it come with that dollar bill? Or can I get a crisp one with mine?

**jahoney** · 02-08-2007, 12:24 AM

i've never been in an avy, but it seems to me like it'd be scary as shit. would people have the time to think of pulling the ripcord?

**LeeLau** · 02-08-2007, 12:28 AM

Originally Posted by JTWASSOC at Squaw

Testing is complete in Revelstoke, British Columbia. We are back in the Squaw Valley, California office examining our film and data. Bottom line, lift bags tend to become completely exposed on top of the avalanche after it has stopped moving. You definately want to be attached to a lift bag if you find yourself in an avalanche. Lift bags work.

Very cool pictures to come.......

Pleasure to meet you guys in Revy and to see the prototype. Apologies about the hot tub explosive diarrhea

**Lurch** · 02-08-2007, 12:33 AM

Originally Posted by wanghoeby

Looks great!

A few posts ago you were discussing how buoyant the balloon is. Do you think that this will cause such an effect that the user will find it hard to stay in the upright position on the way down? With the use of actual moving limbs in a real human do you think that one might be able to position themselves so that they would be face up even if it was just before they stopped moving?

Will there be actual human guinea pigs making a trial run before it goes out to the testers?

Can't wait to see the photos.

Avy lift bags work via the acron affect not boyancy like a PFD. Basically by making your self bigger than the other objects flowing in the avalanche you will rise to the top. You can see this in action by grabing a bag of mixed nuts and giving it a shake. When you are done shaking the largest nuts are on top and the smallest are at the bottom.

**wanghoeby** · 02-08-2007, 08:34 AM

Originally Posted by Lurch

Avy lift bags work via the acron affect not boyancy like a PFD. Basically by making your self bigger than the other objects flowing in the avalanche you will rise to the top. You can see this in action by grabing a bag of mixed nuts and giving it a shake. When you are done shaking the largest nuts are on top and the smallest are at the bottom.

Right, but reading this:

Originally Posted by jtwassoc

In many avalanche tests the lift bag ALWAYS seeks the surface and is only partially buried after the slide stops. In all of our tests we were never able to bury an inflated lift bag under an avalanche, it’s impossible. Imagine trying to stop a three foot bubble of air under water from reaching the surface. As a result of this tremendous floating force the victim will be pulled to the surface of the avalanche by the lift bag, and whichever side of the person is closest to the lift bag will be closest to the surface....

Makes one believe that buoyancy does have a pretty strong impact, if only seconds before movement stops. Even if you treat the person and the bag as a single object there is an outstanding density difference between the person and the bag, possibly causing the human to be below the balloon.

Edit: Bolding

**mwthomsen** · 02-08-2007, 10:17 AM

As a skydiver there are a couple of similarities to and issues that I may be able to add.

1. Some are concerned about pulling the rip cord in an avalanche, how people respond in a stressful situation is definetely a concern. However, in skydiving we are taught from day one about emergency procedures, how to proceede and are advised to practice simulating the procedure in the air. My first suggestion would be to do practice pulls, simulating reaching for the cord and simulating the pull. Do that while skiing so it becomes second nature. If you are still worried about pulling the cord and saving your own ass don't put yourself in that situation.

2. Traveling with the device will probably be tricky. Many skydivers have AAD's packed in their reserves compartment. An AAD is an automated activation device, that will automatically deploy the reserve when the skydiver is falling at a 75 mph or above through 750 feet AGL. The USPA has spent a lot of time and money educating the FAA and TSA related to AAD's. We have X-ray cards that show what the device looks like and are advised to travel with the TSA statement allowing AAD's on Airlines. Even with this support there are still times when the TSA at a given airport will not let you pass. They have been known to request to see the device and open your reserve. The problem with that is it requires an FAA certified rigger to repack a reserve. So even if you get approval from the TSA it might not always be smooth sailing to travel with this thing. Show up earlier and be prepared to be dicked around.

3. Live firing the device prior to using it only proves that it worked that time. It does not prove that it will work everytime. Mechanicall devices will fail, I trust in the design of the safety equipement I use and pray that it will work according to it's designs. And, although we are taught to practice our emergency procedures the first time you end up under your reserve is typically the first time you have actually experienced all the pull forces related to pulling that rip cord. I would feel no safer knowing that that thing fired properly in my house.

**skibee** · 02-08-2007, 11:57 AM

Any issues with testing and the small waist cord ripping off? The ABS packs I've seen all have leg loops and semi harness systems to stay on the body.

Also, do all test dummies end up face down? That could be an issue with rescuers arriving over 7 minutes post burial. Having said that... if the avalanched person panics and vomits at least the emisis will drain away from the airway.

Thanks for developing a great looking product and concept, I have a 30 year old original ABS pack that takes a full minute to inflate... not very effective but a great party trick!!!

B

**jtwassoc** · 02-13-2007, 06:39 PM

We are back in our Minnesota lab after some great testing in Revelstoke, British Columbia. As they say, a picture is worth a thousand words, so here is a picture taken after our first of three separate tests where we rolled avalanches over crash test dummies harnessed to 3 cubic foot avalanche flotation devices (AFDs). This first slide is a class 1.5 avalanche that dropped 700 vertical feet and ran about 800 to 1000 feet or more. Force indicators attached to the crash test dummies recorded 50 G forces, probably when large pieces of the cornice slammed into the test dummies. As you can see in the picture, all 5 red lift bags can be seen sitting completely exposed on the surface of the debris field after the slide. All of the test dummies were harnessed at the waist with the lift bag attached to the rear. All five dummies were found face down laying horizontal to the surface of the snow and either buried 6 to 10 inches beneath the snow or partially buried with some part of the body exposed.

More to come later this week and next……….

**tomw_n** · 02-13-2007, 08:20 PM

Good thread and well done on what looks like a successful test!

**jtwassoc** · 02-14-2007, 04:52 PM

Here are some initial pics from the first test.

First the explosives are prepped...

Then the test dummies and test dummy logs (200, 150 and 100 pound oak logs) are harnessed to avalanche lift bags and choppered out to the side of the mountain.....

**jtwassoc** · 02-14-2007, 04:59 PM

Then it's bombs away to start the avalanche..........

Here the slide hits some test dummies....

And engulfs them....

**jtwassoc** · 02-14-2007, 05:07 PM

Then the avalanche engulfs the rest of the dummies........

Here the red lift bags begin to re-emerge from the slide.......

**jtwassoc** · 02-14-2007, 05:13 PM

Note how the lift bags continue to fight for the surface even as the avalanche continues to try and rebury the bags.......

Here is the mountain after the slide.........

More to come.

**jtwassoc** · 02-15-2007, 01:18 PM

Here's a pic after the second test avalanche. This slide ran well over 1000 feet and was a class 2 avalanche. Some pretty big cornice chunks were rolling down the hill, and the 50 G force hits were creating some large inner plumes when test dummy and avalanche met. The film reveals the avalanche engulfing the dummies and creating home sized vertical eruptions of snow inside the slide. Lots of force at work here. Keep in mind this is worst case scenario testing being done, a large cornice falling down the mountain and slamming into a victim. As many avalanches involving death or injury are created by the skier, boarder or sledder cutting loose a slab of snow, there is no gigantic chunk of cornice slamming into the victim.

Next year we will be using an accelerometer so we can track the G-forces throughout the avalanche, and not just when the slide slams into the test equipment.

Here you can see the red lift bags sitting on top of the stopped avalanche after the slide........

**jtwassoc** · 02-15-2007, 01:35 PM

Series showing avy slamming into test gear and resulting inner plume....

**Phatstix** · 02-15-2007, 06:35 PM

Great work!

I was wondering if you used a control dummy in any of the tests? I'm curious as to what the comparision burial depths would be etc. to a dummy in the same slide and similar postion without a device.

More pics please!

**jtwassoc** · 02-19-2007, 08:09 AM

Yes we have used control dummies and even control snowmobiles without flotation devices attached in the past. The problem is that it is commonly known that people are buried by avalanches, so the control dummy doesn't end up serving a purpose. It's also a missed chance to test another flotation device. Some of you might question our decision to stop using control dummies without flotation devices in the test, but we felt it was best for the testing.

**jtwassoc** · 02-19-2007, 08:22 AM

Well it's already February 19th and we are still examining the test devices used in the avalanche tests and have NOT shipped out any prototypes to those of you who have returned the paperwork to us and are patiently waiting for your device. Slowly the test season slips away. What to do? A good option may be to ship out enough devices to the hard core types who ski or board late into the season, and hold off on everybody else till this summer. That also gives us precious time to make some refinements to our harness. Several people we showed the harness to in Revelstoke thought it needed work. Granted, these were Dept of Transportation avy control people and such, who wear ski boots for a living and tend to be pretty critical of their equipment, but their input was invaluable and in their opinion the harness needed refining.

Anybody have any thoughts on this?