Saturday, December 24, 2011

Why You Need to Test Your Gear, Part 2: How It's Supposed To Work, And How I Probably Screwed It Up.


Relatively Shiny New Lifejacket - Kokatat Sea02. Purchased because it was the absolute best fit of all the lifejackets Randy had at New York Kayak Company when the poor old Lotus L'Ocean I'd bought from him back when I started gave up the ghost after over a decade of faithful service.

Well, goodness, it's been a while since my Failed (Yet Somehow Still Successful) Gear Test - holiday stuff, a wedding to attend in Michigan (yes, there WILL be a post about what Canoe-Buildin' Uncle is working on these days, he's got a couple of very nice projects in the workshop), and then just trying to wrap up work for the year. I'm on vacation until January now, and I'm hoping to need to do some good end of year trip reports...but first, yoicks, I really need to finish off with this unfinished gear test - because until I do, I'm, er, kindasorta paddling with a non-CG-compliant lifejacket. I need to do my second attempt at a test as soon as I get a nice day to do it and a couple of friends to keep an eye on me and hopefully film my hopefully successful second attempt. After that, I can re-arm the doohickey that makes it all work and then, yay, I'm legal again!

So tonight, I wanted to share how the device is supposed to work, and the stupid mistake I made that made it NOT work.

I'll just start off with an excerpt from the test, which I did in early December because we're getting to the point where a person with a hybrid inflatable lifejacket really wants to know that she can actually make it inflate. This was pretty much the outcome:
video

After I climbed back into my boat, I took a good close look at the device that was supposed to trigger the inflation and...d'oh! discovered I'd made a completely idiotic mistake. I must have been in a rush setting it up because I clearly neither read the instructions or even looked at the simple trigger device closely. Hindsight 20/20, and I'm glad I had the foresight to make sure that the first time I tried the thing WAS under very controlled circumstances.

Here, with a whole lot of pictures, is how it's supposed to work.

The jacket is constructed with PVC foam, same as most normal lifejackets - just a lot less. It has some inherent flotation - seven and a half pounds, when new. My old one, by comparison, had 15.5. The potential limitations of this reduced flatation are VERY clearly spelled out in the warning label inside the vest:


Might not be the right vest for somebody who's not really comfortable in the water. I did swim in it right away, it definitely floats me, but a lot lower.

What covers for the missing flotation? An extra layer built into the lifejacket.


Looks like a paddlefloat, works like a paddlefloat. The air bladder covers the entire front panel -


goes over one shoulder -


and covers the padded area of the back.

When something goes seriously wrong, you pull the tab


and if it's set up right, pffffffssssshhhh...you go from that svelte, low-profile 7.5 pounds of flotation


to a Stay-Puft-esque 22 pounds.


What makes this work, if you've actually read the instructions and been reasonably careful in setting it up, is a very simple little doohicky - a valve with a lever attached to it. In armed mode, the lever nestles neatly into a little slot on the side of the valve. When you jerk the deployment tab, the arm swings down.






Now, nothing happens here because I haven't got it set up - this was just to show the mechanism. Readying it for use requires a couple of other pieces that come with vest:

A cartridge of pressurized C02, and a tiny green plastic pin. You get 2 of each because (as I've shown) you really do need to test the thing once - the spare is for the test run.


The cartridge screws into the top of the valve.


Remember the little hole in the swing arm?


When the arm is properly slotted home ready for use, that hole and the hole in the plastic housing of the valve line up. The green pin is designed to slide in and LOCK there.


Now we're ready:


Once the green pin is in there, the only way it's coming out again is by being broken out - it essentially serves as a seal, and if it's gone, that means the lever's been pulled.

And speaking of seals...here's the last bit in how it works. The C02 cartridge is sealed.


Inside the gray plastic housing, there's a little metal spike. As the lever swings open when you jerk the tag, the spike pushes up into the seal of the C02 cylinder.

I couldn't get a good picture of the spike, but here's what it did to a little plug of tinfoil -

before:


after:


And that's all there is to it.

So how did I manage to screw up something so simple?

The green pin was the giveaway. I don't remember the circumstances under which I "armed" my new lifejacket - but I was clearly in some sort of big rush & just didn't look at the instructions or the device to see how it worked.

Instead, I must've just pulled it partway out from the pocket where it's hidden -



Said, "Oh, yeah, cylinder goes here, pin goes here, yay, let's paddle" -


and here's what I didn't see - until I discovered that the green pin was unbroken after a whole lot of yanking & looked a little closer.


I actually broke the pin trying to get it back out to reset for another try - shows that it's seriously designed to go in and stay in, and I'm told by one who knows that the Coast Guard knows to look for that bit of green plastic - without that seal saying the the jacket is properly set up, it won't pass inspection.

Looking forward to doing a hopefully more successful test - then setting up the 2nd set right!

Thus endeth the geek-out. Geeky enough for you?

4 comments:

adriftatsea said...

One problem with that particular design is that the green "armed" indicator does not necessarily indicate that the system is ready to go.

It just means the seal is locked into place, even though the arm may not be in the correct position, as you found out or the CO2 cylinder may not be properly seated. In either case, the green seal would show it as properly armed, when it is not, and it would fail to fire when the handle is pulled.

Better systems have the indicator that is mechanically designed to show as armed only if the trigger arm is in the proper position and the CO2 cartridge is fully and properly seated.

Always double check your inflatable PFD before use, since the CO2 cartridge can come loose, or be removed. This is especially true if you are traveling and the uneducated goons at the TSA muck with your PFD. The reason I call them uneducated goons, is that many TSA employees do not understand that a PFD with a CO2 cartridge is LEGAL TO CARRY ABOARD A PLANE.

bonnie said...

Thanks, Dan!

Yes, the reason I'm sharing my stupid mistake is 'cause I figure that I can't be the only person out there who's done that & it's probably worth talking about.

Funny but sad about the TSA...did anybody tell them about all those PFD's under the seats?

O Docker said...

This must just happen to water bloggers.

We had an almost identical thing happen when we tested our inflatable vests, and ours were properly armed.

We have two different models - one you pull down to inflate, the other, we eventually learned, you pull out, to the side. No amount of yanking downward would fire the second one.

But ours didn't come with a spare, and it wasn't until we were replacing the expired original cartridge and did a test inflate with it that we discovered this.

I think all of these should come with a spare cartridge and that the instructions should stress doing a test inflation before the vest is ever used.

Adriftatsea said...

One other thing about inflatable PFDs. You really should do a static inflation test at least twice a year.


This is where you inflate the vest manually and let it sit over night to see if it leaks or holds pressure.

One reason it is recommended to manually inflate the PFD rather than use the CO2 cartridge, is it is a lot less stressful and less damaging to the vest.

Obviously, this is somewhat less critical with a hybrid vest like Bonnie's, since it has some inherent buoyancy in the foam, but the sailing PFD I use relies totally on the inflated bladder for buoyancy...so it is very important to check.