Exploding scuba tank kills one - Florida

[Rick Murchison]

Rick,
You keep the first stage on all the time?
Seems like the O ring would eventually become compessed.

No, I put the reg on just before leaving the house. Saves time and helps ensure Oxygen service rating doesn't get compromised in the (sometimes dirty) truck or on the (sometimes dirty) boat. I'd much rather have a deco bottle o-ring go flat than accidentally get a little oil on it that I don't notice.
In this case the tank's sitting beside my desk 'cause I was sucking on it a bit after mowing the lawn
(hey, I admit it, I'm an old fart and occasionally overdo that working-in-the-heat thing)
Rick

 

[Rick Murchison]

Whoa! Look at that!
Ain't that the cutest thing you ever saw?
Somehow I don't think it'll go mainstream, (mainly because a bunch of valves and one reg is a lot cheaper combo than a bunch of these things) but it's at least intriguing...

It's possible the pony had a valve and first stage as a unit.

The new Zeagle RaZor is one, but there are others.

View attachment 103497

 

[Jax]

Look at it this way. If they are comparing a full AL80 to enough explosive energy to LIFT a freaking Locomotive thats enough math for me to know Im carrying a Bomb on my back and my 220lbs of massive muscle made 80% of water will be GONE.... So who need to know what it lifts when compared to a locomotive, sometimes ya got to say... "Thats good enough!"

Steve

WHOA!

Guys, the article simply calculates the energy a sudden decompression of 3000psi releases.

Then, to give the numbers some meaning, that energy would lift 4 locomotives . . . IF the force were sustained and directed in such a manner as to do so!

It's not saying a suddenly failed tank would lift a locomotive if it was under it. This is something scientists / physicists do, to put xyz Joules into perspective.

In other words, it's a lot of f'ing energy . . . . that's all.

 

[Jax]

Since some people are wondering about lifting the rail cars a foot off the ground, he likely got that figure using the particle kinematic equations (think back to basic high school physics):

1) Get rid of imperial units because they're awful:
According to him a tank has E_tank = 1,300,000 ft-lb *1.356 (joules/ft-lb) = 1,760,000 joules
The mass of the rail cars is M = 4 * 88 ton * 2000 (lb/ton) * .4536 (kg/lb) = 319,000 kg

2) Assume all of the potential energy in the tank is instantly and reversibly (impossible, btw) converted to kinetic energy in the rail cars:
E_cars=E_tank

3) Assume all of this kinetic energy is used to lift the rail cars vertically off the ground. At the highest point of its flight (h meters off the ground), all of the kinetic energy will have been converted into gravitational potential energy:
PE = M * g * h = E_cars
where g is the gravitational acceleration constant 9.8 m/s^2

4) Solve for h
h = E_tank / M / g = 1,760,000 (kg*m^2/s^2) / 319,000 kg / 9.8 (m/s^2) = 0.563 m

5) convert to back to feet
0.563 m * (3.28 ft/m) = 1.85 ft*


* (If you use the 1,242,000 joules given in the "How much energy..." link you get 1.3 ft)

I love it!

 

[Jax]

Given that someone on another forum, who correctly identified that the tank went into the ceiling before the info was in the media, and that someone hoped to get photos of the scene . . .

. . . that someone said, they haven't found the valve. I suggest it was the valve they looked for, and perhaps there was a stage on it, so the word regulator came up.

IF this guy indeed stole to support his scuba, this lends credence to the possibility that he would know the tank was 6351 but chose to continue using it. IMO.

 

[DandyDon]

No, I put the reg on just before leaving the house. Saves time and helps ensure Oxygen service rating doesn't get compromised in the (sometimes dirty) truck or on the (sometimes dirty) boat. I'd much rather have a deco bottle o-ring go flat than accidentally get a little oil on it that I don't notice.
In this case the tank's sitting beside my desk 'cause I was sucking on it a bit after mowing the lawn
(hey, I admit it, I'm an old fart and occasionally overdo that working-in-the-heat thing)
Rick

Something you learned from TV sports, that's been proven to not work...??

 

[spoolin01]

I read int that same article that the compressed gas in an AL80 could lift four locomotives 1 foot off the ground. :shocked2:

More reasonable that the energy stored in a full tank is similar to the potential energy of 4 locomotives sitting 1 ft off the ground (I heard it was a fire truck X feet off the ground - can't recall X but it was several feet). The pic of the SUV where the tank exploded inside handily illustrates just how inadequate an exploding tank is from being able to lift 4 locomotives off the ground.

 

[Jax]

More reasonable that the energy stored in a full tank is similar to the potential energy of 4 locomotives sitting 1 ft off the ground (I heard it was a fire truck X feet off the ground - can't recall X but it was several feet). The pic of the SUV where the tank exploded inside handily illustrates just how inadequate an exploding tank is from being able to lift 4 locomotives off the ground.

Yes, yes, I know. It's a lot of energy.

 

[cruiser]

A few new twists in that article.



Is it just me, or is that an odd way to put it: That the regulator was missing from the tank.

I've only rented tanks so in that case of course I set them up when I get to the site, but if one is getting tank(s) ready for a dive at home, and going to put them in the car to drive to the dive site, would one normally mount the reg to the tank then? Would it be different for a stage/pony/deco bottle?

I can see the investigators wanting the regulator for various reasons; it just struck me funny that they made it sound like they expected it to have been mounted to the tank. Maybe just an odd wording in the article Or maybe people normally do mount the reg to a stage or pony before leaving home and I don't know about it since I don't own my own tanks (?).

Thanks for posting the new article, Don.

Blue Sparkle

I thought that was weird, too. I set up my gear at the dive site.

 

[Thalassamania]

"Valve" is also a Britishism for regulator.