Tank Rack in back of truck?

[FW]

Think of the laws of physics and how they affect guns. force=mass*acceleration. When a valve is shot out (if threads are stripped, as FW says, for example), an equal force acts on both the tank and the valve. But, the mass of the valves is much less than the mass of the tank, so the acceleration of the valve will be much greater.

You see this in guns as well: the exploding powder puts equal force on the bullet and the gun. However, the bullet goes much further than the gun, because it has much smaller mass, especially when you consider that the mass of the shooter might well be considered to be part of the mass of the gun, as it must also be moved with the gun, the two are like a connected system.

You are right about the mass difference between tank and valve, but you neglected the mass of the gas trying to make that tank into a "rocket". Someone with more time than I have can calculate just how much acceleration that might give a tank

[JahJahwarrior]

It gets really difficult to use simple math to figure out speeds of these parts. Yes, the mass of the bottle+gas is great, which will mean that the bottle+gas will accelerate even slower than if we ignore the mass of the gas. That's good. But, the valve might not fly all that far, because the force is only applied to it over a fraction of a second. Once it has left the tank, it has no more force acting on itself. However, the tank will continue to be affected by the force stored in the gas pressure until the pressure is equal to the atmospheric pressure. And, the tank+gas will accelerate faster as the mass lowers, assuming force stays constant. How will force change as pressure decreases?

Basically, strap your bottles down.

[Hoska]

for giggles sake here is what mythbusters did with a bottle...

[scblade27]

A tank in the back of a vehicle would not have much room to accelerate before it hit another object. I imagine in the bed of a truck it would just be loud, cold, and pin itself against the side of the bed or just spin around. In a car I doubt it would have much room to move at all before getting stopped by another object. I could see the valve doing some damage though as it would have much more force as soon as it came off the tank.

I think someone needs to donate a car and some tanks for scientific research.

[FW]

....I think someone needs to donate a car and some tanks for scientific research.

If you shear off a SCUBA tank valve, it won't do that, because the body of the valve has a restriction that reduces the flow rate. Like I said earlier, stripped threads could be catastrophic.

[mfascuba]

I purposely put mine in the back of my jeep with the valve forward. My theory is that if someone rear ends me on the highway and the tanks go flying they started it, so they deserve getting the tanks heading their way. Fair is fair.

Mark

[bigken462]

Hey all i am thinking about building some sort of tank carrier for the back of my truck for when i go diving. I will need to be abel to take it out when i need to. The tanks will be my set of doubles, 2 al 40s and some Al 80s. With The 80s will be for open water students also. So i am looking for something that i can use for my cave diving and tech diving but also use to carry open water students tanks. I would like for the tanks to stand up so i could have a little room for other gear. But i guess they could lay down also (just put the gear on top of them. So my question is anyone have or had something like this for travel? If so could you tell me about it or post pictures so i can have an idea at what im looking towards? Or should i just talk to the owner of the store i work at and get a small tralier lol? Thanks

This might work what do you guys think?

http://www.pvcplans.com/scuba.htm

Joseph

Trailers work fine for some applications and some trips. Right now as I write this I'm sitting in the soft bed after completing 4 days of Cavern/Intro. I passed - WHEWWWW, but anyhow, the trailer comes in handy for longer stays where you would normally have to pull your gear into the hotel. However, it's a PITA getting around town, fills at shops, dive sites etc. etc. Today I learned to just unhook the things and work out of the truck from the trailer. I think of single overnighters I'll just leave the trailer at home and put the stuff on the truck to save fuel.

It has it's place, but not the best for everything.

Here is mine below. More pictures in my smugmug site.




Now it's time to chill with another beer and do something about these rather sore fingers. Lol

[bullfrog]

New Skin

[dnscarboro]

Here is my tank hauler-

[bigken462]

Here is my tank hauler-

SWEET!

Ken