Crush Depth for an Empty AL80?

[g2]

Calling all structural engineers!

If I took a sealed, empty aluminum AL80, weighted it, and dropped it into the deep ocean, at approximately what depth might it be crushed?

Really, the question here is whether a cylinder's ability to withstand 200 bar of internal pressure equates to a similar rating for external pressure. Assuming it could withstand an equal external pressure, I figure it would survive to depths greater than 2000 meters. But that seems like a big assumption.

 

[Steve_C]

Not a structural engineer. But generally arches can support more in one direction than another. I would guess that the resistance to external pressure is higher than the resistance to internal pressure.

But I have been wrong before.

 

[Brandon]

According to the math on this site (which is based off research by Wood's Hole OI), an AL80 made out of 6061 aluminum, with a wall thickness of .521" and an OD of 7.25" should yield at about 3500 meters and buckle at about 5750 meters.

This, of course, assuming that by "sealing", you mean that the neck is plugged using a method that's at least as strong as the rest of the tank. A scuba valve should fail long before the cylinder itself does at extreme depths.

Call up Jamie and Adam, and let's start a new thread... "I'd like to see a scuba tank explode... UNDERWATER." =)

 

[rhwestfall]

"I'd like to see a scuba tank explode... UNDERWATER." =)

implode....

nothing exciting there...

 

[tridacna]

Call up Jamie and Adam, and let's start a new thread... "I'd like to see a scuba tank explode... UNDERWATER." =)

You mean 'implode' I'm sure...

 

[Brandon]

implode.... nothing exciting there...

You mean 'implode' I'm sure...

Rofl.. come on, you had to have seen I was paying tribute to an old, ridiculously long running thread. =)

 

[decompression]

Ok, gotta try this......hold my beer....


Sent from my iPhone using Tapatalk

 

[H2Andy]

According to the math on this site (which is based off research by Wood's Hole OI), an AL80 made out of 6061 aluminum, with a wall thickness of .521" and an OD of 7.25" should yield at about 3500 meters and buckle at about 5750 meters.

holy cow! don't you mean feet?

WWII subs had crush depths of around 300 meters, and modern subs something like 750 meters

 

[spectrum]

holy cow! don't you mean feet?

WWII subs had crush depths of around 300 meters, and modern subs something like 750 meters

I'd expect the proportions of a scuba cylinder to be much stronger than a submarine.

 

[Superlyte27]

calling all structural engineers!

If i took a sealed, empty aluminum al80, weighted it, and dropped it into the deep ocean, at approximately what depth might it be crushed?

Really, the question here is whether a cylinder's ability to withstand 200 bar of internal pressure equates to a similar rating for external pressure. Assuming it could withstand an equal external pressure, i figure it would survive to depths greater than 2000 meters. But that seems like a big assumption.

wow!!!