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hatman1967
03-30-2005, 02:16 PM
K ... I know I am a mechanical idiot

But in all these sub movies, when a sub undergoes a depth charge attack water sprays out from all of these valves. Men scramble to tighten these valves and keep the invading ocean at bay. My question is - why are there valves there in the first place, and why were they not tightened to begin with?

Dano

hatman1967
03-30-2005, 02:16 PM
K ... I know I am a mechanical idiot

But in all these sub movies, when a sub undergoes a depth charge attack water sprays out from all of these valves. Men scramble to tighten these valves and keep the invading ocean at bay. My question is - why are there valves there in the first place, and why were they not tightened to begin with?

Dano

Digitalfox1
03-30-2005, 02:43 PM
On ships you have all of the piping running through areas of the ship. These areas are devided into sections. So if your fire main is busted you can A. secumvent the damage by sealing the valve and applying a jumper. B. stop any leaking by sealing the valve before the leak. Or depending on the ships operation status you can set whats call a matiral conditon, which is used to tell people how secure the boat is. Material condition Yoke is used when you are running normaly, no problems or expected problems, Material condition Zebra is used when you have possabilaty of damage. All of the water tight doors are shut and most of the valves are closed. This is done to minimize the amount of damage caused by any problems.

Chuck_Older
03-30-2005, 04:59 PM
It's actually pretty accurate.

All the valves were there for precisely this reason. It's a rare instance of the movie industry getting something right

All the valves *were* tight to begin with. But the problem is:

water is for all intents are purposes non-compressible. What that means is if you jump off a bridge into the ocean, you will likely die, because it's quite nearly like landing on concrete. Add to that the pressure of all the water on top of a submerged u-boat, and you get the idea of the immense pressures involved.

A depth charge goes off and is near enouigh the boat to damage it (let's roughly call this 50 feet away)

It's like a sledge hammer smashing the boat.

there are two hulls in a sub:

The manuevering hull

The pressure hull

The manuevering hull has things like the the dive planes, etc, attached.

the pressure hull is the steel cylinder, capped off by huge milled steel end caps, that keeps the ocean pressure out.

the trouble is, that any system that is on the manuevering hull has some kind of system for control or access that must pass through the pressure hull.

each of those points at which something passes through the pressure hull, be it torpedo hatch, driveshaft, wire raceway for antenna, or the head "exhaust", reduces the pressure hull efficiency

the flip sie is that these things that pass through the pressure hull are not as strong as the pressure hull and are more easily damaged.

The pipe flanges you see in movies that are leaking did not come loose- a bolt or bolts has sheared off the pipe flange. You turn off the local valave and replce the bolt(s)

these broken bolts could produce injuries almost identical to gunshot wounds when they let go: a bolt with a shear strength of 20,000 pounds has quite a bit of energy built up as it is stretched to it's breaking point

hobnail
03-30-2005, 05:02 PM
Just like in Star Trek....Those control panel explosions accounted for 90% of all combat casualties http://forums.ubi.com/images/smilies/35.gif

hatman1967
03-30-2005, 05:10 PM
What is the piping for? To control depth?

Dano

hatman1967
03-30-2005, 05:13 PM
Never mind ... didn't see your reply Chuck. Thanks for the info http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Dano