Can a Bullet Hole Cause Explosive Decompression in a Submarine at 30m Depth?

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Discussion Overview

The discussion revolves around the concept of explosive decompression in a submarine at a depth of 30 meters, particularly in the context of a small opening, such as a bullet hole. Participants explore the implications of pressure differences and material properties related to submarines under water.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions whether explosive decompression would occur at 30m depth with a bullet hole, indicating a lack of familiarity with the term.
  • Another participant suggests that the question is vague and relates to materials' properties.
  • A different participant asserts that explosive decompression would not happen underwater; instead, high pressure would force water into the submarine.
  • An analogy is provided comparing the situation to holding a thumb over a garden hose, illustrating how pressure works in a confined space.
  • It is noted that at 30m depth, the pressure is approximately three times atmospheric pressure, and a bullet-sized hole would not lead to immediate catastrophic failure, though it could cause significant damage.
  • Concerns are raised about the potential for hull integrity to be compromised if a bullet penetrates the submarine, leading to a collapse rather than an explosion.

Areas of Agreement / Disagreement

Participants express differing views on the nature of the pressure effects in a submarine at depth, with some arguing against the possibility of explosive decompression and others highlighting the risks associated with hull integrity. No consensus is reached regarding the initial question.

Contextual Notes

The discussion includes assumptions about pressure dynamics and material responses that are not fully explored, and the implications of a bullet hole on submarine integrity remain unresolved.

Bassalisk
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Quick question, because i am new to this term. Would explosive decompression happen at 30m below sea, in a submarine, if we would make an small opening, like from a bullet?

Thanks
 
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This question is so vague its ridiculous. This is a materials' properties problem.
 
Thanks for the answer
 
No, explosive decompression would not occur in a sub under water. What would occur is the opposite effect. The great pressure on the sub would force water in at tremendous pressure/velocity.

Imagine holding your thumb over the opening in a garden hose. The water pressure behind your thumb has built up, causing you to have a hard time holding it closed. When you release just a small portion the water comes shooting out at high velocity, enabling you to water things from 10-20 ft away depending on your water pressure. Increase the pressure by opening the valve more and you can get a longer stream of water. Decrease it and the stream decreases.

Lets say we have an Aircraft at 40,000 ft. If for some reason his canopy suddenly shattered, then the pressure inside the cockpit would quickly equalize to the lower outside pressure. If this occurs fast enough, with a great enough pressure difference, then we call that explosive decompression.
 
Bassalisk said:
Quick question, because i am new to this term. Would explosive decompression happen at 30m below sea, in a submarine, if we would make an small opening, like from a bullet?

Thanks

As drakkith points out, the pressure is inward. Subs don't explode; they implode.

At 30m, the pressure is 3atm above air pressure.

If 1 square inch hole were made in the sub, it would come through with a force to support 14.7x3 = 44lbs. (A bullet hole is smaller, less than a quarter of that.)

That would do damage to anything in its way, but not immediately catastrophic.

The bigger issue would be that - in order to apply a force to penetrate the sub with a bullet-sized hole - you would possibly rupture its integrity, causing the hull to collapse.
 

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