Engineering question
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At least with a sensor designed specifically for that application. Comparing a structure to a vibration sensor is a little off topic....
Weak is a relative term, see at 7:50
Interesting video.
Weak is a relative term, see at 7:50
At 4:15 they briefly refer to what is explained in detail at 7:50. There is a moment of higher pressure and lower pressure as the ship travels over the underwater mine.
BTW, those pressure mines. How do they blow up a ship when they are sitting at the sea floor? Does the shock wave alone cause the ship to sink?
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Such mines are designed to break the ships keel, they do so by creating an area of vacuum where part of the bottom of the ship is not supported by water as is the rest of the ship. By the way most anti-surface torpedoes since W.W. II work on the same principle they are designed to explode while passing under the ship rather than striking the ship.Interesting video.
At 4:15 they briefly refer to what is explained in detail at 7:50. There is a moment of higher pressure and lower pressure as the ship travels over the underwater mine.
BTW, those pressure minds. How do they blow up a ship when they are sitting at the sea floor? Does the shock wave alone cause the ship to sink?
That is my question which hasn't been answered, is it or isn't it?At least with a sensor designed specifically for that application. Comparing a structure to a vibration sensor is a little off topic.
So what exactly happens when they create this vacuum under the keel?Such mines are designed to break the ships keel, they do so by creating an area of vacuum where part of the bottom of the ship is not supported by water as is the rest of the ship. By the way most anti-surface torpedoes since W.W. II work on the same principle they are designed to explode while passing under the ship rather than striking the ship.
A small (say 35 - 45 foot) section of the ships hull is momentarily not supported by the water while the rest of the ship is, the unsupported section of the ship suffers a structural failure i.e. breaks her back.So what exactly happens when they create this vacuum under the keel?
This is a torpedo, but it shows what I'm writing about.
A small (say 35 - 45 foot) section of the ships hull is momentarily not supported by the water while the rest of the ship is, the unsupported section of the ship suffers a structural failure i.e. breaks her back.
This is a torpedo, but it shows what I'm writing about.
Not quite the analogy that I had in mind since I know it's a direct hit on the ship with an explosive warhead.
So if a mine exploded beneath a ship at the center, the vacuum caused by the blast would be like trying to hold a loaded ship at both ends, but that the ship will break in the middle for lack of support? (Kinda like the Titanic's end breaking off when the other end is submerged while sinking - the ship isn't designed to take that load in the middle of the hull)
P.S. How powerful was that torpedo in the video?
No, that torpedo detonated beneath the ship, it did not strike its side.Not quite the analogy that I had in mind since I know it's a direct hit on the ship with an explosive warhead.
Yes this is spot on.So if a mine exploded beneath a ship at the center, the vacuum caused by the blast would be like trying to hold a loaded ship at both ends, but that the ship will break in the middle for lack of support? (Kinda like the Titanic's end breaking off when the other end is submerged while sinking - the ship isn't designed to take that load in the middle of the hull)
The warhead is somewhere around 650 lb (290 kg)
But I watch movies like Run Silent, Run Deep, or The Hunt For Red October (lol), and I always thought, torpedoes strike the side of a ship and pierce it's armor to cause maximum damage and killing?No, that torpedo detonated beneath the ship, it did not strike its side.
As to the rest of what you wrote you are spot on.
The warhead is somewhere around 650 lb (290 kg)
650 #s does all that? Wow.
(I hope the USN cleaned up the mess in that ocean)
I thought my comment did. A mine is absolutely nothing like a structure. The small pressure differential detected by the sensors on a mine will have absolutely no impact on any structure.That is my question which hasn't been answered, is it or isn't it?
Yes, in WW2 that was the case but as Aardvark stated since the 50s they are designed to detonate under the ship.But I watch movies like Run Silent, Run Deep, or The Hunt For Red October (lol), and I always thought, torpedoes strike the side of a ship and pierce it's armor to cause maximum damage and killing?
650 #s does all that? Wow.
The modern Mk48 torpedo's explosive is Torpex which is ~2X more powerful than TNT. A WW2 battleship had thick armour, void spaces and compartmentalization to mitigate torpedo impacts against the side of the ship - it could take several torpedo hits to sink then (Bismarck is a good example). But modern torpedoes that detonate below a ship cause far more damage for the same yield warhead and it's all but impossible to design or armour a warship hull to mitigate them - better to avoid the torpedo with decoys or prevent being attacked in the first place.
With modern torpedoes, there's actually several things that work together to sink a ship. 1st, There is the initial shock wave that batters the hull from underneath that can fracture hull plates and damage equipment within the ship and possibly force a jet of water into the hull. 2nd the ship is forced slightly upward and then falls in the vacuum with either end supported by the water, breaking the ships back as was explained above.
http://www.armscontrolwonk.com/archive/302709/rok-ship-typical-torpedo-damage/
The link you provided explains that it is the jet of water blasting through the hull when the gas bubble beneath the ship bursts upon striking the keel (instead of a vacuum) that breaks the ship. The initial damage is caused by the shock wave.Yes, in WW2 that was the case but as Aardvark stated since the 50s they are designed to detonate under the ship.
The modern Mk48 torpedo's explosive is Torpex which is ~2X more powerful than TNT. A WW2 battleship had thick armour, void spaces and compartmentalization to mitigate torpedo impacts against the side of the ship - it could take several torpedo hits to sink then (Bismarck is a good example). But modern torpedoes that detonate below a ship cause far more damage for the same yield warhead and it's all but impossible to design or armour a warship hull to mitigate them - better to avoid the torpedo with decoys or prevent being attacked in the first place.
With modern torpedoes, there's actually several things that work together to sink a ship. 1st, There is the initial shock wave that batters the hull from underneath that can fracture hull plates and damage equipment within the ship and possibly force a jet of water into the hull. 2nd the ship is forced slightly upward and then falls in the vacuum with either end supported by the water, breaking the ships back as was explained above.
http://www.armscontrolwonk.com/archive/302709/rok-ship-typical-torpedo-damage/
Look again at the video you can see absolutely everything (the very reason I chose that particular video).The link you provided explains that it is the jet of water blasting through the hull when the gas bubble beneath the ship bursts upon striking the keel (instead of a vacuum) that breaks the ship. The initial damage is caused by the shock wave.
I did, thanks.Look again at the video you can see absolutely everything (the very reason I chose that particular video).
I see what the last link explains. The initial shock wave damages the ship, possible breaching the hull to cause the initial break - then the jet blast shooting upward finishes the job and breaks it in half.
I agree. i think most sites over simplify the explanation by referring to it as a vacuum. The video is very good.The link you provided explains that it is the jet of water blasting through the hull when the gas bubble beneath the ship bursts upon striking the keel (instead of a vacuum) that breaks the ship. The initial damage is caused by the shock wave.
It's a gas bubble, not a vacuum. But if it is a vacuum, the vacuum bubble breaks upon striking the keel, and the rush of surround water comes through to fill the vacuum with incredible pressure and up through the boat to snap it completely in half.I agree. i think most sites over simplify the explanation by referring to it as a vacuum. The video is very good.
