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You're a sub. You want to sink the destroyer above you...

Discussion in 'Ships & Shipborne Weaponry' started by the_diego, Jun 19, 2018.

  1. Carronade

    Carronade Ace

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    I'm not taking a side, but here are a few thoughts about CAC's un-depth charges. I would envision the device being cylindrical rather than round, with a flotation chamber in one end, so when it reached the surface it would float with the explosive charge slightly submerged. We might consider how far out of the water it would extend, i.e. how visible it would be. Its value might be as much deterrence, forcing the attacking ship to avoid it, as actual infliction of damage. Even a small hole near the waterline would be serious for a destroyer or escort size vessel, especially in the open ocean. It would likely prevent them carrying out attacks or steaming at high speed.

    The device(s) would need to move clear of the submarine quickly, either just by buoyancy or by the release mechanism pushing them away. We would probably want some delay in arming the weapon, either a timer or a depth sensor that only activates near the surface. There would also have to be a second arming mechanism which would keep it completely safe until released. One can't take a chance carrying explosive charges just outside the pressure hull; an unplanned detonation would likely be fatal. All these controls would have to be operated from inside the boat, similarly to the external torpedo tubes on many submarine classes including the Type VII.

    A couple of posters have posited the submarine running straight away, with the attacker in pursuit, but another tactic might be to turn a bit and lay a line of several mines, then reverse the turn to put the mines between the sub and the attacker.

    I don't know the details, but I recall reading that having the torpedo tube outer doors open at too great a depth/water pressure could damage the torpedos; that might be an issue for our hypothetical mines.
     
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  2. CAC

    CAC Ace of Spades

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    Nice addition...think about rougher weather too...a bit of chop or fog and these mines become difficult to spot...a well timed release would extend the chance of a hit too.
     
  3. the_diego

    the_diego Member

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    No chance with torps? A friend once told me that American subs have sunk a number of Japanese destroyers by meeting them at the surface head on, firing torpedoes, and then crash-diving. Was this true?
     
  4. CAC

    CAC Ace of Spades

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    A captain/commander should never put his "ship" and crew in unnecessary peril. At the surface the destroyer has all the advantage...
    Having said that people did all sorts of things so im sure this sort of thing happened from time to time...Again it may have been for a good reason we are unaware of (why surface to fire torps?)...personally...IF I was a decent distance and against a flower corvette or something small like that, I may surface, turn the sub to face directly at the corvette giving a slim target and get my deck gun team to have a go...Otherwise a subs advantage is its stealth, so dive FFS!
     
  5. Takao

    Takao Ace

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    He's worth more than his salt, if he can do that...as his own prop noise would preclude that. Or have you stopped propulsion, so that the sonarman can provide you with the necessary data?

    You compound the difficulty by carrying them in an exposed and unprotected position on deck or slightly recessed in the hull.

    Yes, a couple hundred yards behind you...However, it does not require the destroyer to pass over you, unlike DCs.

    The hedgehog mount was trainable up to 25 degrees port/starboard, and had at least twice the range of the K-gun DC side-throwers.

    I would prefer to focus my attention on escape and evasion...Not making myself and even bigger fatter target to get a slim chance at hitting the destroyer with a mine.

    Have you given any thought to ocean currents? How far will a 2 knot current push a mine off your track? How about a 4 knot current. Say from a depth of 200-300 feet with a surfacing time of a minute or so...

    The limited number of mines carried would preclude this from becoming a standard tactic, more so if multiple mines are used in a "string."

    Ignores the fact that submarines were often hunted by more than one escort.

    Timing must be perfect, too soon and the destroyer avoids the mine, too late and you get a string of depth charges for you trouble.

    Too many variables to be reliable defense.

    I could go on.

    The Mark 14 was tested to 135 pounds per square inch of pressure, so the could be fired at up to 180 feet depth under keel. The older S-Boats needed to cross-connect two impulse tanks when firing below periscope depth though. The problem would be for the torpedo to rise fast enough to hit the destroyer, a circular pattern-runner would be necessary for this.

    I would find this option far more preferable than to carrying mines.

    Again, I would believe that surfacing to shoot it out with the destroyer would be the most dangerous option.

    One, I'm not the one that has to defend it.
    Two. I see very few ways that it would work, and far more ways for it to fail.
    Three. Mr. Contradiction...Yes, that is what the Voice of Sanity and Reason is sometimes called.
     
  6. Takao

    Takao Ace

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    The US submarines were usually at periscope depth when this was done...Not running on the surface.
     
  7. Takao

    Takao Ace

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    More to the point, only the 10 Type VIIAs had them. They were dropped from the Bs on.

    The problem will be keeping the submarine slim and trim with these mine tubes, and not turning them into big, fat, unmaneuverable minelayers.

    To a point...Length of time the torpedo was immersed was the usual problem. Too long and it would have to be re-greased, battery checked(if there was one), and and go through all the maintenance again. But, since mines are meant to operate for long periods of time while being submerged, this would not be an issue.

    The effects of water pressure would be very much dependent on the type and construction of the mine used. The torpedo-launched Mk 27 was reported to not function correctly when exposed to water pressure greater than 125 feet.
    US Navy Mines
     
  8. OpanaPointer

    OpanaPointer I Point at Opana Patron   WW2|ORG Editor

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    [derail]Are there documented cases of one sub leading a tin can into a trap where a second sub was set up and waiting for the skimmer to cross in front of her?[/derail]
     
  9. Takao

    Takao Ace

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    None that I am aware of. Closest would be coordinated convoy attacks, wolfpack style.
     
  10. OpanaPointer

    OpanaPointer I Point at Opana Patron   WW2|ORG Editor

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    Yeah, that would be cheating, however. I was thinking of Skimmer not aware of Bubble #2 at all.
     
  11. lwd

    lwd Ace

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    I did it in a miniatures game once. Of course with the rules in play I knew where the other sub was and saw the DDs making a depth charge run on him. Harder to do in real life I expect.

    As for the mines (reverse depth charges). I seem to recall reading somewhere of paired mines connected by a cable that was just short of half the length of the intended target. That way if the target hit the cable it would pull at least one of the charges against it's hull where it would detonate. If it hit near the middle of the cable it got both.
     
  12. Takao

    Takao Ace

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    Robert Fulton, working for the British, in 1806. Tried again in the ACW. Early mine fuses were the problem. Not sure about more recent times.

    I would think the great variety in ship length would make this somewhat of a poser.

    Still, ships through WW1, seemed to suffer heavily from mine strikes.
     
  13. Takao

    Takao Ace

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    Deleted...double post.
     
  14. Takao

    Takao Ace

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    Don't think they had that level of communication and coordination in WW2.
     
  15. OpanaPointer

    OpanaPointer I Point at Opana Patron   WW2|ORG Editor

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    It would have to be pre-planned for sure. Have your own sonar ping in a pattern to indicate speed and direction and let the other other bubble CO work out the attack angle.
     
  16. Takao

    Takao Ace

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    OK...You're the bait going active.

    Who's shooting skills do you trust more...Your's or the other sub skipper?
     
  17. OpanaPointer

    OpanaPointer I Point at Opana Patron   WW2|ORG Editor

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    Who has the broadside shot?

    ETA: I wouldn't do this with a person I didn't trust. In fact I have done something similar with my teammates back in the day. (Filed under "insane shit I have done" of course.)
     

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