Welcome to the WWII Forums! Log in or Sign up to interact with the community.

Bismarck

Discussion in 'Germany at Sea!' started by Ricardo War44, Feb 4, 2008.

Tags:
  1. Thoddy

    Thoddy Member

    Joined:
    Sep 4, 2014
    Messages:
    44
    Likes Received:
    5
    the belt alone
    but

    the ballistic horizontal protection consists of the main belt + scarp + torpedbulkhead

    In "Unterlagen und Richtlinien zur Bestimmung der Hauptkampfentfernung..." they used a additional textual explanation using the wording with regard to side protection:
    " Es muss deswegen angestrebt werden, soweit irgendwie möglich, auch den Horizontalpanzer in das Gesamtsystem des Seitenschutzes einzugliedern. Hierdurch kann erreicht werden, dass wenigstens auf den Hauptgefechtsentfernungen die Zerstörungswirkung von den lebenswichtigen Teilen des Schiffes ferngehalten wird. "
    translation
    "It must therefore be seek for, as far as possible, to integrate the horizontal armor into the overall system of side protection. In this way it can be achieved that at least at the main combat distances [/ b] [/ u] the destructive effect is kept away from the vital parts of the ship."

    As main combat distances they give 12-18 km against various battleships, these distances correspond with distances at wich own guns may defeat enemies side protection completely.


    The side protection requires, depending on angle of fall of the attacking projectile, 550 mm - 750 mm armor grade material in series to be penetrated AND with he the projectile required to remain whole, to allow for full order detonation within the vital area of the ship.
     
  2. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    Yes, after penetrating the 320 mm belt a shell would have to go through the 100 mm Wh (Wotan hart) slope of the deck (the "scarp") and the 45 mm Ww (Wotan weich) vertical torpedo bulkhead. Almost impossible, the vitals of the ship under the main armored decks were almost impregnable at short/medium ranges. If I recall correctly, Okun or somebody else wrote that only the Yamato guns firing at point blank against the lower belt would have made the trick. And any shell at low angle hitting the 80 mm flat portion of the deck would have simply skipped off the plate. In the H39 class the belt would have been reduced to 300 mm and the main deck increased to 120 mm on the slopes and 100 mm on the flat part (Breyer & Koop, Von der Emden zur Tirpitz, 1997).

    Changing slightly the subject, I have found a great video that IMHO gives the most plausible explanation for the loss of HMS Hood. It's a very throughout analysis full of technical details, which goes through all the various hypothesis that have been made to explain the tragic event, and debunks a few myths:



    If you find it too long you could start from 25:33, where IMO the most important stuff is discussed.
     
    belasar and Kai-Petri like this.
  3. Thoddy

    Thoddy Member

    Joined:
    Sep 4, 2014
    Messages:
    44
    Likes Received:
    5
    "Problem" with this analysis is that the author of the video left out a fact completely:

    "The first artillery officer missed one splash out of four impacts"

    That means there was obviously one direct hit
    nevertheless this does not rule out a second hit by a short impact.

    Given distance and movement of both ships also hits through the "upper belt and slope" OR "main belt and slope" are possible explanations.

    Hits trough the deck were unlikely as impact angle was to low to allow a trajectory of a fuzed projectile ending in a magazine.
     
    Last edited: May 20, 2021
  4. Takao

    Takao Ace

    Joined:
    Apr 27, 2010
    Messages:
    9,719
    Likes Received:
    2,352
    Location:
    Reading, PA
    Hood being hit by a short is possible, but improbable. AFAIK, only USS Boise was hit by a short that went into her magazine, and that was with the specialized Japanese diving shell. The fire in the magazine was quenched by the Irish of water through the shell. Hole before a major detonation took place.
     
  5. Kai-Petri

    Kai-Petri Kenraali

    Joined:
    Jul 31, 2002
    Messages:
    25,372
    Likes Received:
    1,900
    Location:
    Finland
    The Royal Navy conducted two inquiries into the reasons for the ship's quick demise. The first, held soon after the ship's loss, concluded that Hood's aft magazine had exploded after one of Bismarck's shells penetrated the ship's armour. A second inquiry was held after complaints that the first board had failed to consider alternative explanations, such as an explosion of the ship's torpedoes. It was more thorough than the first board and concurred with the first board's conclusion. Despite the official explanation, some historians continued to believe that the torpedoes caused the ship's loss, while others proposed an accidental explosion inside one of the ship's gun turrets that reached down into the magazine. Other historians have concentrated on the cause of the magazine explosion. The discovery of the ship's wreck in 2001 confirmed the conclusion of both boards, although the exact reason the magazines detonated is likely to remain unknown since that area of the ship was destroyed in the explosion.

    HMS Hood - Wikipedia
     
  6. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    There could have been a direct hit somewhere in the ship that was not related to the magazine explosion and a short that went just under the belt hitting the water at the wave trough, as explained in the video. Would such a hit have resulted in a clear, easily visible splash? I would guess so, but it's difficult to be sure. Indeed some believe that the Hood was hit by two shells and the observers, as expected in the chaotic and stressful situation of a battle, are not completely consistent in their reports.

    A penetration of the 7" inch belt and the deck slope would have occurred at a 20 degree angle of fall or more, and at the distance when the fatal salvo occurred the angle was much less than that, as explained in the video. Thus the shell would have hit the flat section of the deck and wouldn't have penetrated. I think a direct penetration of the 12" belt cannot be ruled out (at least the Board of Inquiry didn't exclude such possibility), but then the shell should still have penetrated the 2" slope. According to the video at the distance and conditions involved the maximum expected penetration would be 9,5". Maybe a shell performing much better than expected penetrated the 12" belt, hit the slope and someway a fragment managed to reach the 4 inch magazine. In any case it would seem that the loss of the ship was due to an unlikely combination of events. But so was the torpedo hit that crippled the Bismarck. Such things happen in real life.
     
    Thumpalumpacus likes this.
  7. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    I think that the "torpedoes explosion theory" can be reasonably ruled out. It seems that the Hood launched two torpedoes before being destroyed. The explosion of the remaining two torpedoes wouldn't have been enough to kill the Hood. It is of course possible that the German observers were mistaken and no torpedoes were in the water. But even the explosion of all four torpedoes would not have been consistent with the events of Hood's destruction, as the video quite convincingly explains.

    It is ironic that the torpedoes (presumably) fired by the Hood did indeed affect the subsequent events. The Germans changed course to avoid the torpedoes, which disturbed their gunnery and helped the Prince of Wales to avoid more damage.
     
    Kai-Petri likes this.
  8. Kai-Petri

    Kai-Petri Kenraali

    Joined:
    Jul 31, 2002
    Messages:
    25,372
    Likes Received:
    1,900
    Location:
    Finland
    Royal Navy board view. Anyway, I feel we never truly know the true explanation. Only that it exploded
     
  9. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    I had the texts of the two Boards of Inquiry but I lost them. They concluded that the most likely explanation was a 380 mm shell from the Bismarck penetrating in or near the 4-inch magazine, causing the ammo there to explode, which in turn caused the adjacent 15-inch magazine to blow up. The one million dollar question is how the shell arrived there.

    I have seen the schematics of Hood's armor. It's very complex (it was defined "a patchwork" by some). Indeed there was a narrow area of weakness in the deck armor forward of the rear magazines area, which in the right circumstances could have allowed a shell to reach the 4-inch magazine area. This was also mentioned by the Board of Inquiry. Considering the distances at which the actual hit occurred it seems improbable that this happened. Anyway, considering that this weakness was known there would have been a simple solution: to leave the 4-inch magazine empty or semi-empty when the ship was on a mission outside areas covered by enemy aircraft. The Germans didn't have carriers after all.
     
    Kai-Petri likes this.
  10. Carronade

    Carronade Ace

    Joined:
    Feb 17, 2010
    Messages:
    2,836
    Likes Received:
    621
    One more thought, the fatal hit occurred as Hood made a two-point (22.5 degree) turn to port to unmask her after turrets. Turning to port would cause the ship to heel slightly to starboard, presenting her deck armor at a more favorable angle for penetration than when steering a straight course.
     
    Thumpalumpacus likes this.
  11. belasar

    belasar Court Jester

    Joined:
    May 9, 2010
    Messages:
    8,515
    Likes Received:
    1,176
    I tend to think the Drach video is the most plausible explanation for the loss, but we will probably never know for sure.
     
  12. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    Interesting point. I have to re-watch the video, because I remember it addressed the question of the heeling and I seem to remember it said that at the beginning of the turn the ship would have first heeled to port, thus exposing more of the starboard side and reinforcing the hypothesis of the hit under the belt. But I don't remember the details of the physics involved, so maybe I got it wrong. Or the guy who made the video did...

    Btw, I find armor a very interesting topic and I'm tempted to start a thread on the utility of armor on modern warships. But I noticed on other discussion boards that this topic usually raises flame wars, with some people getting incensed and regarding the idea as a sort of heresy.
     
  13. Kai-Petri

    Kai-Petri Kenraali

    Joined:
    Jul 31, 2002
    Messages:
    25,372
    Likes Received:
    1,900
    Location:
    Finland
    Just curious: Do the modern armor of warships stand the hit of a missile like Exocet? Or is the anti-missile system able to destroy the exocet? At least in a document of the Falklands´war it was some 5-7 seconds to fire an anti-rocket missile. Otherwise I have no clue, to be honest.

    Exocet - Wikipedia

    In the years after the Falklands War, it was revealed that the British government and the Secret Intelligence Service had been extremely concerned at the time by the perceived inadequacy of the Royal Navy's anti-missile defences against the Exocet and its potential to tip the naval war decisively in favour of the Argentine forces.
     
  14. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    As far as I know modern warships carry no armor except for Kevlar or similar materials around some key items against splinter damage. They have no armored belts/decks. I read somewhere that the Ticonderoga class has one inch Kevlar on one of the decks but I cannot confirm it. I think even modern super-carriers have no deck armor. The only "traditional" armor on a modern warship that I know of is the 76 mm plating around the reactor compartment of the Kirovs. And I got that info from Wikipedia.
     
    Kai-Petri likes this.
  15. the_diego

    the_diego Active Member

    Joined:
    Sep 16, 2016
    Messages:
    323
    Likes Received:
    60
    The triad of speed-armor-firepower was scrapped almost right after the war, replaced by clearer role recognition for surface units beside carriers (anti-ship, anti-aircraft). The Soviets started developing ship-to-ship capabilities in the 60s, culminating with the Kirov class in the early '80s. Nope, armor was not a crucial factor. With increased recognition of ship-to-ship capability, the triad has become speed-stealth-FIREPOWER.
     
    Kai-Petri likes this.
  16. Thumpalumpacus

    Thumpalumpacus Active Member

    Joined:
    Feb 28, 2021
    Messages:
    120
    Likes Received:
    35
    I've got is saved to HDD but haven't watched it yet. Probably watch it tonight.
     
  17. Carronade

    Carronade Ace

    Joined:
    Feb 17, 2010
    Messages:
    2,836
    Likes Received:
    621
    When the rudder is first put over, the ship heels a little in that direction, port in this case, but as the turn continues she heels the other way.
     
  18. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    To me reintroducing armor to major surface warships makes a lot of sense, and building a 10 000 + tons ship made of glass looks like a folly. The author of this blog is even more sanguine: Navy Matters: Armor For Dummies To make it clear, when I talk about building modern armored warships I don't mean a modern Yamato, but a ship with an updated version of WW2 cruiser-type armor protection, using new technologies and materials.

    But I'm no naval engineer, and there is a simple reason that makes me doubt it would be a good idea. That reason is that no navy in the world is building them - or as far as I know is planning to build them. If it were just the Western navies, that'd be no surprise, they have to contend constantly with budget issues and political interference - plus the Americans seem almost always to prefer high-tech solutions. But Russia and China aren't building them either. China in particular has the money and apparently the will to challenge US naval power in the Western Pacific. If the leaders of the CCP want the best weapon systems they don't need worrying about congressmen constituents or criticism from journalists. Yet they aren't building any armored ships (which in theory would be even more useful in the restricted waters of the Taiwan straits). Since the Chinese aren't stupid that suggests me that maybe building armored ships isn't a great idea after all.
     
  19. the_diego

    the_diego Active Member

    Joined:
    Sep 16, 2016
    Messages:
    323
    Likes Received:
    60
    It makes sense in close littoral warfare, even in river warfare (i.e. monitors). And what if a Somali pirate ship, acting dumb and docile, manages to come close enough to a navy ship and fire an rpg-7?
     
  20. Brutal Truth

    Brutal Truth Active Member

    Joined:
    Mar 13, 2021
    Messages:
    127
    Likes Received:
    49
    The pirate boat would be obliterated by auto-cannon fire but your super-expensive high-tech tin can crammed with unprotected electronics would get some nasty damage and if unlucky would be mission-killed, requiring a long and expensive vacation in a shipyard for repair.
     

Share This Page