Plunging fire

Guns, torpedoes, mines, bombs, missiles, ammunition, fire control, radars, and electronic warfare.
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Re: Plunging fire

Post by delcyros » Sat Mar 19, 2011 1:23 am

don´t misunderstand me, I´m not revisioning the ricochet strories. Just wondering whether the reference for idea that the main belt of BISMARCK was almost submerged was based on anecdotical evidence or the damage controll flooding report of BSIMARCK which is said to exist and was rescued by one of the survivors. I haven´t seen this document, ever.
But what I´have seen is the belt arrangemet of BSIMARCK. It had a comparably high armoured freeboard (for the standarts of the period) with only VANGUARD having an even higher armoured freeboard in service condition. At construction displacement, this belt extended almost 10ft amidships (3.0m) and 12ft at the extreme turrets (+3.6m) above the design waterline, this may have been lower in service conditions at deep load but not by as much as it was for TIRPITZ, displacing a lot more with all the additions TIRPITZ received in the first place:


I don´t know how much fuel, provision, drinking water and ammo was spend by the time of her final battle but he should have been 5,000 metric tons lighter than before leaving Norway (not topped off with max. fuel), hadn´t she been damaged and torpedoed in the meantime. Neither can I assess the flood damage before the final battle but as I mentioned before, in order to levelise the waterline at the level of the upper/main belt joint, another 15,000 tons of flooding are required in addition to the 5,000ts of water I assume to remain in the ship as a cause of the damage and counterfloodings (a wild guess, I admit).
At TIRPITZ deep combat load, the chances are roughly 60/40 for upper belt / main belt hits (50/50 at the turrets) with regards to area´s exposed. It´s still far from the belt going to be submerged or difficult to hit. But then again, by the time, RODNEY was closing in for the kill, a lot has happened and the exact timetable doesn´t exclude that by then BISMARCK´s sea valves already opened and thus the ship starts to sink slowly taking over water.

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Re: Plunging fire

Post by Billy » Sat May 11, 2013 11:24 am

The German cap was a fair bit heavier than its British counterparts. I would find it very unlikely that they would have used old ww1 armor in tests since the newer armor had been around for some time by them. However could it be that the German figures were correct (especially regarding German tradition regarding fastidiousness and accurate records)regarding their figures of their armor penetration. Could it not be that the German shells due to their different design actually exceeded the penetration values of other navies. Given the similarities between German and British armor and the exhaustive tests that the shells were put through, and the thorough record keeping of each navy, and the differences in German shell design,can it not be said that German shells were superior by a large margin.

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Re: Plunging fire

Post by Swiftman » Fri Feb 26, 2016 4:39 am

26-inch thick armor from Japanese Yamato class battleship, pierced by a US Navy 16-inch gun. The armor is on display at the US Navy Museum ... e=574EE2EC

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Re: Plunging fire

Post by Siegfried » Fri Dec 30, 2016 5:54 am

dunmunro wrote:By "belt" I presume you are both talking about the 320mm portion of Bismarck's main belt:
The majority of the belt was located above the waterline (3.0/1.8 meters as designed, but 2.6/2.2 meters in practice), with the reasoning that shells are more likely to hit above than below the waterline.
Bismarck's draft increased by 1.3 meters at 53000 tonnes (extreme deep) from 45.5k tonnes (design). Given the underwater damage and counterflooding required to correct lists prior to the last battle, it seems reasonable that Bismarck was probably displacing somewhere between 52-55k tonnes at the start of the battle and somewhat more than this by the time Rodney closed the range. At 53k tonnes, only 1.7m of the main belt would be exposed above the waterline, and at 57k tonnes only about 1 metre of the main belt would be exposed, and this only represents a small fraction of average target height. At very close range, shells are unlikely to plunge when striking the water and given the gale force weather, shells with a trajectory that would carry them into the main belt are very likely to strike a wave prior to hitting the belt.
Do we know whether the Bismarck's lower deck "Tortoise Shell" armour was ever penetrated?

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