BISMARCK armor scheme = BADEN?

[lwd]

I'm not so certain of that. If you look at the armor scheme posted at http://www.kbismarck.com/proteccioni.html
You'll see for instance that part of Bismrack's bow area has little armor. Now the British shells used a fairly short fuse so a "through and through" shot presupposes on one or more of the following:
1) A very narrow portion of the hull or superstructure.
2) Not encountering a significant enough object to initiate the fuse.
3) Failure of the fuse.
Furthermore the penetration tables at http://www.navweaps.com/index_nathan/Pe ... ritain.htm suggest that given 3 above it might have been possible if the shell only interacted with Bismrack's upper belt.

[madmike]

to lwd ,yeh i can go with the idea of bureaucratic inertia, lol. From what i can find out so far is Bismarck s data was de-classified in the mid 60s by the British and sometime later by the US. And we do have to remember the allies had a HELL of a lot of German documents to go through after the war. And i dont think Bismarck was at the top of the list.

[alecsandros]

to lwd ,yeh i can go with the idea of bureaucratic inertia, lol. From what i can find out so far is Bismarck s data was de-classified in the mid 60s by the British and sometime later by the US. And we do have to remember the allies had a HELL of a lot of German documents to go through after the war. And i dont think Bismarck was at the top of the list.

Actualy Bismarck's armor scheme was carefully scrutinized after the war. The British performed testing in 1945-1946 to assess the effectiveness of the vertical and horizontal armor employed on Tirpitz. The results were very good.

[paul.mercer]

Gentlemen,
Thanks for your replies. Ballantynes book states that the reason that the shells were going straight through was that Rodney was using armour piercing at close range instead of high explosive ones which had been offloaded prior to her refit in the US.
Surely an armour piercing 16" shell travelling at around 3000 Feet per second fired at a range of around 3-4 miles or less is going to penetrate the armoured belt of most ships, even if it did not go right through?

[tommy303]

Ballantynes book states that the reason that the shells were going straight through was that Rodney was using armour piercing at close range instead of high explosive ones which had been offloaded prior to her refit in the US.

Rodney would have used APC in any case against Bismarck. HE was reserved for unarmoured or lightly protected targets and shore bombardment. Rodney would never have used HE against another battleship. Furthermore, a MV of 3000f/s for Rodney's guns is quite optomistic. 2600 f/s was nominally closer to what was achieved in service after the reduction in velocity to limit barrel wear.

[madmike]

hi again, and thanks alec, yes i know the Brits did those test in 46-47, But what i can find states that the British gov, didnt fully de-classified Bismarcks data until mid 60s, and the US sometime later.

[paul.mercer]

Ballantynes book states that the reason that the shells were going straight through was that Rodney was using armour piercing at close range instead of high explosive ones which had been offloaded prior to her refit in the US.

Rodney would have used APC in any case against Bismarck. HE was reserved for unarmoured or lightly protected targets and shore bombardment. Rodney would never have used HE against another battleship. Furthermore, a MV of 3000f/s for Rodney's guns is quite optomistic. 2600 f/s was nominally closer to what was achieved in service after the reduction in velocity to limit barrel wear.

Gentlemen,
Even at 2600 f/s surely a shell weighing around a ton would penetrate most armour at the range that Rodney was firing at Bismarck?

[tommy303]

There is little question that at the ranges at which the battle was fought, Rodney's shells could penetrate the belt armour; however, what is called into question is could they have also penetrated the armoured deck scarp; this offered a second line of defence and would probably have been effective in stopping a shell that had already been decapped, stressed, slowed, and probably yawed by passage through the main belt. This was part of the German design philosophy and there is little reason to doubt that it would have worked.

[Maria465]

The BISMARCK-class and BADEN-class battleships, both products of Imperial German Navy design, shared similar armor schemes. Inspired by the lessons of World War I, they prioritized deck protection and compartmentalization. The armor layouts of BISMARCK and BADEN reflected a commitment to naval innovation and resilience in the face of evolving threats

[Thorsten Wahl]

shared similar armor schemes. ....

your description appears to short

somthing more comprehensive:

Excerpt from "Unterlagen zur Bestimmung der Hauptkampfentfernung..."

Based on the experience of Worldwar I and as a result of the development of weapons, armor protection has been improved primarily in the following aspects:

against hits that can occur on large distances and correspondingly large angles of incidence against the armordeck
against bomb attacks

These two reasons force you to use a significantly larger portion of the armor weight on the horizontal protection and barbettes, but the total proportion of armor to the total weight can not be increased substantially. The barbettes must, if they are not covered by closed casemates, etc., go through at full strength about the main armored deck, as in the case of larger angles of fall of these parts are not completely covered by the side armor. By this new distribution of the armor, it is not possible to make the belt armor so strong, that it cannot be penetrated by “heil” projectiles.

It must therefore be sought, to integrate also the horizontal armor in the system of vertical protection. If this can be achieved, it is possible, at least on the main combat distances to keep the destructive impact away of vital parts of the ship.

The strongest armored deck therefore has to be lay as deep as possible with a flat slope as possible to the lower edge of the main belt, but, unlike previously, now so strong that even projectiles, wich penetrates the belt with a significant surplus of speed and hit the slope, can not penetrate, but get breaked or dismissed.

On the other side the armored deck itself cannot be made as strong to prevent any penetration of projectiles that hit the armored deck directly at the highest distances, because such a substantial reinforcement of the armoured deck, that it also protects against the heaviest AP- shells at larger angles of incidence seems impossible for large parts of the vessel from weight issues . By increasing thickness of armor plate its only possible, to push out the distance at which penetration occurs.

Regarding the safety of horizontal protection against penetration, it should be noted that results at relatively small impact angles can only be an indication for expected penetration. Small material variations frequently have a great impact, so for example, differences in the cap shape (cap removal) and hardness (of the plate) can affect penetration abilities in such a way, that in one case, the projectile enters the plate and in the other case, under otherwise the same conditions, ie at the same impact velocity, but with different cap, the projectile will be rejected. Also, the values, both of the angle as well as the impact speed at which a projectile is dismissed or just penetrates the plate, often influenced each other so closely, that they can not be separated exactly. A further contributing factor is, that in cases of relatively low impact angles, the elusive nature of straightening up of the projectile has even more influence, than at larger impact angles. This effect can be found especially when several plates have to be penetrated. It is even also possible that the projectile enters the plate with an angle to the direction of flight, so it has to penetrate with a much larger cross section.

As these (combined) effects couldnt be explained in every detail they are not considered in the recommendations for optimal combat-distances against enemies.
Insofar the recommendations has to be counted as worst case scenario.

Allied ballistic research during and past ww2 seems to confirm the german approach.
british research for instance consider for horizontal protection a value of 6 inches for a battleshiptarget similar to Tirpitz (SUPP 6/481 Proc q 4,016) against 16 inch projectiles in 01/1946. So "vital parts" of the german ships seem to be save against british projectile at distances up to 30 kyard against horizontal penetration compared with an estimate of ~22 ky according C.B 04039 Armour Protection(1939) addendum no.2 1943.

US research on smaller calibers shows under certain circumstances a potential better protection for spaced plates vs single plates by a net factor of up to 1.3 - 1.5.
http://www.dtic.mil/srch/...ction=t3&id=ADA954865

Regardless from the gain in protection for vital parts, the german approach requires large parts of the ships to be destroyed or crippled. In this context, the assessment of the german authorities is worth mentioning, that turret protection of Bismarck-class was found to be inadequate for the combat-value of the SK 38 weapon.

[chuckfan3@gmail.com]

The BISMARCK-class and BADEN-class battleships, both products of Imperial German Navy design, shared similar armor schemes. Inspired by the lessons of World War I, they prioritized deck protection and compartmentalization. The armor layouts of BISMARCK and BADEN reflected a commitment to naval innovation and resilience in the face of evolving threats

Baden design predated WWI