Bismarck's armor against long range hits

[Alberto Virtuani]

Of course, my mistake. Gneisenau was hit at 23:15 on February 26, 1941 and blew up at around 23:40, according to Whitley.

My question still stands: did the bomb penetrate the main armor deck of the ship ?


Bye, Alberto

[dunmunro]

Of course, my mistake. Gneisenau was hit at 23:15 on February 26, 1941 and blew up at around 23:40, according to Whitley.

My question still stands: did the bomb penetrate the main armor deck of the ship ?


Bye, Alberto

"...Gneisenau was hit at 23:15 on February 26, 1942..."

G&D state that the RAF dropped 1000lb GP bombs which have very limited AP capability, so it seems unlikely.

[Alberto Virtuani]

Hello everybody,

yes, again my mistake re. 1941 vs 1942... Who knows why, I have 1941 in mind...

Here Whitley's pag 177-178 account:

"...It was enough for at 23:15 one bomb hit Gneisenau in the vicinity of "A" turret which caused large casualties to the turret crew and the damage control parties below.
The bomb struck and penetrated the upper deck forward of "A" turret and was deflected aft by the longitudinal armoured bulkhead at frame space 185,6, subsequently exploding on the armoured deck by a hatch and ventilation trunk, in the seaman petty officers' mess. The vertical bulkhead was ruptured and fire spread to the forward crew space through this hole, but the bomb did not penetrate the armoured deck. This was distorted by the force of the explosion. However, the hatch to the 28 cm magazine is believed to have been open (it could not subsequently be found) and the flash and splinters entered the magazine.
About 25 minutes after this first hit, a second huge explosion occurred, thought initially to be a second bomb hit. It was subsequently decided that this was in fact caused by the ignition of fuel gas and fumes in the tank spaces by the earlier bomb hit. This explosion ignited and blew out all the contents of the magazine and a huge jet of flame issued from "A" turret which was totally burned out. The upper deck was torn up.....
...Damage control parties flooded the section aft of "A" turret (i.e. "B" magazine and shell rooms, as well as reserve "A" magazine, thus preventing further explosion. A huge fire raged...."

If this is the case, not only the deck resisted to penetration (as G&D and Koop accounts seem to confim), but there was IMO a severe damage control failure, not inspecting and flooding (I guess some water against fires was available on board even in a dry dock... and 25 minutes are a large time interval even without pumps from sea water) immediately "A" turret magazine after the first hit, while fires were raging in this part of the ship.

Does anybody have more precise info (like a damage report or any official document) describing what happened ? Was any inquiry done ? With which results ?


Bye, Alberto

[lightyear]

1) against 50 mm + 80 mm
ther were several perforations on Scharnhorst(La Pallice) and Tirpitz (Tungsten)but no detonations
the double impact on wheather deck and main armor deck obviously rendered all fuzes from 1600 lb armor piercing bombs into duds.

2) against 50 mm + 110 mm
all bombs that hit break off at the armored deck


3) Special case Gneisenau the bomb was thrown from larger altitude (stationary target in dock - no battlestations(kein Klarschiffzustand))

Got it, Do you know what a usual penetration of the 1600lbs AP bomb? I mean on a certain altitude xx mm?

[spicmart]

for a start
the cited Textband Unterlagen zur Bestimmung der Hauptkampfentfernung und Geschosswahl

-W Hurlich spaced Armor
http://www.dtic.mil/docs/citations/ADA954865

---------------------------------------------------------

SUPP 22-68 SPACED ARMOUR.jpg

The problem of increased deck protection was firstly recognized by british ballistic research in
"High obliquity attack of deck Targets 12/45"
The main reason for projectile failure has been described as topple.

shortly after this report they published target properties of Tirpitz as following
vertical side armour 12 inches
deck armour 6 inches (as far as i remember correctly in SUPP 6-481) with the note that no british battleship shell available at the time was able to defeat 6 inches of horizontal protection at ranges below 30 kyard.

Unfortunately this document was not available in Kew, as it received no modern Access number such as ADM... SUPP or DEFE
compared to the following reports on high obliquity attack II and III and others.

They then systematically researched "the peculiar condition" of increased protection , wich may have some influence on projectile performance against complex (spaced)targets, as decapping, yaw(see also optimum yaw wich may increase penetration on oblique impacts), head shape of projectile, lenght of projectile, different cap types, influence of distance between the armour plates...

The link doesn't work.
Can you provide it it somewhere else?

[Thorsten Wahl]

https://www.google.com/search?q=+dtic+ADA954865

[spicmart]

Thanks! I would like to post that in some groups, of course mentioning you as source. Do you mind?

[spicmart]

@Thorsten Wahl,
Is it possible for you to provide SUPP 22/68?

[Thorsten Wahl]

you may take a recent post of mine at the navweaps forum:

https://www.tapatalk.com/groups/warship ... l#p1102205

SUPP 22/68
https://drive.google.com/file/d/0B12aaM ... cNWCoxs7Ug
SUPP 22-43
https://drive.google.com/file/d/0B12aaM ... 7gqjDKmoEg

[spicmart]

Thanks very much!

[Herr Nilsson]

you may take a recent post of mine at the navweaps forum:

https://www.tapatalk.com/groups/warship ... l#p1102205

SUPP 22/68
https://drive.google.com/file/d/0B12aaM ... cNWCoxs7Ug
SUPP 22-43
https://drive.google.com/file/d/0B12aaM ... 7gqjDKmoEg

Sag mal, haben wir die Sachen damals nicht mit in paar anderen Leuten zusammen bestellt und uns die Kosten geteilt, oder täusche ich mich?

[Thorsten Wahl]

ich hatte glaube ich im Marinearchiv angefragt ob sich wer beteiligt. Leider kann ich den Thread nicht mehr finden.
jedenfalls habe ich bestellt und alles finanziert und die Dokumente aus Kew in Papierform erhalten. waren zwei oder drei Bestellungen eine 2010 2011

Später habe ich die eingescannt und verteilt.

habs gefunden und hochgeholt.

Gruß

[Herr Nilsson]

Genau, und mein Anteil an den Kosten der 3 Sammelbestellungen war insgesamt 71,82€.

[spicmart]

@Thoddy Da dies alles sehr ins technische Detail geht und ich nur ein Laie bin, wollte ich dich fragen, ob es da vielleicht ein Summary gibt, welches die Schlussfolgerungen der Tests zusammenfasst?
Bitte entschuldige, wenn dies peinlich klingt.