Dave Saxton wrote:
In terms of firepower the Bismarck was more powerful. Its 15" guns were more modern than those used by Vanguard. The barrels were significantly longer which creates greater muzzle velocity. This translates into greater belt armour penetration and greater range sans supercharges. Supercharges were available to Vanguard for use in a pinch though. The German 15" L/4.4 armour piercing shell was also of superior design and could penetrate more heavy armour without breaking up at acute obliqities.
In case of higher MV no doubt with all consequencesm, but I'm very interested in data about such "superior" design of German shell.
Hard data from tests.
British 15" shell (Cardonald) were tested at 40 degree oblique angle against British 12" face hardened plate and passed it with condition to burst with striking velocity corresponding to ~15 000 yards (standard charges). Older Hadfield or Mrss shell could not pass that test, but in 1946 Caronalds were available in numbers.
Any data about superiority of German shell? Hard data from test with higher obliquity hit on similar armour?
Many sources list the British 15" as giving impressive deck penetration, but post war tests proved that all British battleship guns could not penetrate more than 5" of deck armour at ranges of less than 32,000 yards or about 30km. The Bismarck's gun penetrated 5.2" of deck armour at 30km, so there's virtually no difference there.
Could You give data from live tests?
And another thing into considerations.
At high obliques British shell could brake up but will generate considerable flash and splinters (see Dunkreque turret roof hit). Bismarck magazines were just under the deck, so those splinters could start fire.
In case of Vanguard shell had to make similar hit as Mass made on Jean Bart.
Added
Why I'm asking about data? At 30 km range, striking angle of 15" shell is ~40 degree (standard charges), so oblique ~50 degree.
At 40 degree oblique, those shells passed penetration of 12" face hardened plate. 10 more degree such removes capability? Possible, as armour is different, but see another thing
BUt tests of armour taken from Tirpitz. 15" shell, penetration of German 200 lbs plate (~5") with 65 degree oblique, with 1100 fs.
65 degree oblique = 25 degree descend = ~25 000 yards = ~23 000 m, and at that range striking velocity s 1400+ f/s, so easy penetration with considerable remaining velocity
End add
In terms of belt protection the Bismarck was superior to the Vanguard and really all other battleships. It was a heavy belt (320mm) of top quality face hardened armour plus a heavy scarp arranged at an ideal angle. It could not be defeated according to some experts.
The German ballistian B Hoyer stated in 1943 that if the scarp was heavy enough, in order for a shell to defeat this type of arrangement its velocity would need to be so great that it would shatter against the face hardened main belt first.
Vanguard's belt was also from top quality armour but it was 360mm and no heavy scarp. Bismarck's hull IZ was essentially from point blank range to 30km vs most battleship caliber guns. Vanguard's IZ was essentially 21km to 30km vs the same guns.
Depends on definition.
Clearly direct hit into machinery through scrap was not possible (say very low probability), but penetration through 15 cm upper belt or 32 cm belt was quite possible. Detonation over main deck was less disastrous than inside boiler room, but many detonations there could be devastating and ship will loose efficiency after those hits.
Difference is that shell which penetrate belt over say machinery on Vaguard will probably generate more damage, but it does not mean that Bismarck was "invulnerable"
It can now be shown that the Bismarck's two deck system provided at least the sum total of its two armoured decks which would be 130mm over the machinery and 150mm (TP) over the magazines. Vanguard's deck protection was 5" over the machinery and 6" over the magazines, so virtually the same there as well.
If You add 2 thickness of deck on Bismarck add 2 thickness (or more if existed) on other ships.
Vanguard had weather deck ~30 mm thick, so sum was ~180 (magazines) and ~155 (machinery)
It is difference.
And more – magazines of Bismarck were just under the main deck. On Vanguard much deeper and with extra 38 mm splinter protection, to total was much over 200 mm over magazines.
Bismarck's turrets and barbets were better protected with 130mm turret roofs and 360mm turret faces, and 350mm exposed barbets. Vanguard's barbets and turret faces were 330mm. The turret roofs are listed as 180mm but that is laminated plates.
Turret roofs of Vanguard were 152 mm not laminated, with “turret roof quality armour”. That mean stronger requirements than ordinary deck armour.
But it is pure academic. Both could knock out each other turrets in considerable range.
OF course conning tower of Bismarck was considerably thicker. Good question if thick enough to allow command of ship after direct hit. Even non penetrating.