Bismarck vs Iowa class Battlership

[maltesefalcon]

''...never imagined they were to meet each other on the high seas...'

I think we all agree that is not probable they would meet 1:1. But it is not impossible. Either Iowa is transfered to GB and accidentially meets Tirpitz (like Hood vs Bismarck e.g.) or they have a duel amidst other ships. Or on the D day, Tirpitz sails south and Iowa, which is the closest to Tirpitz intercept it before other ships. Not very likely, but not impossible.

The encounter between Hood and P of W with Bismarck and Prinz Eugen was not accidental as the above implies. The RN knew when Bismarck left port and had ships following. In addition there was a determined air search. Although some contact was lost at times at least they knew their approximate location and heading.

Hood and P of W were specifically sent out to engage the German battleship and were actively looking for them when they met up.

On another note I had a bit of a hiccup typing this on my Ipad. For some reason selections from my first post in his thread kept popping in by themselves. This was without using the cut and paste function btw. Not sure if it is a site glitch or my hardware. Has this happened to anyone else?

[Nautilus]

Bismarck class had some disadvantage over any potential USN opponent, as they could not be upgraded to take the 40.6cm SK C/34 guns at all. When the 40.6cm turret had been designed, the rotating mass got ~420 tonnes heavier than for a 38cm and it needed larger barbette diameter, so they could only be installed on a ship designed for them (H39-H41).

When test firing had been performed, the difference in penetration ability between a 38cm and a 40.6cm was not too great, so it was judged the RN possible opponents could not resist the AP shell from a 38cm anyway (As proved by the fight with PoW and Hood). Unfortunately, neither could Bismarck resist a serious pounding from RN 16in Mark I, and the USN 16"/50 Mark 7 was far more destructive.

[Takao]

There was one opportunity for a gun battle vs Tirpitz. USS Alabama was despatched as part of a USN/RN task force in June 1943 as part of an attempt to lure Tirpitz into open waters. But Tirpitz did not fall for the bait, likely remembering the outcome of an unequal duel between Rodney, KGV et al and her sister ship.

On paper at least, Iowa was also despatched to Argentia in August the same year for a similar mission. Nothing came of it either.

One of the difficulties was the narrow waters that Tirpitz would need to negotiate. Depending on the course set, one of the fleets would need to risk coming dangerously close to land based air attack.

July, 1943...You have confused Operation FH with Operation Governor.

Problem was this would not have likely resulted in a one on one, as the two main Allied forces were each composed of 2 battleships and 1 carrier plus escorts.

[maltesefalcon]

There was one opportunity for a gun battle vs Tirpitz. USS Alabama was despatched as part of a USN/RN task force in June 1943 as part of an attempt to lure Tirpitz into open waters. But Tirpitz did not fall for the bait, likely remembering the outcome of an unequal duel between Rodney, KGV et al and her sister ship.

On paper at least, Iowa was also despatched to Argentia in August the same year for a similar mission. Nothing came of it either.

One of the difficulties was the narrow waters that Tirpitz would need to negotiate. Depending on the course set, one of the fleets would need to risk coming dangerously close to land based air attack.

July, 1943...You have confused Operation FH with Operation Governor.

Problem was this would not have likely resulted in a one on one, as the two main Allied forces were each composed of 2 battleships and 1 carrier plus escorts.

Agreed with your analysis on the force composition. In fact, I posted a similar thought earlier in the thread. Was just trying to offer some concept that the Allies had actively sought a way to sink the Tirpitz by conventional means; but the DKM would not come out to play.

Sorry for the date mix-up though.

[Nautilus]

Logical scenarios:

1. The USN assigns, no matter the reason, as in Real Life there was none, a flotilla of BBs to escort a convoy to Britain as of 1941. Which means on one side a North Carolina class BB, 1 or 2 heavy cruisers plus a destroyer escort of 3-4 vessels. On the other side, Bismarck, Prinz Eugen, 3-4 destroyers. (But North Carolinas were not in full commission in May 1941, due to propeller problems.

2. At least one Iowa gets commissioned in late 1943 and gets assigned to convoy duty in the Arctic. This means on one side Iowa, a KGV- class BB, 3-4 British cruisers and a destroyer escort, on the other side Tirpitz, Scharnhorst, 1 heavy cruiser and a destroyer escort.

Of course, if H39 gets built, if a H41 meets a Montana, the possibilities are endless

There was one opportunity for a gun battle vs Tirpitz. USS Alabama was despatched as part of a USN/RN task force in June 1943 as part of an attempt to lure Tirpitz into open waters. But Tirpitz did not fall for the bait, likely remembering the outcome of an unequal duel between Rodney, KGV et al and her sister ship.

Operation Governor aimed to catch a German fleet (Tirpitz, Scharnhorst, Lützow and 11 destroyers) between a "hammer" (HMS Anson, USS Alabama BB-60, HMS Illustrious plus 7 destroyers) and an "anvil" (USS South Dakota BB-57, HMS Duke of York, HMS Unicorn, HMS Bermuda plus 9 destroyers), which would result in a German defeat no matter what.

A Bismarck-class BB, if used properly and not exposed to unnecessary risk, could withstand two similar BB opponents as happened against HMS PoW and HMS Hood. But four of them together, plus two carrier air wings, there's no way out. Of course, Scharnhorst and Lützow could do a lot of major damage with 15 x 28cm guns, but while cruisers, destroyers and BB lighter-armored parts could not resist their shells, neither could they survive a major air attack or 16in pounding.

As the Germans could crack most British Naval ciphers and they expected such a trap, they didn't take the bait.

[Thoddy]

Bismarck class had some disadvantage over any potential USN opponent,

may I ask for the "any" disadvantages?

...neither the Americans planned the Iowas or North Carolinas to fight in the North Sea...

...neither the Germans planned the Bismarcks for use in the North Sea...

[Thoddy]

double post

[Nautilus]

Bismarck class had some disadvantage over any potential USN opponent,

may I ask for the "any" disadvantages?

All potential USN opponents (BBs designed after WWI) mounted either 16in/45 guns or 16in/50 guns. No dreadnought ever commissioned in the USN had 15in guns and the 14in were already called obsolete in WWI.

Bismarck had performed sea trials from September 15, 1940 to December 9, 1940, after which she became fully operational. So, as of the winter of 1940-1941, USN modern battleships were as following:

- USS Colorado BB-45, USS Maryland BB-46 and USS West Virginia BB-48 were in the Pacific;
- USS North Carolina BB-55 was fitting out in New York Naval Shipyard;
- USS Washington BB-56 was fitting out in Philadelphia Naval Shipyard;
- building work on USS Iowa BB-61 had just commenced;
- USS South Dakota BB-57 was still on the slipway.

[Takao]

Bismarck class had some disadvantage over any potential USN opponent,

may I ask for the "any" disadvantages?

All potential USN opponents (BBs designed after WWI) mounted either 16in/45 guns or 16in/50 guns. No dreadnought ever commissioned in the USN had 15in guns and the 14in were already called obsolete in WWI.

Bismarck had performed sea trials from September 15, 1940 to December 9, 1940, after which she became fully operational. So, as of the winter of 1940-1941, USN modern battleships were as following:

- USS Colorado BB-45, USS Maryland BB-46 and USS West Virginia BB-48 were in the Pacific;
- USS North Carolina BB-55 was fitting out in New York Naval Shipyard;
- USS Washington BB-56 was fitting out in Philadelphia Naval Shipyard;
- building work on USS Iowa BB-61 had just commenced;
- USS South Dakota BB-57 was still on the slipway.

Well, the Colorado's were a WWI design, not post-WW1. Maryland was began construction in 1917, although the rest of the class was not laid down until 1919, it was still a WW1 design.

[Nautilus]

But, as of late 1940, the Colorados were the only modern enough class in commission, with guns, armor and carefully designed hull subdivision to withstand a modern opponent.

As they were not deployed in the Atlantic while the "neutrality" shifted step by step towards conflict, this only proves the USN Admirals did not see a clash with German capital ships a serious possibility.

[Thoddy]

Performance of the 16" 2,240 lb projectile at about 20 kyard= 18.560 m (based on USN fireeffect tables) tabulated data from Navweaps.com
-vertical penetration 16" =406 mm
-horizontal pentration 2"= 51 mm

West Virginia a ship of the Colorado class was estimated possessing an
-inner limit of imunity for its belt of 25,700 yds (23,4 km);
-and a outer limit for its main and second deck of 15,500 yds (14,1 km);
versus its own guns as per memorandum report "Battleships - Protection Characteristics", Bureau of Ships 13th July 1942
In WW2 no immunity zone versus its own guns.

Comparative performance of the 38 cm Psgr zu 800 kg at 18.500 m derived from penetration charts Unterlagen zur Bestimmung der Hauptkampfentfernung Schlachtschiffe Bismarck
-vertical penetration ~435 mm
-horizontal penetration und Tirpitz >60 mm (the chart ends at 20 degrees Auftreffwinkel(90°= perpendicular to plate) = 70 degrees obliquity

The german shell appears as the better penetrator at all ranges and the german shell has more explosive effect.
-explosive charge of the 2,240 lb shell 15,2 kg
-explosive charge of the german shell 18,8 kg

Nominally the german ship possess much better vertical and horizontal protection and I do not consider differing qualities of the armor

Coloradoclass was significantly slower, therfore the german ships was able to choose favorable engagement conditions.
The US 16" /45 gun had lower range

Based on numerical values the Colorado class should be in serious trouble in a 1 vs 1 situation.
That of course, doesnt mean that Bismarck wins a confrontation under all circumstances. But the odds are against a Colorado class BB in such confrontation.
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Ballistic protection of Colorado class was designed with performance of WW1 shells in mind
The old Mk 3 AP- shell was able to penetrate 14.8" = 376 mm at 16,000 yards and 11.5 " at 20,000 yards, distances, wich were considered, as long respectivley as extreme long range in WW1.

The german ship was designed considering the improved capabilites of AP shells of the thirties as well as improved fire control at longer ranges, -in short- IZ in between 20 km - 30 km (Kriegsspiel 1938/39) against its own guns based on nominal thicknesses of ballistic protection for vital parts of the ship...
But - with a supplementary comment in the textbook of the "Unterlagen zur Bestimmung der Hauptkampfentfernung" - the belt-slope-triangle offers additonal protection against vertical attack/penetration into vital parts of the ship at the intended combat distances. The combat distances they intended to fight with Bismarck type battleships were usually in the order of 12 km - 18 km.
Penetration capabilites of modern projectiles also likely requires larger target angles to increase protection but, this may lead to considerably reduced battledistances within minutes(Kriesspiel 1938/39). And what happens then...
(the germans tested their own as well as known foreign armor schemes against full sized ballistic attack at realistic impact conditions)