The drawing is ok Nighthunter, but I am not sold on it being a Deutschland killer, I would rate its chances as only 50/50 in a one on one battle.
The Wichita is credited with a 6.4" strake of belt armour, but as you can see from your drawing, that armour only covers the boilers and engine rooms and is very narrow. Reading the service record in Wiki, the Wichita was hit with a 4-5" shell 5 foot below the waterline which pierced the side and damaged a fuel tank. Taking that further it would mean that the magazines are not heavily protected and are a vulnerable point. The Deutschlands 11" guns would be capable of penetrating about 95% of the available target. Your 12" would have the same penetration ability on the Deutschland. However the range of the 11" on the Deutschland was 40,000 yards. The original twin 12" on yours only fired 24,000 yards, and even with increasing the elevation a bit you might make 30,000 yards. That's 10,000 yards you could be under fire for, before your guns could open fire. You had better hope for some bad weather and 25,000 yard ranges. Also the extra weight of the 12" gun installation would slow your ship down. The Wichita is credited with 100,000 for 33 knots, that would probably reduce to 30-31 knots. Add some extra armour and that speed would drop to the point where your ship is not much faster than the Deutschland, and thus the amount of time you could be under fire without reply could see your ship sunk without firing a shot.
For a Wichita type hull and 12", I would increase the length of the hull (and breadth), fit 8x12" (new mark of gun and turret for better range) to give a firepower superiority, enlarge the armour scheme by a lot, increase the propulsion systems to take the extra weight, use the extra length to improve your secondaries to 4 a side minimum. Lots more of that 6.4" armour belt.
None of the guns on any of the ships in this thread (except possibly the French 16") can match the Deutschland for range. So they need to have a marked speed advantage, better armour, and better firepower to be able to sink a Deutschland and not take too much damage themselves.
Hi! My first post.
First of all, let me say the artwork of the ship under discussion (Wichita AU ) is beautiful.
Second of all, the (technical) commentary back and forth is quite good. All I want to do is raise some points that I think might further that discussion a wee bit.
With that in mind I would like to suggest the following addenda;
a. I assume the proviso that this will be pre-radar era hunters and this is a USN ship, the omission of spotter plane scouting and gunnery and the importance of that asset is somewhat surprising to me as a consequence. US warships (cruisers and above) were trained in aircraft spotter co-operation for long range fire against surface targets. This would be over the horizon type shooting. The results of fire director restricted gunfire observed beyond 20,000 meters (OTH) and 30+ seconds flight time was that an alert maneuvering target was almost impossible to hit as you could not predict which way it would zig or zag to dodge your shell ladders. The first long ranged shots had better hit and they better cripple. With that lesson in mind, the Americans designed tight turning warships and only required guns mounted (cruisers and below) that were effective to the observed ship's fire director horizon. Any gunfire 35,000 meters range (~50+ seconds flight time) simply gave an enemy ship too much time to dodge, the second salvo. You had to have aircraft to correct by looking top-down.
b. Part of a USN spotter plane's drill was to feed observation corrections via radio to the firing ship of the target ship's turns and course changes to dodge. This improved accuracy marginally enough to make OTH shooting to cripple worth it. So putting a plane up when encountering suspicious smoke or an RRR signal was almost axiomatic.
c. Given the paucity of long range hits and the penny pinching Congress insisting on long barrel liner wear for the artillery, this would tend to make American naval rifles above 20.3 cm bore of the era to have lower muzzle velocities than Italian, French, or German artillery of similar class. To compensate, the Americans did two things. They designed for the higher working gas pressures anyway as a safety cushion, and they used the higher energies to drive mass instead of achieving velocity for added range. So, if you do use a post 1925 designed gun, you will also use a heavyweight shell (about roughly equivalent kinetically to an early British 13.5 inch bore WWI naval rifle's projectile, but with significantly better accuracy over the length of the effective range, which for
the expected Mark 8 30.5 cm gun was about 35,000 meters maximum and about ~25,000 meters effective.
d. Which brings me to my final point. The Lutzow class ships carried
an inferior naval rifle whose ballistic performance in the shells was no better than the Pre WW I Krupp design it replaced. According to Nathan Okun, the shell fired would have been ineffective at long range (+20,000 meters) in scoring a single crippling hit against a treaty cruiser. The battle of the River Platte seems to confirm that observation. Of course no-one prior to armed contact with a German panzer ship, would know about this model German naval rifles' inaccuracy or of mutual shell interference in flight that added to the surprising single barrel shot inaccuracy or the lack of punch in their shells. Except maybe the Germans would have known that fact, which accounts for instructions to the Scharnhorst and Gneisenau to avoid engagement with anything larger than a heavy cruiser.
While that does not mean the relatively unarmored "Wichita" could or would seriously engage in a single ship duel with a Lutzow, since American hunter groups would have adopted British style tactics to ensure a kill, it does mean that the Lutzow would not actually have the ten thousand meter cushion assumed at all. Not even against American heavy cruisers whose own heavyweight shells would have pierced and entered the German panzer ship's belt armor easily as the ranges fell between 17,000 to 5,000 meters, the purported panzer ship's immunity zone and the effective artillery engagement range those American cruisers' naval rifles were actually designed to fight.