There is no point in building 6 battleships. They will be hugely outmatched by the UK, US or Japan. Essentially useless.
Set 2 main objectives;
1. Deny the Indian Ocean to the UK
2. Deny the Pacific to the US and Japan
Both things call for long range but not necessarily high speed. Your treaty cruiser is armed with 8x8" guns. Your ship should be armed with a larger weapon to combat this. 6x254mm should be adequate against CAs. A few secondary weapons as well. We'll throw in a few aircraft. 4 scouts will enable this ship to; find targets; find raiders. A strike group of 12 or more torpedo bombers will be enough to destroy a single ship. If its a merchant vessel close to gun range and sink her. If its a cruiser cripple her with torpedoes rather than risk shell hits. Build 10 or more of these vessels and don't build battleships, carriers or large cruisers.
Something like this;
Alexander Schlosser, Germany Fleuzer laid down 1938
Displacement:
19 945 t light; 20 684 t standard; 22 935 t normal; 24 735 t full load
Dimensions: Length overall / water x beam x draught
740,22 ft / 718,50 ft x 75,95 ft (Bulges 81,86 ft) x 26,25 ft (normal load)
225,62 m / 219,00 m x 23,15 m (Bulges 24,95 m) x 8,00 m
Armament:
6 - 9,45" / 240 mm guns (2x3 guns), 420,00lbs / 190,51kg shells, 1938 Model
Breech loading guns in turrets (on barbettes)
on centreline, all forward
14 - 5,00" / 127 mm guns (7x2 guns), 61,00lbs / 27,67kg shells, 1938 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread, 1 raised mount
16 - 1,46" / 37,0 mm guns (8x2 guns), 1,64lbs / 0,74kg shells, 1938 Model
Dual purpose guns in deck mounts
on side, evenly spread, 2 raised mounts
30 - 0,79" / 20,0 mm guns (12 mounts), 0,32lbs / 0,15kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 5 raised mounts
Weight of broadside 3 410 lbs / 1 547 kg
Shells per gun, main battery: 140
8 - 17,7" / 450 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 7,87" / 200 mm 459,32 ft / 140,00 m 11,48 ft / 3,50 m
Ends: Unarmoured
Upper: 1,97" / 50 mm 442,91 ft / 135,00 m 11,32 ft / 3,45 m
Main Belt covers 98 % of normal length
- Torpedo Bulkhead and Bulges:
1,57" / 40 mm 492,13 ft / 150,00 m 22,15 ft / 6,75 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 7,09" / 180 mm 3,54" / 90 mm 7,48" / 190 mm
2nd: 0,47" / 12 mm 0,16" / 4 mm 0,98" / 25 mm
3rd: 0,20" / 5 mm - -
4th: 0,20" / 5 mm - -
- Armour deck: 3,35" / 85 mm, Conning tower: 1,97" / 50 mm
Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 116 339 shp / 86 789 Kw = 32,00 kts
Range 12 000nm at 15,00 kts
Bunker at max displacement = 4 051 tons
Complement:
931 - 1 211
Cost:
£8,483 million / $33,931 million
Distribution of weights at normal displacement:
Armament: 430 tons, 1,9 %
Armour: 5 723 tons, 25,0 %
- Belts: 2 160 tons, 9,4 %
- Torpedo bulkhead: 635 tons, 2,8 %
- Armament: 509 tons, 2,2 %
- Armour Deck: 2 385 tons, 10,4 %
- Conning Tower: 34 tons, 0,1 %
Machinery: 3 186 tons, 13,9 %
Hull, fittings & equipment: 9 406 tons, 41,0 %
Fuel, ammunition & stores: 2 990 tons, 13,0 %
Miscellaneous weights: 1 200 tons, 5,2 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
50 862 lbs / 23 070 Kg = 120,6 x 9,4 " / 240 mm shells or 6,8 torpedoes
Stability (Unstable if below 1.00): 1,21
Metacentric height 4,7 ft / 1,4 m
Roll period: 15,9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,46
Seaboat quality (Average = 1.00): 2,00
Hull form characteristics:
Hull has rise aft of midbreak, low quarterdeck
and transom stern
Block coefficient: 0,520
Length to Beam Ratio: 8,78 : 1
'Natural speed' for length: 30,84 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 30,00 degrees
Stern overhang: 6,56 ft / 2,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 26,25 ft / 8,00 m
- Forecastle (15 %): 18,04 ft / 5,50 m
- Mid (29 %): 18,86 ft / 5,75 m (38,55 ft / 11,75 m aft of break)
- Quarterdeck (5 %): 18,04 ft / 5,50 m (38,55 ft / 11,75 m before break)
- Stern: 17,22 ft / 5,25 m
- Average freeboard: 32,11 ft / 9,79 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 89,7 %
- Above water (accommodation/working, high = better): 256,3 %
Waterplane Area: 38 530 Square feet or 3 580 Square metres
Displacement factor (Displacement / loading): 137 %
Structure weight / hull surface area: 132 lbs/sq ft or 644 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,89
- Longitudinal: 2,86
- Overall: 1,00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather