The Ultimate Japanese Battlecruiser: J/CB/1941

The J/CB/1941 is a very large ship that is still extremely capable. I would argue that the large battlecruiser of this type, that is well-protected, is analogous to the Iowa class battleships. They are fast, well-armed, adequately protected, and have great strategic mobility. This design is significant in that it uses the 21in gun for the main armament. This is the Springsharp report:

J/CB/1941, Japan Battlecruiser laid down 1941

Displacement:
 92,016 t light; 96,104 t standard; 102,200 t normal; 107,077 t full load

Dimensions: Length overall / water x beam x draught
 1,041.78 ft / 1,035.00 ft x 128.00 ft x 35.00 ft (normal load)
 317.54 m / 315.47 m x 39.01 m  x 10.67 m

Armament:
      8 - 21.00" / 533 mm guns (4x2 guns), 4,630.50lbs / 2,100.36kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 6.00" / 152 mm guns (4x3 guns), 108.00lbs / 48.99kg shells, 1941 Model
   Quick firing guns in turrets (on barbettes)
   on side, all amidships
      24 - 5.00" / 127 mm guns (12x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      64 - 2.24" / 57.0 mm guns (32x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 18 raised mounts
 Weight of broadside 40,202 lbs / 18,235 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 15.0" / 381 mm 680.00 ft / 207.26 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 680.00 ft / 207.26 m 8.00 ft / 2.44 m
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 680.00 ft / 207.26 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 12.0" / 305 mm  15.0" / 381 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 8.00" / 203 mm, Conning tower: 15.00" / 381 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 374,336 shp / 279,255 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,972 tons

Complement:
 2,857 - 3,715

Cost:
 £54.565 million / $218.260 million

Distribution of weights at normal displacement:
 Armament: 5,025 tons, 4.9 %
 Armour: 38,598 tons, 37.8 %
    - Belts: 6,730 tons, 6.6 %
    - Torpedo bulkhead: 6,844 tons, 6.7 %
    - Armament: 7,591 tons, 7.4 %
    - Armour Deck: 16,726 tons, 16.4 %
    - Conning Tower: 706 tons, 0.7 %
 Machinery: 9,893 tons, 9.7 %
 Hull, fittings & equipment: 38,501 tons, 37.7 %
 Fuel, ammunition & stores: 10,184 tons, 10.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   152,591 lbs / 69,214 Kg = 33.0 x 21.0 " / 533 mm shells or 29.8 torpedoes
 Stability (Unstable if below 1.00): 1.14
 Metacentric height 9.3 ft / 2.8 m
 Roll period: 17.6 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.76
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.771
 Length to Beam Ratio: 8.09 : 1
 'Natural speed' for length: 32.17 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 6.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.56 ft / 9.01 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 81.3 %
  - Above water (accommodation/working, high = better): 218.5 %
 Waterplane Area: 113,017 Square feet or 10,500 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 255 lbs/sq ft or 1,246 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.04
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent