The J/CB/1923 design

The J/CB/1923 design ballooned considerably over the corresponding battleship design. That was mostly driven by the desire for a 33-knot speed. Very likely, the design is not very well-protected against gunfire, but it is a battlecruiser so we would accept that as the price for speed and gunpower. The armour design is somewhat different from the J/BB/1923 design in that the deck is thicker. The range was also extended to 12,000nm at 15 knots, as befitted a ship that would be a fast wing of the battlefleet, able to make long strategic moves. This is the Springsharp report:

J/CB/1923, Japan Battlecruiser laid down 1923

Displacement:
 72,137 t light; 75,354 t standard; 81,455 t normal; 86,337 t full load

Dimensions: Length overall / water x beam x draught
 978.06 ft / 975.00 ft x 118.00 ft x 35.00 ft (normal load)
 298.11 m / 297.18 m x 35.97 m  x 10.67 m

Armament:
      10 - 18.00" / 457 mm guns (4 mounts), 2,916.00lbs / 1,322.68kg shells, 1923 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1923 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 8 raised mounts - superfiring
      12 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1923 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, 6 raised mounts
      32 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1923 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 31,295 lbs / 14,195 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 660.00 ft / 201.17 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 10.0" / 254 mm 660.00 ft / 201.17 m 8.00 ft / 2.44 m
   Main Belt covers 104 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 660.00 ft / 201.17 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 14.0" / 356 mm 11.0" / 279 mm  14.0" / 356 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 322,007 shp / 240,217 Kw = 33.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,983 tons

Complement:
 2,410 - 3,134

Cost:
 £21.287 million / $85.149 million

Distribution of weights at normal displacement:
 Armament: 3,912 tons, 4.8 %
 Armour: 27,829 tons, 34.2 %
    - Belts: 5,520 tons, 6.8 %
    - Torpedo bulkhead: 3,321 tons, 4.1 %
    - Armament: 6,435 tons, 7.9 %
    - Armour Deck: 12,027 tons, 14.8 %
    - Conning Tower: 526 tons, 0.6 %
 Machinery: 10,762 tons, 13.2 %
 Hull, fittings & equipment: 29,634 tons, 36.4 %
 Fuel, ammunition & stores: 9,318 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   102,797 lbs / 46,628 Kg = 35.3 x 18.0 " / 457 mm shells or 15.1 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 8.1 ft / 2.5 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.708
 Length to Beam Ratio: 8.26 : 1
 'Natural speed' for length: 31.22 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  35.00 ft / 10.67 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (67 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.64 ft / 8.42 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 95.2 %
  - Above water (accommodation/working, high = better): 198.2 %
 Waterplane Area: 92,874 Square feet or 8,628 Square metres
 Displacement factor (Displacement / loading): 101 %
 Structure weight / hull surface area: 232 lbs/sq ft or 1,132 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.02
  - Longitudinal: 0.99
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent