The J/BB/1923 design

The next step seemed to be to increase the number of guns to ten. I would choose to have 2-twin and 2-triple turrets to do that, although the historically correct version might need to have 5 twin turrets. The hull is now flush-decked with a high freeboard. This is the Springsharp report:

J/BB/1923, Japan Battleship laid down 1923

Displacement:
 59,714 t light; 62,646 t standard; 67,200 t normal; 70,843 t full load

Dimensions: Length overall / water x beam x draught
 867.89 ft / 865.00 ft x 112.00 ft x 33.00 ft (normal load)
 264.53 m / 263.65 m x 34.14 m  x 10.06 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: 14.0" / 356 mm 600.00 ft / 182.88 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 10.0" / 254 mm 600.00 ft / 182.88 m 8.00 ft / 2.44 m
   Main Belt covers 107 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 600.00 ft / 182.88 m 32.00 ft / 9.75 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: 6.00" / 152 mm, Conning tower: 14.00" / 356 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 208,789 shp / 155,757 Kw = 30.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 8,198 tons

Complement:
 2,086 - 2,712

Cost:
 £18.481 million / $73.925 million

Distribution of weights at normal displacement:
 Armament: 3,912 tons, 5.8 %
 Armour: 23,776 tons, 35.4 %
    - Belts: 5,264 tons, 7.8 %
    - Torpedo bulkhead: 2,842 tons, 4.2 %
    - Armament: 6,277 tons, 9.3 %
    - Armour Deck: 8,895 tons, 13.2 %
    - Conning Tower: 499 tons, 0.7 %
 Machinery: 6,978 tons, 10.4 %
 Hull, fittings & equipment: 25,048 tons, 37.3 %
 Fuel, ammunition & stores: 7,486 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   85,000 lbs / 38,555 Kg = 29.1 x 18.0 " / 457 mm shells or 12.8 torpedoes
 Stability (Unstable if below 1.00): 1.08
 Metacentric height 6.9 ft / 2.1 m
 Roll period: 17.9 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.94
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.736
 Length to Beam Ratio: 7.72 : 1
 'Natural speed' for length: 29.41 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:  33.00 ft / 10.06 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (67 %):  26.00 ft / 7.92 m
    - Quarterdeck (15 %): 26.00 ft / 7.92 m
    - Stern:  26.00 ft / 7.92 m
    - Average freeboard: 26.56 ft / 8.10 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 94.2 %
  - Above water (accommodation/working, high = better): 190.3 %
 Waterplane Area: 80,136 Square feet or 7,445 Square metres
 Displacement factor (Displacement / loading): 97 %
 Structure weight / hull surface area: 228 lbs/sq ft or 1,114 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.99
  - Longitudinal: 1.12
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent