The J/CA/1933 design

The J/CA/1933 design was converted to be flush-decked with a higher speed (36 knots). The range is still 10,000nm at 15 knots, although I experimented with lowering the range to 9,500nm and then to 9,000nm. The light AA armament is increased with the non-standard twin 57mm AA guns. The ship is now a much better seaboat and has a 14.5 second roll period, which is better. This is the Springsharp report:

J/CA/1933, Japan Heavy Cruiser laid down 1933 (Engine 1942)

Displacement:
 14,836 t light; 15,400 t standard; 17,000 t normal; 18,280 t full load

Dimensions: Length overall / water x beam x draught
 687.89 ft / 682.00 ft x 64.00 ft x 23.00 ft (normal load)
 209.67 m / 207.87 m x 19.51 m  x 7.01 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1933 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      8 - 4.70" / 119 mm guns in single mounts, 51.91lbs / 23.55kg shells, 1933 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      36 - 2.24" / 57.0 mm guns (18x2 guns), 5.65lbs / 2.56kg shells, 1933 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 12 raised mounts - superfiring
 Weight of broadside 3,179 lbs / 1,442 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 184,611 shp / 137,720 Kw = 36.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,881 tons

Complement:
 743 - 967

Cost:
 £7.224 million / $28.897 million

Distribution of weights at normal displacement:
 Armament: 397 tons, 2.3 %
 Armour: 2,995 tons, 17.6 %
    - Belts: 1,044 tons, 6.1 %
    - Torpedo bulkhead: 333 tons, 2.0 %
    - Armament: 388 tons, 2.3 %
    - Armour Deck: 1,173 tons, 6.9 %
    - Conning Tower: 57 tons, 0.3 %
 Machinery: 4,823 tons, 28.4 %
 Hull, fittings & equipment: 6,621 tons, 38.9 %
 Fuel, ammunition & stores: 2,164 tons, 12.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   17,723 lbs / 8,039 Kg = 69.2 x 8.0 " / 203 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.17
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.5 seconds
 Steadiness - As gun platform (Average = 50 %): 58 %
   - Recoil effect (Restricted arc if above 1.00): 0.73
 Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.593
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 26.12 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  33.00 ft / 10.06 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.64 ft / 7.82 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 160.0 %
  - Above water (accommodation/working, high = better): 136.2 %
 Waterplane Area: 31,706 Square feet or 2,946 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 117 lbs/sq ft or 573 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.75
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent