The J/CL/1916 design

The goal of the J/CL/1916 design was to reach 33 knots. This design probably needs lighter weight machinery than it currently has. The armament is still the modest 6-5.5in QF guns but with 4-4in AA and 12-57mm AA guns. The torpedo armament is now 6-21in TT. The belt is still 3in and the deck is 1in. This is the Springsharp report:

J/CL/1916, Japan Light Cruiser laid down 1916 (Engine 1923)

Displacement:
 6,595 t light; 6,817 t standard; 7,350 t normal; 7,776 t full load

Dimensions: Length overall / water x beam x draught
 518.36 ft / 515.00 ft x 46.00 ft x 19.00 ft (normal load)
 158.00 m / 156.97 m x 14.02 m  x 5.79 m

Armament:
      6 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1916 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, all amidships
      12 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1916 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships
 Weight of broadside 695 lbs / 315 kg
 Shells per gun, main battery: 180
 6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 405.00 ft / 123.44 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 121 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 3.00" / 76 mm 2.00" / 51 mm  2.00" / 51 mm

   - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 85,627 shp / 63,877 Kw = 33.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 959 tons

Complement:
 396 - 515

Cost:
 £1.153 million / $4.611 million

Distribution of weights at normal displacement:
 Armament: 87 tons, 1.2 %
 Armour: 989 tons, 13.5 %
    - Belts: 588 tons, 8.0 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 65 tons, 0.9 %
    - Armour Deck: 312 tons, 4.2 %
    - Conning Tower: 24 tons, 0.3 %
 Machinery: 2,862 tons, 38.9 %
 Hull, fittings & equipment: 2,657 tons, 36.1 %
 Fuel, ammunition & stores: 755 tons, 10.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   5,216 lbs / 2,366 Kg = 62.7 x 5.5 " / 140 mm shells or 0.8 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 2.3 ft / 0.7 m
 Roll period: 12.8 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.42
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.572
 Length to Beam Ratio: 11.20 : 1
 'Natural speed' for length: 22.69 kts
 Power going to wave formation at top speed: 62 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 3.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  26.00 ft / 7.92 m
    - Forecastle (20 %): 23.00 ft / 7.01 m
    - Mid (67 %):  23.00 ft / 7.01 m (15.00 ft / 4.57 m aft of break)
    - Quarterdeck (15 %): 15.00 ft / 4.57 m
    - Stern:  15.00 ft / 4.57 m
    - Average freeboard: 20.60 ft / 6.28 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 135.5 %
  - Above water (accommodation/working, high = better): 139.2 %
 Waterplane Area: 16,870 Square feet or 1,567 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 79 lbs/sq ft or 385 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.90
  - Longitudinal: 2.40
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily