The US/CL/1941 design

The main improvement in the US/CL/1941 design is a 4in armoured deck. The other improvement is a modern LAA armament, with 12-5in DP, 48-40mm AA, and 24-2omm AA guns. A distortion, because of Springsharp, is that the beam is reduced. Springsharp rewards that with increased strength and seakeeping capability. This is the Springsharp report:

US/CL/1941, United States Light Cruiser laid down 1941 (Engine 1950)

Displacement:
 16,624 t light; 17,222 t standard; 18,750 t normal; 19,972 t full load

Dimensions: Length overall / water x beam x draught
 688.80 ft / 684.00 ft x 63.00 ft x 26.00 ft (normal load)
 209.95 m / 208.48 m x 19.20 m  x 7.92 m

Armament:
      15 - 6.00" / 152 mm guns (5x3 guns), 108.00lbs / 48.99kg shells, 1941 Model
   Quick firing guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      48 - 1.57" / 40.0 mm guns (12x4 guns), 1.95lbs / 0.89kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, evenly spread, 8 raised mounts
      24 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1941 Model
   Breech loading guns in deck mounts 
   on side, evenly spread, 16 raised mounts
 Weight of broadside 2,470 lbs / 1,120 kg
 Shells per gun, main battery: 150
 12 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 146 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 650.00 ft / 198.12 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  4.00" / 102 mm
 2nd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

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

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 189,631 shp / 141,465 Kw = 37.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 2,750 tons

Complement:
 800 - 1,041

Cost:
 £9.126 million / $36.504 million

Distribution of weights at normal displacement:
 Armament: 309 tons, 1.6 %
 Armour: 5,296 tons, 28.2 %
    - Belts: 1,632 tons, 8.7 %
    - Torpedo bulkhead: 601 tons, 3.2 %
    - Armament: 604 tons, 3.2 %
    - Armour Deck: 2,398 tons, 12.8 %
    - Conning Tower: 61 tons, 0.3 %
 Machinery: 4,537 tons, 24.2 %
 Hull, fittings & equipment: 6,483 tons, 34.6 %
 Fuel, ammunition & stores: 2,126 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,699 lbs / 10,750 Kg = 219.4 x 6.0 " / 152 mm shells or 2.8 torpedoes
 Stability (Unstable if below 1.00): 1.13
 Metacentric height 3.1 ft / 1.0 m
 Roll period: 14.9 seconds
 Steadiness - As gun platform (Average = 50 %): 50 %
   - Recoil effect (Restricted arc if above 1.00): 0.54
 Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.586
 Length to Beam Ratio: 10.86 : 1
 'Natural speed' for length: 29.41 kts
 Power going to wave formation at top speed: 62 %
 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:  32.00 ft / 9.75 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.64 ft / 7.51 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 134.5 %
  - Above water (accommodation/working, high = better): 149.6 %
 Waterplane Area: 32,402 Square feet or 3,010 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 114 lbs/sq ft or 556 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.64
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent