My 1921 battlecruiser design from the Red Book

My 1921-style British battlecruiser from the Red Book sketch and specifications works pretty well. This is a 30-knot design with 9-16in and 20-5in guns. A feature of Springsharp is that hull weights are much greater than I had expected, when I did my designs in the 1970's. This is a much more conventional layout than the actual British 1921 ships, which had the really strange layouts. This is the Springsharp report:

GB/CB/1921, Great Britain Battlecruiser laid down 1921 (Engine 1927)

Displacement:
 45,030 t light; 47,014 t standard; 49,400 t normal; 51,309 t full load

Dimensions: Length overall / water x beam x draught
 856.73 ft / 855.00 ft x 105.00 ft x 33.30 ft (normal load)
 261.13 m / 260.60 m x 32.00 m  x 10.15 m

Armament:
      9 - 16.00" / 406 mm guns (3x3 guns), 2,048.00lbs / 928.96kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 1 raised mount - superfiring
      20 - 5.00" / 127 mm guns (10x2 guns), 62.50lbs / 28.35kg shells, 1921 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 19,682 lbs / 8,928 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 590.00 ft / 179.83 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 10.0" / 254 mm 590.00 ft / 179.83 m 8.00 ft / 2.44 m
   Main Belt covers 106 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 590.00 ft / 179.83 m 32.00 ft / 9.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 10.0" / 254 mm  13.0" / 330 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 13.00" / 330 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 161,662 shp / 120,600 Kw = 30.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 4,294 tons

Complement:
 1,656 - 2,153

Cost:
 £11.091 million / $44.363 million

Distribution of weights at normal displacement:
 Armament: 2,460 tons, 5.0 %
 Armour: 17,352 tons, 35.1 %
    - Belts: 4,897 tons, 9.9 %
    - Torpedo bulkhead: 2,096 tons, 4.2 %
    - Armament: 4,031 tons, 8.2 %
    - Armour Deck: 5,952 tons, 12.0 %
    - Conning Tower: 377 tons, 0.8 %
 Machinery: 5,103 tons, 10.3 %
 Hull, fittings & equipment: 20,114 tons, 40.7 %
 Fuel, ammunition & stores: 4,370 tons, 8.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   71,260 lbs / 32,323 Kg = 34.8 x 16.0 " / 406 mm shells or 11.0 torpedoes
 Stability (Unstable if below 1.00): 1.05
 Metacentric height 5.9 ft / 1.8 m
 Roll period: 18.2 seconds
 Steadiness - As gun platform (Average = 50 %): 69 %
   - Recoil effect (Restricted arc if above 1.00): 0.95
 Seaboat quality  (Average = 1.00): 1.38

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.578
 Length to Beam Ratio: 8.14 : 1
 'Natural speed' for length: 29.24 kts
 Power going to wave formation at top speed: 49 %
 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:  33.00 ft / 10.06 m
    - Forecastle (20 %): 27.00 ft / 8.23 m
    - Mid (50 %):  27.00 ft / 8.23 m
    - Quarterdeck (15 %): 27.00 ft / 8.23 m
    - Stern:  27.00 ft / 8.23 m
    - Average freeboard: 27.48 ft / 8.38 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 87.9 %
  - Above water (accommodation/working, high = better): 199.8 %
 Waterplane Area: 64,342 Square feet or 5,978 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 213 lbs/sq ft or 1,039 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.37
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily