My Ger/BB/1916 concept with 20in guns

When I was working in Minneapolis, in early 2002, I had this concept for a German battleship that I called the Ger/BB/1916, that had 9-20in guns. This version has a fast battleship speed, at least by American standards in 1940. My sketch design had twin funnels and a tower foremast topped by a gun director with a long rangefinder. This is my Springsharp report:

Ger/BB/1916, Germany Battleship laid down 1916 (Engine 1927)

Displacement:
 70,188 t light; 73,852 t standard; 79,390 t normal; 83,821 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (792.64 ft / 785.00 ft) x 138.00 ft x (38.00 / 39.83 ft)
 (241.60 m / 239.27 m) x 42.06 m  x (11.58 / 12.14 m)

Armament:
      9 - 20.00" / 508 mm 45.0 cal guns - 4,320.00lbs / 1,959.52kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts, 1916 Model
   3 x Single mounts on centreline ends, majority forward
      24 - 5.00" / 127 mm 50.0 cal guns - 66.16lbs / 30.01kg shells, 150 per gun
   Quick firing guns in turret on barbette mounts, 1916 Model
   12 x Twin mounts on sides, evenly spread
  4 raised mounts
      Weight of broadside 40,468 lbs / 18,356 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 20.0" / 508 mm 430.00 ft / 131.06 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 84 % of normal length

   - Torpedo Bulkhead:
  7.00" / 178 mm 430.00 ft / 131.06 m 38.00 ft / 11.58 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 20.0" / 508 mm 15.0" / 381 mm  20.0" / 508 mm
 2nd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm

   - Armoured deck - multiple decks: 8.00" / 203 mm For and Aft decks
 Forecastle: 6.00" / 152 mm  Quarter deck: 8.00" / 203 mm

   - Conning towers: Forward 20.00" / 508 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 160,628 shp / 119,828 Kw = 27.00 kts
 Range 7,500nm at 18.00 kts
 Bunker at max displacement = 9,970 tons

Complement:
 2,364 - 3,074

Cost:
 £10.990 million / $43.961 million

Distribution of weights at normal displacement:
 Armament: 6,867 tons, 8.6 %
 Armour: 32,576 tons, 41.0 %
    - Belts: 6,872 tons, 8.7 %
    - Torpedo bulkhead: 4,232 tons, 5.3 %
    - Armament: 8,512 tons, 10.7 %
    - Armour Deck: 12,165 tons, 15.3 %
    - Conning Tower: 796 tons, 1.0 %
 Machinery: 5,070 tons, 6.4 %
 Hull, fittings & equipment: 25,675 tons, 32.3 %
 Fuel, ammunition & stores: 9,203 tons, 11.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   126,859 lbs / 57,542 Kg = 31.7 x 20.0 " / 508 mm shells or 27.7 torpedoes
 Stability (Unstable if below 1.00): 1.30
 Metacentric height 13.0 ft / 4.0 m
 Roll period: 16.1 seconds
 Steadiness - As gun platform (Average = 50 %): 59 %
   - Recoil effect (Restricted arc if above 1.00): 0.44
 Seaboat quality  (Average = 1.00): 1.18

Hull form characteristics:
 Hull has a flush deck,
   an extended bulbous bow and a cruiser stern
 Block coefficient (normal/deep): 0.675 / 0.680
 Length to Beam Ratio: 5.69 : 1
 'Natural speed' for length: 28.02 kts
 Power going to wave formation at top speed: 53 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 8.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 30.00 %,  33.00 ft / 10.06 m,  26.00 ft / 7.92 m
    - Forward deck: 25.00 %,  26.00 ft / 7.92 m,  23.00 ft / 7.01 m
    - Aft deck: 30.00 %,  23.00 ft / 7.01 m,  23.00 ft / 7.01 m
    - Quarter deck: 15.00 %,  23.00 ft / 7.01 m,  23.00 ft / 7.01 m
    - Average freeboard:  25.12 ft / 7.66 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 72.0 %
  - Above water (accommodation/working, high = better): 162.0 %
 Waterplane Area: 84,899 Square feet or 7,887 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 256 lbs/sq ft or 1,248 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.59
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent