My attempt at a German L20b battleship

I own the book Deutsche Grosskampfschiffe 1915-1918, by Friedrich Forstmeier and Siegfried Breyer. That book has inboard profiles, dimensions, and armour specifications for the various German capital ship projects in the Dreadnought era. One interesting ship is the L20b design with 8-16.5in guns. This is my attempt at the design in Springsharp, although the displacement is greatly inflated and the draft increased to achieve adequate strength:

L20b, Germany Battleship laid down 1918

Displacement:
 41,346 t light; 43,380 t standard; 46,500 t normal; 48,996 t full load

Dimensions: Length overall / water x beam x draught
 772.25 ft / 771.00 ft x 104.99 ft x 31.17 ft (normal load)
 235.38 m / 235.00 m x 32.00 m  x 9.50 m

Armament:
      8 - 16.54" / 420 mm guns (4x2 guns), 2,260.56lbs / 1,025.37kg shells, 1918 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1918 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
   12 guns in hull casemates - Limited use in heavy seas
      8 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1918 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 19,603 lbs / 8,892 kg
 Shells per gun, main battery: 100
 5 - 23.6" / 600 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 577.43 ft / 176.00 m 9.84 ft / 3.00 m
 Ends: 5.12" / 130 mm 114.83 ft / 35.00 m 9.84 ft / 3.00 m
   78.74 ft / 24.00 m Unarmoured ends
 Upper: 9.84" / 250 mm 577.43 ft / 176.00 m 9.84 ft / 3.00 m
   Main Belt covers 115 % of normal length

   - Torpedo Bulkhead:
  2.36" / 60 mm 577.43 ft / 176.00 m 29.53 ft / 9.00 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.8" / 350 mm 9.84" / 250 mm  13.8" / 350 mm
 2nd: 6.69" / 170 mm 6.69" / 170 mm  1.50" / 38 mm

   - Armour deck: 5.91" / 150 mm, Conning tower: 15.75" / 400 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Geared drive, 4 shafts, 55,778 shp / 41,610 Kw = 22.50 kts
 Range 5,600nm at 15.00 kts
 Bunker at max displacement = 5,616 tons (100% coal)

Complement:
 1,583 - 2,058

Cost:
 £7.631 million / $30.522 million

Distribution of weights at normal displacement:
 Armament: 2,450 tons, 5.3 %
 Armour: 18,908 tons, 40.7 %
    - Belts: 5,852 tons, 12.6 %
    - Torpedo bulkhead: 1,490 tons, 3.2 %
    - Armament: 4,383 tons, 9.4 %
    - Armour Deck: 6,744 tons, 14.5 %
    - Conning Tower: 439 tons, 0.9 %
 Machinery: 2,213 tons, 4.8 %
 Hull, fittings & equipment: 17,774 tons, 38.2 %
 Fuel, ammunition & stores: 5,154 tons, 11.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   84,648 lbs / 38,396 Kg = 37.4 x 16.5 " / 420 mm shells or 14.6 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 6.6 ft / 2.0 m
 Roll period: 17.1 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.83
 Seaboat quality  (Average = 1.00): 1.65

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.645
 Length to Beam Ratio: 7.34 : 1
 'Natural speed' for length: 27.77 kts
 Power going to wave formation at top speed: 39 %
 Trim (Max stability = 0, Max steadiness = 100): 39
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: -6.56 ft / -2.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.53 ft / 9.00 m
    - Mid (60 %):  29.53 ft / 9.00 m (19.69 ft / 6.00 m aft of break)
    - Quarterdeck (15 %): 19.69 ft / 6.00 m
    - Stern:  19.69 ft / 6.00 m
    - Average freeboard: 26.11 ft / 7.96 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 70.9 %
  - Above water (accommodation/working, high = better): 191.2 %
 Waterplane Area: 61,730 Square feet or 5,735 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 204 lbs/sq ft or 997 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.42
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather