An upgunned Koenig class battleship

I thought that a Springsharp design for a 17in-gunned Koenig class battleship would be interesting. I was pleased that 8-17in guns was possible. I had expected to have to accept 6-17in guns. You can judge if what I have done was reasonable. The hull is bulged and new barbettes and gun turrets are required. This is the Springsharp report:

Koenig class-upgunned, Germany Battleship laid down 1911 (Engine 1912)

Displacement:
 25,534 t light; 27,184 t standard; 29,500 t normal; 31,353 t full load

Dimensions: Length overall / water x beam x draught
 579.72 ft / 573.16 ft x 96.78 ft (Bulges 100.07 ft) x 31.17 ft (normal load)
 176.70 m / 174.70 m x 29.50 m (Bulges 30.50 m)  x 9.50 m

Armament:
      8 - 16.93" / 430 mm guns (4x2 guns), 2,425.91lbs / 1,100.37kg shells, 1911 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount - superfiring
      14 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1911 Model
   Quick firing guns in casemate mounts 
   on side, all amidships
      4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1911 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 20,932 lbs / 9,495 kg
 Shells per gun, main battery: 90
 5 - 19.7" / 500 mm submerged torpedo tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.8" / 350 mm 344.49 ft / 105.00 m 9.84 ft / 3.00 m
 Ends: Unarmoured
 Upper: 7.09" / 180 mm 344.49 ft / 105.00 m 9.84 ft / 3.00 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead and Bulges:
  1.57" / 40 mm 344.49 ft / 105.00 m 31.17 ft / 9.50 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 11.8" / 300 mm 5.91" / 150 mm  11.8" / 300 mm
 2nd: 6.69" / 170 mm 1.18" / 30 mm  1.57" / 40 mm

   - Armour deck: 2.36" / 60 mm, Conning tower: 11.81" / 300 mm

Machinery:
 Coal and oil fired boilers, steam turbines, 
 Direct drive, 3 shafts, 34,844 shp / 25,994 Kw = 21.00 kts
 Range 8,000nm at 12.00 kts
 Bunker at max displacement = 4,168 tons (80% coal)

Complement:
 1,125 - 1,463

Cost:
 £3.301 million / $13.205 million

Distribution of weights at normal displacement:
 Armament: 2,617 tons, 8.9 %
 Armour: 8,945 tons, 30.3 %
    - Belts: 3,175 tons, 10.8 %
    - Torpedo bulkhead: 626 tons, 2.1 %
    - Armament: 3,165 tons, 10.7 %
    - Armour Deck: 1,736 tons, 5.9 %
    - Conning Tower: 243 tons, 0.8 %
 Machinery: 1,498 tons, 5.1 %
 Hull, fittings & equipment: 12,475 tons, 42.3 %
 Fuel, ammunition & stores: 3,966 tons, 13.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   34,533 lbs / 15,664 Kg = 14.2 x 16.9 " / 430 mm shells or 5.0 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 6.1 ft / 1.9 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.89
 Seaboat quality  (Average = 1.00): 1.63

Hull form characteristics:
 Hull has rise forward of midbreak, low quarterdeck 
 Block coefficient: 0.578
 Length to Beam Ratio: 5.73 : 1
 'Natural speed' for length: 23.94 kts
 Power going to wave formation at top speed: 45 %
 Trim (Max stability = 0, Max steadiness = 100): 33
 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:  26.25 ft / 8.00 m
    - Forecastle (20 %): 24.61 ft / 7.50 m
    - Mid (72 %):  24.61 ft / 7.50 m (14.76 ft / 4.50 m aft of break)
    - Quarterdeck (15 %): 14.76 ft / 4.50 m (16.40 ft / 5.00 m before break)
    - Stern:  14.76 ft / 4.50 m
    - Average freeboard: 22.09 ft / 6.73 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 107.7 %
  - Above water (accommodation/working, high = better): 153.4 %
 Waterplane Area: 39,730 Square feet or 3,691 Square metres
 Displacement factor (Displacement / loading): 90 %
 Structure weight / hull surface area: 217 lbs/sq ft or 1,061 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.91
  - Longitudinal: 2.15
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather