Reducing the maximum speed to 30 knots improves the design

Reducing the maximum speed to 30 knots helps the design that I had just presented. I was able to increase the protection to an 8in belt and increase the range to 5,200 nm. Admittedly, the Germans never adopted the "all-or-nothing" protection scheme, but it had already been invented by 1915. You just have to allow for high-power machinery. The main armament 8-15in guns is in twin-superfiring turrets. The secondary armament of 12-6in guns is in shields on the forecastle deck. This is the revised Springsharp report:

Ger/CB/1915 Design Study, Germany Battlecruiser laid down 1915 (Engine 1945)

Displacement:
 24,103 t light; 25,132 t standard; 26,250 t normal; 27,144 t full load

Dimensions: Length overall / water x beam x draught
 700.00 ft / 700.00 ft x 90.00 ft x 26.50 ft (normal load)
 213.36 m / 213.36 m x 27.43 m  x 8.08 m

Armament:
      8 - 13.50" / 343 mm guns (2x4 guns), 1,230.19lbs / 558.00kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 1 raised mount
   Main guns limited to end-on fire
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1915 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 11,138 lbs / 5,052 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 460.00 ft / 140.21 m 17.00 ft / 5.18 m
 Ends: Unarmoured
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 460.00 ft / 140.21 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 3.00" / 76 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 117,273 shp / 87,486 Kw = 30.00 kts
 Range 5,200nm at 15.00 kts
 Bunker at max displacement = 2,012 tons

Complement:
 1,030 - 1,340

Cost:
 £3.531 million / $14.124 million

Distribution of weights at normal displacement:
 Armament: 1,392 tons, 5.3 %
 Armour: 7,424 tons, 28.3 %
    - Belts: 2,667 tons, 10.2 %
    - Torpedo bulkhead: 851 tons, 3.2 %
    - Armament: 1,313 tons, 5.0 %
    - Armour Deck: 2,441 tons, 9.3 %
    - Conning Tower: 152 tons, 0.6 %
 Machinery: 2,961 tons, 11.3 %
 Hull, fittings & equipment: 12,325 tons, 47.0 %
 Fuel, ammunition & stores: 2,147 tons, 8.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   40,780 lbs / 18,497 Kg = 33.1 x 13.5 " / 343 mm shells or 5.9 torpedoes
 Stability (Unstable if below 1.00): 1.08
 Metacentric height 4.9 ft / 1.5 m
 Roll period: 17.0 seconds
 Steadiness - As gun platform (Average = 50 %): 65 %
   - Recoil effect (Restricted arc if above 1.00): 1.01
 Seaboat quality  (Average = 1.00): 1.30

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.550
 Length to Beam Ratio: 7.78 : 1
 'Natural speed' for length: 26.46 kts
 Power going to wave formation at top speed: 54 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -2.00 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 %): 29.00 ft / 8.84 m
    - Mid (67 %):  29.00 ft / 8.84 m (21.00 ft / 6.40 m aft of break)
    - Quarterdeck (15 %): 21.00 ft / 6.40 m
    - Stern:  21.00 ft / 6.40 m
    - Average freeboard: 26.68 ft / 8.13 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 98.1 %
  - Above water (accommodation/working, high = better): 217.8 %
 Waterplane Area: 43,980 Square feet or 4,086 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 187 lbs/sq ft or 914 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.83
  - 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