I am embarrassed to say that I hoped for 46 knots from the Ger/CB/1915 design

I had high hopes, back in the early 1970's, for what I am calling the Ger/CB/1915 Design Study. I hoped for 46 knots at full power, and 47.8 knots on 10% overload. I thought that I should be able to get 385,000 SHP from the powerplant, at 40 SHP/ton. The dimensions were 850ft x 105ft x 26.3ft, with a 50ft hull depth. The armament was 6-18in/45 and 16-5in QF guns. The problem is that in Springsharp, even 38 knots is 354,949 tons. That kills the hull strength and seakeeping ability. I had to settle for 35 knots:

Ger/CB/1915 Design Study, Germany Battlecruiser laid down 1915 (Engine 1950)

Displacement:
 35,546 t light; 37,147 t standard; 38,500 t normal; 39,582 t full load

Dimensions: Length overall / water x beam x draught
 851.73 ft / 850.00 ft x 105.00 ft x 28.00 ft (normal load)
 259.61 m / 259.08 m x 32.00 m  x 8.53 m

Armament:
      6 - 18.00" / 457 mm guns (2x3 guns), 2,916.00lbs / 1,322.68kg shells, 1915 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      16 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1915 Model
   Quick firing guns in deck mounts with hoists
   on side, all forward, 4 raised mounts - superfiring
 Weight of broadside 18,496 lbs / 8,390 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 320.00 ft / 97.54 m 19.00 ft / 5.79 m
 Ends: 7.00" / 178 mm 180.00 ft / 54.86 m 12.00 ft / 3.66 m
   350.00 ft / 106.68 m Unarmoured ends
   Main Belt covers 58 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 500.00 ft / 152.40 m 25.00 ft / 7.62 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 253,699 shp / 189,259 Kw = 35.00 kts
 Range 5,000nm at 15.00 kts
 Bunker at max displacement = 2,435 tons

Complement:
 1,373 - 1,786

Cost:
 £5.870 million / $23.482 million

Distribution of weights at normal displacement:
 Armament: 2,312 tons, 6.0 %
 Armour: 7,846 tons, 20.4 %
    - Belts: 2,889 tons, 7.5 %
    - Torpedo bulkhead: 925 tons, 2.4 %
    - Armament: 1,751 tons, 4.5 %
    - Armour Deck: 2,281 tons, 5.9 %
    - Conning Tower: 0 tons, 0.0 %
 Machinery: 6,069 tons, 15.8 %
 Hull, fittings & equipment: 19,319 tons, 50.2 %
 Fuel, ammunition & stores: 2,954 tons, 7.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   50,876 lbs / 23,077 Kg = 17.4 x 18.0 " / 457 mm shells or 6.1 torpedoes
 Stability (Unstable if below 1.00): 1.18
 Metacentric height 7.3 ft / 2.2 m
 Roll period: 16.3 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.75
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.539
 Length to Beam Ratio: 8.10 : 1
 'Natural speed' for length: 29.15 kts
 Power going to wave formation at top speed: 56 %
 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 %): 29.00 ft / 8.84 m
    - Mid (50 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.32 ft / 8.94 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 118.1 %
  - Above water (accommodation/working, high = better): 248.1 %
 Waterplane Area: 61,661 Square feet or 5,728 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 216 lbs/sq ft or 1,056 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.50
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent