The 18in gun version of the Ger/CB/1937

The version of the Ger/CB/1937 design with 18in guns seems more battlecruiser-like, in that the armour is on the thin size for the guns (a 15in belt). The displacement seems quite appropriate for a ship with 18in guns. The protective deck and torpedo bulkhead would seem to be quite adequate. Perhaps, the light AA armament should be larger, but this seems at least minimally adequate. This is the Springsharp report:

Ger/CB/1937  18in guns, Germany Battlecruiser laid down 1937

Displacement:
 67,848 t light; 71,929 t standard; 76,264 t normal; 79,732 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (924.80 ft / 915.00 ft) x 130.00 ft x (34.00 / 35.32 ft)
 (281.88 m / 278.89 m) x 39.62 m  x (10.36 / 10.77 m)

Armament:
      9 - 18.00" / 457 mm 50.0 cal guns - 3,200.00lbs / 1,451.50kg shells, 150 per gun
   Breech loading guns in turret on barbette mounts , 1937 Model
   3 x Triple mounts on centreline ends, majority forward
  1 raised mount - superfiring
      12 - 6.00" / 152 mm 55.0 cal guns - 116.57lbs / 52.88kg shells, 150 per gun
   Quick firing guns in turret on barbette mounts , 1937 Model
   6 x Single mounts on sides, forward deck aft
      12 - 4.00" / 102 mm 45.0 cal guns - 32.27lbs / 14.64kg shells, 150 per gun
   Anti-air guns in deck mount , 1937 Model
   1 x Single mount on sides amidships
      48 - 1.46" / 37.0 mm 60.0 cal guns - 1.69lbs / 0.77kg shells, 150 per gun
   Anti-air guns in deck mounts , 1937 Model
   24 x Twin mounts on sides, evenly spread
  16 raised mounts
 Weight of broadside 30,667 lbs / 30,667 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 15.0" / 381 mm 600.00 ft / 182.88 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 12.0" / 305 mm 600.00 ft / 182.88 m 8.00 ft / 2.44 m
   Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
  6.00" / 152 mm 600.00 ft / 182.88 m 34.00 ft / 10.36 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 12.0" / 305 mm  16.0" / 406 mm
 2nd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm

   - Armour deck: 7.00" / 178 mm, Conning tower: 16.00" / 406 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 218,857 shp / 163,268 Kw = 30.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 7,804 tons

Complement:
 2,293 - 2,982

Cost:
 £34.295 million / $137.181 million

Distribution of weights at normal displacement:
 Armament: 5,357 tons, 7.0 %
 Armour: 28,611 tons, 37.5 %
    - Belts: 5,621 tons, 7.4 %
    - Torpedo bulkhead: 4,529 tons, 5.9 %
    - Armament: 5,932 tons, 7.8 %
    - Armour Deck: 11,909 tons, 15.6 %
    - Conning Tower: 620 tons, 0.8 %
 Machinery: 6,066 tons, 8.0 %
 Hull, fittings & equipment: 29,524 tons, 38.7 %
 Fuel, ammunition & stores: 8,416 tons, 11.0 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   127,908 lbs / 58,018 Kg = 43.9 x 18.0 " / 457 mm shells or 26.3 torpedoes
 Stability (Unstable if below 1.00): 1.22
 Metacentric height 10.7 ft / 3.3 m
 Roll period: 16.7 seconds
 Steadiness - As gun platform (Average = 50 %): 62 %
   - Recoil effect (Restricted arc if above 1.00): 0.55
 Seaboat quality  (Average = 1.00): 1.23

Hull form characteristics:
 Hull has a flush deck,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.660 / 0.664
 Length to Beam Ratio: 7.04 : 1
 'Natural speed' for length: 30.25 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 11.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  35.00 ft / 10.67 m,  29.00 ft / 8.84 m
    - Forward deck: 30.00 %,  29.00 ft / 8.84 m,  26.00 ft / 7.92 m
    - Aft deck: 30.00 %,  26.00 ft / 7.92 m,  27.00 ft / 8.23 m
    - Quarter deck: 20.00 %,  27.00 ft / 8.23 m,  28.00 ft / 8.53 m
    - Average freeboard:  27.98 ft / 8.53 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 75.2 %
  - Above water (accommodation/working, high = better): 206.3 %
 Waterplane Area: 91,960 Square feet or 8,543 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 241 lbs/sq ft or 1,176 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.98
  - Longitudinal: 1.23
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily