I couldn't resist trying the GB/CB/1921 Super Fast design

After the success with the Ger/CBL/1915 Mod.A, faster version, I thought I would try the GB/CB/1921 "Super Fast" battlecruiser design from the Red Book. I used the specified dimensions, although the freeboard is higher. One variation is that the displacement IS LESS than I had specified. Very lightweight machinery is required, but not the lightest weight. The protection is modest, but more than the Ger/CBL/1915 design. 40 knots was not achievable, but 37 knots was, with a not very excessive SHP, and with four shafts, not six or eight. The armament is the 4-17in BLR and 16-4in QF guns. A higher speed could have been achieved, but seakeeping was an issue, partly due to the narrow beam. Seakeeping drove the displacement lower, as 32,000 tons was not compatible with adequate seakeeping. I may experiment with making design changes to see if 40 knots might be possible. This is the Springsharp report:

GB/CB/1921 Super Fast  Red Book, Great Britain Battlecruiser laid down 1921 (Engine 1945)

Displacement:
 24,968 t light; 25,985 t standard; 27,600 t normal; 28,892 t full load

Dimensions: Length overall / water x beam x draught
 802.31 ft / 800.00 ft x 85.00 ft x 29.70 ft (normal load)
 244.54 m / 243.84 m x 25.91 m  x 9.05 m

Armament:
      4 - 17.00" / 432 mm guns (2x2 guns), 2,456.50lbs / 1,114.25kg shells, 1921 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      4 - 4.00" / 102 mm guns (2x2 guns), 32.00lbs / 14.51kg shells, 1921 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, all raised mounts
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1921 Model
   Breech loading guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 10,338 lbs / 4,689 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 470.00 ft / 143.26 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 90 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 470.00 ft / 143.26 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  6.00" / 152 mm
 2nd: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm
 3rd: 3.00" / 76 mm 3.00" / 76 mm  3.00" / 76 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 250,474 shp / 186,853 Kw = 37.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 2,907 tons

Complement:
 1,069 - 1,391

Cost:
 £7.242 million / $28.966 million

Distribution of weights at normal displacement:
 Armament: 1,292 tons, 4.7 %
 Armour: 4,711 tons, 17.1 %
    - Belts: 1,438 tons, 5.2 %
    - Torpedo bulkhead: 504 tons, 1.8 %
    - Armament: 1,007 tons, 3.6 %
    - Armour Deck: 1,644 tons, 6.0 %
    - Conning Tower: 118 tons, 0.4 %
 Machinery: 6,325 tons, 22.9 %
 Hull, fittings & equipment: 12,639 tons, 45.8 %
 Fuel, ammunition & stores: 2,632 tons, 9.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   26,956 lbs / 12,227 Kg = 11.0 x 17.0 " / 432 mm shells or 3.0 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 5.1 ft / 1.6 m
 Roll period: 15.8 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.78
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.478
 Length to Beam Ratio: 9.41 : 1
 'Natural speed' for length: 28.28 kts
 Power going to wave formation at top speed: 57 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  33.00 ft / 10.06 m
    - Forecastle (20 %): 30.00 ft / 9.14 m
    - Mid (40 %):  30.00 ft / 9.14 m (23.00 ft / 7.01 m aft of break)
    - Quarterdeck (15 %): 23.00 ft / 7.01 m
    - Stern:  23.00 ft / 7.01 m
    - Average freeboard: 26.04 ft / 7.94 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 142.5 %
  - Above water (accommodation/working, high = better): 199.2 %
 Waterplane Area: 44,434 Square feet or 4,128 Square metres
 Displacement factor (Displacement / loading): 100 %
 Structure weight / hull surface area: 178 lbs/sq ft or 869 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent