I decided to see what it would take for the GB/CB/1915 design to reach 35 knots

I thought that the next logical step was to see what would be required for the GB/CB/1915 design to reach 35 knots. I made a few modest reductions in protection and actually increased the range to 7,500nm. The four most significant changes were to lighten the machinery, to increase the draft to 29ft, to increase the freeboard, and to adjust the displacement to achieve adequate strength with the new parameters. This was intended to be somewhat like the Hood class prior to the big increase in protection after Jutland. This is the Springsharp report:

GB/CB/1915 design study, Great Britain Battlecruiser laid down 1915 (Engine 1931)

Displacement:
 36,643 t light; 38,338 t standard; 40,673 t normal; 42,540 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (856.17 ft / 850.00 ft) x 105.00 ft x (29.00 / 30.05 ft)
 (260.96 m / 259.08 m) x 32.00 m  x (8.84 / 9.16 m)

Armament:
      8 - 15.00" / 381 mm 42.0 cal guns - 1,920.00lbs / 870.90kg shells, 90 per gun
   Breech loading guns in turret on barbette mounts , 1915 Model
   4 x Twin mounts on centreline ends, evenly spread
  2 raised mounts - superfiring
      16 - 5.50" / 140 mm 50.0 cal guns - 85.00lbs / 38.56kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts , 1915 Model
   16 x Single mounts on sides, evenly spread
  4 raised mounts
 Weight of broadside 16,720 lbs / 16,720 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 560.00 ft / 170.69 m 16.00 ft / 4.88 m
 Ends: 4.00" / 102 mm 250.00 ft / 76.20 m 12.00 ft / 3.66 m
   40.00 ft / 12.19 m Unarmoured ends
   Main Belt covers 101 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 560.00 ft / 170.69 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 6.00" / 152 mm  8.00" / 203 mm
 2nd: 3.00" / 76 mm 1.00" / 25 mm  3.00" / 76 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 263,473 shp / 196,551 Kw = 35.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 4,203 tons

Complement:
 1,431 - 1,861

Cost:
 £5.343 million / $21.371 million

Distribution of weights at normal displacement:
 Armament: 2,446 tons, 6.0 %
 Armour: 8,667 tons, 21.3 %
    - Belts: 2,726 tons, 6.7 %
    - Torpedo bulkhead: 1,077 tons, 2.6 %
    - Armament: 2,355 tons, 5.8 %
    - Armour Deck: 2,305 tons, 5.7 %
    - Conning Tower: 204 tons, 0.5 %
 Machinery: 7,879 tons, 19.4 %
 Hull, fittings & equipment: 18,564 tons, 45.6 %
 Fuel, ammunition & stores: 4,030 tons, 9.9 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   53,667 lbs / 24,343 Kg = 31.8 x 15.0 " / 381 mm shells or 6.6 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 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.74
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.550 / 0.555
 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): 10.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 25.00 %,  35.00 ft / 10.67 m,  31.00 ft / 9.45 m
    - Forward deck: 38.00 %,  31.00 ft / 9.45 m,  31.00 ft / 9.45 m
    - Aft deck: 22.00 %,  23.00 ft / 7.01 m,  24.00 ft / 7.32 m
    - Quarter deck: 15.00 %,  24.00 ft / 7.32 m,  25.00 ft / 7.62 m
    - Average freeboard:  28.78 ft / 8.77 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 113.5 %
  - Above water (accommodation/working, high = better): 234.2 %
 Waterplane Area: 62,287 Square feet or 5,787 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 206 lbs/sq ft or 1,004 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.97
  - Longitudinal: 1.36
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent