The very fast version of the GB/CB/1905 design

This is the GB/CB/1905 as a very fast battlecruiser. I had assumed that it would not be as fast as the GB/CB/1907 very fast version. The GB/CB/1905 from Springsharp is still a bit light, as the idea was to have a Standard displacement of 25,000 tons. I tried "de-rating" the machinery to 1921, but when I went to an 18 knot cruising speed, for a range of 7,500nm, Springsharp reduced the Standard displacement. This is the Springsharp report:

GB/CB/1905 very fast, Great Britain Battlecruiser laid down 1905 (Engine 1921)

Displacement:
 24,039 t light; 24,824 t standard; 27,800 t normal; 30,181 t full load

Dimensions: Length overall / water x beam x draught
 770.00 ft / 770.00 ft x 85.00 ft x 27.00 ft (normal load)
 234.70 m / 234.70 m x 25.91 m  x 8.23 m

Armament:
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      8 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1905 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
      1 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1905 Model
   Quick firing gun in a deck mount with hoist
   on centreline aft, 1 raised gun
 Weight of broadside 4,428 lbs / 2,009 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 465.00 ft / 141.73 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 4.00" / 102 mm 345.00 ft / 105.16 m 8.00 ft / 2.44 m
   Main Belt covers 93 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 550.00 ft / 167.64 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  7.00" / 178 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm
 3rd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

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

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 238,727 shp / 178,090 Kw = 36.00 kts
 Range 7,500nm at 18.00 kts
 Bunker at max displacement = 5,357 tons

Complement:
 1,076 - 1,399

Cost:
 £2.457 million / $9.829 million

Distribution of weights at normal displacement:
 Armament: 554 tons, 2.0 %
 Armour: 4,936 tons, 17.8 %
    - Belts: 1,131 tons, 4.1 %
    - Torpedo bulkhead: 1,099 tons, 4.0 %
    - Armament: 857 tons, 3.1 %
    - Armour Deck: 1,691 tons, 6.1 %
    - Conning Tower: 158 tons, 0.6 %
 Machinery: 8,221 tons, 29.6 %
 Hull, fittings & equipment: 10,328 tons, 37.2 %
 Fuel, ammunition & stores: 3,761 tons, 13.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   29,577 lbs / 13,416 Kg = 34.2 x 12.0 " / 305 mm shells or 3.4 torpedoes
 Stability (Unstable if below 1.00): 1.31
 Metacentric height 6.4 ft / 1.9 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.33
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.551
 Length to Beam Ratio: 9.06 : 1
 'Natural speed' for length: 27.75 kts
 Power going to wave formation at top speed: 59 %
 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:  34.00 ft / 10.36 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (73 %):  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: 27.24 ft / 8.30 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 145.1 %
  - Above water (accommodation/working, high = better): 222.7 %
 Waterplane Area: 45,703 Square feet or 4,246 Square metres
 Displacement factor (Displacement / loading): 108 %
 Structure weight / hull surface area: 145 lbs/sq ft or 710 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.36
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent