My GB/CB/1905 design study

This is my design study for a British 1905 battlecruiser with 8-12in guns, 16-4in QF guns, and a 25.5 knot speed. The armour basis is 6in with a 2in deck. The main issue is caused by Springsharp requiring too much power to reach 25.5 knots (over 50,000 SHP). I used turbine machinery with direct drive and coal-fired boilers. This is the Springsharp report:

GB/CB/1905 design study, Great Britain Battlecruiser laid down 1905 (Engine 1907)

Displacement:
 16,457 t light; 17,249 t standard; 19,991 t normal; 22,184 t full load

Dimensions: Length overall / water x beam x draught
 567.00 ft / 567.00 ft x 78.00 ft x 26.50 ft (normal load)
 172.82 m / 172.82 m x 23.77 m  x 8.08 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
      4 - 12.00" / 305 mm guns (2x2 guns), 864.00lbs / 391.90kg shells, 1905 Model
   Breech loading guns in turrets (on barbettes)
   on side, all amidships
      16 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1905 Model
   Quick firing guns in casemate mounts 
   on side, evenly spread, 8 raised mounts
 Weight of broadside 7,424 lbs / 3,367 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 6.00" / 152 mm 340.00 ft / 103.63 m 8.00 ft / 2.44 m
 Ends: 4.00" / 102 mm 220.00 ft / 67.06 m 8.00 ft / 2.44 m
   7.00 ft / 2.13 m Unarmoured ends
 Upper: 4.00" / 102 mm 340.00 ft / 103.63 m 8.00 ft / 2.44 m
   Main Belt covers 92 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 340.00 ft / 103.63 m 26.50 ft / 8.08 m

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

   - Armour deck: 2.00" / 51 mm, Conning tower: 7.00" / 178 mm

Machinery:
 Coal fired boilers, steam turbines, 
 Direct drive, 4 shafts, 57,545 shp / 42,929 Kw = 25.50 kts
 Range 5,200nm at 15.00 kts
 Bunker at max displacement = 4,935 tons (100% coal)

Complement:
 839 - 1,092

Cost:
 £1.859 million / $7.436 million

Distribution of weights at normal displacement:
 Armament: 928 tons, 4.6 %
 Armour: 4,564 tons, 22.8 %
    - Belts: 1,454 tons, 7.3 %
    - Torpedo bulkhead: 500 tons, 2.5 %
    - Armament: 1,306 tons, 6.5 %
    - Armour Deck: 1,193 tons, 6.0 %
    - Conning Tower: 111 tons, 0.6 %
 Machinery: 3,597 tons, 18.0 %
 Hull, fittings & equipment: 7,368 tons, 36.9 %
 Fuel, ammunition & stores: 3,533 tons, 17.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   23,414 lbs / 10,621 Kg = 27.1 x 12.0 " / 305 mm shells or 3.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 4.7 ft / 1.4 m
 Roll period: 15.1 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.70
 Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.597
 Length to Beam Ratio: 7.27 : 1
 'Natural speed' for length: 23.81 kts
 Power going to wave formation at top speed: 53 %
 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:  26.00 ft / 7.92 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
    - Quarterdeck (15 %): 16.00 ft / 4.88 m
    - Stern:  16.00 ft / 4.88 m
    - Average freeboard: 21.52 ft / 6.56 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 125.4 %
  - Above water (accommodation/working, high = better): 159.5 %
 Waterplane Area: 32,256 Square feet or 2,997 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 152 lbs/sq ft or 742 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.73
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily