A new Ideal Battleship design

I have changed my mind about one aspect of Colonel Cuniberti's Ideal Battleship design. If built, they would have had turbine machinery, not reciprocating. They also would have been started about the date that construction of the Dreadnought commenced. The one other aspect that I was not able to reproduce is that to achieve adequate characteristics, the displacement has to be much larger than 17,000 tons. The dimensions were retained: 521-1/2ft x 82ft x 27-1/2ft. The armament is the original 12-12in, but 40 caliber, not 45 caliber. The secondary armament is the 12-12pdr QF guns in casemates, with 6-47mm 3pdr pom-poms. There is the amazing 12in complete belt and 24 knot speed. I have assumed that the machinery would have to have been very light, and therefore, a possible weakness, rather than the usual heavy and robust machinery usually specified. This is the Springsharp 3.0b1 Beta report:

Ideal Battleship, Great Britain Battleship laid down 1905 (Engine 1912)

Displacement:
 18,945 t light; 19,960 t standard; 20,832 t normal; 21,529 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (533.50 ft / 521.50 ft) x 82.00 ft x (27.50 / 28.27 ft)
 (162.61 m / 158.95 m) x 24.99 m  x (8.38 / 8.62 m)

Armament:
      8 - 12.00" / 305 mm 40.0 cal guns - 850.00lbs / 385.55kg shells, 80 per gun
   Breech loading guns in turret on barbette mounts , 1905 Model
   2 x Twin mounts on centreline ends, evenly spread
   2 x Twin mounts on sides, forward deck aft
  2 raised mounts
      4 - 12.00" / 305 mm 40.0 cal guns - 850.00lbs / 385.55kg shells, 150 per gun
   Breech loading guns in turret on barbette mounts , 1905 Model
   2 x Single mounts on sides, forward evenly spread
   2 x Single mounts on sides, aft deck forward
      12 - 3.00" / 76.2 mm 45.0 cal guns - 12.00lbs / 5.44kg shells, 150 per gun
   Quick firing guns in casemate mounts , 1905 Model
   12 x Single mounts on sides, forward deck aft
      6 - 1.85" / 47.0 mm 45.0 cal guns - 3.00lbs / 1.36kg shells, 150 per gun
   Quick firing guns in deck mounts , 1905 Model
   6 x Single mounts on sides, evenly spread
  6 raised mounts
 Weight of broadside 10,362 lbs / 10,362 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 350.00 ft / 106.68 m 8.00 ft / 2.44 m
 Ends: 12.0" / 305 mm 171.50 ft / 52.27 m 8.00 ft / 2.44 m
 Upper: 12.0" / 305 mm 280.00 ft / 85.34 m 8.00 ft / 2.44 m
   Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 350.00 ft / 106.68 m 27.50 ft / 8.38 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 7.00" / 178 mm  12.0" / 305 mm
 2nd: 12.0" / 305 mm 7.00" / 178 mm  12.0" / 305 mm
 3rd: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Coal and oil fired boilers, steam turbines, 
 ERROR: Revise drives, 4 shafts, 49,144 shp / 36,662 Kw = 24.00 kts
 Range 4,500nm at 12.00 kts
 Bunker at max displacement = 1,569 tons

Complement:
 866 - 1,127

Cost:
 £1.771 million / $7.085 million

Distribution of weights at normal displacement:
 Armament: 1,725 tons, 8.3 %
 Armour: 8,006 tons, 38.4 %
    - Belts: 3,304 tons, 15.9 %
    - Torpedo bulkhead: 356 tons, 1.7 %
    - Armament: 2,971 tons, 14.3 %
    - Armour Deck: 1,179 tons, 5.7 %
    - Conning Tower: 196 tons, 0.9 %
 Machinery: 1,960 tons, 9.4 %
 Hull, fittings & equipment: 7,987 tons, 38.3 %
 Fuel, ammunition & stores: 1,887 tons, 9.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   28,458 lbs / 12,908 Kg = 32.9 x 12.0 " / 305 mm shells or 4.7 torpedoes
 Stability (Unstable if below 1.00): 1.02
 Metacentric height 3.9 ft / 1.2 m
 Roll period: 17.5 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.89
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has raised forecastle,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.620 / 0.623
 Length to Beam Ratio: 6.36 : 1
 'Natural speed' for length: 22.84 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 49
 Bow angle (Positive = bow angles forward): -2.00 degrees
 Stern overhang: 4.00 ft / 1.22 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 15.00 %,  27.00 ft / 8.23 m,  27.00 ft / 8.23 m
    - Forward deck: 30.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Aft deck: 40.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Quarter deck: 15.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Average freeboard:  20.20 ft / 6.16 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 89.5 %
  - Above water (accommodation/working, high = better): 133.2 %
 Waterplane Area: 31,864 Square feet or 2,960 Square metres
 Displacement factor (Displacement / loading): 105 %
 Structure weight / hull surface area: 172 lbs/sq ft or 841 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.82
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent