Another attempt at the Super Fast Battlecruiser

My drawing of the Super Fast Battlecruiser for the British is dated 18 July 1973. I had recently finished redesigning my earlier ships and thought that I would experiment with what was possible for a similarly armed battlecruiser. All these ships were armed with two twin turrets and a secondary armament. The sole goal was to reach the highest speed. The idea was to use 40SHP/ton machinery. I had always known that very high power machinery with a light weight would be needed. The speed goals were fanciful: 52 knots. Even my scaled back goal of 46.54 knots was out of reach. Seakeeping is the greatest problem. The hull strength is overly high, but if any of the other factors are increased, the seakeeping falls below 1.0. This is my working Springsharp report. It shows what can be done rather easily, if you allow for using light weight machinery. It is within the displacement and dimensions, except the freeboard and draft were increased to achieve the necessary seakeeping ability:

Super Fast Battlecruiser, Great Britain Battlecruiser laid down 1918 (Engine 1950)

Displacement:
 31,118 t light; 32,195 t standard; 33,500 t normal; 34,544 t full load

Dimensions: Length overall / water x beam x draught
 800.00 ft / 800.00 ft x 85.00 ft x 33.00 ft (normal load)
 243.84 m / 243.84 m x 25.91 m  x 10.06 m

Armament:
      4 - 17.00" / 432 mm guns (2x2 guns), 2,456.50lbs / 1,114.25kg shells, 1918 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, 1918 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread, all raised mounts - superfiring
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1918 Model
   Quick firing guns in deck mounts with hoists
   on side, evenly spread
 Weight of broadside 10,338 lbs / 4,689 kg
 Shells per gun, main battery: 70

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 420.00 ft / 128.02 m 9.00 ft / 2.74 m
 Ends: Unarmoured
 Upper: 5.00" / 127 mm 230.00 ft / 70.10 m 8.00 ft / 2.44 m
   Main Belt covers 81 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.50" / 38 mm 420.00 ft / 128.02 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  8.00" / 203 mm
 2nd: 2.00" / 51 mm       -         -
 3rd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 5.00" / 127 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 321,949 shp / 240,174 Kw = 38.00 kts
 Range 5,400nm at 15.00 kts
 Bunker at max displacement = 2,349 tons

Complement:
 1,237 - 1,609

Cost:
 £6.506 million / $26.023 million

Distribution of weights at normal displacement:
 Armament: 1,292 tons, 3.9 %
 Armour: 5,536 tons, 16.5 %
    - Belts: 1,772 tons, 5.3 %
    - Torpedo bulkhead: 629 tons, 1.9 %
    - Armament: 1,311 tons, 3.9 %
    - Armour Deck: 1,711 tons, 5.1 %
    - Conning Tower: 112 tons, 0.3 %
 Machinery: 7,702 tons, 23.0 %
 Hull, fittings & equipment: 16,587 tons, 49.5 %
 Fuel, ammunition & stores: 2,382 tons, 7.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   35,149 lbs / 15,943 Kg = 14.3 x 17.0 " / 432 mm shells or 3.6 torpedoes
 Stability (Unstable if below 1.00): 1.07
 Metacentric height 4.5 ft / 1.4 m
 Roll period: 16.9 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.91
 Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.523
 Length to Beam Ratio: 9.41 : 1
 'Natural speed' for length: 28.28 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 34.00 ft / 10.36 m
    - Mid (46 %):  34.00 ft / 10.36 m (26.00 ft / 7.92 m aft of break)
    - Quarterdeck (15 %): 26.00 ft / 7.92 m
    - Stern:  26.00 ft / 7.92 m
    - Average freeboard: 29.84 ft / 9.10 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 134.8 %
  - Above water (accommodation/working, high = better): 208.0 %
 Waterplane Area: 46,254 Square feet or 4,297 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 210 lbs/sq ft or 1,025 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 1.11
  - Longitudinal: 2.25
  - Overall: 1.19
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent