The GB/BB/1912 design study

My friend Cliff ultimately decided to build a more heavily armed ship in 1912, in our game. He toyed with a more lightly-armed fast battleship, instead: the GB/BB/1912. I had thought this was an earlier design, but the sketch design is clearly marked as 1912. This is the original specification:

1912  29,000 tons  9-12in/50, 8-6in QF guns
13in belt  24-25 knots  650ft x 100ft x 28.7ft
Cp=0.56  Cm=0.97
80,000 SHP @16 SHP/ton  100,000 SHP Max.
Mach =  5,000 tons
Hull = 12,180 tons
Misc =  2,340 tons
Arm  =  1,345 tons
Prot =  8,180 tons

29,045 tons Standard
 4,000 tons oil fuel
33,045 tons full load

We typically either were over optimistic or over specified our designs. You can see the result in the Springsharp 3.0b2 Beta result:

GB/BB/1912 design study, Great Britain Battleship laid down 1912

Displacement:
 24,879 t light; 26,101 t standard; 29,848 t normal; 32,846 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (653.00 ft / 650.00 ft) x 100.00 ft x (28.70 / 30.99 ft)
 (199.03 m / 198.12 m) x 30.48 m  x (8.75 / 9.45 m)

Armament:
      9 - 12.00" / 305 mm 50.0 cal guns - 914.66lbs / 414.88kg shells, 120 per gun
   Breech loading guns in turret on barbette mounts, 1912 Model
   3 x Triple mounts on centreline ends, majority forward
  1 raised mount - superfiring
      8 - 6.00" / 152 mm 50.0 cal guns - 114.33lbs / 51.86kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1912 Model
   8 x Single mounts on sides amidships
      Weight of broadside 9,147 lbs / 4,149 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 13.0" / 330 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 9.00" / 229 mm 390.00 ft / 118.87 m 8.00 ft / 2.44 m
   Main Belt covers 92 % of normal length

   - Torpedo Bulkhead:
  2.00" / 51 mm 390.00 ft / 118.87 m 28.70 ft / 8.75 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 13.0" / 330 mm 9.00" / 229 mm  13.0" / 330 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 3.00" / 76 mm For and Aft decks
 Forecastle: 3.00" / 76 mm  Quarter deck: 3.00" / 76 mm

   - Conning towers: Forward 13.00" / 330 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 4 shafts, 78,876 shp / 58,842 Kw = 26.25 kts
 Range 6,500nm at 18.00 kts
 Bunker at max displacement = 6,745 tons

Complement:
 1,135 - 1,476

Cost:
 £2.261 million / $9.043 million

Distribution of weights at normal displacement:
 Armament: 1,896 tons, 6.4 %
 Armour: 9,142 tons, 30.6 %
    - Belts: 3,036 tons, 10.2 %
    - Torpedo bulkhead: 828 tons, 2.8 %
    - Armament: 2,448 tons, 8.2 %
    - Armour Deck: 2,560 tons, 8.6 %
    - Conning Tower: 269 tons, 0.9 %
 Machinery: 3,145 tons, 10.5 %
 Hull, fittings & equipment: 10,696 tons, 35.8 %
 Fuel, ammunition & stores: 4,969 tons, 16.6 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   54,373 lbs / 24,663 Kg = 62.9 x 12.0 " / 305 mm shells or 8.9 torpedoes
 Stability (Unstable if below 1.00): 1.21
 Metacentric height 7.1 ft / 2.2 m
 Roll period: 15.8 seconds
 Steadiness - As gun platform (Average = 50 %): 76 %
   - Recoil effect (Restricted arc if above 1.00): 0.51
 Seaboat quality  (Average = 1.00): 1.52

Hull form characteristics:
 Hull has rise forward of midbreak,
   a ram bow and a cruiser stern
 Block coefficient (normal/deep): 0.560 / 0.571
 Length to Beam Ratio: 6.50 : 1
 'Natural speed' for length: 25.50 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): -3.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 30.00 %,  29.00 ft / 8.84 m,  28.00 ft / 8.53 m
    - Forward deck: 37.00 %,  28.00 ft / 8.53 m,  28.00 ft / 8.53 m
    - Aft deck: 18.00 %,  20.00 ft / 6.10 m,  20.00 ft / 6.10 m
    - Quarter deck: 15.00 %,  20.00 ft / 6.10 m,  20.00 ft / 6.10 m
    - Average freeboard:  25.48 ft / 7.77 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 79.7 %
  - Above water (accommodation/working, high = better): 195.0 %
 Waterplane Area: 45,790 Square feet or 4,254 Square metres
 Displacement factor (Displacement / loading): 122 %
 Structure weight / hull surface area: 175 lbs/sq ft or 853 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 1.85
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather