The extended version of the Ger/BB/1907 design

In about 1973, I started to experiment with what extended versions of my original designs for the wargame building program. For the Ger/BB/1907 design, I decided to go for lighter weight machinery and reduced side armour coverage, so the result was more like an 1870's design, with unarmoured ends, except for the deck. I thought that about 120,000 SHP would produce 30 knots, and that proved to be correct. I was able to stay within the 27,500 tons normal displacement. I had thought that the Standard displacement would be 25,847 tons, and the Springsharp design proved to be very close at 25,830 tons. The ship carries 8-12in and 12-4in guns, and the armour basis is 12in with a 4in deck. I did have to increase the draft at normal displacement to 27.5ft, to help achieve adequate strength. The steadiness and seakeeping are both just barely adequate, I suppose due to the high speed that the design is trying to achieve. This is a photo of one of the ships:

This is the Springsharp report:

Ger/BB/1907 Extended, Germany Battleship laid down 1907 (Engine 1925)

Displacement:
    24,910 t light; 25,830 t standard; 27,500 t normal; 28,836 t full load

Dimensions: Length overall / water x beam x draught
    620.00 ft / 620.00 ft x 105.00 ft x 27.50 ft (normal load)
    188.98 m / 188.98 m x 32.00 m  x 8.38 m

Armament:
      8 - 12.00" / 305 mm guns (4x2 guns), 864.00lbs / 391.90kg shells, 1907 Model
      Breech loading guns in turrets (on barbettes)
      on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1907 Model
      Quick firing guns in deck mounts with hoists
      on side, all amidships
    Weight of broadside 7,296 lbs / 3,309 kg
    Shells per gun, main battery: 90

Armour:
   - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    12.0" / 305 mm    360.00 ft / 109.73 m    8.00 ft / 2.44 m
    Ends:    Unarmoured
    Upper:    10.0" / 254 mm    340.00 ft / 103.63 m    8.00 ft / 2.44 m
      Main Belt covers 89 % of normal length

   - Torpedo Bulkhead:
        2.00" / 51 mm    360.00 ft / 109.73 m    26.00 ft / 7.92 m

   - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    12.0" / 305 mm    9.00" / 229 mm        11.0" / 279 mm
    2nd:    4.00" / 102 mm    4.00" / 102 mm        4.00" / 102 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
    Oil fired boilers, steam turbines,
    Direct drive, 4 shafts, 120,174 shp / 89,650 Kw = 29.33 kts
    Range 6,500nm at 15.00 kts
    Bunker at max displacement = 3,006 tons

Complement:
    1,067 - 1,388

Cost:
    £2.184 million / $8.737 million

Distribution of weights at normal displacement:
    Armament: 912 tons, 3.3 %
    Armour: 9,438 tons, 34.3 %
       - Belts: 2,814 tons, 10.2 %
       - Torpedo bulkhead: 693 tons, 2.5 %
       - Armament: 2,373 tons, 8.6 %
       - Armour Deck: 3,323 tons, 12.1 %
       - Conning Tower: 236 tons, 0.9 %
    Machinery: 3,902 tons, 14.2 %
    Hull, fittings & equipment: 10,659 tons, 38.8 %
    Fuel, ammunition & stores: 2,590 tons, 9.4 %
    Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      44,433 lbs / 20,155 Kg = 51.4 x 12.0 " / 305 mm shells or 7.3 torpedoes
    Stability (Unstable if below 1.00): 1.15
    Metacentric height 7.0 ft / 2.1 m
    Roll period: 16.7 seconds
    Steadiness    - As gun platform (Average = 50 %): 51 %
            - Recoil effect (Restricted arc if above 1.00): 0.33
    Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
    Hull has rise forward of midbreak
    Block coefficient: 0.538
    Length to Beam Ratio: 5.90 : 1
    'Natural speed' for length: 24.90 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:        30.00 ft / 9.14 m
       - Forecastle (20 %):    27.00 ft / 8.23 m
       - Mid (67 %):        27.00 ft / 8.23 m (19.00 ft / 5.79 m aft of break)
       - Quarterdeck (15 %):    19.00 ft / 5.79 m
       - Stern:        19.00 ft / 5.79 m
       - Average freeboard:    24.60 ft / 7.50 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 88.2 %
        - Above water (accommodation/working, high = better): 198.7 %
    Waterplane Area: 44,910 Square feet or 4,172 Square metres
    Displacement factor (Displacement / loading): 112 %
    Structure weight / hull surface area: 171 lbs/sq ft or 836 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.93
        - Longitudinal: 1.83
        - Overall: 1.00
    Hull space for machinery, storage, compartmentation is adequate
    Room for accommodation and workspaces is excellent