The Ger/BB/1915 CDV

We were toying with the idea of having coast defense battleships, back in the early 1970's. Since we were gaming the 1905 to 1918 period, it was only natural to place this design in 1915, as part of the emergency war program for Germany. This is the original specification:

Ger/BB/1915 CDV
D=28,000 tons    585ft x 100ft x 50ft Depth  draft=29.1ft
Cp=0.62  Cm=0.97  V=20 knots
1000 tons oil fuel   150 tons feed water
29,150 tons full load
25,000 SHP at 30SHP/ton
4-18in/45 (180 ton), 20-5in QF (5 ton)

Weights:
 7,000 tons  Hull
   834 tons  Machinery
 1,070 tons  Aux. Machinery
 1,886 tons  Armament
14,970 tons  Protection
 2,240 tons  Miscellaneous

This is the Springsharp report:

Ger/BB/1915 CDV, Germany Coast Defense Battleship laid down 1915 (Engine 1941)

Displacement:
 26,618 t light; 27,829 t standard; 29,083 t normal; 30,086 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (585.00 ft / 585.00 ft) x 100.00 ft x (29.00 / 29.82 ft)
 (178.31 m / 178.31 m) x 30.48 m  x (8.84 / 9.09 m)

Armament:
      4 - 18.00" / 457 mm 45.0 cal guns - 2,950.00lbs / 1,338.10kg shells, 80 per gun
   Breech loading guns in turret on barbette mounts, 1915 Model
   2 x Twin mounts on centreline, forward deck forward
      20 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts, 1915 Model
   10 x Twin mounts on sides, forward deck aft
  4 raised mounts - superfiring
      Weight of broadside 13,061 lbs / 5,924 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 18.0" / 457 mm 330.00 ft / 100.58 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 14.0" / 356 mm 330.00 ft / 100.58 m 8.00 ft / 2.44 m
   Main Belt covers 87 % of normal length

   - Torpedo Bulkhead:
  6.00" / 152 mm 330.00 ft / 100.58 m 29.00 ft / 8.84 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 18.0" / 457 mm 10.0" / 254 mm  18.0" / 457 mm
 2nd: 4.00" / 102 mm 2.00" / 51 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 6.00" / 152 mm For and Aft decks
 Forecastle: 6.00" / 152 mm  Quarter deck: 6.00" / 152 mm

   - Conning towers: Forward 18.00" / 457 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 28,862 shp / 21,531 Kw = 20.00 kts
 Range 4,500nm at 16.00 kts
 Bunker at max displacement = 2,257 tons

Complement:
 1,113 - 1,447

Cost:
 £3.279 million / $13.117 million

Distribution of weights at normal displacement:
 Armament: 2,092 tons, 7.2 %
 Armour: 13,569 tons, 46.7 %
    - Belts: 3,875 tons, 13.3 %
    - Torpedo bulkhead: 2,125 tons, 7.3 %
    - Armament: 2,416 tons, 8.3 %
    - Armour Deck: 4,788 tons, 16.5 %
    - Conning Tower: 367 tons, 1.3 %
 Machinery: 763 tons, 2.6 %
 Hull, fittings & equipment: 10,194 tons, 35.1 %
 Fuel, ammunition & stores: 2,465 tons, 8.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   64,267 lbs / 29,151 Kg = 22.0 x 18.0 " / 457 mm shells or 15.9 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 7.3 ft / 2.2 m
 Roll period: 15.5 seconds
 Steadiness - As gun platform (Average = 50 %): 91 %
   - Recoil effect (Restricted arc if above 1.00): 0.62
 Seaboat quality  (Average = 1.00): 1.81

Hull form characteristics:
 Hull has a flush deck,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.600 / 0.604
 Length to Beam Ratio: 5.85 : 1
 'Natural speed' for length: 24.19 kts
 Power going to wave formation at top speed: 42 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  25.00 ft / 7.62 m,  22.00 ft / 6.71 m
    - Forward deck: 30.00 %,  22.00 ft / 6.71 m,  20.00 ft / 6.10 m
    - Aft deck: 35.00 %,  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:  20.94 ft / 6.38 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 58.4 %
  - Above water (accommodation/working, high = better): 149.8 %
 Waterplane Area: 42,786 Square feet or 3,975 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 185 lbs/sq ft or 903 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.93
  - Longitudinal: 2.05
  - 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