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Tuesday, November 13, 2007

Another run at a Ger/CB/1915 design

There is an interesting 900ft long German battlecruiser in "The Red Book", part of my papers from the early 1970's. The ship is armed with 6-16.5in guns forward and 12-6in guns in turrets. There is minimal armour and a high speed. This is my latest attempt at a Springsharp design:
Ger/CB/1915, Germany Battlecruiser laid down 1915 (Engine 1927)

Displacement:
 40,097 t light; 42,248 t standard; 45,198 t normal; 47,558 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (907.65 ft / 900.00 ft) x 105.00 ft x (31.00 / 32.26 ft)
 (276.65 m / 274.32 m) x 32.00 m  x (9.45 / 9.83 m)

Armament:
      6 - 16.50" / 419 mm 45.0 cal guns - 2,265.21lbs / 1,027.48kg shells, 150 per gun
   Breech loading guns in turret on barbette mounts, 1915 Model
   2 x Triple mounts on centreline, forward deck forward
      12 - 6.00" / 152 mm 50.0 cal guns - 114.33lbs / 51.86kg shells, 150 per gun
   Quick firing guns in turret on barbette mounts, 1915 Model
   2 x Twin mounts on sides, forward deck aft
   4 x Twin mounts on sides, aft deck forward
      Weight of broadside 14,963 lbs / 6,787 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 420.00 ft / 128.02 m 12.00 ft / 3.66 m
 Ends: Unarmoured
 Upper: 5.00" / 127 mm 345.00 ft / 105.16 m 8.00 ft / 2.44 m
   Main Belt covers 72 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 420.00 ft / 128.02 m 31.00 ft / 9.45 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 6.00" / 152 mm  8.00" / 203 mm
 2nd: 5.00" / 127 mm 4.00" / 102 mm  5.00" / 127 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 8.00" / 203 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 303,169 shp / 226,164 Kw = 36.00 kts
 Range 7,500nm at 16.00 kts
 Bunker at max displacement = 5,310 tons

Complement:
 1,549 - 2,014

Cost:
 £6.042 million / $24.168 million

Distribution of weights at normal displacement:
 Armament: 2,526 tons, 5.6 %
 Armour: 9,515 tons, 21.1 %
    - Belts: 2,443 tons, 5.4 %
    - Torpedo bulkhead: 963 tons, 2.1 %
    - Armament: 2,243 tons, 5.0 %
    - Armour Deck: 3,648 tons, 8.1 %
    - Conning Tower: 219 tons, 0.5 %
 Machinery: 9,570 tons, 21.2 %
 Hull, fittings & equipment: 18,487 tons, 40.9 %
 Fuel, ammunition & stores: 5,101 tons, 11.3 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   57,840 lbs / 26,236 Kg = 25.8 x 16.5 " / 419 mm shells or 6.3 torpedoes
 Stability (Unstable if below 1.00): 1.23
 Metacentric height 7.8 ft / 2.4 m
 Roll period: 15.7 seconds
 Steadiness - As gun platform (Average = 50 %): 57 %
   - Recoil effect (Restricted arc if above 1.00): 0.60
 Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
 Hull has low quarterdeck ,
   an extended bulbous bow and a cruiser stern
 Block coefficient (normal/deep): 0.540 / 0.546
 Length to Beam Ratio: 8.57 : 1
 'Natural speed' for length: 30.00 kts
 Power going to wave formation at top speed: 55 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 12.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  36.00 ft / 10.97 m,  32.00 ft / 9.75 m
    - Forward deck: 30.00 %,  32.00 ft / 9.75 m,  30.00 ft / 9.14 m
    - Aft deck: 13.00 %,  30.00 ft / 9.14 m,  30.00 ft / 9.14 m
    - Quarter deck: 37.00 %,  23.00 ft / 7.01 m,  23.00 ft / 7.01 m
    - Average freeboard:  28.43 ft / 8.67 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 121.0 %
  - Above water (accommodation/working, high = better): 246.6 %
 Waterplane Area: 65,336 Square feet or 6,070 Square metres
 Displacement factor (Displacement / loading): 107 %
 Structure weight / hull surface area: 201 lbs/sq ft or 984 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.36
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent

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