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Saturday, September 08, 2007

Another try at the Ger/CB/1915 design form the Red Book

Early in the Red Book from the early 1970's, there is the specification named the Ger/CB/1915:
Ger/CB/1915  Length=900ft  Sqrt(L) = 30.0  V=40 knots  V/sqrt(L)=1.333
  6-16.5in BLR, 12-6in QF guns  5.4 SHP/ton
40,000 tons full load  216,000 SHP  Cp = 0.54  Cm = 0.97
   L=900ft, B=100ft, Depth=58ft  d=29.7ft deep load  c=0.24 (hull weight coefficient)

Weights:
40,000 tons     full load displacement      2500nm @ 40 knots  62.5 hours
 3,620 tons     fuel oil
   543 tons     feed water
35,837 tons     standard
12,528 tons     hull
 7,200 tons     machinery
 2,875 tons     armament
 8,974 tons     protection
 2,860 tons     miscellaneous
 1,400 tons     auxiliary machinery

This is the Springsharp report for the design I implemented:
Ger/CB/1915, Germany Battlecruiser laid down 1915 (Engine 1941)

Displacement:
 34,937 t light; 36,488 t standard; 38,568 t normal; 40,231 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (910.18 ft / 900.00 ft) x 100.00 ft x (29.70 / 30.67 ft)
 (277.42 m / 274.32 m) x 30.48 m  x (9.05 / 9.35 m)

Armament:
      6 - 16.50" / 419 mm 45.0 cal guns - 2,265.21lbs / 1,027.48kg shells, 90 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 - 100.00lbs / 45.36kg shells, 150 per gun
   Quick firing guns in deck and hoist mount, 1915 Model
   1 x Single mount on sides, forward deck aft
  2 raised mounts
      Weight of broadside 14,791 lbs / 6,709 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 535.00 ft / 163.07 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 6.00" / 152 mm 535.00 ft / 163.07 m 8.00 ft / 2.44 m
   Main Belt covers 91 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 535.00 ft / 163.07 m 29.70 ft / 9.05 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 9.00" / 229 mm 7.00" / 178 mm  9.00" / 229 mm
 2nd: 5.00" / 127 mm 3.00" / 76 mm  5.00" / 127 mm

   - Protected 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, 4 shafts, 240,176 shp / 179,171 Kw = 35.00 kts
 Range 7,500nm at 15.00 kts
 Bunker at max displacement = 3,743 tons

Complement:
 1,375 - 1,788

Cost:
 £5.123 million / $20.492 million

Distribution of weights at normal displacement:
 Armament: 2,583 tons, 6.7 %
 Armour: 9,043 tons, 23.4 %
    - Belts: 2,521 tons, 6.5 %
    - Torpedo bulkhead: 1,176 tons, 3.0 %
    - Armament: 1,781 tons, 4.6 %
    - Armour Deck: 3,368 tons, 8.7 %
    - Conning Tower: 197 tons, 0.5 %
 Machinery: 6,347 tons, 16.5 %
 Hull, fittings & equipment: 16,965 tons, 44.0 %
 Fuel, ammunition & stores: 3,630 tons, 9.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   52,706 lbs / 23,907 Kg = 23.5 x 16.5 " / 419 mm shells or 6.7 torpedoes
 Stability (Unstable if below 1.00): 1.15
 Metacentric height 6.5 ft / 2.0 m
 Roll period: 16.5 seconds
 Steadiness - As gun platform (Average = 50 %): 64 %
   - Recoil effect (Restricted arc if above 1.00): 0.72
 Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
 Hull has rise forward of midbreak,
   an extended bulbous bow and a cruiser stern
 Block coefficient (normal/deep): 0.505 / 0.510
 Length to Beam Ratio: 9.00 : 1
 'Natural speed' for length: 30.00 kts
 Power going to wave formation at top speed: 52 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 15.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 30.00 %,  38.00 ft / 11.58 m,  31.00 ft / 9.45 m
    - Forward deck: 37.00 %,  31.00 ft / 9.45 m,  29.00 ft / 8.84 m
    - Aft deck: 18.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
    - Quarter deck: 15.00 %,  21.00 ft / 6.40 m,  21.00 ft / 6.40 m
    - Average freeboard:  28.17 ft / 8.59 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 108.1 %
  - Above water (accommodation/working, high = better): 225.8 %
 Waterplane Area: 60,239 Square feet or 5,596 Square metres
 Displacement factor (Displacement / loading): 110 %
 Structure weight / hull surface area: 198 lbs/sq ft or 968 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.41
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is adequate
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily

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