The Ger/CB/1917 Fast design

The Ger/CB/1917 fast is something of a disappointment, given the hopes for the design. This was a design dating from the early 1970's, and was intended to be a very fast ship armed with two triple 18in gun turrets, one at each end. The draft was to be very shallow, the displacement low, and very great power. Part of the problem was that I was very over optimistic about what could be achieved with 321,000 SHP. In fact, I had to settle for just 260,458 SHP, due to structural strength and seakeeping concerns. The ship, as designed in Springsharp has a top speed of 35 knots. If I had been able to use 321,000 SHP, the best that I could achieve, even at the original 36,500 ton normal displacement and 26.5ft draft was 36.5 knots. That could only be achieved by accepting inadequate seakeeping and strength. This is the Springsharp report for a viable design:

Ger/CB/1917 Fast, Germany Battlecruiser laid down 1917 (Engine 1941)

Displacement:
 37,083 t light; 38,726 t standard; 40,600 t normal; 42,099 t full load

Dimensions: Length overall / water x beam x draught
 853.15 ft / 850.00 ft x 105.00 ft x 30.00 ft (normal load)
 260.04 m / 259.08 m x 32.00 m  x 9.14 m

Armament:
      6 - 18.00" / 457 mm guns (2x3 guns), 2,916.00lbs / 1,322.68kg shells, 1917 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      16 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1917 Model
   Quick firing guns in casemate mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 18,496 lbs / 8,390 kg
 Shells per gun, main battery: 80

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 8.00" / 203 mm 200.00 ft / 60.96 m 17.00 ft / 5.18 m
 Ends: 6.00" / 152 mm 325.00 ft / 99.06 m 9.00 ft / 2.74 m
   325.00 ft / 99.06 m Unarmoured ends
   Main Belt covers 36 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  2.00" / 51 mm 530.00 ft / 161.54 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 8.00" / 203 mm 5.00" / 127 mm  8.00" / 203 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 8.00" / 203 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 260,337 shp / 194,211 Kw = 35.00 kts
 Range 6,500nm at 15.00 kts
 Bunker at max displacement = 3,374 tons

Complement:
 1,429 - 1,859

Cost:
 £7.642 million / $30.568 million

Distribution of weights at normal displacement:
 Armament: 2,312 tons, 5.7 %
 Armour: 8,697 tons, 21.4 %
    - Belts: 2,152 tons, 5.3 %
    - Torpedo bulkhead: 1,059 tons, 2.6 %
    - Armament: 1,887 tons, 4.6 %
    - Armour Deck: 3,395 tons, 8.4 %
    - Conning Tower: 204 tons, 0.5 %
 Machinery: 6,880 tons, 16.9 %
 Hull, fittings & equipment: 19,194 tons, 47.3 %
 Fuel, ammunition & stores: 3,517 tons, 8.7 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   51,205 lbs / 23,226 Kg = 17.6 x 18.0 " / 457 mm shells or 6.1 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 7.4 ft / 2.3 m
 Roll period: 16.2 seconds
 Steadiness - As gun platform (Average = 50 %): 55 %
   - Recoil effect (Restricted arc if above 1.00): 0.71
 Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.531
 Length to Beam Ratio: 8.10 : 1
 'Natural speed' for length: 29.15 kts
 Power going to wave formation at top speed: 56 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: -2.00 ft / -0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  36.00 ft / 10.97 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (50 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.56 ft / 9.01 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 120.0 %
  - Above water (accommodation/working, high = better): 236.5 %
 Waterplane Area: 61,174 Square feet or 5,683 Square metres
 Displacement factor (Displacement / loading): 99 %
 Structure weight / hull surface area: 213 lbs/sq ft or 1,038 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.95
  - Longitudinal: 1.55
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent