A Springsharp 3.0b1 Beta version of the Ger/CBL/1915 Mod.A design

The Ger/CBL/1915 Mod.A design is a "Cruiser Killer". I had designed the ship in the early 1970's to see what might be done for extreme speed. The armament is rather like an 1890's fast Elswick cruiser, except that the main armament is in a turret, rather than some other mount. The ship is designed to run up on lesser ships, hammer them with a quick, close range shot or two from the 12in guns and sink or disable them. This is a photo of one of the ships:

I was able to get an acceptable design with very lightweight machinery and an increased draft. I really like the facility in Springsharp 3.0b1 to be able to see the hull profile after you specifiy the freeboard, in detail. This is the Springsharp report:

Ger/CBL/1915 Mod.A, Germany Light Battlecruiser laid down 1915 (Engine 1945)

Displacement:
 21,642 t light; 22,306 t standard; 23,654 t normal; 24,733 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (804.30 ft / 800.00 ft) x 80.00 ft x (24.00 / 24.85 ft)
 (245.15 m / 243.84 m) x 24.38 m  x (7.32 / 7.58 m)

Armament:
      2 - 12.00" / 305 mm 50.0 cal guns - 910.00lbs / 412.77kg shells, 90 per gun
   Breech loading guns in turret on barbette mount , 1915 Model
   1 x Twin mount on centreline, forward deck centre
      12 - 6.00" / 152 mm 50.0 cal guns - 100.00lbs / 45.36kg shells, 150 per gun
   Quick firing guns in deck and hoist mounts , 1915 Model
   12 x Single mounts on sides, evenly spread
 Weight of broadside 3,020 lbs / 3,020 kg

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 620.00 ft / 188.98 m 12.00 ft / 3.66 m
 Ends: Unarmoured
   Main Belt covers 119 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 6.00" / 152 mm 4.00" / 102 mm  4.00" / 102 mm
 2nd: 4.00" / 102 mm 1.00" / 25 mm  3.00" / 76 mm

   - Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 6 shafts, 321,334 shp / 239,715 Kw = 40.00 kts
 Range 4,500nm at 18.00 kts
 Bunker at max displacement = 2,427 tons

Complement:
 953 - 1,239

Cost:
 £3.240 million / $12.959 million

Distribution of weights at normal displacement:
 Armament: 766 tons, 3.2 %
 Armour: 3,302 tons, 14.0 %
    - Belts: 1,209 tons, 5.1 %
    - Torpedo bulkhead: 0 tons, 0.0 %
    - Armament: 351 tons, 1.5 %
    - Armour Deck: 1,636 tons, 6.9 %
    - Conning Tower: 107 tons, 0.5 %
 Machinery: 8,114 tons, 34.3 %
 Hull, fittings & equipment: 9,828 tons, 41.5 %
 Fuel, ammunition & stores: 2,013 tons, 8.5 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   22,280 lbs / 10,106 Kg = 25.8 x 12.0 " / 305 mm shells or 1.8 torpedoes
 Stability (Unstable if below 1.00): 1.24
 Metacentric height 5.3 ft / 1.6 m
 Roll period: 14.6 seconds
 Steadiness - As gun platform (Average = 50 %): 51 %
   - Recoil effect (Restricted arc if above 1.00): 0.31
 Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
 Hull has low quarterdeck ,
   a normal bow and a cruiser stern
 Block coefficient (normal/deep): 0.539 / 0.544
 Length to Beam Ratio: 10.00 : 1
 'Natural speed' for length: 28.28 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 7.00 degrees
 Stern overhang: -3.00 ft / -0.91 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  35.00 ft / 10.67 m,  32.00 ft / 9.75 m
    - Forward deck: 30.00 %,  32.00 ft / 9.75 m,  29.00 ft / 8.84 m
    - Aft deck: 17.00 %,  29.00 ft / 8.84 m,  29.00 ft / 8.84 m
    - Quarter deck: 33.00 %,  21.00 ft / 6.40 m,  22.00 ft / 6.71 m
    - Average freeboard:  27.82 ft / 8.48 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 123.9 %
  - Above water (accommodation/working, high = better): 264.7 %
 Waterplane Area: 44,207 Square feet or 4,107 Square metres
 Displacement factor (Displacement / loading): 104 %
 Structure weight / hull surface area: 140 lbs/sq ft or 681 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.46
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent