My "Official" design for the German 1915 destroyer

For the wargame building game, from 1971, my "Official" design for the Ger/DD/1915 destroyer that would be built in the "Emergency War Program", was cleaner and more progressive. It was a ship with a forecastle that was 30% of the length, had two funnels and a squat, streamlined bridge structure. The armament was just 2-4in QF guns, 4-21in TT, and 30 mines. The speed was modest, being only 32 knots. There is the usual question whether the 850 tons displacement was "standard" or "normal". My investigation with Springsharp led me to assume that it was "normal". This is the Springsharp report:

Ger/DD/1915, Germany Destroyer laid down 1915 (Engine 1950)

Displacement:
 730 t light; 754 t standard; 850 t normal; 927 t full load

Dimensions: Length overall / water x beam x draught
 263.73 ft / 260.00 ft x 26.00 ft x 9.50 ft (normal load)
 80.39 m / 79.25 m x 7.92 m  x 2.90 m

Armament:
      2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1915 Model
   Quick firing guns in deck mounts with hoists
   on centreline ends, evenly spread
 Weight of broadside 64 lbs / 29 kg
 Shells per gun, main battery: 180
 4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 2 shafts, 27,259 shp / 20,335 Kw = 32.00 kts
 Range 3,750nm at 15.00 kts
 Bunker at max displacement = 174 tons

Complement:
 78 - 102

Cost:
 £0.135 million / $0.539 million

Distribution of weights at normal displacement:
 Armament: 8 tons, 0.9 %
 Machinery: 431 tons, 50.8 %
 Hull, fittings & equipment: 261 tons, 30.7 %
 Fuel, ammunition & stores: 120 tons, 14.1 %
 Miscellaneous weights: 30 tons, 3.5 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   240 lbs / 109 Kg = 7.5 x 4.0 " / 102 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.25
 Metacentric height 1.0 ft / 0.3 m
 Roll period: 11.0 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.28
 Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.463
 Length to Beam Ratio: 10.00 : 1
 'Natural speed' for length: 16.12 kts
 Power going to wave formation at top speed: 73 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  21.00 ft / 6.40 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (30 %):  19.00 ft / 5.79 m (13.00 ft / 3.96 m aft of break)
    - Quarterdeck (15 %): 13.00 ft / 3.96 m
    - Stern:  13.00 ft / 3.96 m
    - Average freeboard: 14.96 ft / 4.56 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 175.1 %
  - Above water (accommodation/working, high = better): 87.8 %
 Waterplane Area: 4,360 Square feet or 405 Square metres
 Displacement factor (Displacement / loading): 61 %
 Structure weight / hull surface area: 23 lbs/sq ft or 114 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.40
  - Longitudinal: 4.66
  - Overall: 0.51
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped