The tiny Ger/DD/1911 design

I was surprised that I could make the Ger/DD/1911 design work in Springsharp. The problem is that the destroyer is only 240ft long and nominally 800 tons. The speed is a moderate 32 knots. It carries 2-4in QF guns 4-21inTT and 20 mines. This was the first of my designs from 1971 to carry mines, and I continued that, as it is very much a part of German smallcraft. To make the design work in Springsharp, it has the usual exaggerated draft. This is the Springsharp report:

Ger/DD/1911, Enter country Enter ship type laid down 1911 (Engine 1937)

Displacement:
 658 t light; 682 t standard; 770 t normal; 841 t full load

Dimensions: Length overall / water x beam x draught
 242.33 ft / 240.00 ft x 26.00 ft x 12.00 ft (normal load)
 73.86 m / 73.15 m x 7.92 m  x 3.66 m

Armament:
      2 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1911 Model
   Quick firing guns in deck mounts 
   on centreline ends, evenly spread, all raised mounts
 Weight of broadside 64 lbs / 29 kg
 Shells per gun, main battery: 250
 4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 25,440 shp / 18,978 Kw = 32.00 kts
 Range 3,200nm at 15.00 kts
 Bunker at max displacement = 159 tons

Complement:
 73 - 95

Cost:
 £0.086 million / $0.344 million

Distribution of weights at normal displacement:
 Armament: 8 tons, 1.0 %
 Machinery: 401 tons, 52.1 %
 Hull, fittings & equipment: 223 tons, 29.0 %
 Fuel, ammunition & stores: 112 tons, 14.6 %
 Miscellaneous weights: 25 tons, 3.2 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   191 lbs / 86 Kg = 6.0 x 4.0 " / 102 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.29
 Metacentric height 1.0 ft / 0.3 m
 Roll period: 10.7 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.15
 Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.360
 Length to Beam Ratio: 9.23 : 1
 'Natural speed' for length: 15.49 kts
 Power going to wave formation at top speed: 72 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 1.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  19.00 ft / 5.79 m
    - Forecastle (22 %): 18.00 ft / 5.49 m
    - Mid (22 %):  18.00 ft / 5.49 m (12.00 ft / 3.66 m aft of break)
    - Quarterdeck (15 %): 12.00 ft / 3.66 m
    - Stern:  12.00 ft / 3.66 m
    - Average freeboard: 13.41 ft / 4.09 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 180.2 %
  - Above water (accommodation/working, high = better): 66.2 %
 Waterplane Area: 3,787 Square feet or 352 Square metres
 Displacement factor (Displacement / loading): 51 %
 Structure weight / hull surface area: 24 lbs/sq ft or 117 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.42
  - Longitudinal: 4.54
  - Overall: 0.53
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is cramped