Another recalculation of the GB/FG/1913

My friend Cliff wanted to build a destroyer-type ship that was primarily gun-armed, with a minimal torpedo armament. He wanted to give it a distinctive designation, it became an FG. This was rather like a later-Marksman class leader with superfiring guns. This is the Springsharp report:

GB/FG/1913, Great Britain Frigate-Gunboat laid down 1913 (Engine 1927)

Displacement:
 1,035 t light; 1,076 t standard; 1,200 t normal; 1,300 t full load

Dimensions: Length overall / water x beam x draught
 315.77 ft / 315.00 ft x 30.00 ft x 10.00 ft (normal load)
 96.25 m / 96.01 m x 9.14 m  x 3.05 m

Armament:
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1913 Model
   Breech loading guns in deck mounts with hoists
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1913 Model
   Quick firing gun in a deck mount with hoist
   on centreline amidships
 Weight of broadside 160 lbs / 73 kg
 Shells per gun, main battery: 180
 2 - 21.0" / 533.4 mm above water torpedoes

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 29,475 shp / 21,988 Kw = 32.00 kts
 Range 3,250nm at 15.00 kts
 Bunker at max displacement = 224 tons

Complement:
 101 - 132

Cost:
 £0.153 million / $0.614 million

Distribution of weights at normal displacement:
 Armament: 20 tons, 1.7 %
 Machinery: 626 tons, 52.2 %
 Hull, fittings & equipment: 389 tons, 32.4 %
 Fuel, ammunition & stores: 165 tons, 13.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   347 lbs / 157 Kg = 10.8 x 4.0 " / 102 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.34
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 10.7 seconds
 Steadiness - As gun platform (Average = 50 %): 63 %
   - Recoil effect (Restricted arc if above 1.00): 0.47
 Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.444
 Length to Beam Ratio: 10.50 : 1
 'Natural speed' for length: 17.75 kts
 Power going to wave formation at top speed: 68 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 2.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 20.00 ft / 6.10 m
    - Mid (42 %):  20.00 ft / 6.10 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: 15.52 ft / 4.73 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 181.5 %
  - Above water (accommodation/working, high = better): 142.2 %
 Waterplane Area: 6,001 Square feet or 557 Square metres
 Displacement factor (Displacement / loading): 59 %
 Structure weight / hull surface area: 28 lbs/sq ft or 138 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.44
  - Longitudinal: 3.00
  - Overall: 0.53
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent
 Good seaboat, rides out heavy weather easily