The 2001 version of the GB/PG/1906 design

In the late summer of 2001, I drew a series of sketches of the British and German designs from the 1971 building program. One of these was the GB/PG/1906 fast gunboat. The pencil drawing was a very nice, British-looking three-stacked destroyer-like vessel drawn at 1in = 40ft. The specification for this design was for a ship with 3-4in QF guns (or maybe even 20pdrs) and a 32-knot speed. This is the Springsharp report:

GB/PG/1906  2001 version, Great Britain Fast Gunboat laid down 1906 (Engine 1937)

Displacement:
 795 t light; 823 t standard; 950 t normal; 1,051 t full load

Dimensions: Length overall / water x beam x draught
 275.73 ft / 275.00 ft x 28.00 ft x 11.00 ft (normal load)
 84.04 m / 83.82 m x 8.53 m  x 3.35 m

Armament:
      3 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1906 Model
   Quick firing guns in deck mounts with hoists
   on centreline, evenly spread
   Aft Main mounts separated by engine room
 Weight of broadside 96 lbs / 44 kg
 Shells per gun, main battery: 180

Machinery:
 Oil fired boilers, steam turbines, 
 Direct drive, 2 shafts, 26,941 shp / 20,098 Kw = 32.00 kts
 Range 4,200nm at 15.00 kts
 Bunker at max displacement = 228 tons

Complement:
 85 - 111

Cost:
 £0.107 million / $0.427 million

Distribution of weights at normal displacement:
 Armament: 12 tons, 1.3 %
 Machinery: 492 tons, 51.8 %
 Hull, fittings & equipment: 290 tons, 30.6 %
 Fuel, ammunition & stores: 155 tons, 16.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   276 lbs / 125 Kg = 8.6 x 4.0 " / 102 mm shells or 0.2 torpedoes
 Stability (Unstable if below 1.00): 1.43
 Metacentric height 1.4 ft / 0.4 m
 Roll period: 10.0 seconds
 Steadiness - As gun platform (Average = 50 %): 53 %
   - Recoil effect (Restricted arc if above 1.00): 0.25
 Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.393
 Length to Beam Ratio: 9.82 : 1
 'Natural speed' for length: 16.58 kts
 Power going to wave formation at top speed: 70 %
 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:  21.00 ft / 6.40 m
    - Forecastle (20 %): 19.00 ft / 5.79 m
    - Mid (32 %):  19.00 ft / 5.79 m (11.00 ft / 3.35 m aft of break)
    - Quarterdeck (15 %): 11.00 ft / 3.35 m
    - Stern:  11.00 ft / 3.35 m
    - Average freeboard: 13.72 ft / 4.18 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 177.1 %
  - Above water (accommodation/working, high = better): 132.0 %
 Waterplane Area: 4,721 Square feet or 439 Square metres
 Displacement factor (Displacement / loading): 60 %
 Structure weight / hull surface area: 27 lbs/sq ft or 132 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.45
  - Longitudinal: 3.19
  - Overall: 0.55
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent