Antisubmarine Gunboat laid down 1941
Displacement: 168 t light; 175 t standard; 200 t normal; 220 t full load
Dimensions: Length overall / water x beam x draught
122.59 ft / 116.47 ft x 18.21 ft x 7.87 ft (normal load) [37.37 m / 35.50 m x 5.55 m x 2.40 m]
Armament:
1 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1936 Model Anti-aircraft gun in deck mount on centreline forward
1 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1930 Model Anti-aircraft gun in deck mount on centreline aft
2 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1934 Model Machineguns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 21 lbs / 10 kg
Shells per gun, main battery: 300
Machinery:
Diesel Internal combustion motors, Geared drive, 2 shafts, 1,056 shp / 788 Kw = 16.50 kts
Range 2,550nm at 13.00 kts
Bunker at max displacement = 45 tons
Complement: 26 - 34
Cost: £0.074 million / $0.296 million
Distribution of weights at normal displacement:
Armament: 3 tons, 1.3 %
Machinery: 28 tons, 14.0 %
Hull, fittings & equipment: 117 tons, 58.5 %
Fuel, ammunition & stores: 32 tons, 16.2 %
Miscellaneous weights: 20 tons, 10.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship): 379 lbs / 172 Kg = 18.2 x 3.5 " / 88 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.5 ft / 0.1 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 41 %
- Recoil effect (Restricted arc if above 1.00): 0.12
Seaboat quality (Average = 1.00): 1.03
Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.419
Length to Beam Ratio: 6.40: 1
'Natural speed' for length: 10.79 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 33
Bow angle (Positive = bow angles forward): 26.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 9.19 ft / 2.80 m
- Forecastle (15 %): 8.53 ft / 2.60 m (8.20 ft / 2.50 m aft of break)
- Mid (50 %): 7.55 ft / 2.30 m
- Quarterdeck (25 %): 7.55 ft / 2.30 m
- Stern: 7.55 ft / 2.30 m
- Average freeboard: 7.85 ft / 2.39 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 68.2 %
- Above water (accommodation/working, high = better): 74.9 %
Waterplane Area: 1,321 Square feet or 123 Square metres
Displacement factor (Displacement / loading): 206 %
Structure weight / hull surface area: 43 lbs/sq ft or 209 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.37
- Longitudinal: 11.91
- Overall: 1.71
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is cramped
Wooden hull
Miscellaneous weight = depth charges and handling gear