So, I've decided to try out submarines.
290 Ton Class Submarine, Poland Midget Submarine laid down 1940
Displacement:
290 t light; 297 t standard; 325 t normal; 348 t full load
Dimensions: Length overall / water x beam x draught
128.12 ft / 128.12 ft x 14.76 ft (Bulges 16.40 ft) x 9.84 ft (normal load)
39.05 m / 39.05 m x 4.50 m (Bulges 5.00 m) x 3.00 m
2 - 21.0" / 533.4 mm submerged torpedo tubes
Machinery:
Diesel Internal combustion engines plus batteries,
Electric cruising motors plus geared drives, 1 shaft, 1,704 shp / 1,271 Kw = 18.00 kts
Range 3,000nm at 12.00 kts
Bunker at max displacement = 51 tons
Complement:
37 - 49
Cost:
£0.099 million / $0.397 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.0 %
Machinery: 46 tons, 14.0 %
Hull, fittings & equipment: 170 tons, 52.3 %
Fuel, ammunition & stores: 35 tons, 10.7 %
Miscellaneous weights: 75 tons, 23.1 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
115 lbs / 52 Kg = 1.1 x 6 " / 152 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.3 ft / 0.1 m
Roll period: 13.0 seconds
Steadiness - As gun platform (Average = 50 %): 0 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.550
Length to Beam Ratio: 7.81 : 1
'Natural speed' for length: 13.10 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 0.10 ft / 0.03 m
- Forecastle (0 %): 0.10 ft / 0.03 m
- Mid (0 %): 0.10 ft / 0.03 m
- Quarterdeck (0 %): 0.10 ft / 0.03 m
- Stern: 0.10 ft / 0.03 m
- Average freeboard: 0.10 ft / 0.03 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 118.9 %
- Above water (accommodation/working, high = better): 0.7 %
Waterplane Area: 1,374 Square feet or 128 Square metres
Displacement factor (Displacement / loading): 196 %
Structure weight / hull surface area: 81 lbs/sq ft or 395 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 3.61
- Longitudinal: 2.67
- Overall: 2.88
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability