Petrel class, French Coastal Submarine laid down 1907
Displacement:
435 t light; 447 t standard; 540 t normal; 612 t full load
Loading submergence
52 tons/feet
Dimensions:
149.28 ft x 19.69 ft x 13.12 ft (normal load)
45.50 m x 6.00 m x 4.00 m
Armament:
1 - 2.95" / 75 mm guns
Weight of broadside 13 lbs / 6 kg
4 - 17.7" / 450
mm submerged torpedo tubes forward
Operational depth - 108m/353 ft
Emergency depth - 172m/565 ft
Crush depth - 269m/882 ft
Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 1 shaft, 920 shp
/ 686 Kw = 14.00 kts
Range 5,000nm at 10.00 kts
Complement:
28 - 36
Cost:
£0.024 million / $0.096 million
Distribution of weights at normal displacement:
Armament: 2 tons, 0.3 %
Machinery: 52 tons, 9.7 %
Hull,
fittings & equipment: 291 tons, 54.0 %
Fuel, ammunition & stores: 105 tons, 19.4 %
Miscellaneous
weights: 90 tons, 16.7 %
Metacentric height 0.5
Remarks:
Hull space for machinery, storage & compartmentation is adequate
Room for accommodation
& workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks
seaworthiness - very limited seakeeping ability
Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.11
Shellfire
needed to sink: 271 lbs / 123 Kg = 21.1 x 3.0 " / 75 mm shells
(Approx weight of penetrating shell hits needed
to sink ship excluding critical hits)
Torpedoes needed to sink: 0.2
(Approx number of typical torpedo
hits needed to sink ship)
Relative steadiness as gun platform: 0 %
(Average = 50 %)
Relative
rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.00
Hull form characteristics:
Block coefficient: 0.490
Sharpness coefficient: 0.36
Hull speed
coefficient 'M': 5.60
'Natural speed' for length: 12.22 kts
Power going to wave formation at top speed:
51 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)
Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces:
102.4 %
Relative accommodation and working space: 0.0 %
(Average = 100%)
Displacement factor:
260 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 3.55
(Structure weight / hull surface area: 99 lbs / square foot or 483 Kg / square metre)
Relative longitudinal hull
strength: 3.52
(for 0.00 ft / 0.00 m average freeboard, freeboard adjustment -8.45 ft)
Relative composite
hull strength: 3.53