[SIZE=1]Image by Wes/thesmilingassassin and colored by me.[/SIZE]
Delfi-class, Atlantean-built Bulgarian Coastal Submarine laid down 1937
Displacement:
479 t light; 491 t standard; 537 t normal; 574 t full load
Dimensions: Length overall / water x beam x draught
165.00 ft / 165.00 ft x 22.00 ft x 12.00 ft (normal load)
50.29 m / 50.29 m x 6.71 m x 3.66 m
Armament:
1 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1937 Model
Breech loading gun in deck mount
on centreline forward
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on centreline, all aft, all raised mounts - superfiring
4 - 0.50" / 12.7 mm guns (2x2 guns), 0.06lbs / 0.03kg shells, 1937 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 15 lbs / 7 kg
Shells per gun, main battery: 150
5 - 21.0" / 533.4 mm submerged torpedo tubes
Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 1,129 shp / 842 Kw = 15.00 kts
Range 3,000nm at 12.50 kts
Bunker at max displacement = 82 tons
Complement:
55 - 72
Cost:
£0.124 million / $0.495 million
Distribution of weights at normal displacement:
Armament: 2 tons, 0.3 %
Machinery: 31 tons, 5.8 %
Hull, fittings & equipment: 306 tons, 57.0 %
Fuel, ammunition & stores: 58 tons, 10.8 %
Miscellaneous weights: 140 tons, 26.1 %
Overall survivability and seakeeping ability:[/B]
Survivability (Non-critical penetrating hits needed to sink ship):
187 lbs / 85 Kg = 13.8 x 3.0 " / 76 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.04
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.3 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
Block coefficient: 0.431
Length to Beam Ratio: 7.50 : 1
'Natural speed' for length: 12.85 kts
Power going to wave formation at top speed: 49 %
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: 0.00 ft / 0.00 m
- Forecastle (20 %): 0.00 ft / 0.00 m
- Mid (50 %): 0.00 ft / 0.00 m
- Quarterdeck (15 %): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 0.00 ft / 0.00 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 121.1 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 2,282 Square feet or 212 Square metres
Displacement factor (Displacement / loading): 247 %
Structure weight / hull surface area: 95 lbs/sq ft or 464 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 3.39
- Longitudinal: 2.55
- Overall: 2.74
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
Performance:
Operational depth: 274 feet
Emergency depth: 438.4 feet
Crush depth: 685 feet
Breakdown of Miscellaneous Weights:
- 105 tons for ballast
- 15 tons for 10 reload torpedo's
- 10 for "improved hydrophones"
- 10 tons for Fallax system
Ships in Class:
- BVK
Delfi/Dolphin (PB-1) - 1937
- BVK
Syomga/Salmon (PB-2) - 1938
- BVK
Esetra/Sturgeon (PB-3) - 1938
- BVK
Pastarva/Trout (PB-4) - 1938
Notes:
The
Delfi is an updated version of the Atlantean
R-74-class coastal submarine.