WesWorld

Perla Class Submarine, laid down 1933

Displacement:
390 t light; 400 t standard; 423 t normal; 441 t full load

Dimensions: Length overall / water x beam x draught
147.64 ft / 147.64 ft x 15.09 ft x 13.12 ft (normal load)
45.00 m / 45.00 m x 4.60 m x 4.00 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 30.51lbs / 13.84kg shells, 1933 Model
Quick firing gun in deck mount
on centreline amidships
2 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1933 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 31 lbs / 14 kg
Shells per gun, main battery: 100
4 - 21.0" / 533 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion engines plus batteries,
Electric cruising motors plus geared drives, 1 shaft, 773 shp / 577 Kw = 13.90 kts
Range 2,700nm at 10.00 kts
Bunker at max displacement = 41 tons

Complement:
46 - 60

Cost:
£0.095 million / $0.380 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.9 %
Machinery: 23 tons, 5.3 %
Hull, fittings & equipment: 293 tons, 69.1 %
Fuel, ammunition & stores: 33 tons, 7.8 %
Miscellaneous weights: 71 tons, 16.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
68 lbs / 31 Kg = 2.2 x 3.9 " / 100 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 0.3 ft / 0.1 m
Roll period: 11.5 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: 0.506
Length to Beam Ratio: 9.78 : 1
'Natural speed' for length: 12.15 kts
Power going to wave formation at top speed: 47 %
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): 177.5 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 1,437 Square feet or 133 Square metres
Displacement factor (Displacement / loading): 287 %
Structure weight / hull surface area: 112 lbs/sq ft or 546 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 4.52
- Longitudinal: 4.58
- Overall: 4.52
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

Thirteen units


Image by Red Admiral

Dolphin, Thai Submarine laid down 1940

Displacement:
288 t light; 296 t standard; 310 t normal; 321 t full load

Dimensions: Length overall / water x beam x draught
131.23 ft / 131.23 ft x 14.76 ft x 9.51 ft (normal load)
40.00 m / 40.00 m x 4.50 m x 2.90 m

Armament:
1 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1940 Model
Dual purpose gun in deck mount
on centreline amidships
1 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1940 Model
Machine gun in deck mount
on centreline amidships, 1 raised gun
Weight of broadside 2 lbs / 1 kg
Shells per gun, main battery: 1,500
2 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 380 shp / 284 Kw = 12.03 kts
Range 5,000nm at 7.00 kts
Bunker at max displacement = 25 tons

Complement:
36 - 48

Cost:
£0.070 million / $0.281 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.1 %
Machinery: 10 tons, 3.3 %
Hull, fittings & equipment: 203 tons, 65.4 %
Fuel, ammunition & stores: 22 tons, 7.0 %
Miscellaneous weights: 75 tons, 24.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
224 lbs / 102 Kg = 144.9 x 1.5 " / 37 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.01
Metacentric height 0.3 ft / 0.1 m
Roll period: 11.5 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: 0.589
Length to Beam Ratio: 8.89 : 1
'Natural speed' for length: 11.46 kts
Power going to wave formation at top speed: 47 %
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): 69.6 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 1,402 Square feet or 130 Square metres
Displacement factor (Displacement / loading): 319 %
Structure weight / hull surface area: 97 lbs/sq ft or 476 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 4.86
- Longitudinal: 2.92
- Overall: 3.32
Hull space for machinery, storage, compartmentation is excellent
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

Operational Depth: 100.2m
Emergenty Diving Depth: 160.32m
Crush Depth:250.5m
Actual Crew: 18-24

Six units


Image by Daidalos

J class Submarines
Laid down: 1915-16
Dimensions: 275 x 23.5 x 14 feet
Displacment: 1,210 surfaced, 1,800 submerged
Armament: 1 x 4" deck gun, 6 x 18" tt (4Fow, 2Aft)
Speed: 19 knots on the surface, 9.5 submerged.
Range: 5000 nm @ 12.5 knots
Complement: 44 Officers and Ratings

Six units

Dolphin II, Thai Submarine laid down 1941

Displacement:
600 t light; 618 t standard; 665 t normal; 702 t full load

Dimensions: Length overall / water x beam x draught
209.97 ft / 209.97 ft x 19.03 ft x 14.44 ft (normal load)
64.00 m / 64.00 m x 5.80 m x 4.40 m

Armament:
1 - 3.94" / 100 mm guns in single mounts, 30.86lbs / 14.00kg shells, 1941 Model
Quick firing gun in deck mount
on centreline amidships
1 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1941 Model
Dual purpose gun in deck mount
on centreline amidships
2 - 0.79" / 20.0 mm guns (1x2 guns), 0.24lbs / 0.11kg shells, 1941 Model
Machine guns in deck mount
on centreline amidships, all raised guns - superfiring
Weight of broadside 33 lbs / 15 kg
Shells per gun, main battery: 250
5 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 1,533 shp / 1,144 Kw = 16.00 kts
Range 7,500nm at 8.00 kts
Bunker at max displacement = 84 tons

Complement:
65 - 85

Cost:
£0.186 million / $0.744 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.6 %
Machinery: 41 tons, 6.1 %
Hull, fittings & equipment: 423 tons, 63.6 %
Fuel, ammunition & stores: 65 tons, 9.7 %
Miscellaneous weights: 133 tons, 20.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
326 lbs / 148 Kg = 10.7 x 3.9 " / 100 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.4 ft / 0.1 m
Roll period: 12.4 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: 0.404
Length to Beam Ratio: 11.03 : 1
'Natural speed' for length: 14.49 kts
Power going to wave formation at top speed: 39 %
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): 100.7 %
- Above water (accommodation/working, high = better): 0.0 %
Waterplane Area: 2,465 Square feet or 229 Square metres
Displacement factor (Displacement / loading): 270 %
Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 3.54
- Longitudinal: 2.54
- Overall: 2.76
Hull space for machinery, storage, compartmentation is adequate
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

Operational Depth: 82.8m
Emergenty Diving Depth: 132.48m
Crush Depth: 207m
Actual Crew: 32-42

As the first submarines constructed in Thailand were being layed down in the middle of 1940, the Thai navy was already looking to build bigger boats. At almost double the size of the original Dolphin I design, the Dolphin II class subs bring the Thai navy to the ranks of nations with capable domestic submarine programs. Equipped with five 21" torpedo tubes and a 100mm gun, these subs have a considerable armament. A 37mm dual purpose anti-aircraft gun compliments both the anti-ship battery and aids the 20mm guns in fending off aircraft. With over 1.5 times the range of the Dolphin I class, the Dolphin II allows for a much greater projection of the Thai Navy's power. The dolphin II class brings both the abilities of the Thai Navy and the domestic shipyards up to producing subs that can compare with modern types in service the world over.



Image by Daidalos