I-300, Japan Experimental Submarine laid down 1940
5 submarines built to test out various design ideas to improve the abilities of future IJN submarines including torpedo loading, electric engines and batteries. This eventually led to the construction of the bigger I-305 in 1944.
Displacement:
1,069 t light; 1,099 t standard; 1,456 t normal; 1,742 t full load
Dimensions: Length overall / water x beam x draught
259.19 ft / 259.19 ft x 19.03 ft x 22.97 ft (normal load)
79.00 m / 79.00 m x 5.80 m x 7.00 m
Armament:
2 - 0.98" / 25.0 mm guns in single mounts, 0.57lbs / 0.26kg shells, 1940 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
Weight of broadside 1 lbs / 1 kg
Shells per gun, main battery: 1,500
4 - 21.0" / 533.4 mm submerged torpedo tubes (all forward)
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured
Upper: 1.69" / 43 mm 180.45 ft / 55.00 m 19.69 ft / 6.00 m (see below)
Machinery:
Oil fired boilers, steam turbines,
Electric cruising motors plus geared drives, 2 shafts, 4,673 shp / 3,486 Kw = 19.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 643 tons
Complement:
117 - 153
Cost:
£0.330 million / $1.320 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.0%
Armour: 242 tons, 16.6%
- Belts: 242 tons, 16.6%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 0 tons, 0.0%
- Armour Deck: 0 tons, 0.0%
- Conning Tower: 0 tons, 0.0%
Machinery: 125 tons, 8.6%
Hull, fittings & equipment: 702 tons, 48.2%
Fuel, ammunition & stores: 387 tons, 26.6%
Miscellaneous weights: 0 tons, 0.0%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,592 lbs / 722 Kg = 3,340.3 x 1.0 " / 25 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.4 ft / 0.1 m
Roll period: 12.5 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: 0.450
Length to Beam Ratio: 13.62 : 1
'Natural speed' for length: 16.10 kts
Power going to wave formation at top speed: 40 %
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): 44.9%
- Above water (accommodation/working, high = better): 0.0%
Waterplane Area: 3,146 Square feet or 292 Square metres
Displacement factor (Displacement / loading): 296%
Structure weight / hull surface area: 102 lbs/sq ft or 496 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 2.82
- Longitudinal: 3.22
- Overall: 2.86
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
Upper belt used to sim ballast tank.
Speed (surface): 15.8 knots
Speed (submerged): 19 knots
Actual range (surface): 5,800nm at 14 knots
Range (submerged): 135nm at 3 knots
Diving depth: 286 feet
Test Depth (*): 358 feet
Emergency Depth: 458 feet
Crush Depth: 715 feet
Actual bunker size: 329 tons
10 Type 99 torpedoes: 18 tons (used bunker)
Ninjatousaya System: 10 tons (used bunker)
Experimental stuff: 286 tons (used bunker)
(*) read: Limit of a crew member's life insurance.