Shimushu, Japan Kaibokan laid down 1941
Ships: 18. Shimushu, Hachijo, Kunashiri, Ishigaki, Etorofu, Hirado, Tsushima, Fukue, Matsuwa, Mutsure, Sado, Oki, Manju, Kanju, Iki, Amakusa, Wakamiya, Kasado.
Displacement:
880 t light; 938 t standard; 1,174 t normal; 1,363 t full load
Dimensions: Length overall / water x beam x draught
264.41 ft / 260.00 ft x 32.00 ft x 11.30 ft (normal load)
80.59 m / 79.25 m x 9.75 m x 3.44 m
Armament:
1 - 5.00" / 127 mm guns in single mounts, 55.12lbs / 25.00kg shells, 1941 Model
Automatic rapid fire gun in a deck mount with hoist
on centreline forward
2 - 5.00" / 127 mm guns (1x2 guns), 55.12lbs / 25.00kg shells, 1941 Model
Automatic rapid fire guns in a deck mount with hoist
on centreline aft
12 - 0.98" / 25.0 mm guns (4x3 guns), 0.57lbs / 0.26kg shells, 1941 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread, all raised mounts - superfiring
1 - 0.98" / 25.0 mm guns in single mounts, 0.57lbs / 0.26kg shells, 1941 Model
Anti-aircraft gun in deck mount
on centreline forward, 1 raised gun
3 - 0.98" / 25.0 mm guns (1x3 guns), 0.57lbs / 0.26kg shells, 1941 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
Weight of broadside 174 lbs / 79 kg
Shells per gun, main battery: 300
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 1.00" / 25 mm -
3rd: 1.00" / 25 mm - -
5th: 1.00" / 25 mm - -
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 6,920 shp / 5,162 Kw = 22.00 kts
Range 6,000nm at 16.00 kts
Bunker at max displacement = 425 tons
Complement:
99 - 130
Cost:
£0.500 million / $1.998 million
Distribution of weights at normal displacement:
Armament: 29 tons, 2.5%
Armour: 7 tons, 0.6%
- Belts: 0 tons, 0.0%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 7 tons, 0.6%
- Armour Deck: 0 tons, 0.0%
- Conning Tower: 0 tons, 0.0%
Machinery: 183 tons, 15.6%
Hull, fittings & equipment: 431 tons, 36.7%
Fuel, ammunition & stores: 294 tons, 25.1%
Miscellaneous weights: 230 tons, 19.6%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,370 lbs / 621 Kg = 21.9 x 5.0 " / 127 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 1.1 ft / 0.3 m
Roll period: 12.9 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.23
Seaboat quality (Average = 1.00): 1.04
Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.437
Length to Beam Ratio: 8.13 : 1
'Natural speed' for length: 16.12 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 48
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 16.47 ft / 5.02 m
- Forecastle (25%): 14.76 ft / 4.50 m
- Mid (27%): 14.76 ft / 4.50 m (8.07 ft / 2.46 m aft of break)
- Quarterdeck (15%): 8.07 ft / 2.46 m
- Stern: 8.07 ft / 2.46 m
- Average freeboard: 10.05 ft / 3.06 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 92.7%
- Above water (accommodation/working, high = better): 83.8%
Waterplane Area: 5,252 Square feet or 488 Square metres
Displacement factor (Displacement / loading): 141%
Structure weight / hull surface area: 50 lbs/sq ft or 247 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 2.01
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is cramped
40t - 2x Active Sonar
10t - Hydrophones
20t - Air Search Radar
10t - Surface Search Radar
15t - Fire Control
4t - 2 Depth Charge Projectors
16t - 16 Depth Charge Throwers
4t - 2 Depth Charge Chutes
40t - 120 Depth Charges
2t - 81mm mortar + ammunition
15t - 1200 additional 25mm rounds per gun
2t - 2 paravanes
17t - air condition system
10t - emergency diesel generators
25 t - miscellaneous
230t total