Undiine class (Former Aria class) Atena Gurourii version, Japan Light Cruiser laid down 1934
Displacement:
8,067 t light; 8,419 t standard; 9,975 t normal; 11,219 t full load
Dimensions: Length overall / water x beam x draught
619.29 ft / 610.00 ft x 61.00 ft x 19.75 ft (normal load)
188.76 m / 185.93 m x 18.59 m x 6.02 m
Armament:
9 - 5.91" / 150 mm guns (3x3 guns), 105.00lbs / 47.63kg shells, 1934 Model
Quick firing guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 4.13" / 105 mm guns (4x2 guns), 34.00lbs / 15.42kg shells, 1934 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships
16 - 1.57" / 40.0 mm guns (2x8 guns), 2.00lbs / 0.91kg shells, 1934 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread, all raised mounts
24 - 0.98" / 25.0 mm guns (8x3 guns), 0.57lbs / 0.26kg shells, 1934 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 4 raised mounts
32 - 0.52" / 13.2 mm guns (4x8 guns), 0.09lbs / 0.04kg shells, 1934 Model
Machine guns in deck mounts
on side ends, evenly spread
Weight of broadside 1,266 lbs / 574 kg
Shells per gun, main battery: 200
12 - 24.0" / 609.6 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4.00" / 102 mm 365.00 ft / 111.25 m 9.50 ft / 2.90 m
Ends: Unarmoured
Main Belt covers 92% of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4.00" / 102 mm 3.00" / 76 mm 3.00" / 76 mm
2nd: 2.00" / 51 mm 1.00" / 25 mm 2.00" / 51 mm
3rd: 1.00" / 25 mm 1.00" / 25 mm -
4th: 1.00" / 25 mm 1.00" / 25 mm -
5th: 0.50" / 13 mm 0.50" / 13 mm -
- Armour deck: 1.50" / 38 mm, Conning tower: 2.75" / 70 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 76,163 shp / 56,818 Kw = 32.50 kts
Range 8,900nm at 18.00 kts
Bunker at max displacement = 2,800 tons
Complement:
498 - 648
Cost:
£3.539 million / $14.154 million
Distribution of weights at normal displacement:
Armament: 157 tons, 1.6%
Armour: 1,576 tons, 15.8%
- Belts: 584 tons, 5.9%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 265 tons, 2.7%
- Armour Deck: 699 tons, 7.0%
- Conning Tower: 27 tons, 0.3%
Machinery: 2,191 tons, 22.0%
Hull, fittings & equipment: 3,743 tons, 37.5%
Fuel, ammunition & stores: 1,907 tons, 19.1%
Miscellaneous weights: 400 tons, 4.0%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
13,281 lbs / 6,024 Kg = 129.0 x 5.9 " / 150 mm shells or 1.8 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 3.0 ft / 0.9 m
Roll period: 14.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.30
Seaboat quality (Average = 1.00): 1.05
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.475
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 28.27 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.20 ft / 8.29 m
- Forecastle (20%): 17.20 ft / 5.24 m
- Mid (50%): 17.20 ft / 5.24 m
- Quarterdeck (15%): 17.20 ft / 5.24 m
- Stern: 15.20 ft / 4.63 m
- Average freeboard: 17.85 ft / 5.44 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 88.8%
- Above water (accommodation/working, high = better): 117.7%
Waterplane Area: 25,198 Square feet or 2,341 Square metres
Displacement factor (Displacement / loading): 131%
Structure weight / hull surface area: 98 lbs/sq ft or 481 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.12
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform