Improved Philomedes, Atlantean Battleship, designed for 1937 to replace the planned two Massinissa and four Oberoth designs with six standard designs.
Ship names: Neptune, Oberoth, Leviathan, Orion laid down 1937, two additional ships ordered.
Displacement:
47,370 t light; 50,322 t standard; 55,157 t normal; 59,024 t full load
Dimensions: Length overall / water x beam x draught
844.37 ft / 825.00 ft x 110.00 ft x 33.50 ft (normal load)
257.36 m / 251.46 m x 33.53 m x 10.21 m
Armament:
9 - 16.50" / 419 mm guns (3x3 guns), 2,246.06lbs / 1,018.80kg shells, 1937 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
24 - 5.10" / 130 mm guns (12x2 guns), 66.33lbs / 30.08kg shells, 1937 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread, 4 raised mounts
16 - 1.58" / 40.0 mm guns (8x2 guns), 1.95lbs / 0.89kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 6 raised mounts
28 - 0.79" / 20.0 mm guns (7x4 guns), 0.24lbs / 0.11kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
16 - 0.50" / 12.7 mm guns (8x2 guns), 0.06lbs / 0.03kg shells, 1937 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 21,845 lbs / 9,909 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 15.0" / 381 mm 450.00 ft / 137.16 m 14.76 ft / 4.50 m
Ends: Unarmoured
Main Belt covers 84 % of normal length
- Torpedo Bulkhead:
2.15" / 55 mm 450.00 ft / 137.16 m 32.00 ft / 9.75 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 15.0" / 381 mm 11.7" / 297 mm 15.0" / 381 mm
2nd: 2.00" / 51 mm 1.00" / 25 mm 1.58" / 40 mm
3rd: 1.00" / 25 mm - -
4th: 0.79" / 20 mm - -
5th: 0.50" / 13 mm - -
- Armour deck: 6.75" / 171 mm, Conning tower: 15.00" / 381 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 158,000 shp / 117,868 Kw = 30.01 kts
Range 15,000nm at 15.00 kts
Bunker at max displacement = 8,702 tons
Complement:
1,799 - 2,339
Cost:
£24.899 million / $99.596 million
Distribution of weights at normal displacement:
Armament: 2,731 tons, 5.0 %
Armour: 19,067 tons, 34.6 %
- Belts: 4,451 tons, 8.1 %
- Torpedo bulkhead: 1,146 tons, 2.1 %
- Armament: 4,072 tons, 7.4 %
- Armour Deck: 8,930 tons, 16.2 %
- Conning Tower: 468 tons, 0.8 %
Machinery: 4,379 tons, 7.9 %
Hull, fittings & equipment: 20,993 tons, 38.1 %
Fuel, ammunition & stores: 7,787 tons, 14.1 %
Miscellaneous weights: 200 tons, 0.4 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
79,249 lbs / 35,947 Kg = 35.3 x 16.5 " / 419 mm shells or 12.0 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 6.0 ft / 1.8 m
Roll period: 18.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.78
Seaboat quality (Average = 1.00): 1.09
Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.635
Length to Beam Ratio: 7.50 : 1
'Natural speed' for length: 33.06 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 64
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 5.00 ft / 1.52 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30.82 ft / 9.39 m
- Forecastle (20 %): 23.00 ft / 7.01 m
- Mid (50 %): 23.00 ft / 7.01 m
- Quarterdeck (15 %): 23.00 ft / 7.01 m
- Stern: 23.00 ft / 7.01 m
- Average freeboard: 23.63 ft / 7.20 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.6 %
- Above water (accommodation/working, high = better): 174.2 %
Waterplane Area: 71,514 Square feet or 6,644 Square metres
Displacement factor (Displacement / loading): 111 %
Structure weight / hull surface area: 219 lbs/sq ft or 1,067 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.01
- Longitudinal: 1.25
- Overall: 1.04
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform