ISV Hydra, Arcaenia Battlecruiser laid down 1921
Displacement:
54,244 t light; 57,366 t standard; 59,335 t normal; 60,910 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(896.54 ft / 885.83 ft) x 108.27 ft x (36.09 / 36.84 ft)
(273.27 m / 270.00 m) x 33.00 m x (11.00 / 11.23 m)
Armament:
9 - 18.00" / 457 mm 48.0 cal guns - 3,399.99lbs / 1,542.21kg shells, 100 per gun
Breech loading guns in turret on barbette mounts, 1921 Model
3 x 3-gun mounts on centreline ends, majority forward
1 raised mount - superfiring
16 - 6.00" / 152 mm 53.0 cal guns - 105.01lbs / 47.63kg shells, 200 per gun
Breech loading guns in turret on barbette mounts, 1921 Model
8 x 2-gun mounts on sides, evenly spread
2 raised mounts
8 - 5.00" / 127 mm 25.0 cal guns - 55.01lbs / 24.95kg shells, 200 per gun
Anti-air guns in deck and hoist mounts, 1921 Model
8 x Single mounts on sides, evenly spread
8 raised mounts
Weight of broadside 32,720 lbs / 14,842 kg
Main Torpedoes
6 - 21.0" / 533 mm, 24.00 ft / 7.32 m torpedoes - 1.543 t each, 9.261 t total
In 2 sets of deck mounted side rotating tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 14.0" / 356 mm 637.80 ft / 194.40 m 12.50 ft / 3.81 m
Ends: Unarmoured
Main Belt covers 111 % of normal length
Main Belt inclined 20.00 degrees (positive = in)
- Torpedo Bulkhead - Strengthened structural bulkheads:
4.00" / 102 mm 637.80 ft / 194.40 m 33.86 ft / 10.32 m
Beam between torpedo bulkheads 88.58 ft / 27.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 17.0" / 432 mm 9.00" / 229 mm 14.0" / 356 mm
2nd: 4.00" / 102 mm 2.00" / 51 mm 2.00" / 51 mm
3rd: 0.50" / 13 mm - -
- Armoured deck - multiple decks:
For and Aft decks: 8.00" / 203 mm
- Conning towers: Forward 9.00" / 229 mm, Aft 0.00" / 0 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 230,001 shp / 171,581 Kw = 33.08 kts
Range 9,651nm at 10.00 kts
Bunker at max displacement = 3,544 tons
Complement:
1,900 - 2,471
Cost:
£15.194 million / $60.777 million
Distribution of weights at normal displacement:
Armament: 6,212 tons, 10.5 %
- Guns: 6,194 tons, 10.4 %
- Weapons: 19 tons, 0.0 %
Armour: 21,736 tons, 36.6 %
- Belts: 4,648 tons, 7.8 %
- Torpedo bulkhead: 3,196 tons, 5.4 %
- Armament: 4,258 tons, 7.2 %
- Armour Deck: 9,340 tons, 15.7 %
- Conning Tower: 295 tons, 0.5 %
Machinery: 7,920 tons, 13.3 %
Hull, fittings & equipment: 18,375 tons, 31.0 %
Fuel, ammunition & stores: 5,091 tons, 8.6 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
58,131 lbs / 26,368 Kg = 19.9 x 18.0 " / 457 mm shells or 7.2 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 5.8 ft / 1.8 m
Roll period: 18.8 seconds
Steadiness - As gun platform (Average = 50 %): 48 %
- Recoil effect (Restricted arc if above 1.00): 0.97
Seaboat quality (Average = 1.00): 0.75
Hull form characteristics:
Hull has a flush deck,
an extended bulbous bow and large transom stern
Block coefficient (normal/deep): 0.600 / 0.603
Length to Beam Ratio: 8.18 : 1
'Natural speed' for length: 34.14 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 60
Bow angle (Positive = bow angles forward): 17.00 degrees
Stern overhang: 4.40 ft / 1.34 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 14.00 %, 20.67 ft / 6.30 m, 20.67 ft / 6.30 m
- Forward deck: 30.00 %, 20.67 ft / 6.30 m, 20.67 ft / 6.30 m
- Aft deck: 42.00 %, 20.67 ft / 6.30 m, 20.67 ft / 6.30 m
- Quarter deck: 14.00 %, 20.67 ft / 6.30 m, 20.67 ft / 6.30 m
- Average freeboard: 20.67 ft / 6.30 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 108.4 %
- Above water (accommodation/working, high = better): 150.3 %
Waterplane Area: 73,106 Square feet or 6,792 Square metres
Displacement factor (Displacement / loading): 90 %
Structure weight / hull surface area: 245 lbs/sq ft or 1,196 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.03
- Overall: 1.00
Adequate machinery, storage, compartmentation space
Excellent accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather