HMS Zoraster, Aztec/Parthian Built Seaplane/EX Carrier laid down 1920
Displacement:
6,494 t light; 6,737 t standard; 7,568 t normal; 8,233 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(489.04 ft / 485.56 ft) x 55.77 ft x (17.16 / 18.37 ft)
(149.06 m / 148.00 m) x 17.00 m x (5.23 / 5.60 m)
Armament:
10 - 5.12" / 130 mm 50.0 cal guns - 70.97lbs / 32.19kg shells, 200 per gun
Quick firing guns in deck mounts, 1920 Model
10 x Single mounts on sides, evenly spread
6 - 2.76" / 70.0 mm 50.0 cal guns - 11.08lbs / 5.03kg shells, 300 per gun
Anti-air guns in deck mounts, 1920 Model
6 x Single mounts on sides, evenly spread
6 raised mounts
24 - 0.47" / 12.0 mm 70.0 cal guns - 0.06lbs / 0.03kg shells, 2,000 per gun
Machine guns in deck mounts, 1920 Model
12 x Twin mounts on sides, evenly spread
12 raised mounts
Weight of broadside 778 lbs / 353 kg
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured
- Torpedo Bulkhead - Additional damage containing bulkheads:
1.18" / 30 mm 393.70 ft / 120.00 m 14.76 ft / 4.50 m
Beam between torpedo bulkheads 32.81 ft / 10.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 1.10" / 28 mm -
- Box over machinery & magazines:
1.97" / 50 mm
- Conning towers: Forward 1.97" / 50 mm, Aft 0.00" / 0 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 2 shafts, 25,641 shp / 19,128 Kw = 24.00 kts
Range 8,000nm at 14.00 kts
Bunker at max displacement = 1,496 tons
Complement:
405 - 527
Cost:
£0.933 million / $3.732 million
Distribution of weights at normal displacement:
Armament: 153 tons, 2.0%
- Guns: 153 tons, 2.0%
Armour: 708 tons, 9.4%
- Torpedo bulkhead: 254 tons, 3.4%
- Armament: 83 tons, 1.1%
- Armour Deck: 354 tons, 4.7%
- Conning Tower: 16 tons, 0.2%
Machinery: 897 tons, 11.8%
Hull, fittings & equipment: 2,797 tons, 37.0%
Fuel, ammunition & stores: 1,074 tons, 14.2%
Miscellaneous weights: 1,940 tons, 25.6%
- Hull below water: 994 tons
- Hull above water: 770 tons
- On freeboard deck: 100 tons
- Above deck: 76 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
19,102 lbs / 8,664 Kg = 285.0 x 5.1 " / 130 mm shells or 2.9 torpedoes
Stability (Unstable if below 1.00): 1.28
Metacentric height 3.3 ft / 1.0 m
Roll period: 13.0 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.19
Seaboat quality (Average = 1.00): 2.00
Hull form characteristics:
Hull has low forecastle, low quarterdeck ,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.570 / 0.579
Length to Beam Ratio: 8.71 : 1
'Natural speed' for length: 22.04 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00%, 19.69 ft / 6.00 m, 19.69 ft / 6.00 m
- Forward deck: 30.00%, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Aft deck: 35.00%, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Quarter deck: 15.00%, 9.84 ft / 3.00 m, 9.84 ft / 3.00 m
- Average freeboard: 24.61 ft / 7.50 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 119.9%
- Above water (accommodation/working, high = better): 267.4%
Waterplane Area: 19,258 Square feet or 1,789 Square metres
Displacement factor (Displacement / loading): 156%
Structure weight / hull surface area: 81 lbs/sq ft or 394 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.87
- Longitudinal: 3.41
- Overall: 1.00
Cramped machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
1540t - 14 x Twin Engine Seaplanes (Torpedo Bombers)
16t - 1918 FC
25t - LR Radio
10t - Additional SR Radio
25t - 1918 NF Devices
50t - Aft Crane
50t - Flying Off Platform Forward
224t - Electric Drives