A major refit of the Zara class heavy cruisers after over ten years of service. The internal fittings have been refurbished for life extension purposes and more modern equipment added, especially electronics. The secondary armament has been altered with the removal of the 100/47 battery and it's replacement by more modern 76/62 and 25mm weapons. It is expected that the ships may serve another decade before being obsolete; already there are much larger and newer cruisers afloat.
RM Zara, Italian Cruiser laid down 1927, Refitted 1941
Displacement:
11,239 t light; 11,843 t standard; 13,155 t normal; 14,206 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(603.33 ft / 590.55 ft) x 67.59 ft x (23.79 / 25.19 ft)
(183.89 m / 180.00 m) x 20.60 m x (7.25 / 7.68 m)
Armament:
8 - 8.00" / 203 mm 53.0 cal guns - 276.24lbs / 125.30kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1927 Model
4 x 2-gun mounts on centreline ends, evenly spread
2 raised mounts - superfiring
16 - 3.00" / 76.2 mm 62.0 cal guns - 14.86lbs / 6.74kg shells, 1,000 per gun
Auto rapid fire guns in deck and hoist mounts, 1941 Model
16 x Single mounts on sides, forward evenly spread
4 raised mounts
20 - 0.98" / 25.0 mm 77.0 cal guns - 0.54lbs / 0.24kg shells, 4,000 per gun
Anti-air guns in deck mounts, 1927 Model
20 x Single mounts on sides amidships
Weight of broadside 2,458 lbs / 1,115 kg
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.91" / 150 mm 370.73 ft / 113.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 97 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.91" / 150 mm 3.94" / 100 mm 3.94" / 100 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm - -
- Armoured deck - multiple decks: 2.76" / 70 mm For and Aft decks
Forecastle: 2.76" / 70 mm Quarter deck: 2.76" / 70 mm
- Conning towers: Forward 5.91" / 150 mm, Aft 0.00" / 0 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 96,400 shp / 71,914 Kw = 31.62 kts
Range 4,215nm at 20.00 kts
Bunker at max displacement = 2,363 tons
Complement:
613 - 798
Cost:
£3.987 million / $15.949 million
Distribution of weights at normal displacement:
Armament: 855 tons, 6.5 %
Armour: 2,852 tons, 21.7 %
- Belts: 898 tons, 6.8 %
- Armament: 535 tons, 4.1 %
- Armour Deck: 1,348 tons, 10.2 %
- Conning Tower: 71 tons, 0.5 %
Machinery: 3,043 tons, 23.1 %
Hull, fittings & equipment: 4,425 tons, 33.6 %
Fuel, ammunition & stores: 1,916 tons, 14.6 %
Miscellaneous weights: 65 tons, 0.5 %
- Above deck: 65 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
15,808 lbs / 7,170 Kg = 61.7 x 8.0 " / 203 mm shells or 1.9 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 3.6 ft / 1.1 m
Roll period: 15.0 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.45
Seaboat quality (Average = 1.00): 1.00
Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.485 / 0.495
Length to Beam Ratio: 8.74 : 1
'Natural speed' for length: 24.30 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 18.93 %, 26.08 ft / 7.95 m, 22.80 ft / 6.95 m
- Forward deck: 46.07 %, 22.80 ft / 6.95 m, 22.80 ft / 6.95 m
- Aft deck: 16.07 %, 12.96 ft / 3.95 m, 12.96 ft / 3.95 m
- Quarter deck: 18.93 %, 12.96 ft / 3.95 m, 12.96 ft / 3.95 m
- Average freeboard: 19.61 ft / 5.98 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 95.8 %
- Above water (accommodation/working, high = better): 165.1 %
Waterplane Area: 26,236 Square feet or 2,437 Square metres
Displacement factor (Displacement / loading): 113 %
Structure weight / hull surface area: 120 lbs/sq ft or 584 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.47
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
30t = RaA.2 Air Search Radar and IFF
10t = RaS.4 Surface Warning Radar
5t = Radio Beacon
20t = 2 x GDR.101