Ships in Class
Impavido Layed down 1933, refited 1943
Indomito Layed down 1933, refited 1943
Impetuoso Layed down 1933, refited 1943
Insidioso Layed down 1933, refited 1943
Picture is pre-refit. By RA.
Displacement:
2,104 t light; 2,231 t standard; 2,644 t normal; 2,974 t full load
Dimensions: Length overall / water x beam x draught
393.70 ft / 393.70 ft x 42.65 ft x 13.78 ft (normal load)
120.00 m / 120.00 m x 13.00 m x 4.20 m
Armament:
8 - 3.94" / 100 mm guns in single mounts, 33.07lbs / 15.00kg shells, 1943 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, 4 raised mounts - superfiring
8 - 1.46" / 37.0 mm guns (4x2 guns), 1.55lbs / 0.70kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
16 - 1.46" / 37.0 mm guns (8x2 guns), 1.55lbs / 0.70kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
8 - 0.98" / 25.0 mm guns in single mounts, 0.53lbs / 0.24kg shells, 1943 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 306 lbs / 139 kg
Shells per gun, main battery: 400
8 - 23.6" / 600 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
2nd: 0.39" / 10 mm - -
3rd: 0.39" / 10 mm - -
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 40,000 shp / 29,840 Kw = 32.94 kts
Range 4,000nm at 20.00 kts
Bunker at max displacement = 743 tons
Complement:
183 - 239
Cost:
£1.248 million / $4.992 million
Distribution of weights at normal displacement:
Armament: 36 tons, 1.3 %
Armour: 24 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 24 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,146 tons, 43.3 %
Hull, fittings & equipment: 798 tons, 30.2 %
Fuel, ammunition & stores: 540 tons, 20.4 %
Miscellaneous weights: 100 tons, 3.8 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,140 lbs / 517 Kg = 37.4 x 3.9 " / 100 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.39
Metacentric height 2.5 ft / 0.8 m
Roll period: 11.4 seconds
Steadiness - As gun platform (Average = 50 %): 62 %
- Recoil effect (Restricted arc if above 1.00): 0.27
Seaboat quality (Average = 1.00): 1.23
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 9.23 : 1
'Natural speed' for length: 23.11 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.89 ft / 8.50 m
- Forecastle (15 %): 21.33 ft / 6.50 m
- Mid (53 %): 21.33 ft / 6.50 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (15 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 17.86 ft / 5.45 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 156.7 %
- Above water (accommodation/working, high = better): 114.7 %
Waterplane Area: 10,727 Square feet or 997 Square metres
Displacement factor (Displacement / loading): 96 %
Structure weight / hull surface area: 40 lbs/sq ft or 197 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.52
- Longitudinal: 2.01
- Overall: 0.59
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Good seaboat, rides out heavy weather easily
20t RaA.5 Air Search radar
20t RaS.4 Surface Search radar
30t 1 x GDR5 FC Systems
10t Sonar
15t ASW Weapons
5t Construction reserve