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Francesco Morosini

Ships in class; Francesco Morosini reconstructed 1926







Francesco Morosini, Italian Aircraft Carrier laid down 1920

Displacement:
24,922 t light; 25,542 t standard; 28,236 t normal; 30,277 t full load
Loading submergence 1,310 tons/feet

Dimensions:
695.54 ft x 98.43 ft x 26.25 ft (normal load)
212.00 m x 30.00 m x 8.00 m

Armament:
Airgroup of 72: 3 squadrons of 12 Fighters. 1 squadrons of 12 Reconaissance. 2 squadrons of 12 Torpedo bombers.
16 - 130mm / 50 guns carried in 2 single and 7 duple mounts
40 - 13.7 mm machine guns carried in 6 quaduple and 8 duple mounts

Armour:
Belt 5.91" / 150 mm, upper belt 3.94" / 100 mm, ends unarmoured
Belts cover 95 % of normal area
Main gun shields 0.79" / 20 mm
Armour deck 3.94" / 100 mm, Conning tower 2.76" / 70 mm
Torpedo bulkhead 1.57" / 35 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 130,000 shp / 96,980 Kw = 30.29 kts
Range 5,000nm at 20.00 kts

Complement:
1,089 - 1,415

Cost:
£3.733 million / $14.932 million

Distribution of weights at normal displacement:
Armament: 84 tons, 0.3 %
Armour: 5,986 tons, 21.2 %
Belts: 1,864 tons, 6.6 %, Armament: 35 tons, 0.1 %, Armour Deck: 3,340 tons, 11.8 %
Conning Tower: 55 tons, 0.2 %, Torpedo bulkhead: 691 tons, 2.4 %
Machinery: 4,545 tons, 16.1 %
Hull, fittings & equipment: 9,105 tons, 32.2 %
Fuel, ammunition & stores: 3,314 tons, 11.7 %
Miscellaneous weights: 5,200 tons, 18.4 %

Metacentric height 7.1

Remarks:
Hull space for machinery, storage & compartmentation is adequate
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable and able to fight her guns in the heaviest weather

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.22
Shellfire needed to sink: 41,671 lbs / 18,901 Kg = 1,365.7 x 3.9 " / 100 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 5.1
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.02
Relative quality as seaboat: 1.68

Hull form characteristics:
Block coefficient: 0.550
Sharpness coefficient: 0.39
Hull speed coefficient 'M': 6.99
'Natural speed' for length: 26.37 kts
Power going to wave formation at top speed: 55 %
Trim: 42
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 94.6 %
Relative accommodation and working space: 263.2 %
(Average = 100%)
Displacement factor: 135 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.93
(Structure weight / hull surface area: 127 lbs / square foot or 622 Kg / square metre)
Relative longitudinal hull strength: 1.96
(for 32.81 ft / 10.00 m average freeboard, freeboard adjustment 14.17 ft)
Relative composite hull strength: 1.01



RM Francesco Morosini, Italian Portaerei laid down 1920 (Engine 1927)

Displacement:
27,085 t light; 27,986 t standard; 32,953 t normal; 36,927 t full load

Dimensions: Length overall / water x beam x draught
822.75 ft / 787.40 ft x 98.43 ft x 27.56 ft (normal load)
250.77 m / 240.00 m x 30.00 m x 8.40 m

Aircraft:
Airgroup of 72; 2 squadrons of fighters, 4 squadrons of T-bombers

Armament:
16 - 5.12" / 130 mm guns (8x2 guns), 70.55lbs / 32.00kg shells, 1927 Model
Breech loading guns in deck mounts with hoists
on side ends, evenly spread
16 - 2.56" / 65.0 mm guns in single mounts, 9.00lbs / 4.08kg shells, 1927 Model
Quick firing guns in deck mounts with hoists
on side ends, evenly spread
32 - 1.46" / 37.0 mm guns (12 mounts), 2.20lbs / 1.00kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 1,343 lbs / 609 kg
Shells per gun, main battery: 300

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.91" / 150 mm 428.54 ft / 130.62 m 11.91 ft / 3.63 m
Ends: Unarmoured
Upper: 3.94" / 100 mm 459.32 ft / 140.00 m 16.40 ft / 5.00 m
Main Belt covers 84 % of normal length

Upper belt covers lower hangar for its entirety.

- Torpedo Bulkhead:
1.38" / 35 mm 428.67 ft / 130.66 m 25.13 ft / 7.66 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 1.18" / 30 mm -
2nd: 0.79" / 20 mm 0.39" / 10 mm -
3rd: 0.79" / 20 mm - -

- Armour deck: 3.94" / 100 mm, Conning tower: 5.91" / 150 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 140,000 shp / 104,440 Kw = 30.66 kts
Range 5,940nm at 24.00 kts
Bunker at max displacement = 8,941 tons

Complement:
1,222 - 1,589

Cost:
£4.015 million / $16.059 million

Distribution of weights at normal displacement:
Armament: 157 tons, 0.5 %
Armour: 7,295 tons, 22.1 %
- Belts: 2,618 tons, 7.9 %
- Torpedo bulkhead: 549 tons, 1.7 %
- Armament: 94 tons, 0.3 %
- Armour Deck: 3,903 tons, 11.8 %
- Conning Tower: 131 tons, 0.4 %
Machinery: 4,419 tons, 13.4 %
Hull, fittings & equipment: 9,714 tons, 29.5 %
Fuel, ammunition & stores: 5,868 tons, 17.8 %
Miscellaneous weights: 5,500 tons, 16.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
57,527 lbs / 26,094 Kg = 858.2 x 5.1 " / 130 mm shells or 8.2 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 7.3 ft / 2.2 m
Roll period: 15.3 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.540
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 28.06 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 16.40 ft / 5.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.81 ft / 10.00 m
- Forecastle (23 %): 32.81 ft / 10.00 m (23.62 ft / 7.20 m aft of break)
- Mid (50 %): 23.62 ft / 7.20 m
- Quarterdeck (23 %): 23.62 ft / 7.20 m
- Stern: 23.62 ft / 7.20 m
- Average freeboard: 25.71 ft / 7.84 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.7 %
- Above water (accommodation/working, high = better): 197.3 %
Waterplane Area: 53,583 Square feet or 4,978 Square metres
Displacement factor (Displacement / loading): 144 %
Structure weight / hull surface area: 126 lbs/sq ft or 615 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.13
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

1924. Giuseppe Miraglia

Ships in class; Giuseppe Miraglia




RM Giuseppe Miraglia, Italian Seaplane Carrier laid down 1918

Displacement:
3,872 t light; 4,000 t standard; 5,242 t normal; 6,215 t full load
Loading submergence 442 tons/feet

Dimensions:
393.04 ft x 52.49 ft x 13.68 ft (normal load)
119.80 m x 16.00 m x 4.17 m

Armament:
24 seaplanes in 2 squadrons; 12 x M.71 reconnasaince and 12 x M.26 fighters
4 - 130mm / 50 M1924 guns in new experimental mounts
Weight of broadside 268 lbs / 122 kg
1500t Misc. weight


Armour:
Main gun shields 1.18" / 30 mm
Conning tower 2.76" / 70 mm

Machinery:
Oil fired boilers, complex reciprocating steam engines,
Geared drive, 2 shafts, 12,000 ihp / 8,952 Kw = 20.25 kts
Range 4,000nm at 20.00 kts

Complement:
308 - 400

Cost:
£0.526 million / $2.103 million

Distribution of weights at normal displacement:
Armament: 34 tons, 0.6 %
Armour: 26 tons, 0.5 %
Belts: 0 tons, 0.0 %, Armament: 8 tons, 0.2 %, Armour Deck: 0 tons, 0.0 %
Conning Tower: 18 tons, 0.3 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 708 tons, 13.5 %
Hull, fittings & equipment: 1,604 tons, 30.6 %
Fuel, ammunition & stores: 1,370 tons, 26.1 %
Miscellaneous weights: 1,500 tons, 28.6 %

Metacentric height 2.5

Remarks:
Hull space for machinery, storage & compartmentation is excellent
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable and able to fight her guns in the heaviest weather

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.15
Shellfire needed to sink: 8,340 lbs / 3,783 Kg = 124.4 x 5.1 " / 130 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.6
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 84 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.06
Relative quality as seaboat: 1.68

Hull form characteristics:
Block coefficient: 0.650
Sharpness coefficient: 0.42
Hull speed coefficient 'M': 6.92
'Natural speed' for length: 19.83 kts
Power going to wave formation at top speed: 49 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 80.5 %
Relative accommodation and working space: 158.1 %
(Average = 100%)
Displacement factor: 163 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.98
(Structure weight / hull surface area: 70 lbs / square foot or 344 Kg / square metre)
Relative longitudinal hull strength: 1.52
(for 16.54 ft / 5.04 m average freeboard, freeboard adjustment 3.23 ft)
Relative composite hull strength: 1.03

1927, Aquila Class Portaerei

Ships in class;

Aquila Laid down 1927
Europa Laid down 1927



- 130mm/45 guns with 28kg shells. Previous shell weight being 32kg. Lighter shell hopes to reduce strain in loading continuously for long periods. Using both LA and AA mounts.

- 100mm thick deck armour on upper hangar floor. Upper hangar is light open superstructure with lower hangar being part of the ship's structure. 100mm thick lower hangar side armour

- Smaller lift serves only upper hangar

- Seaplane recovery apparatus at the stern


RN Europa, Italian Portaerei laid down 1927

Displacement:
22,092 t light; 22,813 t standard; 26,826 t normal; 30,036 t full load

Dimensions: Length overall / water x beam x draught
751.14 ft / 721.78 ft x 91.86 ft x 27.23 ft (normal load)
228.95 m / 220.00 m x 28.00 m x 8.30 m

Armament:
16 - 5.12" / 130 mm guns (8x2 guns), 61.73lbs / 28.00kg shells, 1927 Model
Breech loading guns in deck mounts with hoists
on side ends, evenly spread, all raised mounts - superfiring
32 - 1.46" / 37.0 mm guns (12 mounts), 2.20lbs / 1.00kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1,058 lbs / 480 kg
Shells per gun, main battery: 300

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.91" / 150 mm 379.07 ft / 115.54 m 11.52 ft / 3.51 m
Ends: Unarmoured
Upper: 3.94" / 100 mm 379.07 ft / 115.54 m 16.40 ft / 5.00 m
Main Belt covers 81 % of normal length

- Torpedo Bulkhead:
1.57" / 40 mm 379.07 ft / 115.54 m 24.44 ft / 7.45 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 1.18" / 30 mm -
2nd: 0.39" / 10 mm - -

- Armour deck: 3.94" / 100 mm, Conning tower: 5.91" / 150 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 110,000 shp / 82,060 Kw = 30.74 kts
Range 6,000nm at 24.00 kts
Bunker at max displacement = 7,224 tons

Complement:
1,047 - 1,362

Cost:
£5.008 million / $20.031 million

Distribution of weights at normal displacement:
Armament: 140 tons, 0.5 %
Armour: 6,376 tons, 23.8 %
- Belts: 2,235 tons, 8.3 %
- Torpedo bulkhead: 540 tons, 2.0 %
- Armament: 77 tons, 0.3 %
- Armour Deck: 3,410 tons, 12.7 %
- Conning Tower: 114 tons, 0.4 %
Machinery: 3,472 tons, 12.9 %
Hull, fittings & equipment: 8,204 tons, 30.6 %
Fuel, ammunition & stores: 4,734 tons, 17.6 %
Miscellaneous weights: 3,900 tons, 14.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
51,235 lbs / 23,240 Kg = 764.3 x 5.1 " / 130 mm shells or 7.7 torpedoes
Stability (Unstable if below 1.00): 1.22
Metacentric height 6.3 ft / 1.9 m
Roll period: 15.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.08
Seaboat quality (Average = 1.00): 1.52

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0.520
Length to Beam Ratio: 7.86 : 1
'Natural speed' for length: 31.19 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 46
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 33.79 ft / 10.30 m
- Forecastle (24 %): 33.79 ft / 10.30 m (23.95 ft / 7.30 m aft of break)
- Mid (50 %): 23.95 ft / 7.30 m
- Quarterdeck (24 %): 23.95 ft / 7.30 m
- Stern: 23.95 ft / 7.30 m
- Average freeboard: 26.29 ft / 8.01 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 80.8 %
- Above water (accommodation/working, high = better): 204.0 %
Waterplane Area: 46,815 Square feet or 4,349 Square metres
Displacement factor (Displacement / loading): 146 %
Structure weight / hull surface area: 120 lbs/sq ft or 588 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.40
- Overall: 1.00
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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

RM Giovanni Caboto , Aiviation Training Ship

Giovanni Caboto, Italian Portaerei laid down 1930

Displacement:
12,749 t light; 13,114 t standard; 15,512 t normal; 17,430 t full load

Dimensions: Length overall / water x beam x draught
671.99 ft / 656.17 ft x 69.09 ft x 23.95 ft (normal load)
204.82 m / 200.00 m x 21.06 m x 7.30 m

Armament:
Designed for, but not with;

6 - 3.94" / 100 mm guns (3x2 guns), 33.07lbs / 15.00kg shells, 1930 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships, 2 raised mounts - superfiring
16 - 1.46" / 37.0 mm guns (4x4 guns), 1.83lbs / 0.83kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 228 lbs / 103 kg
Shells per gun, main battery: 400

Armour:
Officially None
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.18" / 30 mm 459.32 ft / 140.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Upper: 1.18" / 30 mm 459.32 ft / 140.00 m 16.40 ft / 5.00 m
Main Belt covers 108 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm 0.39" / 10 mm -

- Armour deck: 0.79" / 20 mm, Conning tower: 2.76" / 70 mm

Machinery:
Officially 20knts maximum speed
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 82,000 shp / 61,172 Kw = 29.93 kts
Range 7,400nm at 20.00 kts
Bunker at max displacement = 4,316 tons

Complement:
694 - 903

Cost:
£3.412 million / $13.648 million

Distribution of weights at normal displacement:
Armament: 26 tons, 0.2 %
Armour: 1,083 tons, 7.0 %
- Belts: 588 tons, 3.8 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 17 tons, 0.1 %
- Armour Deck: 440 tons, 2.8 %
- Conning Tower: 37 tons, 0.2 %
Machinery: 2,485 tons, 16.0 %
Hull, fittings & equipment: 4,956 tons, 31.9 %
Fuel, ammunition & stores: 2,763 tons, 17.8 %
Miscellaneous weights: 4,200 tons, 27.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
23,109 lbs / 10,482 Kg = 757.4 x 3.9 " / 100 mm shells or 2.4 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 3.7 ft / 1.1 m
Roll period: 15.1 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.70

Hull form characteristics:
Hull has rise forward of midbreak
Block coefficient: 0.500
Length to Beam Ratio: 9.50 : 1
'Natural speed' for length: 25.62 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 30
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 34.45 ft / 10.50 m
- Forecastle (20 %): 27.89 ft / 8.50 m
- Mid (50 %): 27.89 ft / 8.50 m (19.69 ft / 6.00 m aft of break)
- Quarterdeck (23 %): 19.69 ft / 6.00 m
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 24.31 ft / 7.41 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.6 %
- Above water (accommodation/working, high = better): 199.0 %
Waterplane Area: 30,207 Square feet or 2,806 Square metres
Displacement factor (Displacement / loading): 148 %
Structure weight / hull surface area: 98 lbs/sq ft or 478 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.55
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

RN Alberico da Barbiano ex-cruiser, refitted 1935, Sold to Siam 1940
RN Bartolomeo Colloeoni ex-cruiser. refitted 1935, Sold to Siam 1940

Condottieri I, Italian Light Cruiser laid down 1925 (Engine 1930)

Displacement:
5,935 t light; 6,101 t standard; 6,664 t normal; 7,115 t full load

Dimensions: Length overall / water x beam x draught
539.12 ft / 524.93 ft x 52.49 ft x 19.69 ft (normal load)
164.32 m / 160.00 m x 16.00 m x 6.00 m

Armament:
4 - 3.94" / 100 mm guns (2x2 guns), 33.07lbs / 15.00kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
12 - 0.98" / 25.0 mm guns (3x4 guns), 0.52lbs / 0.24kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 139 lbs / 63 kg
Shells per gun, main battery: 400

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.76" / 70 mm 449.48 ft / 137.00 m 8.69 ft / 2.65 m
Ends: Unarmoured
Main Belt covers 132 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm - -

- Armour deck: 1.38" / 35 mm, Conning tower: 0.79" / 20 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 72,600 shp / 54,159 Kw = 33.96 kts
Range 3,000nm at 20.00 kts
Bunker at max displacement = 1,014 tons

Complement:
368 - 479

Cost:
£1.732 million / $6.927 million

Distribution of weights at normal displacement:
Armament: 16 tons, 0.2 %
Armour: 898 tons, 13.5 %
- Belts: 428 tons, 6.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.1 %
- Armour Deck: 458 tons, 6.9 %
- Conning Tower: 6 tons, 0.1 %
Machinery: 2,200 tons, 33.0 %
Hull, fittings & equipment: 2,323 tons, 34.9 %
Fuel, ammunition & stores: 729 tons, 10.9 %
Miscellaneous weights: 498 tons, 7.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
5,836 lbs / 2,647 Kg = 191.3 x 3.9 " / 100 mm shells or 1.0 torpedoes
Stability (Unstable if below 1.00): 1.11
Metacentric height 2.3 ft / 0.7 m
Roll period: 14.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.03

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.430
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 26.38 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 68
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (38 %): 22.97 ft / 7.00 m (14.76 ft / 4.50 m aft of break)
- Quarterdeck (15 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 18.01 ft / 5.49 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 117.6 %
- Above water (accommodation/working, high = better): 158.4 %
Waterplane Area: 17,967 Square feet or 1,669 Square metres
Displacement factor (Displacement / loading): 113 %
Structure weight / hull surface area: 78 lbs/sq ft or 380 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.57
- Overall: 1.00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Barbettes = 98tons
400tons = 12 fighters



As refitted 1935

Condottieri I, Italian Light Cruiser laid down 1925 (Engine 1934)

Displacement:
5,602 t light; 5,781 t standard; 6,664 t normal; 7,371 t full load

Dimensions: Length overall / water x beam x draught
539.12 ft / 524.93 ft x 52.49 ft x 19.69 ft (normal load)
164.32 m / 160.00 m x 16.00 m x 6.00 m

Armament:
1 - 5.98" / 152 mm guns in single mounts, 110.23lbs / 50.00kg shells, 1925 Model
Breech loading gun in deck mount
on centreline forward
12 - 1.85" / 47.0 mm guns (3x4 guns), 3.86lbs / 1.75kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
4 - 1.85" / 47.0 mm guns (2x2 guns), 3.86lbs / 1.75kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, all forward
Weight of broadside 172 lbs / 78 kg
Shells per gun, main battery: 400

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.76" / 70 mm 449.48 ft / 137.00 m 8.69 ft / 2.65 m
Ends: Unarmoured
Main Belt covers 132 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Armour deck: 1.38" / 35 mm, Conning tower: 1.42" / 36 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 2 shafts, 62,000 shp / 46,252 Kw = 32.63 kts
Range 5,000nm at 20.00 kts
Bunker at max displacement = 1,589 tons

Complement:
368 - 479

Cost:
£1.513 million / $6.053 million

Distribution of weights at normal displacement:
Armament: 20 tons, 0.3 %
Armour: 903 tons, 13.6 %
- Belts: 428 tons, 6.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.1 %
- Armour Deck: 458 tons, 6.9 %
- Conning Tower: 11 tons, 0.2 %
Machinery: 1,784 tons, 26.8 %
Hull, fittings & equipment: 2,096 tons, 31.4 %
Fuel, ammunition & stores: 1,062 tons, 15.9 %
Miscellaneous weights: 800 tons, 12.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
6,924 lbs / 3,141 Kg = 64.6 x 6.0 " / 152 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 2.3 ft / 0.7 m
Roll period: 14.6 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.14

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.430
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 26.38 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 62
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (38 %): 22.97 ft / 7.00 m (14.76 ft / 4.50 m aft of break)
- Quarterdeck (15 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 18.01 ft / 5.49 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 103.1 %
- Above water (accommodation/working, high = better): 158.4 %
Waterplane Area: 17,967 Square feet or 1,669 Square metres
Displacement factor (Displacement / loading): 123 %
Structure weight / hull surface area: 70 lbs/sq ft or 343 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.87
- Longitudinal: 1.41
- Overall: 0.91
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Barbettes = 98tons
700tons = aircraft and vehicles

It hasn't been a great secret that Italy has wanted another large carrier for some time. With the existing ships it would allow for having one in refit, two together and one somewhere else.

The design has come out of the previous set of design studies.

The hull makes use of the same B2 hullform as the armoured cruisers but considerably scaled up. The large dimensions of the hull represent an attempt to future-proof the hull. We have already gone from 2500kg biplanes to 6000kg monoplanes in only 5 years, it can only be assumed that future aircraft will be considerably heavier. The hangar size and catapult size is factored into this. The shallow draught hull lessens the hydrostatic forces on bulkheads in the event of flooding.

The airgroup has stayed at 60 aircraft. Experience with similar sized Morosini, nominally a 72-plane ship has found that only 60 aircraft can be operated effectively. The extra numbers rapidly cut down efficiency. Having fewer planes to store also means that more room for workshops can be built in. A typical airgroup, from current usage, will be 12 fighters and 48 attack aircraft.

The main armament comprises of 152/53 dual-purpose guns in single mountings. This mount is designed around the starboard gun in the twin turret resulting in a strange appearance. The turrets also mount secondary FC directors. The light AA armament should comprise of 65/64 guns in duple and single mountings though 47mm might have to be substituted in their place. It is likely that single 25mm mountings will be added to the final design when she completes.

The armour comprises of a long 150mm belt with splinter plates at each end. The belt is topped by 40mm deck armour on No.2 hangar floor level. Above the belt and inboard are the hangar sides which have splinter protection. The main armour deck is on the flight deck, with 100mm armour covering the hangar. The hangar itself is split into 6 sections by fire screens. The TDS is extremely deep as there is plenty of internal volume. It should be able to withstand a 750kg charge.

He uses a 140,000shp powerplant to reach a speed of around 32knts. Considerable bunkerage is included so as not to disrupt flight operations too often.

The main hangar is 150x25x6 with two smaller hangar/workshops on the deck below. There are two main lifts at either end of the hangar and a smaller lift servicing the upper hangar only on the port side. Two large catapults are mounted over the bow with another mounted on the port side. This will allow quicker launching times as aircraft can be carried up and launched at both ends of the flight deck. Also included in the design is considerable extra munitions and fuel storage for the aircraft.

The island is split into two to improve the aerodynamics, it resulting in a smoother flow of air and less disruption aft. The islands are dominated by the flight operations centres fore and aft with large perspex windows. A considerable electronics fit is pictured, from fore to aft; secondary air search, AA FC, surface search / FC, main air search, AA FC.

Guiseppe Garibaldi laid down 1935
Cavour Laid down 1936


Giuseppe Garibaldi, Italian Portaaerei laid down 1934

Displacement:
29,201 t light; 30,227 t standard; 35,866 t normal; 40,378 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(847.07 ft / 820.21 ft) x 102.53 ft x (29.86 / 32.57 ft)
(258.19 m / 250.00 m) x 31.25 m x (9.10 / 9.93 m)

Armament:
12 - 5.98" / 152 mm 53.0 cal guns - 110.23lbs / 50.00kg shells, 200 per gun
Dual purpose guns in deck and hoist mounts, 1934 Model
12 x Single mounts on centreline, aft deck forward
44 - 1.85" / 47.0 mm 40.0 cal guns - 3.04lbs / 1.38kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1934 Model
11 x Quad mounts on sides, evenly spread
4 - 1.85" / 47.0 mm 40.0 cal guns - 3.04lbs / 1.38kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1934 Model
4 x Single mounts on centreline, aft deck forward
4 double raised mounts
Weight of broadside 1,469 lbs / 666 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.91" / 150 mm 426.51 ft / 130.00 m 9.84 ft / 3.00 m
Ends: 1.42" / 36 mm 393.70 ft / 120.00 m 9.84 ft / 3.00 m
Upper: 1.42" / 36 mm 426.51 ft / 130.00 m 36.09 ft / 11.00 m
Main Belt covers 80 % of normal length

- Torpedo Bulkhead:
2.76" / 70 mm 426.51 ft / 130.00 m 26.25 ft / 8.00 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 1.57" / 40 mm 1.57" / 40 mm
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Armoured deck - multiple decks: 1.97" / 50 mm For and Aft decks
Forecastle: 0.00" / 0 mm Quarter deck: 1.97" / 50 mm

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 140,000 shp / 104,440 Kw = 31.63 kts
Range 7,000nm at 25.00 kts
Bunker at max displacement = 10,151 tons

Complement:
1,303 - 1,694

Cost:
£8.575 million / $34.300 million

Distribution of weights at normal displacement:
Armament: 485 tons, 1.4 %
Armour: 5,713 tons, 15.9 %
- Belts: 2,259 tons, 6.3 %
- Torpedo bulkhead: 1,141 tons, 3.2 %
- Armament: 175 tons, 0.5 %
- Armour Deck: 2,074 tons, 5.8 %
- Conning Tower: 65 tons, 0.2 %
Machinery: 4,028 tons, 11.2 %
Hull, fittings & equipment: 10,240 tons, 28.5 %
Fuel, ammunition & stores: 6,666 tons, 18.6 %
Miscellaneous weights: 8,735 tons, 24.4 %
- Hull below water: 1,000 tons
- Hull above water: 2,000 tons
- On freeboard deck: 3,000 tons
- Above deck: 2,735 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
76,442 lbs / 34,673 Kg = 713.4 x 6.0 " / 152 mm shells or 14.3 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 7.4 ft / 2.3 m
Roll period: 15.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.05
Seaboat quality (Average = 1.00): 1.43

Hull form characteristics:
Hull has raised forecastle,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.500 / 0.516
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 33.29 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 49
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 10.00 %, 55.77 ft / 17.00 m, 55.77 ft / 17.00 m
- Forward deck: 40.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Aft deck: 35.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Quarter deck: 15.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Average freeboard: 24.77 ft / 7.55 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 63.9 %
- Above water (accommodation/working, high = better): 181.6 %
Waterplane Area: 58,266 Square feet or 5,413 Square metres
Displacement factor (Displacement / loading): 149 %
Structure weight / hull surface area: 129 lbs/sq ft or 631 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.08
- Overall: 1.00
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
Good seaboat, rides out heavy weather easily

100mm deck armour 130x25 = 2535tons

6000t misc weight = 60 aircraft
100 tons flag facilities
100 tons radars

Giovanni delle Bande Nere
Sold to Argentina 1940

Reconstructed in 1934, he gets a new steam/diesel powerplant and additional bunkerage. The four barbettes are removed and a single 152mm mount is added in their place. A large transport deck is built along the weather deck. Alongside of the new superstructure is a small flying off deck for light aircraft and autogyros. On the starboard side of the superstructure is a large gangway for ease of embarkation in port. Aft is a 50t crane and two assault boats.

She is expected to serve as an aircraft transport, replenishment vessel or a landing support vessel. Below decks are accomodations for 300 troops. Between this ship and the ten MZ700 craft it is possible to transport a battalion of soldiers over short distances.

Condottieri I, Italian Light Cruiser laid down 1925 (Engine 1934)

Displacement:
5,602 t light; 5,781 t standard; 6,664 t normal; 7,371 t full load

Dimensions: Length overall / water x beam x draught
539.12 ft / 524.93 ft x 52.49 ft x 19.69 ft (normal load)
164.32 m / 160.00 m x 16.00 m x 6.00 m

Armament:
1 - 5.98" / 152 mm guns in single mounts, 110.23lbs / 50.00kg shells, 1925 Model
Breech loading gun in deck mount
on centreline forward
12 - 1.85" / 47.0 mm guns (3x4 guns), 3.86lbs / 1.75kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
4 - 1.85" / 47.0 mm guns (2x2 guns), 3.86lbs / 1.75kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, all forward
Weight of broadside 172 lbs / 78 kg
Shells per gun, main battery: 400

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.76" / 70 mm 449.48 ft / 137.00 m 8.69 ft / 2.65 m
Ends: Unarmoured
Main Belt covers 132 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Armour deck: 1.38" / 35 mm, Conning tower: 1.42" / 36 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 2 shafts, 62,000 shp / 46,252 Kw = 32.63 kts
Range 5,000nm at 20.00 kts
Bunker at max displacement = 1,589 tons

Complement:
368 - 479

Cost:
£1.513 million / $6.053 million

Distribution of weights at normal displacement:
Armament: 20 tons, 0.3 %
Armour: 903 tons, 13.6 %
- Belts: 428 tons, 6.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.1 %
- Armour Deck: 458 tons, 6.9 %
- Conning Tower: 11 tons, 0.2 %
Machinery: 1,784 tons, 26.8 %
Hull, fittings & equipment: 2,096 tons, 31.4 %
Fuel, ammunition & stores: 1,062 tons, 15.9 %
Miscellaneous weights: 800 tons, 12.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
6,924 lbs / 3,141 Kg = 64.6 x 6.0 " / 152 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 2.3 ft / 0.7 m
Roll period: 14.6 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.04
Seaboat quality (Average = 1.00): 1.14

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.430
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 26.38 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 62
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 9.84 ft / 3.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.61 ft / 7.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (38 %): 22.97 ft / 7.00 m (14.76 ft / 4.50 m aft of break)
- Quarterdeck (15 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 18.01 ft / 5.49 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 103.1 %
- Above water (accommodation/working, high = better): 158.4 %
Waterplane Area: 17,967 Square feet or 1,669 Square metres
Displacement factor (Displacement / loading): 123 %
Structure weight / hull surface area: 70 lbs/sq ft or 343 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.87
- Longitudinal: 1.41
- Overall: 0.91
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

700tons = aircraft and vehicles

Pisa Class

Pisa Converted 1937
Amalfi Converted 1937
Marco Polo Converted 1938
Agordat Converted 1939

The Pisa Class of light cruisers were getting on for being 15 years old and were in need of bringing up to modern standards. This presented somewhat of a problem as it was quite a tight design, especially with regards to increasing AA armament. A number of extensive rebuilding schemes were examined but none was found satisfactory given the considerable expense that would have to be undertaken.

Instead, the possibility of converting some of the ships into light carriers was examined. This lead towards a more extensive reconstruction. The bow was extended forwards and large bulges were added which considerably increased stability and size. A simple scheme was looked at, using a single hangar on top of the main deck and an enclosed bow. A small island was added and the uptakes from the boiler rooms lead out to the side. For stability considerations, the only armament included were light AA guns.

Airgroup; Maximum 36, usually 24.

RM Pisa, Italian Light Cruiser laid down 1924 (Engine 1937)

Displacement:
9,755 t light; 10,098 t standard; 12,586 t normal; 14,577 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(608.16 ft / 590.55 ft) x 62.66 ft (Bulges 75.79 ft) x (19.69 / 22.51 ft)
(185.37 m / 180.00 m) x 19.10 m (Bulges 23.10 m) x (6.00 / 6.86 m)

Armament:
20 - 1.85" / 47.0 mm 40.0 cal guns - 3.04lbs / 1.38kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1937 Model
5 x Quad mounts on centreline ends, majority forward
1 raised mount - superfiring
7 - 1.85" / 47.0 mm 40.0 cal guns - 3.04lbs / 1.38kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1924 Model
7 x Single mounts on side ends, majority forward
7 raised mounts
Weight of broadside 82 lbs / 37 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.42" / 36 mm 373.20 ft / 113.75 m 9.51 ft / 2.90 m
Ends: Unarmoured
Main Belt covers 97 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.39" / 10 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm - -

- Armoured deck - multiple decks: 1.18" / 30 mm For and Aft decks

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 90,000 shp / 67,140 Kw = 31.07 kts
Range 5,000nm at 25.00 kts
Bunker at max displacement = 4,479 tons

Complement:
593 - 772

Cost:
£2.148 million / $8.591 million

Distribution of weights at normal displacement:
Armament: 15 tons, 0.1 %
Armour: 696 tons, 5.5 %
- Belts: 209 tons, 1.7 %
- Armament: 13 tons, 0.1 %
- Armour Deck: 442 tons, 3.5 %
- Conning Tower: 32 tons, 0.3 %
Machinery: 2,494 tons, 19.8 %
Hull, fittings & equipment: 3,850 tons, 30.6 %
Fuel, ammunition & stores: 2,831 tons, 22.5 %
Miscellaneous weights: 2,700 tons, 21.5 %
- Hull below water: 500 tons
- Hull above water: 700 tons
- On freeboard deck: 1,500 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
19,001 lbs / 8,619 Kg = 5,998.0 x 1.9 " / 47 mm shells or 2.6 torpedoes
Stability (Unstable if below 1.00): 1.33
Metacentric height 4.1 ft / 1.3 m
Roll period: 15.7 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.22

Hull form characteristics:
Hull has raised forecastle,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.500 / 0.506
Length to Beam Ratio: 7.79 : 1
'Natural speed' for length: 24.30 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 58
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: 20.00 %, 39.37 ft / 12.00 m, 32.81 ft / 10.00 m
- Forward deck: 30.00 %, 18.04 ft / 5.50 m, 18.04 ft / 5.50 m
- Aft deck: 35.00 %, 18.04 ft / 5.50 m, 18.04 ft / 5.50 m
- Quarter deck: 15.00 %, 18.04 ft / 5.50 m, 18.04 ft / 5.50 m
- Average freeboard: 21.52 ft / 6.56 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 76.6 %
- Above water (accommodation/working, high = better): 142.9 %
Waterplane Area: 24,656 Square feet or 2,291 Square metres
Displacement factor (Displacement / loading): 149 %
Structure weight / hull surface area: 93 lbs/sq ft or 454 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.31
- Overall: 1.00
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
Good seaboat, rides out heavy weather easily

Andrea Doria Class

Andrea Doria Laid down 1939

Marcantonio Colonna Laid down 1941


The Development of the Aircraft Carrier in the Italian Navy

In designing a new aircraft carrier in the late 1930s, the Italian design teams had to answer two main questions; how many aircraft, and, how much armour?

The Regia Marina had plenty of experience operating largish carriers with airgroups of 60-70 aircraft which was a bit less than most other countries with similar sized vessels. The comparatively large hull and low aircraft complement greatly facilitated aircraft handling with 3 to 4 sorties being possible per aircraft per day. This effectively increased the airgroup available. In the late 1930s, designers began to sketch a number of hull layouts with a view towards deriving an optimum aircraft complement. It was felt that the largest number of aircraft that could be operated effectively would be between 90 and 100. The sortie rate could not be increased further due to the time needed for flying on and flying off. Concurrent operations would allow the sortie rate to be increased but this could not be accomplished with the current deck arrangement due to aircraft landing into those already struck. A larger ship to accommodate the larger aircraft complement would allow for safer operations with landed aircraft forwards of the barrier being taken down on the forward lift. Lifts at the side of the flight deck would quickly remove aircraft from the landing area and reduce the cutout of the strength deck. At the same time as landing on, catapults could be used to launch aircraft off the bow. The ability for conventional rolling takeoffs would be retained for rapidly launching smaller aircraft types.

The growing size of aircraft was also a pressing consideration. The new carrier’s role was expected to place a much greater emphasis on land strikes in support of allied forces. For this role a number of large twin engine aircraft were considered which again increased the size of the ship. It was decided to adopt a weight limit of 15000kg in order to cover expected growths in the next decade. Increased aviation ordnance and fuel were also considerations as the carrier was likely to be operating away from easy resupply. Along with the increased aircraft complement, the individual aircraft were larger which put pressure on increasing the size of the ship.

Protection was a greater problem for the designers with the more potent modern weapons being developed. The South African carrier Hammer had been sunk in short order by 305mm and 152mm gunfire after being surprised in heavy weather. Some initial considerations were given to see how much armour would be needed to protect against large calibre hits but such schemes just took up too much weight. A different form of protection would be needed instead. Some countries had started to develop armour piercing bombs up to 1000kg for which an armoured thickness of 180mm was required to confidently stop. The large size of such a weapon would impose a significant range restriction on whatever aircraft carrying it, but future advances might see the vessel under attack from such weapons. Larger diameter torpedoes with larger warheads were also being used by cruisers and destroyers but the 450mm remained standard for aircraft usage.

The threat from torpedoes was felt to be the greatest. A modified version of Pugliese’s protective scheme was implemented, with greater depth from the beamier hull and liquid loading for fuel oil. A high internal bulkhead was used, stretching up to the main deck armour. From tests, it was found to be able to resist a 750kg charge. Internally, the machinery spaces were extensively subdivided with 4 engine rooms and 8 boiler rooms. The great internal subdivision formed the basis of the protection against shellfire, with hits unlikely to cause damage to all critical systems. Only splinter armour was used externally, it not being practical to armour even against 152mm gunfire. The thick, deep bulkhead of the torpedo protection scheme formed an extra internal layer to stop shells from penetrating the vital spaces. As with usual Italian practice, triple rudders are fitted which give good redundancy and a small turning circle.

A closed hangar was used as with previous Italian practice, giving some measure of protection. Extra armour was also mounted on the hangar sides to protect from shells and steeply falling bombs. The previous Garibaldi Class of carriers had used an armoured flight deck, but it was no longer a practical proposition given the heavier bombs available. Instead a layered scheme was envisaged with a light unarmoured flight deck. A 50mm layer of armour was placed at the gallery deck to reject light AP and HE bombs with another similar layer on the hangar deck. A thinner splinter deck was placed lower in the ship. It was thought that the first layer of armour would fuse AP weapons allowing the blast to be kept out of the vital parts of the ship. In previous designs the hangar had been considered as such, but would now be used as a sacrificial space. Large, heavy duty partitions would limit the explosion.

Other protective measures related more to the doctrine of the ship itself. A large powerplant was installed which gave the design a speed of over 33knts. The large seaworthy hull meant that this speed could be sustained in almost any seaway, making her one of the fastest ships afloat. The increasingly commonality of radar reduced the likelihood of surprise attacks from the surface or the air.

The previous class had mounted 152mm guns with which to engage cruisers, destroyers and aircraft. These were heavy and not found to be particularly effective against aircraft. A similar armament was also mounted on RSAN Hammer but was wholly ineffective when used against surface ships. The reduced likelihood of attack and limited utility of the weapons resulted in their removal. Instead a large battery optimised for anti-aircraft gunnery was installed, with automatic 76mm weapons and quadruple 37mm guns. When commissioned, the 37mm mountings would be replaced by 76mm ones which had been found to be more effective.

Andrea Doria, Italian Portaaerei laid down 1939

Displacement:
37,879 t light; 39,239 t standard; 44,435 t normal; 48,593 t full load

Dimensions:Length (overall / waterline) x beam x draught (normal/deep)
(936.89 ft / 885.83 ft) x 110.79 ft x (34.45 / 36.67 ft)
(285.56 m / 270.00 m) x 33.77 m x (10.50 / 11.18 m)

Armament:
16 - 3.00" / 76.2 mm 62.0 cal guns - 14.86lbs / 6.74kg shells, 2,000 per gun
Auto rapid fire guns in deck and hoist mounts, 1939 Model
16 x Single mounts on sides, evenly spread
56 - 1.46" / 37.0 mm 54.0 cal guns - 1.66lbs / 0.75kg shells, 4,000 per gun
Anti-air guns in deck mounts, 1939 Model
13 x Quad mounts on sides, evenly spread
1 raised mount
1 x Quad mount on sides amidships
1 double raised mount
Weight of broadside 331 lbs / 150 kg

Aircraft:
48 x Caproni Re.2005 Fighters
36 x Caproni Ca.180 Strike
8 x Cierva R1 ASW/Rec
92 Total

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.42" / 36 mm 620.08 ft / 189.00 m 13.12 ft / 4.00 m
Ends: 1.42" / 36 mm 265.72 ft / 80.99 m 13.12 ft / 4.00 m
Upper: 1.42" / 36 mm 688.98 ft / 210.00 m 32.81 ft / 10.00 m
Main Belt covers 108 % of normal length

- Torpedo Bulkhead:
2.36" / 60 mm 620.08 ft / 189.00 m 41.01 ft / 12.50 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -

- Armoured deck - multiple decks: 2.95" / 75 mm For and Aft decks
Forecastle: 0.00" / 0 mm Quarter deck: 1.57" / 40 mm

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 180,000 shp / 134,280 Kw = 33.01 kts
Range 6,000nm at 25.00 kts
Bunker at max displacement = 9,354 tons


Complement:
1,529 - 1,989


Cost:
£11.914 million / $47.658 million

Distribution of weights at normal displacement:
Armament: 151 tons, 0.3 %
Armour: 7,610 tons, 17.1 %
- Belts: 1,961 tons, 4.4 %
- Torpedo bulkhead: 2,223 tons, 5.0 %
- Armament: 108 tons, 0.2 %
- Armour Deck: 3,244 tons, 7.3 %
- Conning Tower: 74 tons, 0.2 %
Machinery: 4,870 tons, 11.0 %
Hull, fittings & equipment: 12,622 tons, 28.4 %
Fuel, ammunition & stores: 6,556 tons, 14.8 %
Miscellaneous weights: 12,627 tons, 28.4 %
- Hull below water: 2,048 tons
- Hull above water: 3,584 tons
- On freeboard deck: 4,608 tons
- Above deck: 2,387 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
89,155 lbs / 40,440 Kg = 6,604.1 x 3.0 " / 76 mm shells or 18.2 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 8.5 ft / 2.6 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.01
Seaboat quality (Average = 1.00): 1.55


Hull form characteristics:
Hull has raised forecastle,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.460 / 0.473
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 34.78 kts
Power going to wave formation at top speed: 50 %
Trim (Max stability = 0, Max steadiness = 100): 45
Bow angle (Positive = bow angles forward): 37.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 15.00 %, 59.06 ft / 18.00 m, 59.06 ft / 18.00 m
- Forward deck: 30.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Aft deck: 40.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Quarter deck: 15.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Average freeboard: 26.98 ft / 8.22 m


Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 64.0 %
- Above water (accommodation/working, high = better): 174.2 %
Waterplane Area: 65,587 Square feet or 6,093 Square metres
Displacement factor (Displacement / loading): 146 %
Structure weight / hull surface area: 135 lbs/sq ft or 661 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.15
- Overall: 1.00
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
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

48 x Caproni Ca.2005 fighter-bombers
36 x Caproni Ca.180 Strike (spot factor 2)
8 x Cierva R1 ASW/Rec
92 Total

or

120 x Caproni Ca.2005 fighter-bombers
8 x Cierva R1 ASW/Rec
128 Total

80t per aircraft
10240t 45/35/20%
Space for 131aircraft
500t extra ordnance
2 x C-39 hydraulic catapults (58m stroke)
9 x 15000kg arrestor wires
3 elevators 18 x 15m

200t Aircraft operations centre
50t RaA.6 Air Search radar
20t RaA.5 Air Search radar
20t RaS.4 Surface Search radar x2
30t 2 x GDR1R FC Systems
30t 6 x GDR5 FC Systems

Armour
50mm Gallery Deck 170 x 30 1997t
50mm Hangar Deck
25mm splinter deck