3 Ships laid down in 1931;
San Pietro, San Sylvestro, San Gregorio Magno
Original Design as laid down 1931
Displacement:
13,874 t light; 14,550 t standard; 16,585 t normal; 18,213 t full load
Dimensions: Length overall / water x beam x draught
637.63 ft / 623.36 ft x 65.62 ft (Bulges 75.69 ft) x 24.61 ft (normal load)
194.35 m / 190.00 m x 20.00 m (Bulges 23.07 m) x 7.50 m
Armament:
12 - 7.99" / 203 mm guns (4x3 guns), 291.01lbs / 132.00kg shells, 1931 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
14 - 3.94" / 100 mm guns (7x2 guns), 33.07lbs / 15.00kg shells, 1931 Model
Anti-aircraft guns in deck mounts with hoists
on side, all forward, 3 raised mounts - superfiring
16 - 1.46" / 37.0 mm guns (4x4 guns), 1.83lbs / 0.83kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, all forward, 2 raised mounts - superfiring
8 - 1.00" / 25.4 mm guns in single mounts, 0.52lbs / 0.24kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
Weight of broadside 3,989 lbs / 1,809 kg
Shells per gun, main battery: 150
16 - 23.6" / 600 mm above water torpedoes
Armour:
Currently secret
- Belts: Width (max) Length (avg) Height (avg)
Main: 7.29" / 185 mm 433.07 ft / 132.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Upper: 0.79" / 20 mm 65.62 ft / 20.00 m 8.20 ft / 2.50 m
Main Belt covers 107 % of normal length
- Torpedo Bulkhead and Bulges:
1.57" / 40 mm 305.12 ft / 93.00 m 32.81 ft / 10.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 7.48" / 190 mm 4.92" / 125 mm 5.91" / 150 mm
2nd: 0.79" / 20 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm 0.39" / 10 mm -
- Armour deck: 2.97" / 75 mm, Conning tower: 7.48" / 190 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 86,000 shp / 64,156 Kw = 30.87 kts
Range 6,540nm at 20.00 kts
Bunker at max displacement = 3,663 tons
Complement:
729 - 949
Cost:
£5.302 million / $21.210 million
Distribution of weights at normal displacement:
Armament: 440 tons, 2.7 %
Armour: 4,397 tons, 26.5 %
- Belts: 1,317 tons, 7.9 %
- Torpedo bulkhead: 583 tons, 3.5 %
- Armament: 836 tons, 5.0 %
- Armour Deck: 1,555 tons, 9.4 %
- Conning Tower: 105 tons, 0.6 %
Machinery: 2,572 tons, 15.5 %
Hull, fittings & equipment: 6,166 tons, 37.2 %
Fuel, ammunition & stores: 2,711 tons, 16.3 %
Miscellaneous weights: 300 tons, 1.8 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
24,591 lbs / 11,154 Kg = 96.3 x 8.0 " / 203 mm shells or 4.0 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 3.7 ft / 1.1 m
Roll period: 16.6 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.45
Seaboat quality (Average = 1.00): 1.05
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 8.24 : 1
'Natural speed' for length: 28.95 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 48
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: 30.18 ft / 9.20 m
- Forecastle (20 %): 21.98 ft / 6.70 m
- Mid (70 %): 21.98 ft / 6.70 m (13.78 ft / 4.20 m aft of break)
- Quarterdeck (20 %): 13.78 ft / 4.20 m
- Stern: 13.78 ft / 4.20 m
- Average freeboard: 20.18 ft / 6.15 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 106.2 %
- Above water (accommodation/working, high = better): 100.6 %
Waterplane Area: 28,340 Square feet or 2,633 Square metres
Displacement factor (Displacement / loading): 124 %
Structure weight / hull surface area: 134 lbs/sq ft or 654 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.35
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is adequate
Belt; 30+150@15°+40
0 forward 80 machinery 100 magazines 50 aft = 75.35 average
40tons for 25mm deck over torpedoes
40tons for 4x37mm quadruple mounts
48tons for 16x600mm torpedoes
75tons for 2 aircraft
50tons for CIC
50tons for diesel generators
=300tons
30.87knts sea speed in state 4.
30.43knts at deep load
31.71knts at light load
Included for completeness
Immunity zone vs. 8"/55 APC 260lb 30° TA
Magazines
5,000 - Infinty yds
Machinery
5,000 - 30,000yds
150mm/60 100lb 30° TA
Magazines
Proof, else 3000yds @ 0° TA
Machinery
Proof, else 3000yds @ 0° TA
Final Design, 1933
Displacement:
13,005 t light; 13,667 t standard; 16,585 t normal; 18,920 t full load
Dimensions: Length overall / water x beam x draught
637.63 ft / 623.36 ft x 65.62 ft (Bulges 75.69 ft) x 24.61 ft (normal load)
194.35 m / 190.00 m x 20.00 m (Bulges 23.07 m) x 7.50 m
Armament:
12 - 7.99" / 203 mm guns (4x3 guns), 291.01lbs / 132.00kg shells, 1931 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 3.94" / 100 mm guns (6 mounts), 33.07lbs / 15.00kg shells, 1931 Model
Anti-aircraft guns in deck mounts with hoists
on side, all forward
28 - 1.85" / 47.0 mm guns (7x4 guns), 3.17lbs / 1.44kg shells, 1933 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
Weight of broadside 3,845 lbs / 1,744 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.12" / 130 mm 419.95 ft / 128.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 104 % of normal length
- Torpedo Bulkhead and Bulges:
1.57" / 40 mm 305.12 ft / 93.00 m 32.81 ft / 10.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 7.48" / 190 mm 4.92" / 125 mm 5.91" / 150 mm
2nd: 0.79" / 20 mm 0.79" / 20 mm -
3rd: 0.39" / 10 mm 0.39" / 10 mm -
- Armour deck: 2.97" / 75 mm, Conning tower: 5.91" / 150 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 86,000 shp / 64,156 Kw = 30.87 kts
Range 9,500nm at 20.00 kts
Bunker at max displacement = 5,253 tons
Complement:
729 - 949
Cost:
£5.113 million / $20.453 million
Distribution of weights at normal displacement:
Armament: 424 tons, 2.6 %
Armour: 3,932 tons, 23.7 %
- Belts: 879 tons, 5.3 %
- Torpedo bulkhead: 583 tons, 3.5 %
- Armament: 831 tons, 5.0 %
- Armour Deck: 1,555 tons, 9.4 %
- Conning Tower: 83 tons, 0.5 %
Machinery: 2,572 tons, 15.5 %
Hull, fittings & equipment: 5,977 tons, 36.0 %
Fuel, ammunition & stores: 3,580 tons, 21.6 %
Miscellaneous weights: 100 tons, 0.6 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
24,915 lbs / 11,301 Kg = 97.6 x 8.0 " / 203 mm shells or 4.2 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 3.9 ft / 1.2 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.39
Seaboat quality (Average = 1.00): 1.02
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 8.24 : 1
'Natural speed' for length: 28.95 kts
Power going to wave formation at top speed: 56 %
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 (% = measuring location as a percentage of overall length):
- Stem: 30.18 ft / 9.20 m
- Forecastle (20 %): 21.98 ft / 6.70 m
- Mid (60 %): 21.98 ft / 6.70 m (13.78 ft / 4.20 m aft of break)
- Quarterdeck (20 %): 13.78 ft / 4.20 m
- Stern: 13.78 ft / 4.20 m
- Average freeboard: 19.36 ft / 5.90 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 103.3 %
- Above water (accommodation/working, high = better): 142.5 %
Waterplane Area: 28,340 Square feet or 2,633 Square metres
Displacement factor (Displacement / loading): 132 %
Structure weight / hull surface area: 131 lbs/sq ft or 640 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.27
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent