Casa de Avis, Portuguese Battleship laid down in 1927-28, commissioned in 1931-32
Displacement:
25,775 t light; 27,167 t standard; 29,406 t normal; 31,197 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(711.94 ft / 666.01 ft) x 91.86 ft x (26.57 / 27.88 ft)
(217.00 m / 203.00 m) x 28.00 m x (8.10 / 8.50 m)
Armament:
6 - 14.57" / 370 mm 44.0 cal guns - 1,765.90lbs / 801.00kg shells, 120 per gun
Breech loading guns in turret on barbette mounts, 1923 Model
2 x Triple mounts on centreline, forward deck forward
1 raised mount - superfiring
12 - 5.51" / 140 mm 50.0 cal guns - 82.01lbs / 37.20kg shells, 150 per gun
Breech loading guns in deck and hoist mounts, 1913 Model
12 x Single mounts on centreline, evenly spread
4 - 4.02" / 102 mm 45.0 cal guns - 31.09lbs / 14.10kg shells, 220 per gun
Anti-air guns in deck mounts, 1914 Model
4 x Single mounts on sides, evenly spread
Weight of broadside 11,704 lbs / 5,309 kg
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.0" / 280 mm 269.03 ft / 82.00 m 26.25 ft / 8.00 m
Ends: 4.02" / 102 mm 262.47 ft / 80.00 m 26.25 ft / 8.00 m
134.51 ft / 41.00 m Unarmoured ends
Main Belt covers 62 % of normal length
- Torpedo Bulkhead - Strengthened structural bulkheads:
4.02" / 102 mm 426.51 ft / 130.00 m 16.40 ft / 5.00 m
Beam between torpedo bulkheads 91.86 ft / 28.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 16.0" / 406 mm 5.98" / 152 mm 16.0" / 406 mm
2nd: 2.99" / 76 mm - 5.00" / 127 mm
- Armoured deck - multiple decks:
For and Aft decks: 2.99" / 76 mm
Forecastle: 2.99" / 76 mm Quarter deck: 2.99" / 76 mm
- Conning towers: Forward 11.02" / 280 mm, Aft 11.02" / 280 mm
Machinery:
Oil fired boilers, steam turbines, plus diesel motors,
Geared drive, 4 shafts, 88,107 shp / 65,728 Kw = 28.00 kts
Range 7,700nm at 15.00 kts
Bunker at max displacement = 4,030 tons
Complement:
1,122 - 1,459
Cost:
£8.158 million / $32.633 million
Distribution of weights at normal displacement:
Armament: 1,839 tons, 6.3 %
- Guns: 1,839 tons, 6.3 %
Armour: 11,140 tons, 37.9 %
- Belts: 4,784 tons, 16.3 %
- Torpedo bulkhead: 1,040 tons, 3.5 %
- Armament: 2,180 tons, 7.4 %
- Armour Deck: 2,684 tons, 9.1 %
- Conning Towers: 453 tons, 1.5 %
Machinery: 2,781 tons, 9.5 %
Hull, fittings & equipment: 10,015 tons, 34.1 %
Fuel, ammunition & stores: 3,631 tons, 12.3 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
45,978 lbs / 20,855 Kg = 29.7 x 14.6 " / 370 mm shells or 8.2 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 4.4 ft / 1.4 m
Roll period: 18.3 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.85
Seaboat quality (Average = 1.00): 1.07
Hull form characteristics:
Hull has a flush deck,
an extended bulbous bow and large transom stern
Block coefficient (normal/deep): 0.633 / 0.640
Length to Beam Ratio: 7.25 : 1
'Natural speed' for length: 29.79 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 45.00 degrees
Stern overhang: 13.12 ft / 4.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 35.00 %, 31.17 ft / 9.50 m, 23.62 ft / 7.20 m
- Forward deck: 30.00 %, 23.62 ft / 7.20 m, 18.37 ft / 5.60 m
- Aft deck: 25.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Quarter deck: 10.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Average freeboard: 22.05 ft / 6.72 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61.5 %
- Above water (accommodation/working, high = better): 161.8 %
Waterplane Area: 48,122 Square feet or 4,471 Square metres
Displacement factor (Displacement / loading): 114 %
Structure weight / hull surface area: 180 lbs/sq ft or 879 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.47
- Overall: 1.00
BACKSTORY: Following the end of the First World War, a new naval race was brewing between the Americans, British, and Japanese. In OTL, this resulted in the Washington Naval Treaty. However, in this timeline, the WNT is discarded as the British, Japanese, and Americans are hampered by constantly varying views of how the naval restrictions should go. Thus, the new battleship race ignites, and eventually, even smaller nations are forced to begin building new warships. One class of ships was the Spanish "Reina Victoria Eugenia" class, which was nearly identical to the proposed version of it OTL, but was upgunned to 14in cannons, with tonnage increasing accordingly. Viewing this as a threat to their Colonial Empire, the Portuguese Second Republic in return ordered a class of two battleships from British shipyards. Finding both British 14 inch and 15 inch guns as not satisfying their requirements, the Portuguese asked for an intermediate to these two options. Elswick responded with the 370mm 44 calibre gun, with which the Portuguese became enamored, deciding to arm their ships with 6 of these in two triple turrets fore. The first ship was laid down in 1927, the second following a year later, and both were completed 4 years after their laying down.
Displacement:
25,775 t light; 27,167 t standard; 29,406 t normal; 31,197 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(711.94 ft / 666.01 ft) x 91.86 ft x (26.57 / 27.88 ft)
(217.00 m / 203.00 m) x 28.00 m x (8.10 / 8.50 m)
Armament:
6 - 14.57" / 370 mm 44.0 cal guns - 1,765.90lbs / 801.00kg shells, 120 per gun
Breech loading guns in turret on barbette mounts, 1923 Model
2 x Triple mounts on centreline, forward deck forward
1 raised mount - superfiring
12 - 5.51" / 140 mm 50.0 cal guns - 82.01lbs / 37.20kg shells, 150 per gun
Breech loading guns in deck and hoist mounts, 1913 Model
12 x Single mounts on centreline, evenly spread
4 - 4.02" / 102 mm 45.0 cal guns - 31.09lbs / 14.10kg shells, 220 per gun
Anti-air guns in deck mounts, 1914 Model
4 x Single mounts on sides, evenly spread
Weight of broadside 11,704 lbs / 5,309 kg
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 11.0" / 280 mm 269.03 ft / 82.00 m 26.25 ft / 8.00 m
Ends: 4.02" / 102 mm 262.47 ft / 80.00 m 26.25 ft / 8.00 m
134.51 ft / 41.00 m Unarmoured ends
Main Belt covers 62 % of normal length
- Torpedo Bulkhead - Strengthened structural bulkheads:
4.02" / 102 mm 426.51 ft / 130.00 m 16.40 ft / 5.00 m
Beam between torpedo bulkheads 91.86 ft / 28.00 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 16.0" / 406 mm 5.98" / 152 mm 16.0" / 406 mm
2nd: 2.99" / 76 mm - 5.00" / 127 mm
- Armoured deck - multiple decks:
For and Aft decks: 2.99" / 76 mm
Forecastle: 2.99" / 76 mm Quarter deck: 2.99" / 76 mm
- Conning towers: Forward 11.02" / 280 mm, Aft 11.02" / 280 mm
Machinery:
Oil fired boilers, steam turbines, plus diesel motors,
Geared drive, 4 shafts, 88,107 shp / 65,728 Kw = 28.00 kts
Range 7,700nm at 15.00 kts
Bunker at max displacement = 4,030 tons
Complement:
1,122 - 1,459
Cost:
£8.158 million / $32.633 million
Distribution of weights at normal displacement:
Armament: 1,839 tons, 6.3 %
- Guns: 1,839 tons, 6.3 %
Armour: 11,140 tons, 37.9 %
- Belts: 4,784 tons, 16.3 %
- Torpedo bulkhead: 1,040 tons, 3.5 %
- Armament: 2,180 tons, 7.4 %
- Armour Deck: 2,684 tons, 9.1 %
- Conning Towers: 453 tons, 1.5 %
Machinery: 2,781 tons, 9.5 %
Hull, fittings & equipment: 10,015 tons, 34.1 %
Fuel, ammunition & stores: 3,631 tons, 12.3 %
Miscellaneous weights: 0 tons, 0.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
45,978 lbs / 20,855 Kg = 29.7 x 14.6 " / 370 mm shells or 8.2 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 4.4 ft / 1.4 m
Roll period: 18.3 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.85
Seaboat quality (Average = 1.00): 1.07
Hull form characteristics:
Hull has a flush deck,
an extended bulbous bow and large transom stern
Block coefficient (normal/deep): 0.633 / 0.640
Length to Beam Ratio: 7.25 : 1
'Natural speed' for length: 29.79 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 45.00 degrees
Stern overhang: 13.12 ft / 4.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 35.00 %, 31.17 ft / 9.50 m, 23.62 ft / 7.20 m
- Forward deck: 30.00 %, 23.62 ft / 7.20 m, 18.37 ft / 5.60 m
- Aft deck: 25.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Quarter deck: 10.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Average freeboard: 22.05 ft / 6.72 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61.5 %
- Above water (accommodation/working, high = better): 161.8 %
Waterplane Area: 48,122 Square feet or 4,471 Square metres
Displacement factor (Displacement / loading): 114 %
Structure weight / hull surface area: 180 lbs/sq ft or 879 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.47
- Overall: 1.00
BACKSTORY: Following the end of the First World War, a new naval race was brewing between the Americans, British, and Japanese. In OTL, this resulted in the Washington Naval Treaty. However, in this timeline, the WNT is discarded as the British, Japanese, and Americans are hampered by constantly varying views of how the naval restrictions should go. Thus, the new battleship race ignites, and eventually, even smaller nations are forced to begin building new warships. One class of ships was the Spanish "Reina Victoria Eugenia" class, which was nearly identical to the proposed version of it OTL, but was upgunned to 14in cannons, with tonnage increasing accordingly. Viewing this as a threat to their Colonial Empire, the Portuguese Second Republic in return ordered a class of two battleships from British shipyards. Finding both British 14 inch and 15 inch guns as not satisfying their requirements, the Portuguese asked for an intermediate to these two options. Elswick responded with the 370mm 44 calibre gun, with which the Portuguese became enamored, deciding to arm their ships with 6 of these in two triple turrets fore. The first ship was laid down in 1927, the second following a year later, and both were completed 4 years after their laying down.