Aurora , laid down 1924, refitted 1942
Bellona , laid down 1925, refitted 1942
Carmenta , laid down 1926, refitted 1942
Dira , laid down 1926, refitted 1942
Displacement:
7.919 t light; 8.183 t standard (8.000 t officially); 9.358 t normal; 10.298 t full load
Dimensions: Length overall / water x beam x draught
557,69 ft / 547,90 ft x 58,40 ft x 19,69 ft (normal load)
169,98 m / 167,00 m x 17,80 m x 6,00 m
Armament:
8 - 5,91" / 150 mm guns (4x2 guns), 102,98lbs / 46,71kg shells, 1922 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
6 - 4,13" / 105 mm guns in single mounts, 35,32lbs / 16,02kg shells, 1921 Model
Anti-aircraft guns in deck mounts
on side, all amidships
16 - 1,57" / 40,0 mm guns (5 mounts), 1,95lbs / 0,88kg shells, 1924 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
12 - 0,79" / 20,0 mm guns (7 mounts), 0,24lbs / 0,11kg shells, 1923 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 1.070 lbs / 485 kg
Shells per gun, main battery: 120
12 - 21,0" / 533 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4,72" / 120 mm 369,16 ft / 112,52 m 9,84 ft / 3,00 m
Ends: Unarmoured
Main Belt covers 104% of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4,13" / 105 mm 2,36" / 60 mm 3,15" / 80 mm
2nd: 0,98" / 25 mm 0,59" / 15 mm -
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -
- Armour deck: 1,77" / 45 mm, Conning tower: 3,15" / 80 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 80.429 shp / 60.000 Kw = 31,54 kts
Range 9.000nm at 15,00 kts (Bunkerage = 2.115 tons)
Complement:
475 - 618
Cost:
£2,350 million / $9,401 million
Distribution of weights at normal displacement:
Armament: 134 tons, 1,4%
Armour: 1.727 tons, 18,5%
- Belts: 715 tons, 7,6%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 270 tons, 2,9%
- Armour Deck: 712 tons, 7,6%
- Conning Tower: 30 tons, 0,3%
Machinery: 2.649 tons, 28,3%
Hull, fittings & equipment: 3.360 tons, 35,9%
Fuel, ammunition & stores: 1.438 tons, 15,4%
Miscellaneous weights: 50 tons, 0,5%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
10.800 lbs / 4.899 Kg = 104,9 x 5,9 " / 150 mm shells or 1,4 torpedoes
Stability (Unstable if below 1.00): 1,11
Metacentric height 2,7 ft / 0,8 m
Roll period: 14,8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,37
Seaboat quality (Average = 1.00): 1,00
Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0,520
Length to Beam Ratio: 9,38 : 1
'Natural speed' for length: 23,41 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 15,00 degrees
Stern overhang: 3,28 ft / 1,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24,28 ft / 7,40 m
- Forecastle (20%): 20,51 ft / 6,25 m
- Mid (50%): 20,51 ft / 6,25 m
- Quarterdeck (25%): 12,47 ft / 3,80 m (20,51 ft / 6,25 m before break)
- Stern: 12,47 ft / 3,80 m
- Average freeboard: 18,80 ft / 5,73 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 103,6%
- Above water (accommodation/working, high = better): 132,5%
Waterplane Area: 21.714 Square feet or 2.017 Square metres
Displacement factor (Displacement / loading): 115%
Structure weight / hull surface area: 97 lbs/sq ft or 475 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,96
- Longitudinal: 1,37
- 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
After refit
Aurora, laid down 1924, refitted 1942
Bellona, laid down 1925, refitted 1942
Carmenta, laid down 1926, refitted 1942
Dira, laid down 1926, refitted 1942
Displacement:
7.908 t light; 8.183 t standard; 9.358 t normal; 10.298 t full load
Dimensions: Length overall / water x beam x draught
557,69 ft / 547,90 ft x 58,40 ft x 19,69 ft (normal load)
169,98 m / 167,00 m x 17,80 m x 6,00 m
Armament:
8 - 5,91" / 150 mm guns (4x2 guns), 102,98lbs / 46,71kg shells, 1922 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 4,53" / 115 mm guns (4x2 guns), 46,40lbs / 21,05kg shells, 1940 Model
Dual purpose guns in deck mounts
on side, all amidships
8 - 1,57" / 40,0 mm guns (4x2 guns), 1,95lbs / 0,88kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
12 - 0,79" / 20,0 mm guns (2x6 guns), 0,24lbs / 0,11kg shells, 1938 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
6 - 0,79" / 20,0 mm guns in single mounts, 0,24lbs / 0,11kg shells, 1931 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1.215 lbs / 551 kg
Shells per gun, main battery: 120
6 - 21,0" / 533 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4,72" / 120 mm 373,20 ft / 113,75 m 9,84 ft / 3,00 m
Ends: Unarmoured
Main Belt covers 105% of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4,13" / 105 mm 2,36" / 60 mm 3,15" / 80 mm
2nd: 0,98" / 25 mm 0,59" / 15 mm -
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -
- Armour deck: 1,77" / 45 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 80.429 shp / 60.000 Kw = 31,54 kts
Range 9.000nm at 15,00 kts
Bunker at max displacement = 2.115 tons
Complement:
475 - 618
Cost:
£2,396 million / $9,585 million
Distribution of weights at normal displacement:
Armament: 152 tons, 1,6%
Armour: 1.706 tons, 18,2%
- Belts: 722 tons, 7,7%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 273 tons, 2,9%
- Armour Deck: 712 tons, 7,6%
- Conning Tower: 0 tons, 0,0%
Machinery: 2.649 tons, 28,3%
Hull, fittings & equipment: 3.381 tons, 36,1%
Fuel, ammunition & stores: 1.450 tons, 15,5%
Miscellaneous weights: 20 tons, 0,2%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
10.636 lbs / 4.824 Kg = 103,3 x 5,9 " / 150 mm shells or 1,4 torpedoes
Stability (Unstable if below 1.00): 1,13
Metacentric height 2,8 ft / 0,9 m
Roll period: 14,7 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,40
Seaboat quality (Average = 1.00): 1,00
Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0,520
Length to Beam Ratio: 9,38 : 1
'Natural speed' for length: 23,41 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 15,00 degrees
Stern overhang: 3,28 ft / 1,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24,28 ft / 7,40 m
- Forecastle (20%): 20,51 ft / 6,25 m
- Mid (50%): 20,51 ft / 6,25 m
- Quarterdeck (25%): 12,47 ft / 3,80 m (20,51 ft / 6,25 m before break)
- Stern: 12,47 ft / 3,80 m
- Average freeboard: 18,80 ft / 5,73 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 104,7%
- Above water (accommodation/working, high = better): 155,5%
Waterplane Area: 21.714 Square feet or 2.017 Square metres
Displacement factor (Displacement / loading): 114%
Structure weight / hull surface area: 98 lbs/sq ft or 478 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,96
- Longitudinal: 1,37
- 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