In late 1925 the CV Alioth was laid down to replace the elderly Siboney, while the CL Ares class cruisers will replace the elderly Brencis and Nereus class cruisers now scrapped. The R-62 class coastal sub is a new design that will be used with the Efficax class multi purpose sub support ships.
Alioth, Atlantis Aircraft Carrier laid down 1925
Displacement:
13,051 t light; 13,401 t standard; 14,678 t normal; 15,699 t full load
Dimensions: Length overall / water x beam x draught
660.10 ft / 655.00 ft x 72.00 ft x 22.60 ft (normal load)
201.20 m / 199.64 m x 21.95 m x 6.89 m
Armament:
6 - 5.50" / 140 mm guns in single mounts, 83.19lbs / 37.73kg shells, 1925 Model
Breech loading guns in deck mounts with hoists
on centreline ends, evenly spread
8 - 3.00" / 76.2 mm guns (4x2 guns), 13.50lbs / 6.12kg shells, 1925 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread
8 - 1.57" / 39.9 mm guns (4x2 guns), 1.93lbs / 0.88kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
12 - 1.00" / 25.4 mm guns (6x2 guns), 0.50lbs / 0.23kg shells, 1925 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 629 lbs / 285 kg
Shells per gun, main battery: 150
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.95" / 100 mm 430.00 ft / 131.06 m 12.00 ft / 3.66 m
Ends: Unarmoured
Main Belt covers 101 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -
2nd: 1.00" / 25 mm - -
- Armour deck: 1.57" / 40 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 103,177 shp / 76,970 Kw = 32.00 kts
Range 12,000nm at 12.00 kts
Bunker at max displacement = 2,298 tons
Complement:
666 - 866
Cost:
£3.246 million / $12.983 million
Distribution of weights at normal displacement:
Armament: 79 tons, 0.5 %
Armour: 1,775 tons, 12.1 %
- Belts: 853 tons, 5.8 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 23 tons, 0.2 %
- Armour Deck: 898 tons, 6.1 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 3,350 tons, 22.8 %
Hull, fittings & equipment: 4,848 tons, 33.0 %
Fuel, ammunition & stores: 1,627 tons, 11.1 %
Miscellaneous weights: 3,000 tons, 20.4 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
16,598 lbs / 7,529 Kg = 199.5 x 5.5 " / 140 mm shells or 1.9 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 3.6 ft / 1.1 m
Roll period: 16.0 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 1.22
Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.482
Length to Beam Ratio: 9.10 : 1
'Natural speed' for length: 25.59 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 24.00 ft / 7.32 m
- Forecastle (20 %): 22.00 ft / 6.71 m (20.00 ft / 6.10 m aft of break)
- Mid (0 %): 20.00 ft / 6.10 m
- Quarterdeck (15 %): 20.00 ft / 6.10 m
- Stern: 20.00 ft / 6.10 m
- Average freeboard: 20.56 ft / 6.27 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 100.8 %
- Above water (accommodation/working, high = better): 176.8 %
Waterplane Area: 30,917 Square feet or 2,872 Square metres
Displacement factor (Displacement / loading): 121 %
Structure weight / hull surface area: 103 lbs/sq ft or 501 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 1.20
- Overall: 1.02
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
Good seaboat, rides out heavy weather easily
------------------------------------------------------------------------
Ares, Atlantis Light Cruiser laid down 1926
Displacement:
7,973 t light; 8,240 t standard; 9,133 t normal; 9,847 t full load
Dimensions: Length overall / water x beam x draught
580.31 ft / 575.00 ft x 62.00 ft x 19.20 ft (normal load)
176.88 m / 175.26 m x 18.90 m x 5.85 m
Armament:
10 - 6.00" / 152 mm guns (4 mounts), 108.00lbs / 48.99kg shells, 1926 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 3.00" / 76.2 mm guns (4x2 guns), 13.50lbs / 6.12kg shells, 1926 Model
Anti-aircraft guns in deck mounts with hoists
on side, all amidships
8 - 1.57" / 39.9 mm guns (4x2 guns), 1.93lbs / 0.88kg shells, 1926 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
12 - 1.00" / 25.4 mm guns (4x3 guns), 0.50lbs / 0.23kg shells, 1926 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 1,209 lbs / 549 kg
Shells per gun, main battery: 120
12 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 380.00 ft / 115.82 m 9.84 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 102 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 3.95" / 100 mm 2.35" / 60 mm 3.15" / 80 mm
2nd: 1.00" / 25 mm - -
- Armour deck: 1.57" / 40 mm, Conning tower: 3.15" / 80 mm
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 75,388 shp / 56,240 Kw = 31.50 kts
Range 7,000nm at 15.00 kts
Bunker at max displacement = 1,607 tons
Complement:
466 - 607
Cost:
£2.570 million / $10.280 million
Distribution of weights at normal displacement:
Armament: 151 tons, 1.7 %
Armour: 1,512 tons, 16.6 %
- Belts: 491 tons, 5.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 321 tons, 3.5 %
- Armour Deck: 670 tons, 7.3 %
- Conning Tower: 30 tons, 0.3 %
Machinery: 2,413 tons, 26.4 %
Hull, fittings & equipment: 3,817 tons, 41.8 %
Fuel, ammunition & stores: 1,159 tons, 12.7 %
Miscellaneous weights: 80 tons, 0.9 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
12,608 lbs / 5,719 Kg = 116.7 x 6.0 " / 152 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 3.2 ft / 1.0 m
Roll period: 14.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.36
Seaboat quality (Average = 1.00): 1.26
Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.467
Length to Beam Ratio: 9.27 : 1
'Natural speed' for length: 23.98 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 12.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.00 ft / 7.62 m
- Forecastle (20 %): 24.50 ft / 7.47 m (24.00 ft / 7.32 m aft of break)
- Mid (50 %): 24.00 ft / 7.32 m
- Quarterdeck (15 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 21.22 ft / 6.47 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 99.6 %
- Above water (accommodation/working, high = better): 156.3 %
Waterplane Area: 23,067 Square feet or 2,143 Square metres
Displacement factor (Displacement / loading): 120 %
Structure weight / hull surface area: 102 lbs/sq ft or 500 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.95
- Longitudinal: 1.60
- 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
Good seaboat, rides out heavy weather easily
------------------------------------------------------------------------
R-62 class sub, Atlantis Coastal submarine laid down 1925
Displacement:
410 t light; 421 t standard; 438 t normal; 451 t full load
Dimensions: Length overall / water x beam x draught
135.01 ft / 135.00 ft x 15.00 ft (Bulges 22.00 ft) x 12.00 ft (normal load)
41.15 m / 41.15 m x 4.57 m (Bulges 6.71 m) x 3.66 m
Armament:
2 - 2.95" / 74.9 mm guns in single mounts, 12.84lbs / 5.82kg shells, 1925 Model
Breech loading guns in deck mounts
on centreline, evenly spread
2 - 1.00" / 25.4 mm guns (1x2 guns), 0.50lbs / 0.23kg shells, 1925 Model
Breech loading guns in deck mount
on centreline
Weight of broadside 27 lbs / 12 kg
Shells per gun, main battery: 150
3 - 21.0" / 533.4 mm submerged torpedo tubes
Machinery:
Diesel Internal combustion generators,
Electric motors, 2 shafts, 1,102 shp / 822 Kw = 15.00 kts
Range 6,000nm at 6.00 kts
Bunker at max displacement = 31 tons
Complement:
47 - 62
Cost:
£0.072 million / $0.290 million
Distribution of weights at normal displacement:
Armament: 3 tons, 0.8 %
Machinery: 36 tons, 8.2 %
Hull, fittings & equipment: 291 tons, 66.4 %
Fuel, ammunition & stores: 28 tons, 6.4 %
Miscellaneous weights: 80 tons, 18.3 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
261 lbs / 118 Kg = 20.3 x 3.0 " / 75 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 0.4 ft / 0.1 m
Roll period: 14.5 seconds
Steadiness - As gun platform (Average = 50 %): 1 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.430
Length to Beam Ratio: 6.14 : 1
'Natural speed' for length: 11.62 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 5.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 0.10 ft / 0.03 m
- Forecastle (30 %): 0.10 ft / 0.03 m
- Mid (0 %): 0.10 ft / 0.03 m
- Quarterdeck (55 %): 0.10 ft / 0.03 m
- Stern: 0.10 ft / 0.03 m
- Average freeboard: 0.10 ft / 0.03 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 92.7 %
- Above water (accommodation/working, high = better): 0.5 %
Waterplane Area: 1,272 Square feet or 118 Square metres
Displacement factor (Displacement / loading): 246 %
Structure weight / hull surface area: 122 lbs/sq ft or 596 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 4.25
- Longitudinal: 4.53
- Overall: 4.28
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability
operational diving depth: 428 feet
Emergency diving depth: 684 feet
Crush depth: 1070 feet