WesWorld

I've been working on some carriers to do some tests on sizes and airwing capabilities. Since I'm spanish I've thought about probable purposes for spanish carriers of the era, focusing on the atlantic ocean (so the ship should have high freeboard and good seakeeping capabilites)

I've done some sketches going from 22000 tons down to 5000t...want to hear some feedback on them so any comment will be welcome


Decurion, Spanish carrier laid down 1925

Displacement:
21.883 t light; 22.456 t standard; 25.800 t normal; 28.373 t full load
Loading submergence 1.156 tons/feet

Dimensions:
760,00 ft x 82,00 ft x 27,60 ft (normal load)
231,65 m x 24,99 m x 8,41 m

Armament:
4 - 6,00" / 152 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 692 lbs / 314 kg

Armour:
Belt 2,00" / 51 mm, ends unarmoured
Belts cover 101 % of normal area
2nd turrets 1,00" / 25 mm
AA gun shields 0,50" / 13 mm
Armour deck 3,50" / 89 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 2,50" / 64 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 109.028 shp / 81.335 Kw = 30,00 kts
Range 14.000nm at 15,00 kts

Complement:
1.017 - 1.323

Cost:
£4,366 million / $17,464 million

Distribution of weights at normal displacement:
Armament: 86 tons, 0,3 %
Armour: 4.399 tons, 17,0 %
Belts: 448 tons, 1,7 %, Armament: 50 tons, 0,2 %, Armour Deck: 2.620 tons, 10,2 %
Conning Tower: 19 tons, 0,1 %, Torpedo bulkhead: 1.261 tons, 4,9 %
Machinery: 3.540 tons, 13,7 %
Hull, fittings & equipment: 7.258 tons, 28,1 %
Fuel, ammunition & stores: 3.918 tons, 15,2 %
Miscellaneous weights: 6.600 tons, 25,6 %

Metacentric height 4,4

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
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,10
Shellfire needed to sink: 26.824 lbs / 12.167 Kg = 248,4 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 3,6
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 71 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,03
Relative quality as seaboat: 1,45

Hull form characteristics:
Block coefficient: 0,525
Sharpness coefficient: 0,35
Hull speed coefficient 'M': 7,87
'Natural speed' for length: 27,57 kts
Power going to wave formation at top speed: 48 %
Trim: 49
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 100,1 %
Relative accommodation and working space: 166,8 %
(Average = 100%)
Displacement factor: 137 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 1,00
(Structure weight / hull surface area: 114 lbs / square foot or 558 Kg / square metre)
Relative longitudinal hull strength: 1,01
(for 22,00 ft / 6,71 m average freeboard, freeboard adjustment 3,70 ft)
Relative composite hull strength: 1,00


Air group: 81 aircraft

this one displaces 19000tons:


Decurion, Spanish carrier laid down 1925

Displacement:
18.528 t light; 19.027 t standard; 22.069 t normal; 24.414 t full load
Loading submergence 986 tons/feet

Dimensions:
700,00 ft x 75,00 ft x 27,50 ft (normal load)
213,36 m x 22,86 m x 8,38 m

Armament:
4 - 6,00" / 152 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 692 lbs / 314 kg

Armour:
Belt 2,00" / 51 mm, ends unarmoured
Belts cover 106 % of normal area
2nd turrets 1,00" / 25 mm
AA gun shields 0,50" / 13 mm
Armour deck 4,00" / 102 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 2,50" / 64 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 102.032 shp / 76.116 Kw = 30,00 kts
Range 14.000nm at 15,00 kts

Complement:
905 - 1.176

Cost:
£3,878 million / $15,511 million

Distribution of weights at normal displacement:
Armament: 86 tons, 0,4 %
Armour: 4.192 tons, 19,0 %
Belts: 414 tons, 1,9 %, Armament: 49 tons, 0,2 %, Armour Deck: 2.555 tons, 11,6 %
Conning Tower: 17 tons, 0,1 %, Torpedo bulkhead: 1.157 tons, 5,2 %
Machinery: 3.313 tons, 15,0 %
Hull, fittings & equipment: 6.037 tons, 27,4 %
Fuel, ammunition & stores: 3.541 tons, 16,0 %
Miscellaneous weights: 4.900 tons, 22,2 %

Metacentric height 3,7

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
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,07
Shellfire needed to sink: 20.288 lbs / 9.203 Kg = 187,9 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 2,8
(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: 0,04
Relative quality as seaboat: 1,33

Hull form characteristics:
Block coefficient: 0,535
Sharpness coefficient: 0,35
Hull speed coefficient 'M': 7,63
'Natural speed' for length: 26,46 kts
Power going to wave formation at top speed: 51 %
Trim: 53
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 104,5 %
Relative accommodation and working space: 152,6 %
(Average = 100%)
Displacement factor: 134 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,99
(Structure weight / hull surface area: 108 lbs / square foot or 529 Kg / square metre)
Relative longitudinal hull strength: 1,10
(for 21,00 ft / 6,40 m average freeboard, freeboard adjustment 3,26 ft)
Relative composite hull strength: 1,00

air group: 70 aircraft

14000 tons:


Decurion, Spanish carrier laid down 1925

Displacement:
13.839 t light; 14.217 t standard; 15.999 t normal; 17.362 t full load
Loading submergence 745 tons/feet

Dimensions:
610,00 ft x 68,00 ft x 27,00 ft (normal load)
185,93 m x 20,73 m x 8,23 m

Armament:
4 - 6,00" / 152 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 692 lbs / 314 kg

Armour:
Belt 1,00" / 25 mm, ends unarmoured
Belts cover 131 % of normal area
2nd turrets 2,00" / 51 mm
AA gun shields 0,50" / 13 mm
Armour deck 3,00" / 76 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 2,00" / 51 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 99.573 shp / 74.281 Kw = 31,00 kts
Range 10.000nm at 15,00 kts

Complement:
711 - 924

Cost:
£3,304 million / $13,216 million

Distribution of weights at normal displacement:
Armament: 86 tons, 0,5 %
Armour: 2.569 tons, 16,1 %
Belts: 213 tons, 1,3 %, Armament: 103 tons, 0,6 %, Armour Deck: 1.447 tons, 9,0 %
Conning Tower: 14 tons, 0,1 %, Torpedo bulkhead: 792 tons, 5,0 %
Machinery: 3.233 tons, 20,2 %
Hull, fittings & equipment: 4.815 tons, 30,1 %
Fuel, ammunition & stores: 2.160 tons, 13,5 %
Miscellaneous weights: 3.136 tons, 19,6 %

Metacentric height 3,1

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,05
Shellfire needed to sink: 10.317 lbs / 4.680 Kg = 95,5 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,5
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 71 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,07
Relative quality as seaboat: 1,42

Hull form characteristics:
Block coefficient: 0,500
Sharpness coefficient: 0,34
Hull speed coefficient 'M': 7,40
'Natural speed' for length: 24,70 kts
Power going to wave formation at top speed: 56 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 129,7 %
Relative accommodation and working space: 167,6 %
(Average = 100%)
Displacement factor: 124 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,94
(Structure weight / hull surface area: 104 lbs / square foot or 506 Kg / square metre)
Relative longitudinal hull strength: 1,73
(for 24,00 ft / 7,32 m average freeboard, freeboard adjustment 7,36 ft)
Relative composite hull strength: 1,00

air group: 56 aircraft

12000 tons:

Decurion, Spanish carrier laid down 1925

Displacement:
11.423 t light; 11.732 t standard; 13.351 t normal; 14.593 t full load
Loading submergence 628 tons/feet

Dimensions:
585,00 ft x 61,00 ft x 27,00 ft (normal load)
178,31 m x 18,59 m x 8,23 m

Armament:
4 - 4,92" / 125 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 498 lbs / 226 kg

Armour:
Belt 1,00" / 25 mm, ends unarmoured
Belts cover 140 % of normal area
2nd turrets 2,00" / 51 mm
AA gun shields 0,50" / 13 mm
Armour deck 3,00" / 76 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 2,00" / 51 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 89.348 shp / 66.654 Kw = 31,00 kts
Range 10.000nm at 15,00 kts

Complement:
621 - 807

Cost:
£2,809 million / $11,235 million

Distribution of weights at normal displacement:
Armament: 62 tons, 0,5 %
Armour: 2.272 tons, 17,0 %
Belts: 205 tons, 1,5 %, Armament: 75 tons, 0,6 %, Armour Deck: 1.220 tons, 9,1 %
Conning Tower: 12 tons, 0,1 %, Torpedo bulkhead: 760 tons, 5,7 %
Machinery: 2.901 tons, 21,7 %
Hull, fittings & equipment: 3.878 tons, 29,0 %
Fuel, ammunition & stores: 1.928 tons, 14,4 %
Miscellaneous weights: 2.310 tons, 17,3 %

Metacentric height 2,5

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,02
Shellfire needed to sink: 6.949 lbs / 3.152 Kg = 64,3 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,2
(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: 0,07
Relative quality as seaboat: 1,27

Hull form characteristics:
Block coefficient: 0,485
Sharpness coefficient: 0,33
Hull speed coefficient 'M': 7,54
'Natural speed' for length: 24,19 kts
Power going to wave formation at top speed: 55 %
Trim: 55
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 138,9 %
Relative accommodation and working space: 141,5 %
(Average = 100%)
Displacement factor: 123 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,95
(Structure weight / hull surface area: 96 lbs / square foot or 468 Kg / square metre)
Relative longitudinal hull strength: 1,62
(for 21,00 ft / 6,40 m average freeboard, freeboard adjustment 4,96 ft)
Relative composite hull strength: 1,00


air group: 48 aircraft

10000 tons:


Decurion, Spanish carrier laid down 1925

Displacement:
9.439 t light; 9.704 t standard; 11.152 t normal; 12.265 t full load
Loading submergence 566 tons/feet

Dimensions:
555,00 ft x 58,00 ft x 25,00 ft (normal load)
169,16 m x 17,68 m x 7,62 m

Armament:
4 - 4,92" / 125 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 498 lbs / 226 kg

Armour:
Belt 1,00" / 25 mm, ends unarmoured
Belts cover 140 % of normal area
2nd turrets 2,00" / 51 mm
AA gun shields 0,50" / 13 mm
Armour deck 2,00" / 51 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 1,00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 71.544 shp / 53.372 Kw = 30,00 kts
Range 10.000nm at 15,00 kts

Complement:
542 - 705

Cost:
£2,317 million / $9,266 million

Distribution of weights at normal displacement:
Armament: 62 tons, 0,6 %
Armour: 1.343 tons, 12,0 %
Belts: 190 tons, 1,7 %, Armament: 75 tons, 0,7 %, Armour Deck: 733 tons, 6,6 %
Conning Tower: 11 tons, 0,1 %, Torpedo bulkhead: 334 tons, 3,0 %
Machinery: 2.323 tons, 20,8 %
Hull, fittings & equipment: 3.947 tons, 35,4 %
Fuel, ammunition & stores: 1.712 tons, 15,4 %
Miscellaneous weights: 1.764 tons, 15,8 %

Metacentric height 2,4

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,05
Shellfire needed to sink: 6.301 lbs / 2.858 Kg = 58,3 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,1
(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: 0,08
Relative quality as seaboat: 1,40

Hull form characteristics:
Block coefficient: 0,485
Sharpness coefficient: 0,33
Hull speed coefficient 'M': 7,60
'Natural speed' for length: 23,56 kts
Power going to wave formation at top speed: 55 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 136,8 %
Relative accommodation and working space: 146,3 %
(Average = 100%)
Displacement factor: 135 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 1,11
(Structure weight / hull surface area: 107 lbs / square foot or 524 Kg / square metre)
Relative longitudinal hull strength: 2,00
(for 21,00 ft / 6,40 m average freeboard, freeboard adjustment 5,52 ft)
Relative composite hull strength: 1,18

Air group: 42

5000 tons. This one would be a CVE, and it's air group would be 12 or 16 fighters and 8 or 4 scout-attack aircraft, it's purpose would be to give fighter cover to naval task forces far from land:


Decurion, Spanish escort carrier laid down 1925

Displacement:
4.751 t light; 4.900 t standard; 5.897 t normal; 6.670 t full load
Loading submergence 365 tons/feet

Dimensions:
455,00 ft x 48,00 ft x 21,00 ft (normal load)
138,68 m x 14,63 m x 6,40 m

Armament:
4 - 4,92" / 125 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
4 - 3,94" / 100 mm guns
Weight of broadside 376 lbs / 170 kg

Armour:
2nd turrets 1,00" / 25 mm
AA gun shields 0,50" / 13 mm
Armour deck 1,00" / 25 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 1,00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 39.093 shp / 29.163 Kw = 28,00 kts
Range 10.000nm at 15,00 kts

Complement:
336 - 437

Cost:
£1,255 million / $5,020 million

Distribution of weights at normal displacement:
Armament: 47 tons, 0,8 %
Armour: 512 tons, 8,7 %
Belts: 0 tons, 0,0 %, Armament: 38 tons, 0,6 %, Armour Deck: 237 tons, 4,0 %
Conning Tower: 7 tons, 0,1 %, Torpedo bulkhead: 230 tons, 3,9 %
Machinery: 1.269 tons, 21,5 %
Hull, fittings & equipment: 2.523 tons, 42,8 %
Fuel, ammunition & stores: 1.146 tons, 19,4 %
Miscellaneous weights: 400 tons, 6,8 %

Metacentric height 2,2

Remarks:
Hull space for machinery, storage & compartmentation is cramped
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: 1,16
Shellfire needed to sink: 3.516 lbs / 1.595 Kg = 32,6 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0,7
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 82 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,14
Relative quality as seaboat: 1,96

Hull form characteristics:
Block coefficient: 0,450
Sharpness coefficient: 0,32
Hull speed coefficient 'M': 7,70
'Natural speed' for length: 21,33 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: 144,0 %
Relative accommodation and working space: 152,3 %
(Average = 100%)
Displacement factor: 154 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 1,14
(Structure weight / hull surface area: 97 lbs / square foot or 476 Kg / square metre)
Relative longitudinal hull strength: 2,98
(for 21,00 ft / 6,40 m average freeboard, freeboard adjustment 7,38 ft)
Relative composite hull strength: 1,25


air group: 20 aircraft






well, those are all of them...please feel free to comment

I made one more, this is even lighter, at 3500tons. air group of 16 (12 fighter, 4 scout-attack planes). I'm not sure about the usefulness of such a small mini-carrier in real life...16 planes with this displacement seems very optimistic to say the least, maybe SS rules regarding carriers don't work at all for very small ships...

in any case here's the ship:

Decurion, Spanish escort carrier laid down 1925

Displacement:
3.498 t light; 3.593 t standard; 4.426 t normal; 5.075 t full load
Loading submergence 339 tons/feet

Dimensions:
450,00 ft x 45,00 ft x 17,00 ft (normal load)
137,16 m x 13,72 m x 5,18 m

Armament:
10 - 1,46" / 37 mm AA guns
2 - 3,94" / 100 mm guns
Weight of broadside 76 lbs / 35 kg

Armour:
Belt 1,00" / 25 mm, ends unarmoured
Belts cover 100 % of normal area
AA gun shields 0,50" / 13 mm
Armour deck 1,50" / 38 mm, Conning tower 1,00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 37.505 shp / 27.978 Kw = 29,00 kts
Range 10.000nm at 15,00 kts

Complement:
271 - 352

Cost:
£0,985 million / $3,939 million

Distribution of weights at normal displacement:
Armament: 10 tons, 0,2 %
Armour: 433 tons, 9,8 %
Belts: 97 tons, 2,2 %, Armament: 2 tons, 0,0 %, Armour Deck: 329 tons, 7,4 %
Conning Tower: 6 tons, 0,1 %, Torpedo bulkhead: 0 tons, 0,0 %
Machinery: 1.218 tons, 27,5 %
Hull, fittings & equipment: 1.581 tons, 35,7 %
Fuel, ammunition & stores: 928 tons, 21,0 %
Miscellaneous weights: 256 tons, 5,8 %

Metacentric height 2,3

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
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,28
Shellfire needed to sink: 5.891 lbs / 2.672 Kg = 54,5 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,1
(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: 0,03
Relative quality as seaboat: 1,43

Hull form characteristics:
Block coefficient: 0,450
Sharpness coefficient: 0,31
Hull speed coefficient 'M': 8,38
'Natural speed' for length: 21,21 kts
Power going to wave formation at top speed: 56 %
Trim: 49
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 97,7 %
Relative accommodation and working space: 141,7 %
(Average = 100%)
Displacement factor: 138 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 1,00
(Structure weight / hull surface area: 72 lbs / square foot or 351 Kg / square metre)
Relative longitudinal hull strength: 1,72
(for 17,00 ft / 5,18 m average freeboard, freeboard adjustment 4,13 ft)
Relative composite hull strength: 1,05

Air group: 16 planes

I really like the first design mainly because of its size but I think that 4x6" is less than satisfactory, I'd add at least 2 more guns or maybe substitute it for 8x5" for a main armament. Anything larger than a cruiser is going to eat your carrier for breakfast with only 4x6" guns and she should at least have an armament to defend against DD's and 5" is satisfactory for that.
Also a torpedo bulkhead any thicker than 2" is getting excessive and is eating up tonnage that could be better suited to AA and an increased airgroup wich is definately a CV's best feature.
With those modifications you might be able to get the 81 aircraft specified, early carrier designs tended to have less than satisfactory aircraft numbers. The Couragous class being the same size have only 48 aircraft but then again they were convertions and not purpose designs. Ark Royal had 60 aircraft and she was a 30's design but one also has to remember that the british didn't like deck parking their aircraft, at least not at first.
Your 19,000 ton CV design looks like a slightly smaller version of the Illustrious class CV's but with a better aircraft complement, again I'd change the main armament to something more numerous. Your carriers defence against cruisers and BB's will be its own cruisers and BB's escorting it so i'd main consern should be defence against DD and aircraft.
It all depends on your fleets doctrine and your level of carrier developement. the british had a lead in carrier developement and saw the carrier as more of a scouting type vessel while the Japanese and Americans saw it as a more offensive type of vessel.

the first design I like it too, however the 19000 tons design is not that bad, and one has to ask if 11 planes are worth 3000tons. I suppose it all depends on the tons and hulls I had to play with...if I was too limited, its almost sure I'd go for the 19000 tons one.


The weapons topic is one I wanted to keep more or less historical at the moment, without using hindsight. That means that DP guns are not an option for any of those designs, and that 6' guns would be desirable for the bigger ships as at the time there was concern about carriers being attacked by light forces. The Japanese went with 8' guns for their carrier conversions, but I don't want to be that extreme...6' would be enough

I chose to put 4x6inch guns as antiship battery, no more, because when I design a ship I try to do it with its 3d image on my mind. Those would be two turrets ,forward and aft of the island...I may add 2 more 6' guns on the port side of the ship ,however that'd mean to erase some AAA guns I wanted to place there...and I chose not to do it. It all comes down to doctrine, as you say, and I would say that for that era my carriers would sail with a couple of cruisers and destroyers, so antiship weapons won't be a problem at all and with 4 6' guns I would already have enough.

What I do think is that I may have to increase the numbers of AA 100mm guns ,but I don't see where to emplace more of them, I already put 8 guns, all of them in doubles ...putting more would be probably a good idea, but I simply don't see where to put them on.


Finally, well, I'm not roleplaying any nation here but I'd figure that I'd go with big (22k or 19k ton) carriers for fleet roles (scout&attack&defence) ,and reserve some 20k tons for the smaller 5000 (or 9000 if I don't have enough hulls) ton CVEs for defensive&scouting roles in fast cruiser groups.

I don't like basing my fleet on mid-size carriers, as I think the big ones can attack and defend better... but neither to focus on big ones because that means too few ships. So having 4 small carriers to cover the fast groups the big carriers can't, doesn't seem a bad idea...

The 19,000 to 27,000 ton range can get you a nice carrier but even 15,000 tons will get you a fairly decent carrier but you'll need a few of them to be effective. I think with your 4x6" layout you may not gen enough punch for the armament your shipping. I would even consider an 8x5.5" to be somewhat better but then again that may be a personal preference. keep in mind with Akagi she initially had 10x8" IIRC, two twin mounts forward and 6 casemates aft, the twins being removed when the flight deck was made continuous. One has to consider though that she was a convertion and significantly larger than your purpose designs weighing in at over 38,000 tons standard. I think the gun minded in any fleet would push for more than just 4x6" and you could surely cram in an extra pair. Did you consider casemated main guns?, this was still the in thing to do in the early to mid 20's, and this would be a way for you to increase the main armament on a slightly restricted hull size. Do you have the pictures of your carriers handy? If so Email them to me, my Email should be in the forums list. Do you have ICQ?

I wish I had images of them ,but that's not the case...I still have no software (in this laptop) to do that kind of work, however I'm planning to start drawing the best designs I have as soon as I can get some drawing software able to do this kind of job. I'll have to learn it from start, but what the heck

The idea about casemated guns is a very interesting one, I didn't think about it. That gives me the chance to increase the number of guns I can put on my designs (pre-1930, at least). the problem is that with the design year I have put on my carrier (1925) there's no chance to put guns in casemates, they come out as "secondary guns", so...I don't know the way around this problem.


and no, I don't have ICQ for 80% of the year. I'm currently at my university's residence and the firewall prevents the use of some online programs as ICQ. I have Hotmail messenger, tho... ramjb@hotmail.com

Others here may have a better idea but I think for casemates you would enter them as secondary's in springstyle and in spring sharp you would do the same but specify that they are below the main deck.

already tried to do that, the problem is that if you put a later date than 1919, springstyle won't let you put casemated secondary guns


[edit]well I tested anyway the results of putting casemated guns in SS vs putting them in normal open spots or even turrets...I saw no difference neither in hull strenght nor in seakeeping (wich strikes me as odd), so I simply went on putting four more 6' guns, and changing the report as if they were casemates.

Those guns would be casemated on the port side of the ship, under the flight deck. The starboard side would be covered by the 4 guns in front of and aft of the island (now they are 2 double mounts, not 4 simple mounts)

I then had to increase the belt extension a bit to cover the expanded magazines, that and the extra guns brought the hull strenght under 1, so I had to chop 0.25' of deck armor and increase a bit the BC to give the ship the needed composite strenght...here's the result:


Decurion, Spanish carrier laid down 1925

Displacement:
21.915 t light; 22.526 t standard; 25.899 t normal; 28.493 t full load
Loading submergence 1.159 tons/feet

Dimensions:
760,00 ft x 82,00 ft x 27,60 ft (normal load)
231,65 m x 24,99 m x 8,41 m

Armament:
8 - 6,00" / 152 mm guns (2 2nd turrets x 2 guns, 4 - 6,00" / 152 mm guns mounted low & subject to being washed down in a seaway)
10 - 1,46" / 37 mm AA guns
8 - 3,94" / 100 mm guns
Weight of broadside 1.124 lbs / 510 kg

Armour:
Belt 2,00" / 51 mm, ends unarmoured
Belts cover 102 % of normal area
2nd turrets 1,00" / 25 mm
AA gun shields 0,50" / 13 mm
Armour deck 3,25" / 83 mm, Conning tower 1,00" / 25 mm
Torpedo bulkhead 2,50" / 64 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 109.365 shp / 81.586 Kw = 30,00 kts
Range 14.000nm at 15,00 kts

Complement:
1.020 - 1.327

Cost:
£4,523 million / $18,093 million

Distribution of weights at normal displacement:
Armament: 140 tons, 0,5 %
Armour: 4.229 tons, 16,3 %
Belts: 452 tons, 1,7 %, Armament: 57 tons, 0,2 %, Armour Deck: 2.439 tons, 9,4 %
Conning Tower: 19 tons, 0,1 %, Torpedo bulkhead: 1.261 tons, 4,9 %
Machinery: 3.551 tons, 13,7 %
Hull, fittings & equipment: 7.394 tons, 28,6 %
Fuel, ammunition & stores: 3.984 tons, 15,4 %
Miscellaneous weights: 6.600 tons, 25,5 %

Metacentric height 4,4

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
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,10
Shellfire needed to sink: 25.780 lbs / 11.694 Kg = 238,7 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 3,4
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 71 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,05
Relative quality as seaboat: 1,44

Hull form characteristics:
Block coefficient: 0,527
Sharpness coefficient: 0,35
Hull speed coefficient 'M': 7,86
'Natural speed' for length: 27,57 kts
Power going to wave formation at top speed: 48 %
Trim: 49
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 101,9 %
Relative accommodation and working space: 166,7 %
(Average = 100%)
Displacement factor: 136 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,99
(Structure weight / hull surface area: 116 lbs / square foot or 567 Kg / square metre)
Relative longitudinal hull strength: 1,02
(for 22,00 ft / 6,71 m average freeboard, freeboard adjustment 3,68 ft)
Relative composite hull strength: 1,00

Your carriers are all reasonable good. They all make sense even though I doubt a carrier of 3500ts is of much value at a seastate of 5+. Most likely it will be rendered useless as a carrier due to the hulls motions and become a special version of an AMC - an AAF (Armed Aircraft Ferry). Personally I think ~8kts is the break even point where it makes sense to use a hull as a carrier.

I would like to hear more about the doctrine behind your designs. What is the scenario you have in mind for your fleet/carriers? Without any background information one can hardly judge if your designs meet your requirements. Is there any limit for maximum tonnage? What would you build (more important: What do you need?) over time under a treaty like the CT where you have to keep your CVs for 20 years once build and where you have a max. tonnage of say 90kts at hand to play with?

Read http://wesworld.jk-clan.de/thread.php?th…dbe1e44722a535c to get an idea of what I´m talking about.

Curious to get your input...

HoOmAn

Quoted

Originally posted by HoOmAn

I would like to hear more about the doctrine behind your designs. What is the scenario you have in mind for your fleet/carriers? Without any background information one can hardly judge if your designs meet your requirements. Is there any limit for maximum tonnage? What would you build (more important: What do you need?) over time under a treaty like the CT where you have to keep your CVs for 20 years once build and where you have a max. tonnage of say 90kts at hand to play with?

let's say that I have 90k tons to play with, and a maximum of 8 hulls...

The carrier I designed is spanish, so it's use would be either on the mediterranean or the atlantic. This last one is a very vicious ocean with very bad gales, so the ships required for the job should have good seakeeping and steadiness to allow it's use in heavy seas.


So, we have 90k tons to make some carriers. Let's assume I'm under the CT. Let's assume, too, that Spain still holds Cuba and Puerto Rico (not Phillipines, tho). I want enough carriers to give my fleet a credible strike and defence power, but also to protect the sea lanes to the canary islands and the caribbean possesions.

That means that, if I go with the heaviest design possible (22000tons) I can only put 4 on the water. One should go to the mediterranean to cover the fleet there, three should go to the atlantic...is that enough to give the fleet a credible air power, while helping to cover the sea lanes with the Caribbean islands and the Canary islands against enemy merchant raiders?. I'd say that it won't be enough.


So, we could go with the 19000ton design, put 4 of them on the water (ammounting for 76000 tons) and leaving us with enough space to launch three 5000ton carriers designed to sail with the fast cruiser fleets which should go raider-hunting. They would be no strike carriers, they would be there to give some air protection to the cruisers, and a good scouting capabilities to help them in their mission.

of course, 3x5000+4x19000 ammounts for 91k tons, not 90, but we could cheat here and there, saying the 19000 tonners are in fact 18500 tonners, or redesign the ships so they displace a bit less each.

The main matter here is that I don't really believe in mid-size carriers, so I see as a better choice to have four 19k ton fleet carrier of a slightly less capability than the 22k ton ones, if that allows me to give my cruisers another three ships with a credible air defence and air scouting capability to help them in their role (be it raider-hunting, or anything else).

The Americans and British both beleaved in the midsize carriers. The British Collossus class was 13,200 tons in the begining and they were originally designed to be built in merchant yards while the Independance were even smaller at 11,000 tons after convertion. While they couldn't carry huge strikeloads they could carry the fighters needed to protect the fleet. The Americans usually teamed up two fleet carriers with a smaller light fleet carrier. With 90,000 tons I would build two 21,000 carriers to start off with and then 3 16000 ton carriers balancing size and hull numbers.

huhm. While I think the british "light" carriers were quite good, I think they built them simply because they couldn't afford building more fleet carriers. The Independence class, well, they were cruiser conversions, not pure carriers, and in any case I'd say they did the job but they weren't brilliant either. The other "light" american carriers weren't exactly good either (to say the least).


I base my carrier building in both capability (of which the 19000 ton design has enough, being as it is a 1925 carrier) and numbers (4 19000 tonners+3 5000 carriers...those are 7 hulls, 2 more than with your plan. I still think that for the needs my nation would have in the given situation, 5 carriers simply aren't enough.

maybe three 19000 ton carriers and three carriers of an "enlightened" version of the 12000 ton one might be a better compromise...and the 12000 ton design is quite more capable than the 5000 ton one.

Still I think that six carriers for all the needs described is a bit low...seven would be much better even being of a very limited capability as the very light carrier I designed...

I'm not sure about which of the 2 ways I'd follow ...each one has its advantages and disadvantages, it's a difficult choice...

Previously I'd made the argument that mid-sized carriers weren't such a bad thing; I think Hooman has already alluded to that thread, so won't rehash the subject.

The notion of CVEs is not a bad one, but 5000 t is probably lowballing what is needed to do the job. The ship's dimensions are quite tight and you'll have trouble accommodating many aircraft below decks. Much larger ships such as Hermes and Ryujo saw their airgroups shrink greatly as aircraft grew in size - and that was before we got to the war.

The torpedo bulkhead probably does more harm than good, as the hull is very cramped. Try leaving it out and see if your survivability against torpedoes doesn't improve.

Also, if the CVE is to work with fast cruiser groups, a top speed of more than 28 kts is probably necessary.

A Tone-style cruiser with aviation facilities might be an alternative to consider for your scouting groups.

man, thanks for bringing that to my attention, I thougth I had erased the torpedo bulkhead while designing my ship (I did it based on the bigger 12000 tons, reducing dimensions, and such), seems I forgot it.

the improvement is very noticeable...now the ship is able to sail at 31 knots ,and its machinery&magazines are less cramped than before .


Decurion, Spanish carrier laid down 1925

Displacement:
4.867 t light; 5.018 t standard; 6.020 t normal; 6.797 t full load
Loading submergence 373 tons/feet

Dimensions:
455,00 ft x 49,00 ft x 21,00 ft (normal load)
138,68 m x 14,94 m x 6,40 m

Armament:
4 - 4,92" / 125 mm guns (4 2nd turrets x 1 guns)10 - 1,46" / 37 mm AA guns
4 - 3,94" / 100 mm guns
Weight of broadside 376 lbs / 170 kg

Armour:
2nd turrets 1,00" / 25 mm
AA gun shields 0,50" / 13 mm
Armour deck 1,00" / 25 mm, Conning tower 1,00" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 60.142 shp / 44.866 Kw = 31,00 kts
Range 10.000nm at 15,00 kts

Complement:
341 - 444

Cost:
£1,581 million / $6,325 million

Distribution of weights at normal displacement:
Armament: 47 tons, 0,8 %
Armour: 287 tons, 4,8 %
Belts: 0 tons, 0,0 %, Armament: 38 tons, 0,6 %, Armour Deck: 242 tons, 4,0 %
Conning Tower: 7 tons, 0,1 %, Torpedo bulkhead: 0 tons, 0,0 %
Machinery: 1.953 tons, 32,4 %
Hull, fittings & equipment: 2.180 tons, 36,2 %
Fuel, ammunition & stores: 1.153 tons, 19,2 %
Miscellaneous weights: 400 tons, 6,6 %

Metacentric height 2,4

Remarks:
Hull space for machinery, storage & compartmentation is cramped
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: 1,21
Shellfire needed to sink: 5.409 lbs / 2.454 Kg = 50,1 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0,9
(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: 0,11
Relative quality as seaboat: 1,53

Hull form characteristics:
Block coefficient: 0,450
Sharpness coefficient: 0,32
Hull speed coefficient 'M': 7,65
'Natural speed' for length: 21,33 kts
Power going to wave formation at top speed: 61 %
Trim: 46
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 118,6 %
Relative accommodation and working space: 153,2 %
(Average = 100%)
Displacement factor: 121 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,94
(Structure weight / hull surface area: 84 lbs / square foot or 408 Kg / square metre)
Relative longitudinal hull strength: 2,54
(for 21,00 ft / 6,40 m average freeboard, freeboard adjustment 7,32 ft)
Relative composite hull strength: 1,04

Air group: 20 aircraft


regarding the idea of an air scout cruiser, well,, I also wanted to add some fighter protection for the cruiser groups which would sail with the light carriers...their role would be protection from the air and scouting...and float planes aren't the best fighters around .

also, if their air group is reduced from the original 20 planes down to ,say, 14 or 12 with the time, well, it will be some loss, but they would still be able to do their role...limited air cover and scouting for the fast fleets based on cruisers.

About mid-sized carriers, as you can see, I'm also toying around with them as another path of action, however I'm still undecided on which of both paths I'd follow

I don't think you'll launch all of these ships in one year, otherwise you will wind up with a massive block obsolecance issue down the road. Your smaller 5000 ton CV's may be able to find alternate roles but in essence this ultralight CV option can be used at any moment once war begins by converting cruisers and large merchant ships. Obviously with say 90,000 tons there is no way you will get 8 hulls of maximum size so you biggest question is what limitation are you willing to except, lower numbers or size?
You then have to decide the limitations envolved in your decision. If you go for maximum numbers will your small ships be lacking in overall capability? If you go for maximum tonnage will you have enough ships to complete your overall fleet stradegy? Keep in mind that Britain when fighting Italy could often dictate the outcome of a battle with just one carrier projecting its influence in the region, when Italy could only rely on the land based air cover. HMS Hermes by the war was reduced to little more than an aircraft ferry and was of limited use at least offencively, where as HMS Eagle was of more use.