WesWorld

Navarra, Iberia CA laid down 1922

Displacement:
17,338 t light; 17,714 t standard; 18,600 t normal; 19,234 t full load
Loading submergence 911 tons/feet

Dimensions:
524.93 ft x 93.50 ft x 25.26 ft (normal load)
160.00 m x 28.50 m x 7.70 m

Armament:
8 - 2.24" / 57 mm guns
Weight of broadside 45 lbs / 21 kg

Armour:
Belt 9.02" / 229 mm, upper belt 5.91" / 150 mm, end belts 3.94" / 100 mm
Belts cover 110 % of normal area
Light gun shields 0.79" / 20 mm
Armour deck 2.36" / 60 mm, Torpedo bulkhead 0.79" / 20 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 84,041 shp / 62,695 Kw = 28.00 kts
Range 11,000nm at 10.00 kts

Complement:
796 - 1,035

Cost:
£2.756 million / $11.026 million

Distribution of weights at normal displacement:
Armament: 6 tons, 0.0 %
Armour: 4,504 tons, 24.2 %
Belts: 2,855 tons, 15.4 %, Armament: 5 tons, 0.0 %, Armour Deck: 1,393 tons, 7.5 %
Conning Tower: 0 tons, 0.0 %, Torpedo bulkhead: 251 tons, 1.4 %
Machinery: 2,851 tons, 15.3 %
Hull, fittings & equipment: 4,977 tons, 26.8 %
Fuel, ammunition & stores: 1,262 tons, 6.8 %
Miscellaneous weights: 5,000 tons, 26.9 %

Metacentric height 5.0

Remarks:
Hull space for machinery, storage & compartmentation is adequate
Room for accommodation & workspaces is excellent
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.05
Shellfire needed to sink: 18,617 lbs / 8,444 Kg = 44.1 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 2.9
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 61 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.98

Hull form characteristics:
Block coefficient: 0.525
Sharpness coefficient: 0.41
Hull speed coefficient 'M': 6.06
'Natural speed' for length: 22.91 kts
Power going to wave formation at top speed: 61 %
Trim: 62
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 101.6 %
Relative accommodation and working space: 157.7 %
(Average = 100%)
Displacement factor: 122 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.96
(Structure weight / hull surface area: 109 lbs / square foot or 534 Kg / square metre)
Relative longitudinal hull strength: 1.65
(for 20.67 ft / 6.30 m average freeboard, freeboard adjustment 3.53 ft)
Relative composite hull strength: 1.01

reengined
65 planes

What did you change? You skipped the guns, okay, but did you also play around with armour? Speed? Range?

For a CV it looks like a good design but 65 CVs seems too much for a conversion. You´ve enough weight and your flight deck dimensions are also good enough for 65 planes but I _personally_ think that a conversion will never be as perfect as a purpose build CV and thus should be sub-optimal in using weight and space.

There is no rule of thumb in Ricks SPringstyle Notes and IIRC we also don´t have a rule in our economy rules so it is up to the player if he cuts down a conversions flight group for realisms sake.

What do you think?

HoOmAn

- armour I left well enough alone
- the engines are new but mainly for higher fuel efficiency and lighter weight. yes, she is a bit faster (up from 25.5 kn)

your point about the less efficient conversions is well taken, although Glorious and Courageous seemed to have worked well enough. But my starting desgn is prolly not as well suited. Let me go play with it a bit more.

cheers

Bernhard

May I propose to

- use a flight group of up to 60 WW1-type planes

until you change to

- the use of ~54 WW2-type planes in ~1930

without changing anything else?

If so you could also do another rebuild later on to increase your flight crew to ~65 planes of WW2-vintage (say by adding another hangar(deck)).

From a roleplaying point of view you could be learning some lessons and bring your ship from sup-optimal to optimal status. This would need some more ressources later on but makes up for a good story as well. And it´s realistic, just think of the early IJN conversions. Most of them got another rebuild years later that increased their efficiency.

Just some thoughts...

I think seakeeping is important for carriers, because your poor pilots will have to be landing on them, and a lot of rolling will make that dangerous. 0.98 isn't good...

I'd reduce the belt to free up hull strength for raising the freeboard just a touch more.

I actually have been thinking torpedo bulbs.

will come back

Bernhard

Navarra, Iberia CVX laid down 1922

Displacement:
20,194 t light; 20,670 t standard; 22,586 t normal; 24,029 t full load
Loading submergence 1,189 tons/feet

Dimensions:
524.93 ft x 116.47 ft x 22.97 ft (normal load)
160.00 m x 35.50 m x 7.00 m

Armament:
8 - 3.94" / 100 mm AA guns8 - 2.24" / 57 mm guns
Weight of broadside 289 lbs / 131 kg

Armour:
Belt 9.02" / 229 mm, ends unarmoured
Belts cover 110 % of normal area
Light gun shields 0.79" / 20 mm
Armour deck 2.36" / 60 mm, Torpedo bulkhead 0.79" / 20 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 118,598 shp / 88,474 Kw = 29.00 kts
Range 8,000nm at 15.00 kts

Complement:
921 - 1,197

Cost:
£3.547 million / $14.186 million

Distribution of weights at normal displacement:
Armament: 36 tons, 0.2 %
Armour: 4,061 tons, 18.0 %
Belts: 2,009 tons, 8.9 %, Armament: 6 tons, 0.0 %, Armour Deck: 1,818 tons, 8.1 %
Conning Tower: 0 tons, 0.0 %, Torpedo bulkhead: 228 tons, 1.0 %
Machinery: 4,023 tons, 17.8 %
Hull, fittings & equipment: 7,073 tons, 31.3 %
Fuel, ammunition & stores: 2,392 tons, 10.6 %
Miscellaneous weights: 5,000 tons, 22.1 %

Metacentric height 8.4

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

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.17
Shellfire needed to sink: 30,389 lbs / 13,784 Kg = 72.0 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 4.3
(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: 0.01
Relative quality as seaboat: 1.03

Hull form characteristics:
Block coefficient: 0.563
Sharpness coefficient: 0.46
Hull speed coefficient 'M': 5.68
'Natural speed' for length: 22.91 kts
Power going to wave formation at top speed: 65 %
Trim: 68
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 101.1 %
Relative accommodation and working space: 254.1 %
(Average = 100%)
Displacement factor: 130 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.89
(Structure weight / hull surface area: 124 lbs / square foot or 607 Kg / square metre)
Relative longitudinal hull strength: 2.65
(for 29.53 ft / 9.00 m average freeboard, freeboard adjustment 11.70 ft)
Relative composite hull strength: 1.00

60 planes

Torpedo bulbs, draught reduced by 70 cm. end and upper armour removed, ditto conning tower

cruising and max speed adapted to the standard set for the post WWI Armada

comments: yuck!

If I understand correctly you'll be playing Spain&Portugal. If that is the case you'll need a carrier able to operate in Atlantic Ocean conditions, which are far from the best.


your last design seems good enough, but I would cut a good bit of the belt armor (in fact I'd cut it by half at the very least), and use the cross-sectional strenght margin won to add a good freeboard to improve that seakeeping ability. 1.03 ain't enough for atlantic heavy seas, and you don't want your air complement to be grounded when british swordfishes are buzzing around, I guess


I'd also make the torpedo bulkheads 1.5inches thick (torpedos are the only thing you want a belt for, a carrier will rarely, if ever, be shelled, so what you lose in the belt protection, you partially win in improving the Torpedo bulkhead).


just my thoughts .

actually I think that design with the added torpedo bulbs is abysmal - the term "wallowing tubs" comes to mind. I'll keep your suggestion of removing the main armour and go with:

Navarra, Iberia CVX laid down 1921

Displacement:
16,582 t light; 16,960 t standard; 18,600 t normal; 19,837 t full load
Loading submergence 911 tons/feet

Dimensions:
524.93 ft x 93.50 ft x 25.26 ft (normal load)
160.00 m x 28.50 m x 7.70 m

Armament:
12 - 2.24" / 57 mm AA guns
Weight of broadside 68 lbs / 31 kg

Armour:

Armour deck 2.36" / 60 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 129,027 shp / 96,254 Kw = 31.00 kts
Range 8,000nm at 15.00 kts

Complement:
796 - 1,035

Cost:
£3.079 million / $12.315 million

Distribution of weights at normal displacement:
Armament: 8 tons, 0.0 %
Armour: 1,393 tons, 7.5 %
Belts: 0 tons, 0.0 %, Armament: 0 tons, 0.0 %, Armour Deck: 1,393 tons, 7.5 %
Conning Tower: 0 tons, 0.0 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 4,443 tons, 23.9 %
Hull, fittings & equipment: 5,738 tons, 30.8 %
Fuel, ammunition & stores: 2,017 tons, 10.8 %
Miscellaneous weights: 5,000 tons, 26.9 %

Metacentric height 4.8

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

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.03
Shellfire needed to sink: 20,082 lbs / 9,109 Kg = 47.6 x 6 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 2.2
(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: 0.01
Relative quality as seaboat: 1.10

Hull form characteristics:
Block coefficient: 0.525
Sharpness coefficient: 0.41
Hull speed coefficient 'M': 6.06
'Natural speed' for length: 22.91 kts
Power going to wave formation at top speed: 66 %
Trim: 64
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 107.3 %
Relative accommodation and working space: 225.2 %
(Average = 100%)
Displacement factor: 121 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.90
(Structure weight / hull surface area: 116 lbs / square foot or 564 Kg / square metre)
Relative longitudinal hull strength: 2.85
(for 29.53 ft / 9.00 m average freeboard, freeboard adjustment 12.38 ft)
Relative composite hull strength: 1.01

reengined
60 planes

I'd say she's still a tub, with the length to beam ratio as it is. However, the freeboard and width should allow for a spacious hangar, and the speed and capacity strong points.

5,000 t would be 70 aircraft (70*70 = 4900) - or is your deck area not sufficient for that size of airgroup?

Torpedo bulges are out of the question with that much machinery on board, you're right to leave them out.

You''re not concerned about encountering enemy warships, I take it?

Yes, the ship lacks space for 5 more planes.
(l x b) / 750 gives you 65.44127333(etc), so the limit of the ship would be 65.

Walter

well, yes she is a tub *g* as regards capacity, read my discussion with hooman further up in the thread.

and a) she is experimental and b) she will have escorts (not that the armada believes this sillyness with airplanes flying off a ship will ever lead to anything.)

Bernhard

If you´re changing so many of her specs you´ll end up with a rebuild, not a conversion. Does this make sense? Wouldn´t it be better to spend the money for a purpose build carrier or go with a less good but much cheaper alternative?

Hooman you are trying to make sense again. Tsktsk ...

the roleplaying aspect of this is that HM is no big fan of this newfangled stuff (ie airplanes) and the admiralty are having the devil's own time trying to convince him. He agreed to allow the conversions but was flat out against new construction. And yes, this is planned as a rebuild, Iwas just using incorrect terminology ...

Bernhard