WesWorld

The carrier is a complete rebuild of the Minas Gerais class battleship and the second is a cruiser concept for escorting the new carriers. However, there's no guarantee that either class will be built, or rebuilt in the first instance, simply because I have no idea what my build schedule is going to be like in the 40s outside of the two capship classes.

***

MIBN Falcão, Empire of Brazil Aircraft Carrier laid down 1948

Displacement:
10,520 t light; 10,805 t standard; 11,840 t normal; 12,668 t full load

Dimensions: Length overall / water x beam x draught
541.04 ft / 533.00 ft x 83.00 ft x 24.65 ft (normal load)
164.91 m / 162.46 m x 25.30 m x 7.51 m

Armament:
24 - 3.54" / 90.0 mm guns (8x3 guns), 22.24lbs / 10.09kg shells, 1948 Model
Dual purpose guns in deck mounts with hoists
on side, evenly spread
18 - 1.46" / 37.0 mm guns (6x3 guns), 1.55lbs / 0.70kg shells, 1948 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 562 lbs / 255 kg
Shells per gun, main battery: 150

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4.00" / 102 mm 345.00 ft / 105.16 m 11.00 ft / 3.35 m
Ends: 4.00" / 102 mm 185.00 ft / 56.39 m 11.00 ft / 3.35 m
3.00 ft / 0.91 m Unarmoured ends
Main Belt covers 100 % of normal length

- Torpedo Bulkhead:
1.50" / 38 mm 345.00 ft / 105.16 m 23.80 ft / 7.25 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.50" / 38 mm - -
2nd: 1.00" / 25 mm - -

- Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm

Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 47,251 shp / 35,250 Kw = 28.00 kts
Range 15,000nm at 12.00 kts
Bunker at max displacement = 1,863 tons

Complement:
566 - 737

Cost:
£4.389 million / $17.558 million

Distribution of weights at normal displacement:
Armament: 70 tons, 0.6 %
Armour: 2,561 tons, 21.6 %
- Belts: 951 tons, 8.0 %
- Torpedo bulkhead: 456 tons, 3.8 %
- Armament: 51 tons, 0.4 %
- Armour Deck: 1,035 tons, 8.7 %
- Conning Tower: 67 tons, 0.6 %
Machinery: 1,155 tons, 9.8 %
Hull, fittings & equipment: 5,359 tons, 45.3 %
Fuel, ammunition & stores: 1,320 tons, 11.1 %
Miscellaneous weights: 1,375 tons, 11.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
25,598 lbs / 11,611 Kg = 1,150.8 x 3.5 " / 90 mm shells or 6.4 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 3.8 ft / 1.2 m
Roll period: 17.9 seconds
Steadiness - As gun platform (Average = 50 %): 95 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 1.17

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.380
Length to Beam Ratio: 6.42 : 1
'Natural speed' for length: 27.95 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 81
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17.25 ft / 5.26 m
- Forecastle (20 %): 17.25 ft / 5.26 m
- Mid (50 %): 17.25 ft / 5.26 m
- Quarterdeck (17 %): 17.25 ft / 5.26 m
- Stern: 17.25 ft / 5.26 m
- Average freeboard: 17.25 ft / 5.26 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 66.0 %
- Above water (accommodation/working, high = better): 162.5 %
Waterplane Area: 27,986 Square feet or 2,600 Square metres
Displacement factor (Displacement / loading): 174 %
Structure weight / hull surface area: 140 lbs/sq ft or 685 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.31
- Longitudinal: 2.18
- Overall: 1.38
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Room for 55 aircraft

***

MIBN Executor, Empire of Brazil Heavy Escort Cruiser laid down 1944

Displacement:
15,231 t light; 15,827 t standard; 17,252 t normal; 18,392 t full load

Dimensions: Length overall / water x beam x draught
695.13 ft / 680.00 ft x 77.75 ft x 23.50 ft (normal load)
211.88 m / 207.26 m x 23.70 m x 7.16 m

Armament:
9 - 8.27" / 210 mm guns (3x3 guns), 282.57lbs / 128.17kg shells, 1944 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
12 - 3.54" / 90.0 mm guns (6x2 guns), 25.00lbs / 11.34kg shells, 1944 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, 3 raised mounts - superfiring
24 - 1.46" / 37.0 mm guns (6x4 guns), 2.00lbs / 0.91kg shells, 1944 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
24 - 0.54" / 13.7 mm guns (12x2 guns), 0.08lbs / 0.04kg shells, 1944 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 2,893 lbs / 1,312 kg
Shells per gun, main battery: 150
4 - 21.0" / 533 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 8.00" / 203 mm 465.00 ft / 141.73 m 10.19 ft / 3.11 m
Ends: Unarmoured
Main Belt covers 105 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 8.00" / 203 mm 5.25" / 133 mm 8.00" / 203 mm
2nd: 1.85" / 47 mm 0.98" / 25 mm 1.85" / 47 mm

- Armour deck: 4.50" / 114 mm, Conning tower: 3.50" / 89 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 81,493 shp / 60,793 Kw = 30.50 kts
Range 15,000nm at 12.00 kts
Bunker at max displacement = 2,565 tons

Complement:
752 - 978

Cost:
£7.559 million / $30.234 million

Distribution of weights at normal displacement:
Armament: 356 tons, 2.1 %
Armour: 5,581 tons, 32.3 %
- Belts: 1,581 tons, 9.2 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 939 tons, 5.4 %
- Armour Deck: 3,010 tons, 17.4 %
- Conning Tower: 50 tons, 0.3 %
Machinery: 2,081 tons, 12.1 %
Hull, fittings & equipment: 7,013 tons, 40.6 %
Fuel, ammunition & stores: 2,021 tons, 11.7 %
Miscellaneous weights: 200 tons, 1.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
36,018 lbs / 16,337 Kg = 127.5 x 8.3 " / 210 mm shells or 4.0 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 3.4 ft / 1.0 m
Roll period: 17.7 seconds
Steadiness - As gun platform (Average = 50 %): 99 %
- Recoil effect (Restricted arc if above 1.00): 0.58
Seaboat quality (Average = 1.00): 1.48

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.486
Length to Beam Ratio: 8.75 : 1
'Natural speed' for length: 30.13 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.45 ft / 9.89 m
- Forecastle (17 %): 23.60 ft / 7.19 m
- Mid (50 %): 23.60 ft / 7.19 m
- Quarterdeck (17 %): 23.60 ft / 7.19 m
- Stern: 23.60 ft / 7.19 m
- Average freeboard: 24.20 ft / 7.38 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 57.5 %
- Above water (accommodation/working, high = better): 204.9 %
Waterplane Area: 36,161 Square feet or 3,359 Square metres
Displacement factor (Displacement / loading): 135 %
Structure weight / hull surface area: 129 lbs/sq ft or 629 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.54
- Overall: 1.01
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

I realize we don't have economy rules but can Brazil really afford these ships?

The carrier's block co-efficient is rather low for a ship this size. A cruiser-ish number around .45 to .5 would be more approriate.

I'd also have to point out a miscalculation in the miscellaneous weight. If there's more than 25 aircraft embarked, the weight needed is the square of the number of aircraft - around 3,000 t in this case.

The cruiser's interesting and obviously follows the "Armored Cruiser" concepts that Italy is pioneering. Has there been consideration of a different main gun calibre?

Quoted

Originally posted by thesmilingassassin
I realize we don't have economy rules but can Brazil really afford these ships?

Brazil won't build these ships unless it needs a Pacific fleet. It might not even build these ships anyway.

Quoted

Originally posted by The Rock Doctor
The carrier's block co-efficient is rather low for a ship this size. A cruiser-ish number around .45 to .5 would be more approriate.

I'd also have to point out a miscalculation in the miscellaneous weight. If there's more than 25 aircraft embarked, the weight needed is the square of the number of aircraft - around 3,000 t in this case.

The cruiser's interesting and obviously follows the "Armored Cruiser" concepts that Italy is pioneering. Has there been consideration of a different main gun calibre?

Thanks for the corrections. As for the cruiser, for Brazil it is a somewhat different caliber because it's a balance between the standard 152mm light cruiser guns and the Amazonas' 283mm guns.

I agree on the BC issue, personally I think its waaaay to low. The Atlantean CV Alioth has a BC of .482 on a narrower beam and she's cheaper, £3.246 million / $12.983 million vs. Falcão: £4.389 million / $17.558 million. Alioth is roughly 3,000 tons heavier.

I would think a conversion of one of Brazils current BC's (a third incomplete unit) would make more sence for a CV. It would cut costs somewhat...

I rather doubt that a third BC would be cheaper, considering that it would be 200 feet longer. As for the block coefficient, I think it's rather silly to have a composite strength of 1.51, don't you?

That's why, when you increase the BC, you reduce the draft. I fully agree that 0.38 for a CV is far too low. 0.45 should be considered a solid minimum.

Quoted

Originally posted by Fyrwulf I rather doubt that a third BC would be cheaper, considering that it would be 200 feet longer.

I was refering to Brazil converting its current BC designs hull to a CV variant not build a third BC. When you compair Alioth and Falcão the later design is shorter yet Alioth is cheaper. The costs are more from the armor weapons and fitings rather than dictated by hull size.

Quoted

Originally posted by Swamphen
That's why, when you increase the BC, you reduce the draft. I fully agree that 0.38 for a CV is far too low. 0.45 should be considered a solid minimum.

Presisely and as an example heres a compairison....

Alioth
13,401 t standard
655.00 ft x 72.00 ft x 22.60 ft
6 - 5.50"
8 - 3.00"
8 - 1.57"
12 - 1.00"
Armour:
Main belt: 3.95" / 100 mm 430.00 ft / 131.06 m 12.00 ft / 3.66 m
Gun armour:
Main: 1.00" / 25 mm - -
2nd: 1.00" / 25 mm - -
Armour deck: 1.57" / 40 mm
Aircraft: Max 55, typically 24 fighters, 12 bombers, 19 scout-torpedo bombers
4 shafts, 32.00 kts, Range 12,000nm at 12.00 kts
Cost:
£3.246 million / $12.983 million
Block coefficient: 0.482
Length to Beam Ratio: 9.10 : 1
- Average freeboard: 20.56 ft / 6.27 m
Ship tends to be wet forward
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

Falcão
10,805 t standard
533.00 ft x 83.00 ft x 24.65 ft
24 - 3.54"
18 - 1.46"
Room for 55 aircraft
Armour:
Belt 4.00" / 102 mm 345.00 ft / 105.16 m 11.00 ft / 3.35 m
Ends: 4.00" / 102 mm 185.00 ft / 56.39 m 11.00 ft / 3.35 m
3.00 ft / 0.91 m
Main Belt covers 100 % of normal length
- Torpedo Bulkhead:
1.50" / 38 mm 345.00 ft / 105.16 m 23.80 ft / 7.25 m
Gun armour:Main: 1.50" / 38 mm - - 2nd: 1.00" / 25 mm
Armour deck: 2.00" / 51 mm, Conning tower: 6.00" / 152 mm
4 shafts, 28.00 kts, Range 15,000nm at 12.00 kts
Cost:
£4.389 million / $17.558 million
Block coefficient: 0.380
Average freeboard: 17.25 ft / 5.26 m
Ship tends to be wet forward
Cross-sectional: 1.31
- Longitudinal: 2.18
- Overall: 1.38
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform


Alioth has a higher BC and more shallow draft.

Quoted

Originally posted by Fyrwulf As for the block coefficient, I think it's rather silly to have a composite strength of 1.51, don't you?

Easily altered by making ajustments to hull length, freeboard, Fuel bunkerage armament and armor. Falcão's speed certainly could be raised which would eat up alot of that reserve hull strength.

If you look at cruiser BC's there are few below .480 and none below .400 that I'm aware of.

I'm not going to severely alter this design. It's not meant to be the perfect aircraft carrier, it's based on a battleship hull for God's sake. Later designs will probably be better-suited to the task, but the Pacific Fleet won't be a priority so it's questionable.

Fyrwulf, these were critiques, not efforts to discount your designs completely. Why are you taking it personal?

Your rebuild idea seems much MUCH more difficult, when looking at the orriginal BC, 0.670. You would effectively be completely rebuilding the hull.

Block coefficient is a function of density, is it not? And I'm not taking it personally, I realize they're critiques, I'm just saying the design isn't going to change much from what it is presently, if indeed the conversion happens at all. I might just end up buying a couple carriers second-hand. The cruiser is far more likely, because I do need a cruiser design and a single cruiser class at the ass-end of the fleet makes sense.

If your have a block with the length/beam/draught of your ship, the block co-efficient is a measurement of how of that volume is actually occupied by the hull.

If the block co-efficient is 1.00, you've essentially got a brick. As you start shaving away the corners to get a more streamlined hull, the block-co-efficient goes down.

Doing a more in depth study of your Minas Gerais conversion I've found a huge flaw.

Altering the BC from 0.670 to 0.380 is to my knowledge impossible. Its even more drastic an alteration than lopping off a ships stern and adding a Transom stern, your completely changing the shape of the hull.

From what I can see the ships demensions haven't really changed which further compounds the issue.

Adding buldges and reduced the draft while ajusting the freeboard accordingly would seem more likely an alteration to an elderly BB hull.

*frowns* Hmm... I'll probably put up a tender and sell the two battleships in that case.

I wouldn't write her off that easy, I think your simply aiming for a 10,800 ton CV converted from an 18,000 ton BB.

Well I would personally doubt that a first-generation DN would be feasible for a carrier conversion in 1948...it would be more cost-effective, IMHO, to build new.

There are, however, other uses for such ships...

Quoted

Originally posted by Swamphen
There are, however, other uses for such ships...

I don't follow...

Some are more...nefarious...than others...

(Consider, for instance, the possible ramifications of the 100 tons of miscellaneous weight on the Filipino target ship...)

Quoted

Originally posted by Swamphen
Well I would personally doubt that a first-generation DN would be feasible for a carrier conversion in 1948...it would be more cost-effective, IMHO, to build new.

There are, however, other uses for such ships...

Well IMO the French Bearn never really got the opertunity to providing a valuable training asset for french pilots.

I don't think a first generation DN makes for a poor carrier, at least not in the 30's.