A new CSA BB which-would-you-build

[Guinness]

I've been exploring the implications of trying to attain 1.10 stability and a 70 steadiness score on an 8x15" 23 knot BB. That extra steadiness essentially seems to cost a little more than 3000 tons. So which would you build? The heavier but optimized version, or the lighter version? Or in other words, how much is that "good gun platform" score worth?

Heavier:

1916 BB 8 guns 23 knots 4 turrets, CSA Battleship laid down 1916

Displacement:
   32,200 t light; 34,087 t standard; 35,905 t normal; 37,359 t full load

Dimensions: Length overall / water x beam x draught
   670.00 ft / 657.00 ft x 104.50 ft x 28.83 ft (normal load)
   204.22 m / 200.25 m x 31.85 m  x 8.79 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 2,000.00lbs / 907.18kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns (8x2 guns), 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 1.58" / 40.0 mm guns in single mounts, 2.00lbs / 0.91kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      8 - 1.00" / 25.4 mm guns (4x2 guns), 0.50lbs / 0.23kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      4 - 3.50" / 88.9 mm guns in single mounts, 20.00lbs / 9.07kg shells, 1916 Model
     Anti-aircraft guns in deck mounts with hoists
     on side, evenly spread, all raised mounts
   Weight of broadside 17,292 lbs / 7,844 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.5" / 343 mm   427.00 ft / 130.15 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
      3.00" / 76 mm   427.00 ft / 130.15 m   31.00 ft / 9.45 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   18.0" / 457 mm   8.00" / 203 mm      14.0" / 356 mm
   2nd:   1.50" / 38 mm   1.00" / 25 mm      3.00" / 76 mm
   5th:   1.00" / 25 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 17.00" / 432 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 54,600 shp / 40,732 Kw = 23.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 3,272 tons

Complement:
   1,303 - 1,695

Cost:
   £4.875 million / $19.501 million

Distribution of weights at normal displacement:
   Armament: 1,866 tons, 5.2 %
   Armour: 14,016 tons, 39.0 %
      - Belts: 4,055 tons, 11.3 %
      - Torpedo bulkhead: 1,469 tons, 4.1 %
      - Armament: 3,295 tons, 9.2 %
      - Armour Deck: 4,798 tons, 13.4 %
      - Conning Tower: 399 tons, 1.1 %
   Machinery: 2,034 tons, 5.7 %
   Hull, fittings & equipment: 13,848 tons, 38.6 %
   Fuel, ammunition & stores: 3,705 tons, 10.3 %
   Miscellaneous weights: 435 tons, 1.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     58,657 lbs / 26,606 Kg = 34.8 x 15.0 " / 381 mm shells or 11.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 6.5 ft / 2.0 m
   Roll period: 17.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.74
   Seaboat quality  (Average = 1.00): 1.43

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.635
   Length to Beam Ratio: 6.29 : 1
   'Natural speed' for length: 25.63 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 49
   Bow angle (Positive = bow angles forward): 24.14 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      29.00 ft / 8.84 m
      - Forecastle (18 %):   24.75 ft / 7.54 m
      - Mid (63 %):      23.25 ft / 7.09 m (15.50 ft / 4.72 m aft of break)
      - Quarterdeck (18 %):   15.50 ft / 4.72 m
      - Stern:      15.50 ft / 4.72 m
      - Average freeboard:   21.28 ft / 6.49 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 74.6 %
      - Above water (accommodation/working, high = better): 162.7 %
   Waterplane Area: 51,874 Square feet or 4,819 Square metres
   Displacement factor (Displacement / loading): 107 %
   Structure weight / hull surface area: 199 lbs/sq ft or 973 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.49
      - Overall: 1.00
   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

Misc Weights:
250 t Fire Control
25 t Marconi
25 t Marconi
50 t Flag Facilities
85 t Reserve

Lighter:

1916 BB 8 guns 23 knots 4 turrets less beam, CSA Battleship laid down 1916

Displacement:
   29,500 t light; 31,278 t standard; 32,886 t normal; 34,173 t full load

Dimensions: Length overall / water x beam x draught
   655.00 ft / 643.00 ft x 99.00 ft x 29.40 ft (normal load)
   199.64 m / 195.99 m x 30.18 m  x 8.96 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 2,000.00lbs / 907.18kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns (8x2 guns), 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 1.58" / 40.0 mm guns in single mounts, 2.00lbs / 0.91kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      8 - 1.00" / 25.4 mm guns (4x2 guns), 0.50lbs / 0.23kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      4 - 3.50" / 88.9 mm guns in single mounts, 20.00lbs / 9.07kg shells, 1916 Model
     Anti-aircraft guns in deck mounts with hoists
     on side, evenly spread, all raised mounts
   Weight of broadside 17,292 lbs / 7,844 kg
   Shells per gun, main battery: 115

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.5" / 343 mm   418.00 ft / 127.41 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
      2.50" / 64 mm   418.00 ft / 127.41 m   32.00 ft / 9.75 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   17.0" / 432 mm   7.50" / 191 mm      13.5" / 343 mm
   2nd:   1.50" / 38 mm   1.00" / 25 mm      3.00" / 76 mm
   5th:   1.00" / 25 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 16.00" / 406 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 51,500 shp / 38,419 Kw = 23.03 kts
   Range 7,500nm at 12.00 kts
   Bunker at max displacement = 2,895 tons

Complement:
   1,220 - 1,587

Cost:
   £4.694 million / $18.776 million

Distribution of weights at normal displacement:
   Armament: 1,866 tons, 5.7 %
   Armour: 12,225 tons, 37.2 %
      - Belts: 3,949 tons, 12.0 %
      - Torpedo bulkhead: 1,237 tons, 3.8 %
      - Armament: 3,191 tons, 9.7 %
      - Armour Deck: 3,494 tons, 10.6 %
      - Conning Tower: 354 tons, 1.1 %
   Machinery: 1,919 tons, 5.8 %
   Hull, fittings & equipment: 13,057 tons, 39.7 %
   Fuel, ammunition & stores: 3,387 tons, 10.3 %
   Miscellaneous weights: 432 tons, 1.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     51,280 lbs / 23,260 Kg = 30.4 x 15.0 " / 381 mm shells or 9.0 torpedoes
   Stability (Unstable if below 1.00): 1.16
   Metacentric height 6.5 ft / 2.0 m
   Roll period: 16.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.74
   Seaboat quality  (Average = 1.00): 1.46

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.615
   Length to Beam Ratio: 6.49 : 1
   'Natural speed' for length: 25.36 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 34
   Bow angle (Positive = bow angles forward): 23.02 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      28.25 ft / 8.61 m
      - Forecastle (18 %):   25.50 ft / 7.77 m
      - Mid (60 %):      23.33 ft / 7.11 m (15.66 ft / 4.77 m aft of break)
      - Quarterdeck (18 %):   15.66 ft / 4.77 m
      - Stern:      15.66 ft / 4.77 m
      - Average freeboard:   21.30 ft / 6.49 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 80.7 %
      - Above water (accommodation/working, high = better): 157.6 %
   Waterplane Area: 47,213 Square feet or 4,386 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 200 lbs/sq ft or 979 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.59
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Good seaboat, rides out heavy weather easily

Misc Weights:
250 t Fire Control
25 t Marconi
25 t Marconi
50 t Flag Facilities
82 t Reserve

[Korpen]

I rate the lighter one as superior, the 127mm deck is just overkill, and 76mm TB is also so thick it almost starts to be counterproductive. I do not think either the thicker deck or thicker TB adds to the ships combat capability, while the size difference

[The Rock Doctor]

There's more to shooting than the steadiness - FC, gun quality/quantity, crew quality, etc.  On that basis, I'd go with the smaller design.

[Guinness]

On the heavier one: the deck is a product of having extra weight left over after designing a big enough hull for the "good gun platform" rating. The thick TB (which of course would be a series of thinner bulkheads) is really just there to give it some weight down low.

What's funny is, I can get a similar ship with similar stability and steadiness but with a knot or knot and a half more speed if I eliminate those.

[Guinness]

Now I have a quandry. I considered it ok to raise the battleline speed to 23 knots starting with these ships, but maybe a little faster is a better buy?

1916 BB 8 guns 25.5 knots 4 turrets, CSA Battleship laid down 1916

Displacement:
   31,800 t light; 33,667 t standard; 35,367 t normal; 36,726 t full load

Dimensions: Length overall / water x beam x draught
   670.00 ft / 657.00 ft x 102.00 ft x 29.55 ft (normal load)
   204.22 m / 200.25 m x 31.09 m  x 9.01 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 2,000.00lbs / 907.18kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 5.50" / 140 mm guns (8x2 guns), 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 1.58" / 40.0 mm guns in single mounts, 2.00lbs / 0.91kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      8 - 1.00" / 25.4 mm guns (4x2 guns), 0.50lbs / 0.23kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      4 - 3.50" / 88.9 mm guns in single mounts, 20.00lbs / 9.07kg shells, 1916 Model
     Anti-aircraft guns in deck mounts with hoists
     on side, evenly spread, all raised mounts
   Weight of broadside 17,292 lbs / 7,844 kg
   Shells per gun, main battery: 119

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.5" / 343 mm   427.00 ft / 130.15 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
      2.50" / 64 mm   427.00 ft / 130.15 m   31.00 ft / 9.45 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   18.0" / 457 mm   8.00" / 203 mm      13.5" / 343 mm
   2nd:   1.50" / 38 mm   1.00" / 25 mm      3.00" / 76 mm
   5th:   1.00" / 25 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 17.00" / 432 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 80,000 shp / 59,680 Kw = 25.50 kts
   Range 7,542nm at 12.00 kts
   Bunker at max displacement = 3,059 tons

Complement:
   1,289 - 1,676

Cost:
   £5.069 million / $20.277 million

Distribution of weights at normal displacement:
   Armament: 1,866 tons, 5.3 %
   Armour: 12,675 tons, 35.8 %
      - Belts: 4,041 tons, 11.4 %
      - Torpedo bulkhead: 1,224 tons, 3.5 %
      - Armament: 3,303 tons, 9.3 %
      - Armour Deck: 3,712 tons, 10.5 %
      - Conning Tower: 395 tons, 1.1 %
   Machinery: 2,981 tons, 8.4 %
   Hull, fittings & equipment: 13,845 tons, 39.1 %
   Fuel, ammunition & stores: 3,566 tons, 10.1 %
   Miscellaneous weights: 434 tons, 1.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     51,033 lbs / 23,148 Kg = 30.2 x 15.0 " / 381 mm shells or 8.5 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 6.5 ft / 2.0 m
   Roll period: 16.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.71
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.625
   Length to Beam Ratio: 6.44 : 1
   'Natural speed' for length: 25.63 kts
   Power going to wave formation at top speed: 51 %
   Trim (Max stability = 0, Max steadiness = 100): 42
   Bow angle (Positive = bow angles forward): 24.14 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      29.00 ft / 8.84 m
      - Forecastle (18 %):   26.00 ft / 7.92 m
      - Mid (63 %):      24.00 ft / 7.32 m (16.00 ft / 4.88 m aft of break)
      - Quarterdeck (18 %):   16.00 ft / 4.88 m
      - Stern:      16.00 ft / 4.88 m
      - Average freeboard:   22.06 ft / 6.72 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 86.8 %
      - Above water (accommodation/working, high = better): 165.3 %
   Waterplane Area: 50,167 Square feet or 4,661 Square metres
   Displacement factor (Displacement / loading): 104 %
   Structure weight / hull surface area: 201 lbs/sq ft or 983 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.55
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Good seaboat, rides out heavy weather easily

Misc Weights:
250 t Fire Control
25 t Marconi
25 t Marconi
50 t Flag Facilities
84 t Reserve

[The Rock Doctor]

It'd help control the range against slower battleships, but would not be enough to catch most AC/BC types. 

Still, you might not have to fight with Congress about getting more ACs if you go this route.

[Guinness]

Well, and it would also force a Colombian response, which is pretty much the other issue to consider. At least right now we are competing on equal footings with respect to speed (in general). Going faster will accelerate the increase in size in our ships even more.

[Valles]

I like the first one a whole lot. I'd go for a thicker belt, but that's just me. ^_^

[The Rock Doctor]

Faster speed for the next GC battleships would certainly make it difficult to improve on the Radiante's armament, for sure...

[Guinness]

I like the first one a whole lot. I'd go for a thicker belt, but that's just me. ^_^

Maybe we can be persuaded to sell our Maori friends the blueprints. I'm sure a thicker belt could be had at the expense of speed...

[Borys]

All three are IMO overarmoured.
But I'd build the .70 Fire Platform. That's a battleship's job - shoot straight.
Borys