AC Question

[The Rock Doctor]

Folks:

I'm pondering an armored cruiser that would be intended for:

1)  Smashing similar or small cruisers and AMCs involved in raiding ops
2)  Anchoring the Battle Fleet's scouting force

The ship would not be intended to fight BCs one on one, but might team up in pairs or with lighter cruisers to try for a replay of River Plate.

The hull's about 11,000 t light, speed between 26 and 26.5 knots (1909 tech), and the belt being between 20 cm and 15 cm depending on the speed.

I can put in either twelve 194 mm guns or eight 234 mm guns; the broadside of the larger guns is about 15% heavier.  Given rate-of-fire, range, and penetration considerations, and the ship's missions, which main battery would you prefer?

[P3D]

The need to engage BCs decides for the larger caliber.

[Tanthalas]

yup i have to agree

[Ithekro]

234mm cannon should be adequate to damage the armored sections of a Battlecruiser at present era combat ranges.  194mm cannon may be able to damage the less heavily armored section at those ranges and perhaps penetrate the armor at close ranges, but no Battlecruiser commander would be willing to get in close with an Armored Cruiser if he does not have to do so.

I would note that I speculate based on period armor thicknesses not the heavier armor that seems to be more common on Navalism Battlecruisers.  At extreme ranges (where the 12" guns are still effective but the 234mm cannon would not reach) the Battlecruiser's speed would be the deciding factor on keeping the armored cruiser at range and thus pound it slowly under the water while getting little fire in return.

[Sachmle]

I would tend to agree with Ithekro's statement on the likely outcome of this, or any, AC running into a BC.  Even in a tandem, or with some PC's or a squad of TBs the odds are definately in the BCs favor, even with the 23.4cm.  I would therefore recommend the 19.4cm for its greater rate of fire in the primary misson role of H/K of similar ACs and PCs and smaller vessels and then attemp to avoid BCs or larger at all cost.  Perhaps a little more speed with the lighter MB?  You could even get away with slightly lighter armour, if your intent is to engage smaller vessel most of the time.

[Desertfox]

You could get a license for Constellation, 8x8", 27kts, 7" belt.

[P3D]

There's nothing special about the 26-26.5kts (trial speed does not count) Constellations besides being equipped with weaker guns than other ACs.

[Sachmle]

Without knowing all the exact details you would want included I came up with this. 

1909 AC, Gran Columbia Armoured Cruiser laid down 1909

Displacement:
   11,189 t light; 11,628 t standard; 12,750 t normal; 13,648 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (471.46 ft / 459.32 ft) x 73.82 ft x (25.92 / 27.30 ft)
   (143.70 m / 140.00 m) x 22.50 m  x (7.90 / 8.32 m)

Armament:
      4 - 7.64" / 194 mm 45.0 cal guns - 225.00lbs / 102.06kg shells, 80 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     2 x Twin mounts on centreline amidships (forward deck)
      8 - 7.64" / 194 mm 45.0 cal guns - 225.00lbs / 102.06kg shells, 80 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     4 x Twin mounts on sides, evenly spread
      10 - 5.51" / 140 mm 45.0 cal guns - 85.00lbs / 38.56kg shells, 100 per gun
     Breech loading guns in casemate mounts, 1909 Model
     10 x Single mounts on sides amidships
      10 hull mounts in casemates- Limited use in heavy seas
      8 - 3.94" / 100.0 mm 45.0 cal guns - 30.00lbs / 13.61kg shells, 100 per gun
     Quick firing guns in casemate mounts, 1909 Model
     8 x Single mounts on centreline, evenly spread
      10 - 1.85" / 47.0 mm 45.0 cal guns - 3.00lbs / 1.36kg shells, 150 per gun
     Quick firing guns in deck mounts, 1909 Model
     10 x Single mounts on centreline, evenly spread
      10 raised mounts
      Weight of broadside 3,820 lbs / 1,733 kg
      4 - 1.8" / 46 mm, 19.69 ft / 6.00 m torpedoes - 0.085 t each, 0.338 t total
   In 2 sets of submerged bow & stern tubes
      4 - 1.8" / 46 mm, 19.69 ft / 6.00 m torpedoes - 0.085 t each, 0.338 t total
   In 2 sets of below water reloads

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.87" / 200 mm   328.08 ft / 100.00 m   19.69 ft / 6.00 m
   Ends:   2.76" / 70 mm   129.59 ft / 39.50 m   9.84 ft / 3.00 m
     1.64 ft / 0.50 m Unarmoured ends
   Upper:   3.94" / 100 mm   328.08 ft / 100.00 m   6.56 ft / 2.00 m
     Main Belt covers 110 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   7.87" / 200 mm   3.94" / 100 mm      7.87" / 200 mm
   2nd:   7.87" / 200 mm   3.94" / 100 mm      7.87" / 200 mm
   3rd:   3.94" / 100 mm   0.39" / 10 mm      0.39" / 10 mm
   4th:   1.18" / 30 mm         -               -

   - Armoured deck - multiple decks: 1.57" / 40 mm For and Aft decks
   Forecastle: 0.00" / 0 mm  Quarter deck: 0.79" / 20 mm

   - Conning towers: Forward 7.87" / 200 mm,  Aft 0.00" / 0 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 4 shafts, 50,479 shp / 37,658 Kw = 26.00 kts
   Range 7,000nm at 10.50 kts
   Bunker at max displacement = 2,020 tons (100% coal)

Complement:
   599 - 779

Cost:
   £1.052 million / $4.207 million

Distribution of weights at normal displacement:
   Armament: 785 tons, 6.2 %
      - Guns: 784 tons, 6.2 %
      - Torpedoes: 1 tons, 0.0 %
   Armour: 4,153 tons, 32.6 %
      - Belts: 2,652 tons, 20.8 %
      - Armament: 890 tons, 7.0 %
      - Armour Deck: 518 tons, 4.1 %
      - Conning Tower: 93 tons, 0.7 %
   Machinery: 2,524 tons, 19.8 %
   Hull, fittings & equipment: 3,728 tons, 29.2 %
   Fuel, ammunition & stores: 1,561 tons, 12.2 %
   Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     15,480 lbs / 7,021 Kg = 69.5 x 7.6 " / 194 mm shells or 2.1 torpedoes
   Stability (Unstable if below 1.00): 1.33
   Metacentric height 5.3 ft / 1.6 m
   Roll period: 13.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
   Hull has raised forecastle,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.508 / 0.516
   Length to Beam Ratio: 6.22 : 1
   'Natural speed' for length: 21.43 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   30.00 %,  26.00 ft / 7.92 m,  26.00 ft / 7.92 m
      - Forward deck:   30.00 %,  16.00 ft / 4.88 m,  16.00 ft / 4.88 m
      - Aft deck:   23.00 %,  16.00 ft / 4.88 m,  16.00 ft / 4.88 m
      - Quarter deck:   17.00 %,  16.00 ft / 4.88 m,  16.00 ft / 4.88 m
      - Average freeboard:      19.00 ft / 5.79 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 86.4 %
      - Above water (accommodation/working, high = better): 115.8 %
   Waterplane Area: 22,752 Square feet or 2,114 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 120 lbs/sq ft or 584 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.27
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate

I used the general info on your 1898 ACs and upped the ante a little to meet your new spec.

[Sachmle]

Oops... should have read

Armament:
      4 - 7.64" / 194 mm 45.0 cal guns - 225.00lbs / 102.06kg shells, 80 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     2 x Twin mounts on centreline ends, evenly spread
      8 - 7.64" / 194 mm 45.0 cal guns - 225.00lbs / 102.06kg shells, 80 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     4 x Twin mounts on sides, evenly spread

[Tanthalas]

IDK id like the chance my AC would have against that ship. Honestly i like 6 10" guns, in 2 tripple mounts.  My cruiser may only hit 21 knots, but she would hammer anything in her class.  She is half the weight of her fellows and half the cost, and honestly i plan to build them 2 to 1 I will take my chances on weather or not they will actualy survive.

[Borys]

Ahoj!
4x2x9,2 or 6x2x7,6 - depends on use. If encounters with BC unlikely, go for more guns. If detached, higher risk operations more likely - with large AC or BC encounter possible, the heavier guns are better.
The thing is that there is no signicant difference in ROF between the two, both firing of 2-3 rounds per minute.

12x200* lbs = 2400
8x380 lbs = 3040

Even though I'd have liked to recommend the Blucheresque ship, I fail to see any benefits of it. Unless with local gun control etc. more guns = better.

Of course, 5 or 6 of the nice 5'5 guns on each side are a given.

* I think 200 lbs is more likely than 225
Borys

[The Rock Doctor]

Appreciate the feedback so far. 

Relative speed of the ships is coming up - I'd point out that I envision the 1909-engined version of this vessel to be 26 to 26.4 knots, a good two knots faster than any BCs of the same generation.  Once the 1912 engine tech is available, everything gets faster, but I'd expect the AC to retain some margin of speed over the larger BC.  This is not an old-school 21 knot AC I'm talking about.

The 194 mm layout is akin to the revised Triunfante class, two twins forward and four aft, all on the centreline.  The 234 mm layout is obviously two twins at either end.

Sachmle - not a bad design in general.  I've been working with a longer hull with less draft, to maximize speed on the restricted (48,000 shp) machinery size available at this point. 

Not sure if I'd include 140 mm guns; if I'm already installing a dozen 194 mm, would a few (~8-10) 100 mm guns not suffice as anti-TB weapons?

[Korpen]

Appreciate the feedback so far. 

Not sure if I'd include 140 mm guns; if I'm already installing a dozen 194 mm, would a few (~8-10) 100 mm guns not suffice as anti-TB weapons?

I think that her best anti-TB weapon is 26kts speed, that is almost as fast as most TBs, and fast enogh to force a attacking TB to close to less then 500m if they want to shoot a torpedo with any possibillity of a hit.

[The Rock Doctor]

...which the current war does suggest is not conducive to the TB's long-term health.  Good point.

[Borys]

Ahoj!
Funny about the turret arrangement:)
I imagined the 12 gun version like Blucher,and the 8 gun as 2x2, 4x1 (like the British ACs, or Radetzky).

194 or 234 - both are too slow to be useful against TBs. I think the 140mm is perfect for this job. More agile than the 6 incher, yet a much heavier hitter than the 4 inchers.
But maybe some dozen 4 inchers would suffice ...
Borys