WesWorld

Just like the U.S., Atlantis is observing the large number of cruiser killers being built around the globe and decided to do a study of its own.


Neptune, Atlantean Battlecruiser laid down 1936

Displacement:
30,352 t light; 31,938 t standard; 35,067 t normal; 37,570 t full load

Dimensions: Length overall / water x beam x draught
826.65 ft / 810.00 ft x 98.75 ft x 28.00 ft (normal load)
251.96 m / 246.89 m x 30.10 m x 8.53 m

Armament:
9 - 12.00" / 305 mm guns (3x3 guns), 885.00lbs / 401.43kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
24 - 5.10" / 130 mm guns (12x2 guns), 66.33lbs / 30.09kg shells, 1936 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, 4 raised mounts - superfiring
20 - 1.58" / 40.0 mm guns (10x2 guns), 1.95lbs / 0.88kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
32 - 0.79" / 20.0 mm guns (8x4 guns), 0.24lbs / 0.11kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
8 - 0.50" / 12.7 mm guns (4x2 guns), 0.06lbs / 0.03kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 9,604 lbs / 4,356 kg
Shells per gun, main battery: 160

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 440.00 ft / 134.11 m 12.00 ft / 3.66 m
Ends: Unarmoured
Main Belt covers 84 % of normal length

- Torpedo Bulkhead:
1.58" / 40 mm 440.00 ft / 134.11 m 30.00 ft / 9.14 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12.0" / 305 mm 7.00" / 178 mm 10.0" / 254 mm
2nd: 2.00" / 51 mm 1.00" / 25 mm 1.58" / 40 mm
3rd: 1.00" / 25 mm - -
4th: 0.79" / 20 mm - -
5th: 0.50" / 13 mm - -

- Armour deck: 5.10" / 130 mm, Conning tower: 10.00" / 254 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 149,522 shp / 111,543 Kw = 32.06 kts
Range 12,500nm at 15.00 kts
Bunker at max displacement = 5,632 tons

Complement:
1,280 - 1,665

Cost:
£13.911 million / $55.643 million

Distribution of weights at normal displacement:
Armament: 1,177 tons, 3.4 %
Armour: 11,132 tons, 31.7 %
- Belts: 2,786 tons, 7.9 %
- Torpedo bulkhead: 769 tons, 2.2 %
- Armament: 1,873 tons, 5.3 %
- Armour Deck: 5,473 tons, 15.6 %
- Conning Tower: 231 tons, 0.7 %
Machinery: 4,195 tons, 12.0 %
Hull, fittings & equipment: 13,647 tons, 38.9 %
Fuel, ammunition & stores: 4,715 tons, 13.4 %
Miscellaneous weights: 200 tons, 0.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
56,903 lbs / 25,811 Kg = 65.9 x 12.0 " / 305 mm shells or 8.6 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 6.1 ft / 1.8 m
Roll period: 16.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.48
Seaboat quality (Average = 1.00): 1.11

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.548
Length to Beam Ratio: 8.20 : 1
'Natural speed' for length: 32.82 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 5.00 ft / 1.52 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.00 ft / 9.75 m
- Forecastle (20 %): 22.00 ft / 6.71 m
- Mid (50 %): 22.00 ft / 6.71 m
- Quarterdeck (15 %): 22.00 ft / 6.71 m
- Stern: 22.00 ft / 6.71 m
- Average freeboard: 22.80 ft / 6.95 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.3 %
- Above water (accommodation/working, high = better): 189.9 %
Waterplane Area: 58,005 Square feet or 5,389 Square metres
Displacement factor (Displacement / loading): 120 %
Structure weight / hull surface area: 172 lbs/sq ft or 842 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.01
- Longitudinal: 1.11
- Overall: 1.02
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

I'd call her a small fast battleship, myself. It would certainly do the job of killing large cruisers, but it's pretty big at over 30,000 tons.

Its a large expensive ship with limited capability. It would be far better to build a 40,000ton ship that is capable of taking on this role but others as well. The difference in cost is fairly small.

I agree is too expensive. There similar armed designs cheaper than this one. Maybe Atlantis can afford this but not a smaller navy.

I agree, to expensive for the task but still a nice ship.

Wes, are there end belts on the drawing but not in the sim?

Quoted

Originally posted by Hrolf Hakonson
I'd call her a small fast battleship, myself. It would certainly do the job of killing large cruisers, but it's pretty big at over 30,000 tons.

Armour wise I suppose you could call her that. She's meant to not only act as a cruiser killer but tackle opposing fleets cruiser killers as well, the only way to do that with certainty is a battleship or something like this. The extra tonnage/cost goes into armour and a TDS. She can also act as an AA escort for the carriers.

Hoo, she does not have end belts, its a left over from a quick cut and paste job.

That concept is similar in size to the RSAN Triumph class - which I rate superior except for range and misc weight albeit 5 years older.

While the Triumphs were limited in size by the CT tonnage left over for capital ships I cannot follow your arguments why you chosed that size for your design study. Most heavy cruisers are well below 15ooots and most super-cruisers are in the 20kts range. So why a 30kts ship? Why AA escort (based on what experience?)?

Like the historical ALASKAs I think you´ve designed a white elephant....

I think all these super-cruiser-killer-killers are a waste of tonnage.

They stray too much into battleship size (who knows one day we may have a new Cleito and then these may be classifed as BBs) and are too expensive. Not even the RN wants to build these white elephants. It would be best to build three 15,000 ton heavy cruisers for the price.

*Goes away and dusts off plans for 9.2in armed CAs*

Something along the lines of my Renown modernization would be only 2-3k tons more expensive, be faster, better armed, and some better armour in places.

If you're deadset on a 30k ton ship, I'd say at least upgun it so you have more options, but in general I'd say it's too expensive and valuable to be a cruiser, too small and undergunned to be a capital ship.

Quoted

Originally posted by HoOmAn
That concept is similar in size to the RSAN Triumph class - which I rate superior except for range and misc weight albeit 5 years older.

I would have pegged them as equals myself, Triumphs main guns are heavier but Neptune has superior TDS (and is much better looking ) Neptune also has a heavier secondary armament (not really much of an advantage). Triumph was not on the list of advasary's, an oversight. There is enough room in the design to give her equal/superior armour.
I could use heavier guns but Atlantis already has a 12" gun design.

Quoted

Originally posted by HoOmAn
While the Triumphs were limited in size by the CT tonnage left over for capital ships I cannot follow your arguments why you chosed that size for your design study. Most heavy cruisers are well below 15000ts and most super-cruisers are in the 20kts range. So why a 30kts ship?

For the exact opposite reason. The CT is dead so theres no limit on size. As I said, the extra tonnage goes towards Battlecruiser level armour. The goal was to reach a 20-25,000 ton design, this was the extreme end of that study.

Quoted

Originally posted by HoOmAn
Why AA escort (based on what experience?)?

More hindsight I suppose. The fact remains that CV's are not well armed against surface threats. Atlantean practice mates them with a pair of CA's for protection, 1 Neptune has more firepower than 2 CA's. They also seem ideal for the Caribbean theatre.

Quoted

Originally posted by HoOmAn
Like the historical ALASKAs I think you´ve designed a white elephant....

Unlike the historical Alaska's her percieved advasary's actually exist.

In a straight up fight though, this ship would be mauled by most of its adversaries before it could gain a victory. Also, while this ship has more than double the firepower of 2 CA's it also costs over twice as much as a CA, and needs over twice as many men.

In fact you could build 3 more Daedalus class CA's for only 3-4000t more have the same combined broadside, have a greater rate of fire (useful when combating surface and airborne targets, and need only half as many men again to man them, also allowing for a greater level of redundancy in case of the crippling of 1 ship.

Quoted

Originally posted by thesmilingassassin
I could use heavier guns but Atlantis already has a 12" gun design.

Modern design, or reusing old guns? Judging from the dates on the spring, I'm guessing new....what prompted them, if not this design?

Canada's own forays into designing an adequate heavy/super cruiser run in the 18-19k range, which is still being a bit too expensive for my tastes...but the alternatives are just as disturbing; cheaper, somewhat obsolete 12-13k designs, or more Renowns. Canada's still mulling over it's options in the gap between light cruiser and capital ship as a result.

Both are options. Either a modern copy or simply reuse old guns.

Another design I'm working on has 12x9.2" guns but still weighs in at 27,000 tons. It also still needs some tweaking.

27k? Perhaps the Atlanteans might want to take a look at the Villas . 9x10" guns on half that tonnage.

Let's have a look at the probable opposition. These are all designs with guns between 8" and 12", being "cruiser killers" in the proper sense. I did not list some ships such as the Dutch Zeven Provinciën, as they precede the concept and are battlecruisers proper.

Radiance-class Large Cruiser - South African Empire
- Tonnage: 17,988 t light; 20,143 t normal
- Armament: 8x11"; 12x4.53"
- Armor: 9" Belt, 9.84" turrets, 3.15" deck
- Speed: 33.24 knots

Bohol/Rio-class Battlecruiser - Philippines, Brazil
- Tonnage: 23,609 t light; 26,930 t normal
- Armament: 6x12"; 15x4.72"
- Armor: 8.27" Belt; 8.27" turrets; 4.72" deck
- Speed: 31.75 knots

Capitan Oyama-class Large Cruiser - Chile
- Tonnage: 22,745 t light; 27,000 t normal
- Armament: 9x10"; 20x4.33"
- Armor: 8.5" Belt, 8.5" turrets, 4" deck
- Speed: 33.41 knots

Villa-class Large Cruiser - Mexico
- Tonnage: 13,851 t light; 17,031 t normal
- Armament: 9x10"; 10x5"
- Armor: 7" Belt, 7" turrets, 3" deck
- Speed: 32 knots

Almirante Grau-class Large Cruiser - Peru
- Tonnage: 14,329 t light; 16,673 t
- Armament: 9x10"; 18x4.72"
- Armor: 5.91" Belt, 5.91" turrets, 2.76" deck
- Speed: 32 knots

Delhi-class Large Cruiser - India
- Tonnage: 17,680 t light; 20,755 t normal
- Armament: 9x9.84"; 10x4.72"
- Armor: 11" Belt, 11" turrets, 3.94" deck
- Speed: 33 knots

Kongo-class Large Cruiser - Japan
- Tonnage: 17,999 t light; 21,756 t normal
- Armament: 9x10"; 12x5"
- Armor: 9" Belt, 10" turrets, 3.75" deck
- Speed: 33 knots

Hiei-class Large Cruiser - Japan
- Tonnage: 17,999 t light; 21,756 t normal
- Armament: 6x10"
- Armor: 7" Belt, 10" turrets, 3" deck
- Speed: 36.34 knots

Blucher/Derfflinger-class Large Cruiser - Germany
- Tonnage: 20,038 t light; 22,598 t normal
- Armament: 9x11.14"
- Armor: 8.27" Belt, 9.45" turrets, 3.54" deck
- Speed: 31 knots

Santa Maria-class Large Cruiser - Iberia
- Tonnage: 18,536 t light; 21,005 t normal
- Armament: 10x9.45"; 12x5.12"
- Armor: 9" Belt, 9" turrets, 1.57" deck
- Speed: 30 knots

El Cid-class Large Cruiser - Iberia
- Tonnage: 22,327 t light; 25,156 t normal
- Armament: 12x9.45"; 16x3.94"
- Armor: 9" Belt, 9" turrets, 1.97" deck
- Speed: 31.6 knots

Caesar Agusto-class Large Cruiser - Italy
- Tonnage: 17,142 t light; 20,577 t normal
- Armament: 6x12"; 16x3.94"
- Armor: 9.33" Belt, 10.6" turrets, 4" deck
- Speed: 30 knots

Lew/Dacia-class Large Cruiser - Poland and Romania
- Tonnage: 12 860 t light; 14 380 t normal
- Armament: 6x11.14"; 6x5.91"
- Armor: 3.94" Belt, 9.84" turrets, 2.56" deck
- Speed: 28 knots

Sviatoslav-class Large Cruiser - Russia
- Tonnage: 14,045 t light; 17,002 t normal
- Armament: 9x9.21"; 12x3.94"
- Armor: 4.72" Belt, 6.9" turrets, 2.36" deck
- Speed: 32 knots

Makarov-class Large Cruiser - Russia
- Tonnage: 17,993 t light; 24,183 t normal
- Armament: 12x9.21"; 18x5.12"
- Armor: 7" Belt, 7.97" turrets, 3.03" deck
- Speed: 33.7 knots

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If we're looking for a cruiser-killer, here's what I'd consider mandatory:
- Speed of 30 knots
- Armor sufficient to defeat 6" or 8" gunfire
- At least 6-8 guns of 8" or higher

If we're looking for a full battlecruiser, a ship to kill the cruiser-killers, here's what I'd call the bare minimum:
- Speed of 30 knots
- Armor of 12" or more
- Guns of 12" or higher

If we take WW on to the missile era, then I expect that everybody will be building Kirov-class battlecruisers.

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Hey Wes, if you're looking for a cruiser-killer, there's the Russkie Makarov design, and the Chilean Oyama and my planned Constitution...