Iberia Patrol Cruiser (2,000 tons)

[The Rock Doctor]

"I like big guns, and I can not lie.  You other bruthas can't deny..."

It's the longer range of them, in my case. 

[Guinness]

Assuming it can get close enough to a larger foe to damage it, the torpedoes would be useful, but as small as this ship is, even facing a ~4000t PC with 6" guns or even you're average AMC, I'd be afraid it wouldn't ever be able to get a good shot off. So in that respect, you're right, the 6" is probably superfluous.

If you really want to build a ship this small for patrol, I think the emphasis should be on enough speed and range, that if it finds the average ocean raider (be it AMC or PC or bigger), that it's mission is to shadow and report, not kill it. This would be sufficient to foil the foe's mission, and if you can position a few stronger cruisers about that can respond, maybe a kill.

So in other words, a sort of hunter/killer arrangement, with this ship as the hunter.

[Borys]

Ahoj!
I consider the issue to be enemy light cruisers. The peers of your ship. I believe all of them to sport some sort of protection. And 12cm are no use against armour of any sort.
IMO the ROF of 12cm guns is not so much higher than of 6". Yet the 6" have almost double the shell weight.
An AMC - due to sheer size - will be able to absorb quite a few 4,7" hits. 6" hits will do double the damage.
Range - as mmentoned by others - is also a factor.
Maybe I do not quite understand the mission of these ships - are the "trade protection cruisers", or are they "fleet cruisers"? If the later, then 8x12cm could be better against destroyers. But for independent patrols I'd give them six-inchers.
Borys

[miketr]

OK....  How about a high low mix...

I can fit one 150mm gun in place of two 120mm guns; so that would be four 150's or eight 120's.    I could build half with the 120mm's and half with the 150mm's.  There is no difference in broadside weight between the layouts, its two 50lb shells vs. one 100 lb shel.

The question is do I go with the max speed design or have some armor?  It would be 28 knots with armor or 29.5 knots without armor.  

As to mission... in peace time I need something small enough that I can mass produce to show the flag.  I have a bunch of old PC's from the 19th century that I need to replace.  In war time I plan to operate them with the fleet as DD leaders or as an anti TB screen. 

[Guinness]

My vote would be more speed for less armor. Make sure you have a wireless though :)

These would be pretty specialized ships though. Only useful as part of a larger strategy. I agree with others who've said that if you want a general purpose light cruiser, it's probably going to need to be bigger.

[miketr]

I have 150mm armed cruiser in service and projected.

These smaller cruisers would be built with the 7,000 ton cruisers armed with (5x2) 150mm guns and able to 30 knots.

[Borys]

Put armour. That makes these vessels more versatile.
Borys

[miketr]

OK... then...

I will build the 3,500 ton designs...

Mostly armed with 150mm guns and the 2" belt armor at 28 knots.  A small number of the unarmored, 29.5 knot and armed with 120mm guns to act as DD flotilla leaders.  Figure six and two for a total of eight.

Michael

[miketr]

For pure humor...  Cut back the speed of the 2,500 ton design, switched to pure oil fired boilers and cut speed...  Its not to bad over all but it doesn't quit have the speed I am looking for. 

Michael

PC-1913 2.5k-c, Iberia Patrol Cruiser laid down 1913 (Engine 1912)

Displacement:
   2,485 t light; 2,590 t standard; 2,854 t normal; 3,065 t full load

Dimensions: Length overall / water x beam x draught
   393.70 ft / 393.70 ft x 42.65 ft x 13.12 ft (normal load)
   120.00 m / 120.00 m x 13.00 m  x 4.00 m

Armament:
      6 - 4.72" / 120 mm guns (3x2 guns), 52.72lbs / 23.91kg shells, 1913 Model
     Quick firing guns in deck mounts with hoists
     on centreline ends, majority forward, 1 raised mount - superfiring
      4 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1913 Model
     Quick firing guns in deck mounts
     on side, evenly spread
   Weight of broadside 368 lbs / 167 kg
   Shells per gun, main battery: 225
   6 - 20.0" / 508 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   2nd:   0.98" / 25 mm         -               -

   - Conning tower: 2.36" / 60 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 28,000 shp / 20,888 Kw = 28.37 kts
   Range 7,000nm at 10.00 kts
   Bunker at max displacement = 475 tons

Complement:
   194 - 253

Cost:
   £0.308 million / $1.230 million

Distribution of weights at normal displacement:
   Armament: 46 tons, 1.6 %
   Armour: 29 tons, 1.0 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 19 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 10 tons, 0.4 %
   Machinery: 1,116 tons, 39.1 %
   Hull, fittings & equipment: 1,224 tons, 42.9 %
   Fuel, ammunition & stores: 369 tons, 12.9 %
   Miscellaneous weights: 69 tons, 2.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,073 lbs / 940 Kg = 39.3 x 4.7 " / 120 mm shells or 0.6 torpedoes
   Stability (Unstable if below 1.00): 1.25
   Metacentric height 2.1 ft / 0.6 m
   Roll period: 12.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.30
   Seaboat quality  (Average = 1.00): 1.23

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.453
   Length to Beam Ratio: 9.23 : 1
   'Natural speed' for length: 19.84 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      18.86 ft / 5.75 m
      - Forecastle (20 %):   17.22 ft / 5.25 m
      - Mid (50 %):      14.76 ft / 4.50 m
      - Quarterdeck (15 %):   14.76 ft / 4.50 m
      - Stern:      14.76 ft / 4.50 m
      - Average freeboard:   15.76 ft / 4.80 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 142.3 %
      - Above water (accommodation/working, high = better): 125.6 %
   Waterplane Area: 10,740 Square feet or 998 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 67 lbs/sq ft or 327 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.07
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Long range radio 25 tons, Six 20" torpedos (2x3) 6 tons and 29 tons construction reserve

[Desertfox]

Civilian standards are fine for slow, supporting stuff like minesweepers and sloops.  It is not at all fine for frontline warships.  If we start down that slope, the Swiss will be cranking out battlecruisers built to civvie standards, and nobody wants that.

But they would be merchants! Of death that is... ;D

No, what you have to worry about is, is not warships to civilian standards, but civilian ships to warship standards! Captain Taugon already got himself a nice cruiser, what's to stop other civilians from buying new or sulprus warships?