WesWorld

After the recent exercise has shown the need for more recon seplanes and the Chilean navy wanting to build hybrid carriers the Argentine Navy with the aid of Germany has come up with this.


To compare...


Basically a General Belgrano with a large hangar and more modern Argentine AA weapons (the new 115mm and six-barrelled 20mm). Much thicker deck armour too. She should carry 6-8 aircraft. It would operate with 1-2 Light Scout Cruisers and a couple of destroyers.

Here is the SS report;

Cruiser No 7, Argentina/ Germany Seaplane Carrier/ Cruiser laid down 1934

Displacement:
10,444 t light; 10,825 t standard; 11,886 t normal; 12,735 t full load

Dimensions: Length overall / water x beam x draught
637.98 ft / 623.36 ft x 65.62 ft x 20.34 ft (normal load)
194.46 m / 190.00 m x 20.00 m x 6.20 m

Armament:
9 - 5.91" / 150 mm guns (3x3 guns), 102.98lbs / 46.71kg shells, 1934 Model
Breech loading guns in turrets (on barbettes)
on centreline, all forward, 1 raised mount - superfiring
8 - 4.53" / 115 mm guns (4x2 guns), 46.40lbs / 21.05kg shells, 1933 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
12 - 1.46" / 37.0 mm guns (6x2 guns), 1.55lbs / 0.70kg shells, 1934 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread, 2 raised mounts - superfiring
24 - 0.79" / 20.0 mm guns (4x6 guns), 0.24lbs / 0.11kg shells, 1934 Model
Anti-aircraft guns in deck mounts
on side, all aft, all raised mounts - superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1934 Model
Anti-aircraft guns in deck mounts
on side, all forward, 2 raised mounts - superfiring
Weight of broadside 1,324 lbs / 601 kg
Shells per gun, main battery: 180
8 - 23.6" / 600 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4.72" / 120 mm 405.18 ft / 123.50 m 9.71 ft / 2.96 m
Ends: Unarmoured
Main Belt covers 100 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4.72" / 120 mm 2.76" / 70 mm 4.72" / 120 mm
2nd: 1.97" / 50 mm 0.98" / 25 mm 2.76" / 70 mm
3rd: 0.39" / 10 mm - -
4th: 0.47" / 12 mm - -
5th: 0.39" / 10 mm - -

- Armour deck: 2.76" / 70 mm, Conning tower: 4.72" / 120 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 85,493 shp / 63,778 Kw = 32.50 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 1,910 tons

Complement:
568 - 739

Cost:
£4.168 million / $16.670 million

Distribution of weights at normal displacement:
Armament: 166 tons, 1.4 %
Armour: 2,651 tons, 22.3 %
- Belts: 777 tons, 6.5 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 376 tons, 3.2 %
- Armour Deck: 1,445 tons, 12.2 %
- Conning Tower: 53 tons, 0.4 %
Machinery: 2,460 tons, 20.7 %
Hull, fittings & equipment: 4,818 tons, 40.5 %
Fuel, ammunition & stores: 1,441 tons, 12.1 %
Miscellaneous weights: 350 tons, 2.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
19,633 lbs / 8,905 Kg = 190.7 x 5.9 " / 150 mm shells or 2.2 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 3.4 ft / 1.0 m
Roll period: 14.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.32
Seaboat quality (Average = 1.00): 1.34

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 9.50 : 1
'Natural speed' for length: 28.61 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 52
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 31.17 ft / 9.50 m
- Forecastle (20 %): 22.97 ft / 7.00 m
- Mid (45 %): 22.47 ft / 6.85 m
- Quarterdeck (15 %): 22.47 ft / 6.85 m
- Stern: 22.47 ft / 6.85 m
- Average freeboard: 23.29 ft / 7.10 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 82.1 %
- Above water (accommodation/working, high = better): 177.9 %
Waterplane Area: 28,340 Square feet or 2,633 Square metres
Displacement factor (Displacement / loading): 129 %
Structure weight / hull surface area: 107 lbs/sq ft or 520 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.70
- 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
Good seaboat, rides out heavy weather easily

Are not 20mm GATLING cannon stretching reality a bit????

I don't think they're Gatlings, just six guns per mount.

<snort> Just because they have 6 barrels on the mounting doesn't mean they're Gatlings. Not to mention that there's no reason you COULDN'T use Gatlings at this time period, after all, the Gatling was invented in the 1860s. It just fell out of favor for a while, then returned when some bright spark decided to attach an electric motor to the crank.....

Fyrwulf - If that is so, it would make the centre weapons difficult to reload, or make the mount very wide

Hrolf - Even so, it is a stretch!!

The problem with a Gatling at this time period is keeping the gun fed if you attached an electric motor to it. You'd probably need a linkless feed system, which is a few years down the road, if you wanted to get to rates of fire that are out of reach of a multiple mounting of similar size.

Yeah, the interior guns are probably a little more problematic to reload, just like the inner guns on the British octuple 2-pounder mounts are.

I don't see how the center guns would be hard to load as they are mounted virtical and not horizontal.

They would likely be large mounts, probably around the size of a quad 1.1" or 40mm mount.

I looked into the gatlings a few months back, found historical precedence and a workable design but dismissed them. Towards the end of WWI there were a couple of programs for engine-driven guns working on the gatling principle. The examples built by Siemens worked and were tested reaching a 7200rpm rof. The main reason i dismissed it was the feed. I had no problems coming up with a feed mechanism for horizontal, but when at 80-90° i had serious problems. And of course the actual amount of ammunition needed to be carried is a problem. The calibre was a bit of a problem for me as well, 6x20mm barrels being too heavy I thought and 12.7mm having insufficient range and striking power.

Not much of a problem to load these sorts of guns. The octuple pom-pom didn't have great problems with the centre guns because of the belt feed. Using single cartridges like the Bofors 40mm would pose more problems. I went the other way with a rapid-firing gun, but only 2 per mount rather than 6.

Just to confirm, these are 20mm Orkileon FFL mounted in stacked triples, feed is to be drum, perhaps larger than normal drums used by the land-based versions. Belt-feed would be good, I haven't decided excatly yet. No gatlings in sight...yet.

I'm planning one of these for 1934, of course by then I might be ready for a carrier.

Quoted

The problem with a Gatling at this time period is keeping the gun fed if you attached an electric motor to it.

and

Quoted

The calibre was a bit of a problem for me as well, 6x20mm barrels being too heavy I thought and 12.7mm having insufficient range and striking power.

Yes. Regarding the (lack of) striking power of the 12.7 and the ammunition supply, it was something Gavin mentioned in reply to the Japanese tests with the Model 1903 Gattling Gun (found here).
Unfortunately, Professor Tomoe was using the engine of a car which he attached to the weapon and not an electric engine. If he had used an electric engine, it would have been less traumatic for poor Yûko-san. Of course, it might have ended up being quite a shocking experience for her if something went wrong.

Didn't the US have a 50cal Gatling gun in service? Maybe its wasnt a true Gatling but it did have six barrels.

Quoted

Originally posted by Hood
Just to confirm, these are 20mm Orkileon FFL mounted in stacked triples, feed is to be drum, perhaps larger than normal drums used by the land-based versions. Belt-feed would be good, I haven't decided excatly yet. No gatlings in sight...yet.

I'm planning one of these for 1934, of course by then I might be ready for a carrier.

Seems reasonable, thats the approch I'd take with my own triple 20mm mounts, stack em up!

Quoted

Didn't the US have a 50cal Gatling gun in service? Maybe its wasnt a true Gatling but it did have six barrels.

No Gatlings were in use during this period. The US used multi-barrel .50 caliber mounts, though I can't think of any 6-barrel mountings.