WesWorld

3 ACRs



4 Light Cruisers



4 more Soldati type destroyers



A couple more Argonauta class submarines



AS.3 and AS.4, development vessels fitted with armament and hopefully a more succesful means of launching torpedoes. The arrangement of petrol engines was too complicated so 4 Guidoni-Type diesels used instead, overall power reduced to 16000hp. Speed will consequently be lower.

Lots and lots of quads.

Are those 6 inch guns on the light cruisers?

I forget at this time if you've posted specification on these vessel yet.

Quoted

Are those 6 inch guns on the light cruisers?

Well, 152mm/53.

Quoted

I forget at this time if you've posted specification on these vessel yet.

Soldati and Argonauta already. Others will come in time, there are still a few more new ships to add to the list.

Italian Light Cruiser laid down 1932

Displacement:
8,047 t light; 8,400 t standard; 9,777 t normal; 10,879 t full load

Dimensions: Length overall / water x beam x draught
579.02 ft / 557.74 ft x 65.62 ft x 18.70 ft (normal load)
176.48 m / 170.00 m x 20.00 m x 5.70 m

Armament:
16 - 5.98" / 152 mm guns (4x4 guns), 110.23lbs / 50.00kg shells, 1932 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
20 - 1.85" / 47.0 mm guns (5x4 guns), 3.86lbs / 1.75kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, all forward, 4 raised mounts - superfiring
16 - 0.98" / 25.0 mm guns (8x2 guns), 0.48lbs / 0.22kg shells, 1932 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
Weight of broadside 1,849 lbs / 838 kg
Shells per gun, main battery: 150
16 - 23.6" / 600 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.39" / 137 mm 328.08 ft / 100.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Upper: 0.79" / 20 mm 65.62 ft / 20.00 m 8.20 ft / 2.50 m
Main Belt covers 90 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.31" / 135 mm 2.76" / 70 mm 3.94" / 100 mm
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Armour deck: 1.57" / 40 mm, Conning tower: 5.31" / 135 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 62,000 shp / 46,252 Kw = 30.53 kts
Range 2,512nm at 28.00 kts
Bunker at max displacement = 2,478 tons

Complement:
491 - 639

Cost:
£3.297 million / $13.187 million

Distribution of weights at normal displacement:
Armament: 223 tons, 2.3 %
Armour: 1,961 tons, 20.1 %
- Belts: 780 tons, 8.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 390 tons, 4.0 %
- Armour Deck: 739 tons, 7.6 %
- Conning Tower: 52 tons, 0.5 %
Machinery: 1,830 tons, 18.7 %
Hull, fittings & equipment: 3,865 tons, 39.5 %
Fuel, ammunition & stores: 1,730 tons, 17.7 %
Miscellaneous weights: 168 tons, 1.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
14,281 lbs / 6,478 Kg = 133.3 x 6.0 " / 152 mm shells or 2.1 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 3.1 ft / 0.9 m
Roll period: 15.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.40
Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 8.50 : 1
'Natural speed' for length: 27.31 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 30.00 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 (22 %): 21.33 ft / 6.50 m
- Mid (52 %): 21.33 ft / 6.50 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (19 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 18.25 ft / 5.56 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 81.0 %
- Above water (accommodation/working, high = better): 105.2 %
Waterplane Area: 25,357 Square feet or 2,356 Square metres
Displacement factor (Displacement / loading): 129 %
Structure weight / hull surface area: 106 lbs/sq ft or 517 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.31
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform

48t = 16x600mm torpedoes
80t = 5x quadruple 47mm mounts
40t = 25mm deck over torpedoes

Belt is like Abruzzi, 30+100@12°

Didn't I get talked out of quads for my beasties?

Well, Italy's been doing them since Pisa and Lepanto afaik.. so there's a bit more experience with quads.

Always talk potenial enemies out of doing something you would do.

...tho I think Rules 9 and 31 might apply.

(Not to mention 37.)

But then Rule 36 should also apply for the likes of Greece and Britian.

The ACRs are still treaty cruisers or capital ships by definition of their displacement?

(Or barrel diameter for that matter).

I think RA said the new 1932 model ACRs were a little smaller than the previous model, so they might actually BE Treaty cruisers, rather than capital ships.

Well if Chile is lucky, they will never have to learn first hand in combat what is and what isn't true about Italian warships.

Nice drawings, RA. Cool looking ships indeed. I´d probably raise the CLs bridge by one deck level but that just nit picking. :o)

Isn´t the CL a bit slow?

Is a transome stern a good idea on such a slow vessel?

Aren´t 6" quads too slow firing?

It seems as if you´ve taken the 5" rule to the extreme (8400ts) as a standard design rule - not as a leeway to design ships.

Quoted

I think RA said the new 1932 model ACRs were a little smaller than the previous model, so they might actually BE Treaty cruisers, rather than capital ships.

Increased bunkerage reduced their displacement. A few minor changes to armament and armour made this possible.

Quoted

I´d probably raise the CLs bridge by one deck level but that just nit picking. :o)

I wanted a small silhouette.

In order to cram the requisite armament and armour onto a 8000ton hull I needed to adopt a relatively slow speed and use all of the 5% to make things fit. As can be seen, there was no weight available for HA guns. The slow speed won't really affect operations, its rare to make flank speed even in combat. Usually turns for 20-28knts. The only way for other ships to use any speed advantage is to run straight away - for sea control these little ships are fine. The transom is fine for slower ships - just look at container vessels and more modern warships. The more modern warships use it for different reasons, need to increase buoyancy and waterplane area underneath the helicopter deck. So long as the naval engineers get their calculations right, the transom should give about 0.5-1.0knts advantage over a normal stern, hard to do with slide rules but still possible looking at the US and German cruisers.

Rate of fire for the 152/53 quads is probably around 7-9rpm when comparing it with the US 6"/47 in triple turret. Electrically powered loading and loading at any angle (-10° to +45°) helps a lot as well. Remember that the Regia Marina has had about 6-7years with which to thoroughly debug the previous quadruple 152mm turret.

More detail drawing of ACR-1932

The colours seem obvious, except for the green...?

Rooms for reduction gears and liquid loading on the x-section.

I am a little curious about the 28knt cruising speed.

My recollection is engines are generally designed to optimise fuel consumption for a given speed. Granted I'm trying to recall stuff I read in 1994...

So a ship designed to cruise at 18kts will use less tons/mile of fuel at 18, but if it slowed to 15, would not have the same efficiancy as a ship designed for 15kts.

You have a ship designed to run at very high speeds, given great flexibility, but that even if optimized will use a large amount of fuel/hour. As an economic concern, won't that be terribly expensive to operate in peacetime and a supply burden in wartime?

Quoted

You have a ship designed to run at very high speeds, given great flexibility, but that even if optimized will use a large amount of fuel/hour. As an economic concern, won't that be terribly expensive to operate in peacetime and a supply burden in wartime?

It doesn't really matter that much for operations in the Meditterenean. Cruising for long periods(well up to about 3 days) at nearly full speed is especially useful. Its also a function of the transom stern. This creates a wave with differing wavelength depending on the speed the hull is travelling at. At two(or more) specific speeds the ship is "riding" the wave created by the transom which helps propulsive efficiency. One of these specific points will be around max speed - so its quite possible that the ship will use less oil steaming at 28knts than steaming at 24-25knts. Yes it would be expensive to operate in peacetime, but we have no mechanism to simulate that + Libyan oil.

Nice pics RA as usual and I like the internal diagrams too. Nice to see things fit and not just in Springsharp.

You don't think 16 6" guns on 8500 is over-gunning? After your carrier suffering a rouge wave hit, there aren't concerns in the RM about topweight?

Cheers,

16x152mm is over-gunned

Topweight problems minimised by having not much superstructure, no aircraft and no heavy AA. Only 1 main FC director, others being turret-mounted.