WesWorld

Italy built a large class of destroyers in the early 1930s, the Soldati Class, along similar lines as the preceding classes though the 1920s. The 1930s has brought a new, more global mission, for the Marina Italiana which is felt keenly in the design of destroyers. The majority of the existing types have neither the range nor seakeeping to perform the new missions required. This has lead in the most part to a large increase in the size of destroyers.

After considering the options, Supermarina decided to adopt a hi/lo mixture of types. The Mosto Class laid down in 1937 represent one of the lo types with a more defensive mission and greater AS armament. Their armament is comparatively light, regarded as too light in some quarters, yet the vessels are larger than the previous Soldati Class. In detail, the new ships contain considerably more equipment, and extra fuel for a longer range, both of which pressure the size of the ship.

This class, currently of four ships, presents an example of the hi type of the mix and features greater offensive power. This comes from the greater armament. The previous attempts to utilise 152/53 guns on destroyer hulls had not proved successful, mostly due to too much hull stress. Also the effectiveness against aircraft was less than hoped with the practical rate of fire being overly restricted. As a result a new weapon in 127mm calibre was developed with a lighter shell, and rate of fire almost 50% greater. A return to 135mm was contemplated, but the ballistic superiority of the 127mm was preferred and new ammunition had to be designed anyway. A loadout of SAP and HC shells is envisaged. Along with the new main armament, the light AA battery is increased, with twelve 37mm and twelve 25mm guns. The armament is rounded out by two quintuple banks of 600mm torpedoes. The vessels also feature increased amounts of equipment. It was initially planned to mount a GDR.1 FC director over the bridge but this was in short supply so three lightweight GDR.5 units were substituted instead which are also able to control the light battery. An LL air search radar is mounted atop the second funnel and a new combined sonar/hydrophone D5 set is mounted forwards.


Destroyer Type 1938, laid down 1938

Displacement:
2,323 t light; 2,526 t standard; 2,906 t normal; 3,210 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(405.82 ft / 393.70 ft) x 39.37 ft x (16.40 / 17.48 ft)
(123.69 m / 120.00 m) x 12.00 m x (5.00 / 5.33 m)

Armament:
6 - 5.00" / 127 mm 64.0 cal guns - 67.24lbs / 30.50kg shells, 400 per gun
Dual purpose guns in deck and hoist mounts, 1938 Model
3 x Twin mounts on centreline ends, majority aft
1 raised mount aft - superfiring
12 - 1.46" / 37.0 mm 75.0 cal guns - 1.75lbs / 0.79kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1938 Model
3 x Quad mounts on sides, evenly spread
1 raised mount
12 - 0.98" / 25.0 mm 77.0 cal guns - 0.54lbs / 0.24kg shells, 4,000 per gun
Anti-air guns in deck mounts, 1938 Model
12 x Single mounts on sides amidships
Weight of broadside 431 lbs / 195 kg
10 - 23.6" / 600 mm, 26.25 ft / 8.00 m torpedoes - 2.156 t each, 21.562 t total
In 2 sets of deck mounted centre rotating tubes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 50,000 shp / 37,300 Kw = 34.28 kts
Range 2,000nm at 25.00 kts
Bunker at max displacement = 684 tons

Complement:
197 - 257

Cost:
£1.804 million / $7.216 million

Distribution of weights at normal displacement:
Armament: 167 tons, 5.8 %
- Guns: 146 tons, 5.0 %
- Torpedoes: 22 tons, 0.7 %
Armour: 41 tons, 1.4 %
- Armament: 29 tons, 1.0 %
- Conning Tower: 12 tons, 0.4 %
Machinery: 1,280 tons, 44.1 %
Hull, fittings & equipment: 774 tons, 26.6 %
Fuel, ammunition & stores: 583 tons, 20.0 %
Miscellaneous weights: 65 tons, 2.2 %
- Hull below water: 20 tons
- On freeboard deck: 20 tons
- Above deck: 25 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
920 lbs / 417 Kg = 14.7 x 5.0 " / 127 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 1.8 ft / 0.6 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.44
Seaboat quality (Average = 1.00): 1.03

Hull form characteristics:
Hull has a flush deck,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.400 / 0.415
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 22.95 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 24.28 ft / 7.40 m, 16.08 ft / 4.90 m
- Forward deck: 50.00 %, 16.08 ft / 4.90 m, 16.08 ft / 4.90 m
- Aft deck: 15.00 %, 16.08 ft / 4.90 m, 16.08 ft / 4.90 m
- Quarter deck: 15.00 %, 16.08 ft / 4.90 m, 16.08 ft / 4.90 m
- Average freeboard: 16.73 ft / 5.10 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 164.7 %
- Above water (accommodation/working, high = better): 118.7 %
Waterplane Area: 9,902 Square feet or 920 Square metres
Displacement factor (Displacement / loading): 85 %
Structure weight / hull surface area: 43 lbs/sq ft or 212 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.52
- Longitudinal: 2.02
- Overall: 0.60
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate


20t = sonar/hydrophones
20t = scaricabombe + DC projectors
15t = 3 x GDR.5 FC directors
10t = LL radar

An anti-submarine frigate more suited to open ocean work to augment the previous Vespa and Diana Classes. The new design offers greater capability against submarine and aircraft threats whilst remaining cheap to construct.

The propulsion is the same as the previous Diana Class, with diesel and electric drive, giving long range, rapid response and quiet running at low speeds.

The main armament consists of three 76/62 single weapons. This gun was developed from the 65/64 automatic weapons program. Towards the end of 1937 it was felt that the basis of the weapon's employment had change and a larger calibre was needed to deal with surface threats. As a result, a 76mm gun was built on the same principles, with a heavier shell, a slight reduction in muzzle velocity giving a slightly shorter barrel. The development of the automatic feed continued but in the mean time a manually loaded version was adopted. This is in an enclosed weatherproof mounting with RPC. The mountings are controlled from the two lightweight GDR5 directors. Against aircraft it is expected to give much improved results than the previous classes' armament whilst retaining ability against likely surface threats. The gun armament is rounded out by twelve individual 25mm guns. The anti-submarine armament is unchanged from previous classes, with a quadruple lanciabombe weapon mounted aft and a scariabombe mounted on the fantail. A new more advanced D5 sonar set with better passive ability is mounted for the first time.

Habitability is expected to be good, with a larger superstructure for accommodation spaces than in previous classes, and a more spacious enclosed bridge. The new flush deck has lead to improved structural strength, which along with higher freeboard and thicker hull plating, will give improved capability in heavier seas. It is expected that the ship type will be the mainstay of oceanic escorts.

Fregata Antisom laid down 1938

Displacement:
1,253 t light; 1,310 t standard; 1,570 t normal; 1,777 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(307.51 ft / 295.28 ft) x 35.79 ft x (11.15 / 12.19 ft)
(93.73 m / 90.00 m) x 10.91 m x (3.40 / 3.72 m)

Armament:
3 - 3.00" / 76.2 mm 62.0 cal guns - 13.78lbs / 6.25kg shells, 500 per gun
Anti-air guns in deck and hoist mounts, 1938 Model
3 x Single mounts on centreline ends, evenly spread
1 raised mount - superfiring
12 - 0.98" / 25.0 mm 77.0 cal guns - 0.54lbs / 0.24kg shells, 4,000 per gun
Anti-air guns in deck mounts, 1938 Model
12 x Single mounts on sides amidships
Weight of broadside 48 lbs / 22 kg

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 0.39" / 10 mm - -

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Electric cruising motors plus geared drives, 2 shafts, 8,000 shp / 5,968 Kw = 22.26 kts
Range 6,000nm at 15.00 kts
Bunker at max displacement = 467 tons

Complement:
124 - 162

Cost:
£0.461 million / $1.843 million

Distribution of weights at normal displacement:
Armament: 20 tons, 1.3 %
Armour: 26 tons, 1.6 %
- Armament: 18 tons, 1.1 %
- Conning Tower: 8 tons, 0.5 %
Machinery: 219 tons, 14.0 %
Hull, fittings & equipment: 845 tons, 53.8 %
Fuel, ammunition & stores: 317 tons, 20.2 %
Miscellaneous weights: 143 tons, 9.1 %
- Hull below water: 24 tons
- On freeboard deck: 89 tons
- Above deck: 30 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,915 lbs / 2,230 Kg = 364.1 x 3.0 " / 76 mm shells or 1.7 torpedoes
Stability (Unstable if below 1.00): 1.18
Metacentric height 1.5 ft / 0.4 m
Roll period: 12.4 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.08
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck,
a normal bow and small transom stern
Block coefficient (normal/deep): 0.466 / 0.483
Length to Beam Ratio: 8.25 : 1
'Natural speed' for length: 18.65 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 25
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 24.61 ft / 7.50 m, 19.69 ft / 6.00 m
- Forward deck: 20.00 %, 19.69 ft / 6.00 m, 16.40 ft / 5.00 m
- Aft deck: 35.00 %, 16.40 ft / 5.00 m, 14.76 ft / 4.50 m
- Quarter deck: 25.00 %, 14.76 ft / 4.50 m, 14.76 ft / 4.50 m
- Average freeboard: 17.08 ft / 5.21 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 53.8 %
- Above water (accommodation/working, high = better): 177.0 %
Waterplane Area: 6,993 Square feet or 650 Square metres
Displacement factor (Displacement / loading): 232 %
Structure weight / hull surface area: 60 lbs/sq ft or 293 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.03
- Longitudinal: 6.63
- Overall: 1.25
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

10t per 76/62 mounting
1t per 25mm mounting
10t = 2 x GDR.5 FCS
15t = D5 sonar
7t = Scaricabombe
10t = Lanciabombe AS
50t = 150 Depth charges
9t = 250hp electric creeping motors
121tons

8knts on creeping motors

That frigate I like a lot. Looks like a very handsome ship. Pretty sure her main armament caliber would be rated too small by RSAN experts as it would lack stopping power against fast attack craft or larger vessel a frigate might encounter, such as an AMC for example.

Is there a new version of SS out there that I have missed? I thought we agreed not to use the last draft because of its bugs...?! *confused*

Quoted

Pretty sure her main armament caliber would be rated too small by RSAN experts as it would lack stopping power against fast attack craft or larger vessel a frigate might encounter, such as an AMC for example.

There aren't many other options for what could be mounted instead. Could either mount two twin 100/47 or three single 100/47. Would give slightly better performance against surface targets, but considerably worse against aircraft. It isn't expected for these ships to have to engage large surface ships. The escort groups as a whole will have more capability against surface ships, but these frigates are for ASW more than anything else.

There's no real difference between SS2 and SS3v1, if anything, SS3v1 is better, with revised hull hydrodynamics and more accurate armament and misc weights.

Displacement:
1,282 t light; 1,328 t standard; 1,570 t normal; 1,763 t full load

Dimensions: Length overall / water x beam x draught
307.51 ft / 295.28 ft x 35.79 ft x 11.15 ft (normal load)
93.73 m / 90.00 m x 10.91 m x 3.40 m

Armament:
3 - 3.00" / 76.2 mm guns in single mounts, 13.78lbs / 6.25kg shells, 1938 Model
Anti-aircraft guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount
12 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 47 lbs / 21 kg
Shells per gun, main battery: 500

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm

- Conning tower: 2.76" / 70 mm

Machinery:
Diesel Internal combustion motors,
Electric cruising motors plus geared drives, 2 shafts, 8,000 shp / 5,968 Kw = 22.03 kts
Range 6,000nm at 15.00 kts
Bunker at max displacement = 436 tons

Complement:
124 - 162

Cost:
£0.453 million / $1.812 million

Distribution of weights at normal displacement:
Armament: 6 tons, 0.4 %
Armour: 14 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 8 tons, 0.5 %
Machinery: 219 tons, 14.0 %
Hull, fittings & equipment: 900 tons, 57.3 %
Fuel, ammunition & stores: 288 tons, 18.4 %
Miscellaneous weights: 143 tons, 9.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,289 lbs / 1,945 Kg = 317.7 x 3.0 " / 76 mm shells or 1.5 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 1.4 ft / 0.4 m
Roll period: 12.7 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.08
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.466
Length to Beam Ratio: 8.25 : 1
'Natural speed' for length: 17.18 kts
Power going to wave formation at top speed: 55 %
Trim (Max stability = 0, Max steadiness = 100): 25
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: 24.61 ft / 7.50 m
- Forecastle (20 %): 19.69 ft / 6.00 m
- Mid (40 %): 16.40 ft / 5.00 m
- Quarterdeck (25 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 17.08 ft / 5.21 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 59.9 %
- Above water (accommodation/working, high = better): 173.0 %
Waterplane Area: 6,833 Square feet or 635 Square metres
Displacement factor (Displacement / loading): 245 %
Structure weight / hull surface area: 63 lbs/sq ft or 309 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.10
- Longitudinal: 7.02
- Overall: 1.32
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Quoted

Originally posted by Red Admiral
There's no real difference between SS2 and SS3v1, if anything, SS3v1 is better, with revised hull hydrodynamics and more accurate armament and misc weights.

I thought there are still bugs not worked out?

Has anybody heard anything if there will be a SS3v2? To be honest I wasn´t in contact with Ian for a long time.....

It might encounter fast attack craft or larger vessels but I assume that it will work together with other vessels that can take care of that problem.

Edit: I guess I should check more often to see if something is added before posting something.

Not sure which bugs you are talking about because as far as I see when working with the latest version of SS3 (which is Beta 2 I think), I see the same bugs that SS2 has (as well as the fact that several of the options don't work yet). Still, I could be wrong about that. Would love to know which bugs exist that give SS3(b2) an edge over SS2.

The Destroyer Type 1938 has an unusual layout aft. It seems too cramped to fit all you want. Will those torpedo mounts be able to turn? From the plan both look rather wedged in on the top view.

Blast from Y turret is going to make the torpedo crew's job exicitng to say the least and the X turret is crammed in by the 25mm behind it. Also where are the magazines for X mount? I would assume below the turret is the after turbine room?
Having it further aftwould affect resupply rates.

No problems with the frigate, looks good. I think the 76mm is the right gun, good against aircraft and good RoF for engaing subs caught on the surface. Meeting enemy ships is likely in the cramped Med but at least having three guns gives ample firepower over two 100mm for instance.

Quoted

Would love to know which bugs exist that give SS3(b2) an edge over SS2.

SS3b2 is more restrictive than SS2 due to increased number of options, e.g. more shells for AAA, revised hull model. Its only really in deck armour where there is a real change as SS2 averages over the entire waterplane area whilst SS3b2 splits this into distinct chunks (foredeck, main deck, quarterdeck).

I think SS3b3 still has some problems with it. Ian is slowly progressing but has other commitments.

I don't fancy that destroyer design so much now. I decided to go for a larger more capable design instead that fits into future planning a bit more. I'm still playing with the drawing a bit.

Quoted

Originally posted by Red Admiral

Quoted

Would love to know which bugs exist that give SS3(b2) an edge over SS2.

SS3b2 is more restrictive than SS2 due to increased number of options, e.g. more shells for AAA, revised hull model. Its only really in deck armour where there is a real change as SS2 averages over the entire waterplane area whilst SS3b2 splits this into distinct chunks (foredeck, main deck, quarterdeck).

I think SS3b3 still has some problems with it. Ian is slowly progressing but has other commitments.

I haven't noticed any real problems with SS3b3, it's more that you have to enter a few more things than you're used to and it will complain if you don't in a way that's not really very clear. I really like the ability to set your light gun ammunition, and the increased ability to lay out your guns. The hull modeling improvements are also noticeable, especially with longer-ranged ships, where you may find that transom sterns AREN'T the way to go even for faster designs.

Quoted

Originally posted by Hrolf Hakonson
I haven't noticed any real problems with SS3b3, it's more that you have to enter a few more things than you're used to and it will complain if you don't in a way that's not really very clear. I really like the ability to set your light gun ammunition, and the increased ability to lay out your guns. The hull modeling improvements are also noticeable, especially with longer-ranged ships, where you may find that transom sterns AREN'T the way to go even for faster designs.

I've played around only briefly with it, but this seems to match my opinion of it, too. I've tried to sim a few SS2 designs I've made in SS3, and I was generally able to come fairly close on the light tonnage, too. I still haven't figured out that "beam between bulkheads" issue because SS3 wails that I keep doing it wrong. I think it's was the beam between the inside bulkheads of the TDS, but I've never seen anyone explain it before.

I too like the ability to set the light gun ammo and fuss with the gun layouts. Makes things wonderfully easy.

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by Hrolf Hakonson
I haven't noticed any real problems with SS3b3, it's more that you have to enter a few more things than you're used to and it will complain if you don't in a way that's not really very clear. I really like the ability to set your light gun ammunition, and the increased ability to lay out your guns. The hull modeling improvements are also noticeable, especially with longer-ranged ships, where you may find that transom sterns AREN'T the way to go even for faster designs.

I've played around only briefly with it, but this seems to match my opinion of it, too. I've tried to sim a few SS2 designs I've made in SS3, and I was generally able to come fairly close on the light tonnage, too. I still haven't figured out that "beam between bulkheads" issue because SS3 wails that I keep doing it wrong. I think it's was the beam between the inside bulkheads of the TDS, but I've never seen anyone explain it before.

That's exactly what it is. It basically tells the program how much width you're devoting to the TDS, which affects how much space there is in the hull for other things and how long your belt needs to be to cover those things. But if you don't enter it in a way it understands, SS WILL wail and carry on.

Quoted

I too like the ability to set the light gun ammo and fuss with the gun layouts. Makes things wonderfully easy.

Yep. And I like the ability to set barrel lengths in the sim itself. I haven't looked too closely to see if that affects the weight, but even if it doesn't it makes reading things easy.

Quoted

Originally posted by Hrolf Hakonson

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by Hrolf Hakonson
I haven't noticed any real problems with SS3b3, it's more that you have to enter a few more things than you're used to and it will complain if you don't in a way that's not really very clear. I really like the ability to set your light gun ammunition, and the increased ability to lay out your guns. The hull modeling improvements are also noticeable, especially with longer-ranged ships, where you may find that transom sterns AREN'T the way to go even for faster designs.

I've played around only briefly with it, but this seems to match my opinion of it, too. I've tried to sim a few SS2 designs I've made in SS3, and I was generally able to come fairly close on the light tonnage, too. I still haven't figured out that "beam between bulkheads" issue because SS3 wails that I keep doing it wrong. I think it's was the beam between the inside bulkheads of the TDS, but I've never seen anyone explain it before.

That's exactly what it is. It basically tells the program how much width you're devoting to the TDS, which affects how much space there is in the hull for other things and how long your belt needs to be to cover those things. But if you don't enter it in a way it understands, SS WILL wail and carry on.

Ah, good to know. I played around with it a lot trying to figure it out. My initial thought had been that it was demanding the distance between the frames, so I tried fairly low numbers and was annoyed when it threw a fit; a lot of experimenting finally made be realize that higher numbers worked better but the numbers wouldn't work if I exceeded the beam; that's when I finally determined what the function was actually doing.

Still need to find out how much space makes a well-designed TDS, though. I know that TDS systems work better when they're further from the internal bulkheads, but I've never learned how much is enough. Two feet? Five feet? 10% of hull width? I don't know.

Quoted

Originally posted by Hrolf Hakonson

Quoted

I too like the ability to set the light gun ammo and fuss with the gun layouts. Makes things wonderfully easy.

Yep. And I like the ability to set barrel lengths in the sim itself. I haven't looked too closely to see if that affects the weight, but even if it doesn't it makes reading things easy.

I poked around once and determined it does affect hull strength, particularly for the guns 8" and larger; the usual DP guns don't seem to cause as much fuss, but then again they tend to be shorter anyway and don't have the same weight.

Quoted

Still need to find out how much space makes a well-designed TDS

The KGVs had 4m, Littorio 7.2m, other modern battleships in between. Its a bit more complicated than that as some ships (like the KGVs) had an extra space further inboard of the TDS, but after the thicker plating. I wouldn't go much under 4m for modern ships.

I tried an accurate sim of Littorio using SS3b3 but the program really poo-pooed it so I'm unsure as to how good it actually is.

A large multipurpose destroyer that has increased in size to near cruiser levels. The main role is for surface action against likely threats, e.g. light cruisers, destroyers or AMC. The secondary roles are anti aircraft defence and anti submarine. The need to fit all these roles into a single ship type has lead to a large increase in size over previous destroyers. However the ship is still significantly less expensive than a true cruiser.

The hull design emphasises seakeping and habitability, with a high freeboard and a long piercing bow. A large enclosed bridge gives good all-round vision in all weathers.

The main armament consists of six 152/53 guns in dual purpose mountings giving good capability against cruisers and a long effective range against aircraft. Some studies looked at mounting eight guns but this made the hull too cramped. The short range AA armament consists of twenty eight 37mm guns in stabilised, powered, enclosed mountings. Also present are 25mm guns in plain single mountings. The anti-submarine armament is limited, with a scaricabombe aft belowdecks and four single depth charge projectors. The size of the ship precludes it from actively pursuing submarines but the fit enables it to attack targets of opportunity. No torpedoes are carried due to insufficient space.

Unlike destroyers, some armour is provided to stop splinters and light calibre hits.


Caccia Multiruolo, laid down 1938

Displacement:
4,224 t light; 4,503 t standard; 5,312 t normal; 5,960 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(511.70 ft / 492.13 ft) x 49.21 ft x (17.06 / 18.47 ft)
(155.97 m / 150.00 m) x 15.00 m x (5.20 / 5.63 m)

Armament:
6 - 5.98" / 152 mm 53.0 cal guns - 99.21lbs / 45.00kg shells, 300 per gun
Dual Purpose guns in turret on barbette mounts, 1938 Model
3 x 2-gun mounts on centreline ends, evenly spread
1 raised mount - superfiring
28 - 1.46" / 37.0 mm 54.0 cal guns - 1.66lbs / 0.75kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1938 Model
7 x Quad mounts on sides, evenly spread
7 raised mounts
18 - 0.98" / 25.0 mm 77.0 cal guns - 0.54lbs / 0.24kg shells, 4,000 per gun
Anti-air guns in deck mounts, 1938 Model
18 x Single mounts on sides amidships
Weight of broadside 651 lbs / 295 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.42" / 36 mm 328.08 ft / 100.00 m 9.84 ft / 3.00 m
Ends: Unarmoured
Main Belt covers 103 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.76" / 70 mm 1.97" / 50 mm 1.97" / 50 mm
2nd: 0.39" / 10 mm 0.39" / 10 mm -
3rd: 0.39" / 10 mm - -

- Armoured deck - multiple decks: 0.79" / 20 mm For and Aft decks

- Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 58,000 shp / 43,268 Kw = 32.94 kts
Range 5,000nm at 20.00 kts
Bunker at max displacement = 1,457 tons

Complement:
310 - 404

Cost:
£2.548 million / $10.194 million

Distribution of weights at normal displacement:
Armament: 328 tons, 6.2 %
Armour: 556 tons, 10.5 %
- Belts: 187 tons, 3.5 %
- Armament: 151 tons, 2.9 %
- Armour Deck: 200 tons, 3.8 %
- Conning Tower: 18 tons, 0.3 %
Machinery: 1,588 tons, 29.9 %
Hull, fittings & equipment: 1,566 tons, 29.5 %
Fuel, ammunition & stores: 1,088 tons, 20.5 %
Miscellaneous weights: 186 tons, 3.5 %
- Hull below water: 10 tons
- Hull above water: 10 tons
- Above deck: 166 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,378 lbs / 1,986 Kg = 40.9 x 6.0 " / 152 mm shells or 0.9 torpedoes
Stability (Unstable if below 1.00): 1.18
Metacentric height 2.3 ft / 0.7 m
Roll period: 13.5 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.34
Seaboat quality (Average = 1.00): 1.23

Hull form characteristics:
Hull has a flush deck,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.450 / 0.466
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 25.47 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 41
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 15.00 %, 28.22 ft / 8.60 m, 21.65 ft / 6.60 m
- Forward deck: 20.00 %, 21.65 ft / 6.60 m, 18.37 ft / 5.60 m
- Aft deck: 50.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Quarter deck: 15.00 %, 18.37 ft / 5.60 m, 18.37 ft / 5.60 m
- Average freeboard: 19.59 ft / 5.97 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 113.9 %
- Above water (accommodation/working, high = better): 185.8 %
Waterplane Area: 16,047 Square feet or 1,491 Square metres
Displacement factor (Displacement / loading): 113 %
Structure weight / hull surface area: 63 lbs/sq ft or 306 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.68
- Longitudinal: 1.73
- Overall: 0.75
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily


152/53 mountings simmed as automatics for HA elevation, increased training rate etc.
10t = Scaricabombe
10t = D3 sonar
10t = 1 x AQ1 air search radar
10t = 1 x EC.2 surface search radar
20t = 2 x GDR.1 FCS
126t = 7 x Quadruple 37/54 mountings
=186t

Hmmm...

There's something about it which strikes me a bit... "wrong". It looks like a good design and seems to have good operational parameters, but it seems needlessly expensive and large for taking on the DD role. Flotilla leader, sure.

I wouldn't be comfortable about the lack of torpedo capacity. What is Italy's doctrine regarding use of torpedoes versus gunfire?

The notation at the bottom says the 152mm are simmed as automatics, but the report says DP. This is something of a general nit; the notes section is the place to announce and clarify any issues like that, but I'd prefer it if we'd all leave the actual SS reports unchanged.

Quoted

but it seems needlessly expensive and large for taking on the DD role.

Well, its not a proper destroyer to be sure. One of the reasons its so big is that its jumped up into the 0.75HS category (well out by 3tons) whereas if built to destroyer standard of 0.50CS it'd loose about 1000tons. Then again, with realistic machinery weights you could get around 120,000shp and 39-40knts.

With an escort group of about ten ships I'm figuring on a small carrier, two or three of these ships and the remaining are frigates for ASW. I don't really see the design being used for torpedo runs on capital ships. In all likelihood I don't see anything larger than a cruiser engaging - the bigger ships are for the separate covering forces.

Now for a future version for proper fleet work I could probably jam torpedoes on somewhere. Then again, launch a salvo of eight torpedoes (two quads per side) at around 8-10,000m. Might get 20% hits at most, so 1 or 2 hits. At the same range probably getting 10 hits from the 152mm guns per minute...

4500tons for what is called a destroyer? Looks like politicians mixed it all up. There is a reason why OTL modern German warships are called "frigate" though they reached a size others would call them destroyer at least....

These vessel, while an interesting design, are no expandables. Too me too much is packed into them, too many roles they need to fullfil. This is why cruisers are the smallest possible multi-role vessels.

Anyway, interesting stuff. I would have expected some higher bridge. A low silhouette has its merrits but in a pre-radar era (or where radar is still not reliable) you need lookouts. And the eyaball mk 1 needs height to see far....

I couldn't really figure out what to call it, closer to a destroyer than cruiser in size so I went with that. Its a reasonably expendable ship compared to a 10,000ton cruiser. To me, they're similar to the Didos, with AA focused armament (but no aircraft direction facilities on this ship) and some limited AS armament. Similar size to the Didos are the Arethusas, definitely more like cruisers. Capability against surface vessels is similar, poorer against aircraft, but they're more seaworthy and better suited for longer operations. Mostly it'll probably end up laying down a barrage of AA fire with the 152mm guns over other ships and shooting wildly with the 37mm guns. Or take some of the guns off and use the room for some command and communications facilities.

I don't think the bridge is that low compared to other ships, the long superstructure just makes it look a bit low. I imagine you get a good view from the 100ft foremast as well. Compared to the RSAN's Dione Class, they have a very similar bridge height.