The middle Condottiere

[caption width="798" align="alignnone"] Emanuele Filiberto Duca D'aosta in 1942, showing her unique camouflage - Src Pinterest[/caption]The group IV of the Condottieri cruisers "superclass" included the Emanuele Filiberto Duca d'Aosta (1934) and Eugenio di Savoia (1935), very similar in design and appearance to the previous Raimondo Montecuccoli class. These fleet cruisers were the last armed with "only" (given their tonnage) eight 6-in guns (150 mm). They improved on the previous class on many points, setting them apart eventually despite the obvious similarities. This incremental process allowed to reach the next big step forward that was the Duca Degli Abruzzi class in 1936.The E.F.Duca D'Aosta class was scheduled and planned for the very same 1931-33 naval programme as the Montecuccoli class. There was however a full year gap between their laying down: Both the Group III cruisers were laid down in Ansaldo and CRDA in April (Attendolo) and October (Montecuccoli), while the lead ship D'Aosta was laid down in OTO in October 1932. This full year allowed engineers to gradually improve on their previous designs while keeping the essentials. For various reasons (such as range and habitability) it was preferred a larger hull, which implied greater displacement, requiring greater output, but also allowing for some extra protection and better balance overall. Still, protection remained light.Both cruisers in concert, prewar. During the war they were in separated units most of the time.Both cruisers would have a long active life. They participated in several important battles and survived into the co-belligerence period, but were sent after the war as war reparations to Greece and USSR, as Elli and Kerch, new flags under which they served for many more years, like the Montecuccoli which also seen cold war service with the Marina Militare.

Design Changes

Savoia in 1942 and 1943The major concern of the engineers was to increase protection, even compared to the Montecuccoli class. Therefore they opted for a full, thicker armor, also reflected in the layout plan, which had a larger volume. Yet she was still better protected, between 3 to 4-in (100 and 60 mm) versus for example a mere 1-in at most on Cadorna. This was done by a sacrifice: Speed, and yet based on a better output, 106,000 hp versus 95,000 on the previous class. Displacement But they still managed to crank up 37 knots on trials. In practice it was below 36.5 knots. Armament did not changed, except for a better AA artillery with 4 twin Breda 37mm mount, no 40 mm as on the Montecuccoli.
Cruiser Emanuele Filiberto Duca d'Aosta

Hull Construction and general design

[caption id="attachment_34738" align="aligncenter" width="640"] Launch of Emanuele Filiberto Duca d'Aosta in 1934[/caption]The D'Aosta was virtually a repeat of the montecuccoli design but they were designed with almost a year gap, for the same programme. This left time for plenty of incremental improvements. The hull was the same in shape and form, with the remarkable amount of flare at the bow, which looked from above larger than the more slender poop. New sections were added, and the hull was lenghtened, the making it roomier with an extra 39 feets (12 meters) long, 3.6 feets (1.10 meters) at the beam, and 1.6 feets (0.5 meters) of additional draft, or 186.9 m (613 ft 2 in) overall for 17.5 m (57 ft 5 in) in beam and 6.1 m (20 ft 0 in) draught. Tonnage of course rose to 8,300-8,600 tons standard versus 7,400 on the Montecuccoli, and up to 10,300-10,600 tons fully loaded. Their standard was the Group III cruisers's full load...Full Interior designSuperstructures and general outlook were the same, and in fact Intel service in all admiralties had problem distinguishing Group III and IV, understandably. Main and secondary Artillery was placed exactly the same, they had identical silhouette with same forecastle, proportions, minimalistic tower bridge supporting the main telemeter and FCS, two large funnels with raked caps, an amidship catapult, same tripod mainmast just at the base of the aft funnel. The only light difference was due to the greater powerplant, making the aft funnel the same size of the fore funnel, unlike Group III cruisers. That was still hard to spot from binoculars. As for the crew, they were manned by 27 officers and 580 ratings. They carried 8 service boats amidships on davits, later reduced in wartime to four, but with extra inflatable rafts.

Armour Layout

To summarize, it was improved enough compared to the Cadorna and the Group III to not consider these "tin-clad cruisers", but still unsufficient overall. It did not reached the level of Group V cruisers, which went straight for the Washington limit for this, on the same hull basically. For turrets it's their frontal arc, front plates and sides figures. For the CT, the second value is the roof. Former Group III are marked with a star.Main belt: 70+35 mm (2.8+1.3 in)/60+25 mm*Bulkheads: 50-30 mm (2-1.2 in)/40-20 mm*Deck: 35-30 mm (1.4 in)/30-20 mm*Barbettes: 70-50 mm (2.7-2.1 in)/50-30 mm*Turrets: 90 mm (3.5 in)/70 mm*Conning tower: 100-40 mm (3.9 in)/100-25 mm*Communication Tube: 30-20 mm (1.2-0.7 in)/30 mm*

Powerplant

Cutaway of the Montecucoli showing the location of respective boiler rooms and truncated exhaust pipes.The propulsion comprised two propeller shafts driven by Parsons (Aosta) and Belluzo (Savoia) turbo-reducer groups turbines, fed by steam provided by six water tube boilers of the Yarrow (Aosta) and Regia Marina (Savoia) type, oil-fired with injectors and superheaters. Water flowed through pipes heated externally by combustion gases exploiting to the full all the heat coming from the burners, boilers walls and exhaust gases. They required a special steel and special welding techniques to withstand high temperatures. Total output was 110,000 hp, to compare with 106,000 on Group III, allowing a maximum speed of almost 36.5 knots, a bit less than Group III due to the larger hull. They had a roughly similar range based on 1,653 tons of oil in normal conditions, at cruise speed 14 knots, of 3,900 nautical miles. To compared on Group III this was respectively 1,275-1,295 tons for 4,122 nmi (7,634 km) at 18 knots, so they were not good walkers and range was decreased despite additional fuel on board.Cutaway of the previous Attendolo (src)But the most important was the arrangement of boiler rooms: Previous group had four forward, two aft groups and funnel size accordingly. On group IV, they were placed in two groups and three boilers fore and aft, for a heavenly number of smoke ducts making funnels of identical size. Each boiler room was also positioned in a separate compartment.

Armament

Main: 4x2 6-in/53 (152mm) OTO

Main guns blazing in heavy seas on Savoia in 1937.The main armament comprised eight 152mm/53 A-1932 model gun (6 inches/53) from OTO, in separated single mounts but twin turrets, two superfiring forward and two aft. They used semi-automatic loading guns allowing reload up to 15° elevation. The individual mounts and larger separation, like on the Montecuccoli class, authorized less interference and thus favored accuracy.See more on the weapons section

Sec: 3x2 100 mm/47 DP M28 OTO

The main anti-aircraft armament consisted of six 100/47mm OTO guns modello 1928. Original design was going back to the 1907 Škoda 10 cm K10. First pattern was 1924. They were distributed in three twin mounts like the previous Montecuccoli class, and could take on anti-ship roles as well. Relevant in 1934, but no longer by 1940 they were unable to follow the nex generation of aircraft or to repel diving attacks. By default the tactic was to use them for barrage fire. For their replacement, it was planned to install the new 90/50 mm model A-1938 developed by OTO for the Regia Marina, in single mounts, much faster and stabilized. They were adopted on the rebuilt Duilio and Littorio only however. See more on the weapons section

Torpedo Tubes and ASW

Torpedo Tube banks on SavoiaThe torpedo armament consisted of six 533 mm (21 inches) torpedo tubes, distrubited into two triple banks that located on deck, amidships, abaft the funnels.The models fired were same as the Montecuccoli class: 53.3 cm (21") Si 270/533.4 x 7.2 "M" models with the following specs:Total weight 3,748 lbs. (1,700 kg) for 23 ft. 7 in. (7.200 m)Explosive Charge: 595 lbs. (270 kg)Wet Heater, 4,400 yards (4,000 m)/46 knots or 8,750 yds/35 knots or 13,100 yds/29 ktsAnti-submarine armament: The Aosta class cruisers carried each two depth charge throwers and two racks aft.Paravanes: Both cruiser carried four of them. Used as mine cable cutters, Paravanes were present on all Italian cruisers.

AA Armament

The main anti-aircraft armament consisted of:-8 Breda 37mm/54 heavy machine guns in four twin mounts. They were located They were proved against low-flying torpedo bomber attacks.-8 13.2mm/76 Hotchiss heavy machine guns in four twin mounts. Completely inadequate in 1940 but yet still also shared (in caliber) by French, British and US ships. They were located around the bridge.Note that by the Autumn of 1943 both kept thir six twin 13.2mm/76 Breda but had in addition (and replacement of their 100 mm apparently) ten single 20mm/70 Oerlikon AA guns installed. In 1944, two more added on both ships again. There were no other modifications but the removal of torpedo tubes, catapult and seaplanes to spare weight and stability.Duca d'Aosta in 1941

Sensors

Like most Italian ships in 1940, these cruisers had no radar. With war lessons and availability, by mid-1943, Emanuele Filiberto Duca d`Aosta received a German FuMo 39 radar, provided by its ally. From there, by August 1943 her sister ship Eugenio di Savoia inaugurated the Italian Gufo or EC.3/ter radar. By the Summer of 1944 Duca d'Aosta had both a FuMo 39 radar and a British type 286 radar, quite a unique combination !By early 1945, she only retained her British type 286 radar. USSR apparently fitted Kerch with better sensors while under service (according to navypedia): Giuys and Redan radars. This radar is easy to spot aft of the tower. Greece did received modifications as its radar was installed at the end of a sturdier lattice mast aft of the tower bridge. Presumably the same EC.3/ter radar, but apparently later replaced by an SO-8 surface radar. SrcThe FuMo 39 (Funkmess-Ortung) Radar was for direction finder, active ranging. Derived from FuMo 21, which had a mere 10 nm range.The Type 286 radar made by ECKO had a frequency of 214 MHz. It was a VHF-Band with a PRF of 200 to 800 Hz, 2 µ pulsewidth, 6 kW for a 25 NM (≙ 46 km) range.The EC.3/ter Or "Gufo" was had a 400–750 MHz Frequency, 500 Hz PRF, 6° (horizontal), 12° (vertical) Bdwt, 4 μs Plswt, 3 RPM, 10 KW for a 25–80 km (16–50 mi) range. This was the first Italian radar, invented by navy technicians Ugo Tiberio, Nello Carrara and Alfeo Brandimarte in 1936–1937, stopped in 1941 but revived after Cape Matapan. First tests on TB Giacinto Carini in April 1941. Produced by SAFAR (150+ units) but only 12 on various ships by 8 September 1943. It was however used "officially" rarely, since the German informed the RN not to use it long range, believing it could be spotted by British radar warning such as the Metox (which was not opertational before mid-1944). It seemed to have seen a wide use, but was not mentioned on logbooks. Only Scipione Africano used it in combat on 16-17 July 1943, sinking MTB 316.

On board Aviation

IMAM Ro 43 aboard Trieste..RO 43 being towed back on the catapult, on Eugenio Di Savoia (Luce, src below).The unit embarked two IMAM Ro.43 sea reconnaissance seaplanes two-seater biplanes (300 kph, 1,000 km range). They were launched from the admidship catapult, in between funnels, and max capacity was three, with one on catapult and two on rails on each side, wings folded. They could be picked up with a little traverse by the catapult. The Ro.37 was however too flimsy for landing at sea and be recuperated aboard, and so often instead looked to land on shore.

About the names

The lead ship, often simplified by the allies as "Aosta" was baptized in honor of Emanuele Filiberto di Savoia, the Duke of Aosta, an area bordering France and Switerland, the northermost of Italy and mountainous. He was a general of the Royal Army, son of the King of Spain Amedeo I, brother of Duke of Abruzzi, Luigi Amedeo di Savoia (another cruiser by the way). He was considered a brillant general, leading the third army without ever suffering defeat in WWI. For this he was also nicknamed "Duke Invitto" (the invicible Duke) and conquered Gorizia in the sixth battle of the Isonzo. In 1926 he became Marshal of Italy but passed out in 1931, by his will buried among his soldiers in the Military Memorial of Redipuglia. The cruiser had the motto "Victoria nobis vita" (for us victory is life), the Duke's motto in fact. The cold war cruiser Vittorio Veneto adopted the same. "Emanuele Filiberto" was a name given to a battleship previously.Eugenio di Savoia was named after Eugene of Savoy, a military strategist and general of the late 16th century, which he served with distinction. Prince Eugene Francis of Savoy–Carignano or Carignamo (18 October 1663 – 21 April 1736) "Prince Eugene" became a field marshal both in the army of the Holy Roman Empire, Austrian Habsburg dynasty and one of the most successful military commanders of his time, rising at the top of Imperial court in Vienna, but brought up in the court of King Louis XIV of France, but was denied service in the French army, transferring his loyalty to the Holy Roman Empire, with a career spanning six decades. Victories counts the fields of Blenheim (1704), Oudenarde (1708), Malplaquet (1709), Battle of Turin (1706), battle of Petrovaradin (1716) and Siege of Belgrade (1717). The 1934 cruiser also had the motto of the Aosta Alpine battalion engraved.

Resources

Books

Arrigo. Petacco, Le battaglie navali del Mediterraneo nella seconda guerra mondiale (Mondadori)Michael J. Whitley, Cruisers of World War Two, Londra, Arms and armour Press 1995Robert Gardiner, Stephen C. All the World Fighting's Ships 1922-46 and 1947-1995James Joseph Colledge, Ben Warlow, Ships of the Royal Navy: complete record (Chatham 2006)Gianni Rocca, Fucilate gli ammiragli. La tragedia della marina italiana nella seconda guerra mondiale (Mondadori 1987)Gino Galuppini, Guida alle navi d'Italia dal 1861 a oggi, Milano (Mondadori)Giuseppe Fioravanzo, L'organizzazione della Marina durante il conflitto. Tome II. Ufficio Storico della Marina Militare 1975.Giuseppe Fioravanzo, La Marina Italiana nella Seconda Guerra Mondiale. Vol. IV. Ufficio Storico della Marina Militare 1959.Giuseppe Fioravanzo, La Marina Italiana nella Seconda Guerra Mondiale. Vol. V. Ufficio Storico della Marina Militare 1960.Giuseppe Fioravanzo, La Marina Militare nel suo primo secolo di vita 1861-1961. Ufficio Storico della Marina Militare 1961.Giuseppe Fioravanzo, La Marina dall'8 settembre alla fine del conflitto. Ufficio Storico della Marina Militare 1971.Giuseppe Fioravanzo, La Marina Italiana nella Seconda Guerra Mondiale. Vol. VIII. Ufficio Storico della Marina Militare 1964.Raffaele De Courten, Memories Ufficio Storico della Marina Militare, 1993.Pier Paolo Bergamini, Le forze navali da battaglia e l'armistizio. Rivista Marittima 2002Aldo Cocchia, Filippo De Palma, La Marina Italiana nella Seconda Guerra Mondiale. Vol. VI-Vol. VII Ufficio Storico della Marina MilitareLuis de la Sierra, La guerra navale nel Mediterraneo: 1940-1943. Mursia 1998Erminio Bagnasco, M. Brescia, Cacciatorpediniere classi “Freccia/Folgore”. Albertelli, 1997.

Links

On regiamarinaitaliana.it (archive)On wiki.warthunder.ruItalian Torpedoes on navweaps.comOn uboat.net/On navypedia.org/Kriegsmarine radars on navweaps.comOn associazione-venus.it - many photoson alchetron.comOn agenziabozzo.itKerch 1:700 Kombrig on scalemates.com/1:350 Fine scale models kit review on modellmarine.de

Videos

Catapult Launch on Di Savoia (original Luce Footage)Launch ceremony of Di SavoiaOn world of warshipSame, on "armada"

Model Kits

An extract of Profile Morskie 1/400 shiowing the unique camouflage of D'Aosta1/700 Kombrig kit of the class on scalematesKit review on icsm.it/regiamarina/It was also done in 1:1200 by Xpforge and is available for print.

Profiles:

Author's profileEugenio di Savoia in 1936, showing her two-tone livery, dark hull, light superstructure, quite common at the time. Note also the all metal covering of the forecastle deck. During WW2, aerial recoignition white-red bands were painted. src regiamarinaitaliana.it (archive)The famous and atypical camouflage of E.F. Duca D'Aosta by the time of Operation HarpoonEugenio di Savoia at the time of Operation Harpoon. She would receive later another variation of the same with larger "loops" later.In video games, Duca D'Aosta is a "special" in world on warships.