Italy (1942) - Medium tank - 152 built
The last Italian Tank for 60 yearsThe M15/42 medium tank (carro armato medio) also called M.42, was the ultimate evolution of the M13/40 designed and produced by Ansaldo. In July 1942, the problems and defects of the M13/40 and M14/41 has been well identified. The development of a tank equipped with a better engine started, with an upgraded main gun. In March 1943, the prototype of the M15/42 was approved for production. However that late into the war, only about eighty could be manufactured before the Italian capitlation. The M15/42 was armed with an upgraded version of the same 47 mm cannon derived from the 47/32 Modello 1935. However the armor and its construction method was not changed, while the suspensions remained the same. Basically by the time it entered service, the M15/42 was obsolete. It was only seen in action during the siege of Rome, fighting clashes with the fascists.
Manufacturing of the new tank was interrupted by the Cassibile armistice of September 3. Soon after Nazi Germany captured the faclity and transferred it to the Italian Social Republic. Thelatter used the M15/42 as their main tank until the end of the war.
The M15/42 chasssalso served as an anti-aircraft self-propelled vehicle, and the 105/25 M.43, probably the best Italian tank hunter of the war.
DevelopmentIn December 1940, development of a heavy tank was tasked, but it took years, so in 1942 it became necessary to look for an alternative solution to upgrade and replace the noew obsolete M13/40, or to remedy to the low production rate by simplifying the design. There were negocations with Nazi Germany from officials of the Regia Esercito in the winter of 1940-1941, which ended fruitless as they were asked to sell 800 French tanks previously captured.
In June 1941, negociations led to an opening, as it was assumed a licence to manufacture the Panzer III would be obtained. However, the Germans put so many conditions, like providing half of the components, optics and weapons at standard price, that the project aborted. In the same time indeed, the consortium FIAT-Ansaldo actively lobbied the Fascist regime officials, assuring them they could produce a heavier tank that was at the same time simpler and less expensive to manufacture. They even added it would be operational by early 1942. However by February 1942, Germany proposed the Panzer IV licence, but Italy declined it in the spring of 1942.
Between the long gestation of the Carro pesante M26/40 and negotiations dragging for ever with the Germans, the Royal Army already in the summer of 1941 decided to simply upgrade the M13/40, notbly to face superior British armor in the desert of North africa. This was to be the M14/41.
In July 1942, a technical team assembled by chief engineer Giuseppe Rosini examined the M14/41 to try to solve the two major issues of the design, propulsion and armament. Since 1940, the 47/32 Mod. 1935 cannon has been improved already, with a barrel lengthened to 40 calibers. However it was planned to upgrade the M14/41 and M13/40 but development of the new ordnance was slowed down notably by the manufacturing of new shells. A single M14/41 was experimentally armed with the new gun as soon as it was available, it was used as a basis for further improvements; First the engine was a petrol one, and and its cooling system completely revised according to desert warfare conditions. The M15/42 prototype was extensively tested from December 1942 to March 1943, and as soon they were completed, mass; producion was approved at the same time a service name was given, abbreviated often as "M.42".
Design of the M15/42The M15 / 42 was based on the hull of the M14 / 41: the rear part was redesigned and was extended by 15 cm to allow the installation of a new engine, that is the FIAT-SPA 15TB M.42 with 12 liter displacement .  The apparatus was no longer diesel because gasoline stocks were constantly decreasing,  but it was fueled by petrol; it was 8-cylinder V-shaped and developed a power of 170 hp (190 hp at the test bench).  A new transmission and a manual gearbox were then added with eight forward and two reverse speeds.  The main tank contained 367 liters of fuel and there was a reserve tank with an additional 40 liters; autonomy was 220 kilometers on the road at a speed of 38 km / h and fell to 130 kilometers / ten hours on land at a speed of 20 km / h.  The mechanics remained the same. Each side rested on eight supporting wheels, coupled two by two by horizontal elements; each pair was hooked to an arched bent arm, bound to the other end by a pin attached to the hull. Above each pair of arms a semi-elliptical leaf spring suspension was then secured, connected to them by links and two bushes. The rolling train was completed by three upper rollers, the rear idler wheel and the front driving wheel.  The increased length of the hull advised the adoption of longer tracks with eighty-six links  and 260 mm wide.  However, this system was not updated in relation to the new engine and therefore the tracks tended to come out of place during high speed driving: after the first deliveries, four large teeth were added to the throat of the driving wheel to solve the problem.  The same M15 / 42 of Saumur, frontal three-quarter view: note the pair of Breda machine guns Mod. 38 in casemate and the 47/40 cannon Hull and superstructure were subject to some marginal modifications: the first had been equipped with four circular openings, two rear and one on each side.  The access hatch of the crew was moved to the right side of the superstructure, the armored machine-gun protection in the casemate was better designed, the two mufflers (one on the left and one on the right of the hull) each had an armored heat shield. As the production proceeded, the two canister racks on the nose of the hull (inherited from the last lots of M14 / 41) were integrated with five more placed on the sides of the superstructure and on the back of the hull was installed a box containing smoke bombs. Finally the Breda Mod. 38 8 mm anti-aircraft machine gun was removed, kept in the hull when not used.  The riveted armor of the hull was 42 mm thick on the front and rounded, 25 mm on the vertical sides and back, 6 mm horizontal on the bottom; the riveted armor of the superstructure was 42 mm thick on the front side and was inclined 11 ° to the vertical, 25 mm on the sides (9 °) and rear (20 °), 14 mm on the horizontal roof. The Breda tank machine gun Mod. 38, chambered for the 8 × 59 mm RB Breda cartridge and widely used by the Royal Army The M15/42 was characterized by the new armament in the turret, the 47/40 Mod. 1938 piece of 47 mm long 40 gauge, with superior initial speed, tighter trajectory and greater range compared to the previous cannon of the same caliber 47/32 Mod 1935.  The main grenade supplied was the EP model ("ready effect"), that is a hollow charge that reached 900 m / s: it was able to pierce a 112 mm thick armor of 100 meters, 60 mm thick from 500 meters, 43 mm from 1 000 meters and 24 mm from 2 000 meters. They were also supplied with EPS grenades (due to "special ready effect", ie HESH projectiles) that beat 115 mm thick armor regardless of the target's target distance.  The armament on board was completed by two Breda Mod. 38 machine guns in blockhouse and by a third Breda Mod. 38 coaxial to the cannon, the latter could be removed from its carriage and used in anti-aircraft function.  The loadable reserve amounted to 111 grenades for the cannon and 2 640 cartridges for machine guns.  The turret had a 45 mm (16 °) thick frontal armor and the rounded mantle was 50 mm thick; sides and back were 42 mm (22 °) thick and 15 mm horizontal roof. On both sides a large circular hole was used to use small arms from the inside. The tilting of the tower was achieved by means of an oleodynamic system and covered the entire horizon;  the height of the cannon was manual and ranged from -10 ° to + 20 °.  The crew had four people: the commander sat in the turret along with the gunner / loader; the
Production of the M15/42By October 1942, the Royal Army had ordered 280 M15/42 tanks as tests were not even started. Production plans were revised, but the heavy tank P26/40 was still prioritized, blocking retooling for the new tank. A directive chaged this in March 1943, as the Royal Armt now stressed the massive massive production of simpler self-propelled guns, as the Germans did with the STUG. Because of this, the M15/42 order was scaled down to 220 units. Alas, production started in July 1943.
Conflicting data is observed on the real production figures for the M15/42, going among sources and historians between 112 and 248 vehicles, while other gave 190 or 220 before the September armistice, and possibly 287 ordered by the Germans. This could include however chassis of the M15/42 also used for self-propelled guns. Probably the most accurate so far established a total of eighty-two completed befre the armistice, as registered for service by the Royal Army. Expert Davide Guglielmi in magazine Storia Militareseemed to point out that 124 were effectively captured by the German, and twenty-eight more built under occupation in 1944 for a grand total of 152.
Another Publication in 2013 of the same magazine, provided statistics from an original Ansaldo document and 103 vehicles were listed as completed by 1942, thirty-six in 1943, and eighty planned for December 31, 1943. As for previous designs, Ansaldo created the hull and provided the equipment while Fiat provided the engine and associated tranmission and driver's pedals, dashboard and wheel.
Operational useThe Royal Italian Army seemed to have pressed into service eighty-two M15/42, distributed to the cavalry in rather piece-meal fashion. Most the 135th Armored Division "Aries II" however gained the bulk of these, three Mixed Groups (10th Armored Cavalry Regiment "Lancieri di Vittorio Emanuele II") with a squadron, twenty-five tanks strong while the two other squdrons has Semovente 75/18 SPG, and the 10th reserve squadron, just ten. The XVIII and XIX battalions also had each a single company(twenty wagons M15/42), and the the X created on 1 August 1943 had twelve M15/42, while five were transformed into command tanks (Radio Platoon atached to the 135th Armored Division). The remainder were in reserve with the the 33rd Tank Regiment.
The 135th Armored Division "Aries II" deployed its tank during the defense of Rome on 8-10 September 1943 following the signing of the armistice. Folloiwing this, the remainder that could be catured were used by the Italian Social Republic forces and requisitioned by various German units fighting south of the Gothic line in 1944-45. After the war ended, other M15/42 were deployed by the newly established Italian Army and State Police until the early 1950s.
M15/42 ControcarroThe anti-aircraft model of the M15 / 42, captured by the Germans In the course of 1942 the Royal Army had ordered the development of a self-propelled anti-aircraft vehicle to be used in the theater of North Africa and capable of providing some protection to the mechanized columns, often the target of the British air force without being able to offer any reasonable defense. To save time and materials, the newly designed M15 / 42 hull was taken: the original turret was removed and replaced with a polygonal obtained by welding, open to the sky, swiveling for 360 ° and containing a quadruple implant of 20 guns mm Scotti-Isotta-Fraschini 20/70, with elevation between -5 ° and + 90 °; these pieces had been specially modified so that they could use disintegrating ribbons with a consequent increase in the speed of shooting at 600 rounds per minute per cannon. The only other change concerned the suppression of the two Breda Mod. 38 machine guns in a casemate, whose opening was covered by a 42 mm thick plate; the crew therefore descended to three men, two in the turret and the pilot in the hull. A prototype was built that in January / February 1943 was presented and tested at the Army Motorization Study Center: compared to the original vehicle, the self-propelled vehicle was 14.7 tons, was taller (2.55 meters) and managed slopes of 60%. In March he entered service as "M15 / 42 Carro Contraereo" and was given to the VIII Regiment Autieri stationed in Cecchignola in Rome, where the Germans found him and captured him. Used actively, in April 1945 it was operating in the V SS-Freiwilligen-Gebirgskorps, which fought the last battles against the Red Army in Germany, in the Teupitz area.  One source claims that two prototypes were delivered: one of these would be transported to Tunisia, where it was tested in real combat conditions. He remained on African soil after the surrender of the 1st Italian Army and the 5th Panzerarmee in May 1943.  Command versions
Carro Comando Semovente M42The M15/42 served as the basis for the design of the "M42 Self-Propelled Command Wagon", intended to serve in departments equipped with self-propelled vehicles. The turret was removed and the rolling ring closed with an 8 mm thick armored plate, in which two doors were obtained; on the roof was mounted a Breda Mod. 38 of 8 mm in anti-aircraft function. The two Breda Mod. 38 in the casemate were instead replaced by a single Breda Mod. 31 of 13.2 mm and two Magneti Marelli radios, an RF1 CA and an RF2 CA and two extra batteries were placed in the hull; finally a rangefinder was installed. The M42 was produced in forty-five units in 1943.  A small number were captured by Germany, who placed them in service under the designation Panzerbefehlswagen M42 772 (i):  were employed in the Italian war theater until the end of hostilities. 
M15/42 Centro RadioAnother model was the Cetro Radio or radio command post which did not have machine-guns in the blockhouse to make room for additional radio equipment. The quantity produced is not known. 
Ansaldo 105/25 M.43Towards the end of 1942 the Royal Army requested a new type of self-propelled vehicle, given the good results obtained with those armed with the how-to 75/18 Mod. 1934/1935; on 2 April 1943 the prototype vehicle proposed by Ansaldo was accepted. The hull of the M15 / 42 had been deprived of the turret, the superstructure had been redesigned to form a boxy casemate with a 70 mm front armor. The hull thus obtained was called "M.43" and in the casamate a 105 mm long 25 caliber cannon was installed. The self-propelled was produced in just thirty specimens, most of them used by the 135th Armored Division "Aries II" in the fights held in Rome. Another ninety-one were built by the RSI and also used by the Germans with the designation Sturmgeschütz M43 mit 105/25 853 (i). 
Operators and active serviceNazi Germany: after 8 September 1943 the Germans took ninety-two copies of M15 / 42, including some command cars; they then ordered another twenty-eight M15, delivered in 1944. They renamed them Panzerkampfwagen M15 / 42 738 (i), each equipped with an RF1 CA radio and distributed them both to three armored detachments under the regular army, and to the 22. SS-Freiwilligen -Kavallerie-Division "Maria Theresa", formed mostly by Hungarian personnel in April 1944.  By December 1944 there were still sixty-eight M15s in service in the German army.  A source reports instead that Germany only took twenty-eight or at least forty specimens.  In 1944 at least one of the wagons was converted on the field as a recovery vehicle, mounting a crane on the hull. 
Surviving tanksEsemplari superstiti - L'esemplare conservato presso il Museo storico italiano della guerra di Rovereto Sono attualmente conservati tredici esemplari del carro armato (in neretto quelli meccanicamente funzionanti): M15/42 - Musée des Blindés (Saumur, Francia) M15/42 (due esemplari) - Museo storico della motorizzazione militare (Roma-Cecchignola) M15/42 - Caserma "Ruffo" - Reparto Comando e Supporti tattici "Granatieri di Sardegna" (Roma) M15/42 - Caserma "Babini" - 4º Reggimento carri (Bellinzago Novarese) M15/42 - Caserma "de Carli" - 132º Reggimento carri (Cordenons) M15/42 - Caserma "de Carli" - 132º Reggimento carri (Cordenons) M15/42 - Caserma "Paglieri" - Reggimento "Lancieri di Novara" (5º) (Codroipo) M15/42 - Caserma "Forgiarini" - 32º Reggimento carri (Tauriano di Spilimbergo) M15/42 - Caserma "Zappalà" - Scuola di cavalleria dell'Esercito Italiano (Lecce) M15/42 - Collezione privata di Fabio Teméroli (Repubblica di San Marino) M15/42 - Vojni Muzej (Kalemegdan-Belgrado, Serbia) M15/42 - Centro Radio - Caserma "Durli" - Reggimento "Genova Cavalleria" (4º) (Palmanova) M15/42 - Museo storico italiano della guerra - Rovereto
M15/42 at Saumur museum
Breda Model 38
M 15/42 Tank located in Museo Storico Italiano della Guerra - Rovereto - Italy
M14/41 for comparison.