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WW2 German Tank Destroyers WW2 RSI Armor

Semovente M43 da 75/46 / Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i)

Italian Social Republic/German Reich (1943-1945)
Tank Destroyer – 11 to 18 Built

The Semovente M43 da 75/46 (English: 75 mm L/46 M43 Self-Propelled Gun) was the last self-propelled gun (SPG) produced by Italy during the Second World War. It was based on the previous Semovente M43 (plural semoventi) chassis, but featured new spaced armor that offered better protection to the crew. It was developed by Italian companies after a German request of late 1943.

A total of 11 to 18 vehicles were produced, but most of the vehicles were delivered to the Germans, who deployed them on the Italian peninsula against the Allied forces in the last stages of the Second World War.

Semovente M43 da 75/46 of the production series without the anti-aircraft support and the 20 liter can supports. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

Previous Models

The effective Semovente M40 da 75/18 self-propelled howitzer based on the chassis of the Carro Armato M13/40 IIIa Serie immediately proved to be more potent than Italian-produced medium tanks in terms of firepower. When deployed in North Africa by the Italians, it demonstrated to be an effective support vehicle, and could deal with almost all the Allied tanks in that theater of operations. It was deployed mainly as an assault tank or to support infantry attacks, but it was also deployed to attack Commonwealth armored formations with success.

It was armed with a Obice da 75/18 Modello 1934 (English: 75 mm L/18 Howitzer Model 1934) with 44 rounds and a Fucile Mitragliatore Breda Modello 1930 (English: Breda Light Machine Gun Model 1930) with 600 rounds. Its engine was the FIAT-SPA 8T Modello 1940 diesel giving out 125 hp at 1,800 rpm.

Side view of the Semovente M40 da 75/18 at Ansaldo-Fossati plant. Source: Semovente da 75/18

After the production of a small series of 60 vehicles, the Semovente da 75/18 was changed to the chassis of the more advanced and modern Carro Armato M14/41, becoming the Semovente M41 da 75/18. This vehicle was powered by the new FIAT-SPA 15T Modello 1941 diesel engine with a maximum power of 145 hp at 1,800 rpm. This semovente was also captured by the Germans and renamed as the Beute Sturmgeschütz M41 mit 7,5 cm KwK L/18 850 (Italienisch) (English: Captured Assault Gun M41 with 75 mm L/18 Cannon [Coded] 850 [italian])

Semovente M41 da 75/18 outside the Ansaldo-Fossati plant of Sestri Ponente. Source: fondazioneansaldo.com

In 1942, the chassis was again changed to the Carro Armato M15/42’s, becoming the Semovente M42 da 75/18. It was longer than its predecessors by 14 cm due to the new engine compartment mounting a powerful 190 hp petrol engine, the FIAT-SPA 15TB Modello 1942. The M42 da 75/18 was known in German service as the Beute Sturmgeschütz M42 mit 7,5 cm KwK L/18 850 (Italienisch).

The Obice da 75/18 Modello 1934 had a great High-Explosive Anti-Tank round, but had a short firing range and was imprecise at long ranges. A new armored vehicle with a different gun had to be produced, and, in October 1942, Ansaldo-Fossati started the new development. In February 1943, the prototype of the new semovente was ready.

The new tank destroyer had a casemate that was made 11 cm longer in order to host the Cannone da 75/34 Modello SF [Sfera] (English: 75 mm L/34 Cannon Model [on Spherical Support]), which had more recoil than the previous howitzer.
In German service, the vehicle was known as Beute Sturmgeschütz M42 mit 7,5 cm KwK L/34 851(Italienisch).


 
A Semovente M42 da 75/18 (top) and a Semovente M42M da 75/34 (bottom) outside the Ansaldo-Fossati plant of Sestri Ponente. These are early vehicles from the 1943 production run (the M42M was produced from 26th March 1943). In these 2 images, the different casemate fronts are clearly visible. Sources: La Meccanizzazione dell’Esercito fino al 1943

Other developments were the Semoventi M41M da 90/53 tank destroyer, based on a heavily modified Carro Armato M14/41 chassis with the engine compartment in the center and the main gun on the rear. It was accompanied by the more conventional-shaped Semovente M43 da 105/25, a new self-propelled gun on a completely modified M42 chassis.

The Semovente M43 da 105/25 at the Ansaldo-Fossati plant of Sestri Ponente. Source: pinterest.com

The M43 Chassis

The Semovente M43 chassis, also called in Ansaldo documents Semovente M42L (L for ‘Lungo’ – English: ‘Long’), was 4 cm longer than the M42, reaching a length of 5.10 m. It was also 17 cm wider (2.40 m compared to 2.23 m of the M42) and 10 cm lower (1.75 m compared to 1.85 m of the M42).

A Semovente M42 da 75/18 (left) and the Semovente M43 da 105/25 prototype (right). Note the differences in the chassis’ dimensions. Source: associazioneansaldo.com

Finally, the flameproof bulkhead separating the engine compartment from the fighting compartment was moved back 20 cm, increasing the fighting compartment’s space. All these modifications brought the total weight of the vehicle to 15.7 tonnes battle-ready, compared to the 15 tonnes of the M42.

The Semovente M43 da 105/25 prototype (left) and a Semovente M42 da 75/18 (right). Source: associazioneansaldo.com

The Semovente M43 chassis was first adopted for the Semovente M43 da 105/25 equipped with the Obice da 105/25 Modello SF [Sfera] (English: 105 mm L/25 Cannon Model [on Spherical Support]), which needed more space for the cumbersome gun breech and longer ammunition.

A Semovente M42 da 75/18 (left) and the Semovente M43 da 105/25 prototype (right). Note the differences in the chassis’ dimensions. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

It was also adopted by the Germans as the base for their new chassis, to which some original Italian production documents referred to as Semovente M42T (T for ‘Tedesco’ – English: German), meaning that it was derived from the previous Semovente M42L chassis.

The German ordered the installation of the Cannone da 75/46 Contraerei Modello 1934 (English: 75 mm L/46 Anti-Aircraft Cannon Model 1934) and Cannone da 75/34 Modello SF on this chassis to the Italian Ansaldo factory, which remained in the German controlled zone after the Armistice.

History of the Project

After the Armistice of 8th September 1943 and Operation Achse (English: Axis), the German forces captured thousands of Italian vehicles. Many of these were obsolete or needed to be repaired, but some were immediately redistributed to frontline German units in Italy and Balkans to replace some losses.

The Generalinspekteur der Panzertruppen (English: Inspector General of the Armed Forces) of the Wehrmacht inspected the various Italian factories and their armored vehicle projects in order to reorganize the production of Italian vehicles. He canceled the production of non-suitable vehicles by German Army standards and ordered modification to some vehicles to meet some German tank requirements.

On 18th December 1943, the Abteilung Waffen und Gerät beim Wehrkreiskommando 6 (Italienisch) (English: Weapons and Equipment Department of the Military District Headquarters No. 6 [Italian]) reported the proposal of the modification of the Semovente M43 da 105/25, called by the Germans Beute Sturmgeschütz M43 mit 10,5 cm KwK L/25 853 (italienisch) (English: Captured Assault Gun M43 with 105 mm L/25 Cannon [Coded] 853 [italian]).

After authorization from the LXXXVIII Armee Korps (English: 88th Armored Corps), German Hauptmann Dobiey, commander of the Panzerjäger-Abteilung 356 (English: 356th Anti-Tank Battalion) assigned to the 356. Infanterie-Division, proposed a series of modifications for the Beute Sturmgeschütz M43 mit 10,5 cm KwK L/25 853(i) that his unit had received after the Armistice. The 356. Infanterie-Division was formed in Toulon, France in May 1943, and was moved to northern Italy, between Genoa and Ventimiglia, in November 1943, where it received the Italian Semoventi M43 da 105/25.

Hauptmann Dobiey proposed the addition of 25 mm Schotten-Panzerung (English: Shadow Armor) and Seitenschürzen (English: Side Aprons) to increase the protection on the casemate to 60 mm on the superstructure sides and 34 mm on the chassis.
The German Hauptmann assumed an increase in weight of 600 kg, bringing the vehicle weight to about 16 tonnes, a weight that the original suspensions could withstand.

The Semovente M43 da 75/46 or Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) prototype at the Ansaldo-Fossati plant in Sestri Ponente. The gun barrel had a counterweight on the muzzle and was not painted as the chassis. Apart from the counterweight and the absence of the gun shield and the radio antenna, the prototype is identical to the production vehicles. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano Fino al 1943

It is not clear who proposed to mount the Cannone da 75/46 Contraerei Modello 1934 on this upgraded chassis. It is improbable that Hauptmann Dobiey, a German officer, had such extensive knowledge of the Italian cannon that he knew it was also an adequate anti-tank weapon and could be installed inside an armored vehicle.

Another note on the armament is that it was planned to modify the Cannone da 75/46 Antiaereo Modello 1934 to fire German PaK 40 ammunition. This would have increased the anti-tank performances of the Italian cannon and standardized ammunition production.

The Semovente M43 da 75/46 prototype from another angle. The absence of the gun shield here is more visible. Source: svppbellum.blogspot.com

Major General Ernst von Horstig, head of Dienststelle Italien des Heereswaffenamt (English: Italian Branch of the [German] Army Weapons Office), took the initiative and ordered the development of the vehicle. Ansaldo had to produce the prototype by 15th January 1944, less than a month later. The German general wanted the prototype tested before deciding its fate.

The Semovente M43 da 75/46 was rarely mentioned in Second World War Italian documents. It was barely mentioned by German sources either, but when it was mentioned, it was named with its German designation: Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) (English: Captured Assault Gun M43 with 75 mm L/46 Cannon [Coded] 852 [italian]).

In this article, the vehicle was referred to with both designations. The factory designation Semovente M42T will be used while referring to an up-armored version of the Semovente M42L chassis.

Production and Delivery

It is not known when the Semovente M43 da 75/46 prototype was ready and tested, but the German response was positive. Its production was organized at the Ansaldo-Fossati plant.

Ansaldo archive sources claim a total production of 11 Semoventi M43 da 75/46, 8 (including the prototype) in 1944 and 3 in 1945. The same document reports that only 7 spherical supports for the Cannone da 75/46 Contraerei Modello 1934 were produced, all in 1944. Photographic evidence confirms the existence of 6 production vehicles and a prototype.

A total of 6 Semoventi M43 da 75/46 equipped with guns ready to be delivered at Ansaldo-Fossati plant. This image confirms a production of 6 vehicles and a prototype, as declared by Ansaldo in 1944. Source: wardrawings.be

In the late war, the German Army wanted to save on raw materials, producing only the most powerful and reliable vehicles. This was done in Germany and also in Italy. It was planned to cancel the production of all Italian armored fighting vehicles apart for the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i), the Beute Panzerspähwagen AB43 203(i) (aka the Autoblinda AB43 medium reconnaissance armored car), and the Beute Panzerkampfwagen P40 737(i) (aka the Carro Armato P26/40 heavy tank).

On 20th February 1945, the Wehrmacht planned to equip 4 infantry divisions with Italian armored fighting vehicles. The Aufstellungsstab Sued was in favor of a production contract extension with the Italian factories. They essentially wanted to let all the Italian armored vehicle factories still capable of producing vehicles convert their production lines to Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) and Beute Panzerspähwagen AB43 203(i) (no mention was made of of the Beute Panzerkampfwagen P40 737(i) in this document), with a production estimated at 50 StuG and 50 Pz.Sp.Wg. per month.

The new production schedule for Ansaldo-Fossati plant of Sestri Ponente, where all the semoventi were produced, was of 116 Beute Sturmgeschütz M43 (not specifying the armament) in total until August 1945.

Ansaldo-Fossati production planned by the Germans in early 1945
Vehicle’s Name March April May June July August Total number
Panzerkampfwagen P40 737(i) 2 4 12 12 15 6 51
Beute Sturmgeschütz M43 14 22 25 25 25 5 116
Panzerbefehlswagen M42 772(i) 3 3 8 8 0 0 22

The document did not specify which of the 3 semoventi on the M43 chassis it refers to, but, the Germans wanted to standardize the production of the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i). It could be assumed that, in German plans, all or the majority of Sturmgeschütz M43 mentioned in the document would have been armed with the Cannone da 75/46 Contraerei Modello 1934.

The German document also mentioned that the Ansaldo-Fossati plant produced 7 Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) in 1944. Another 12 vehicles with and without main guns were produced in 1945.

Some of these were produced at the Ansaldo-Fossati plant but then sent to Milan, at the Fonderia Milanese di Acciaio Vanzetti Società Anonima (English: Milanese Steel Foundry Vanzetti Limited Company), which was reconverted into an assembly plant.

In fact, the German report specifically mentions the presence of 12 completed (but without guns) Sturmgeschütz M43 at the Fonderia Milanese di Acciaio Vanzetti S.A. assembly plant. At that plant, the vehicles were equipped with cannons and delivered to their German units, so it is probable that some of the 12 unarmed chassis at Fonderia Milanese di Acciaio Vanzetti S.A. plant of Milan were later equipped with Cannoni da 75/34 in order to send them to the frontline as soon as possible.

At the end of the war, Aufstellungsstab Sued (English: Positioning Staff South) reported the production of a prototype and 7 Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) in 1944 plus 2 Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) between 5th December 1944 and 5th January 1945.

Another 2 were produced between 5th January to 15th February 1945 and another 6 Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) chassis were produced between 16th February and 20th March 1945, of which only 2 equipped with main guns.

Beute Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) Production as Reported in German Documents
Data StuG M43 mit 75/46 852(i) Chassis Produced StuG M43 mit 75/46 852(i) with Main Guns Installed Status
1944 81 8 All delivered
5th January 1945 2 2 All delivered
15th February 1945 2 2 All delivered
20th March 1945 6 2 2 on the way to their unit2
Total 18 14
Note 1Including the prototype
2Nothing is known about the other 4 chassis

The total German number of 18 Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) differs from the Ansaldo-Fossati one, of just 11. This difference in sources can be easily explained as, from early 1945 on, assembly (and probably production) of Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) was moved from the Ansaldo-Fossati plant of Sestri Ponente to Fonderia Milanese di Acciaio Vanzetti S.A. of Milan. When assembly was moved, Ansaldo simply stopped counting the Semoventi M43 da 75/46. Another explanation could be that some chassis meant for other types were armed with the Cannone da 75/34 in order to put them in service as soon as possible.

The same report from 20th February 1945 claimed that Beauftragte für Waffen (English: Weapons Commissioner) Goering had reported that 25 StuG M43 mit 75/46 852(i) should be delivered in March 1945.

A last note about Italian armored vehicle production was sent on 9th April 1945 to the Reichsministerium fuer Rüstung und Kriegsproduktion (English: Reich Ministry for Armaments and War Production), directed to Reichsminister Albert Speer. The note was sent by the Generalinspekteur der Panzertruppen and reported that the Beauftragter fuer Panzerkampfwagen bei Rüstung und Kriegsproduktion (English: Representative for Armored Fighting Vehicles at Armament and War Production) in Milan wanted to order more Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) and Beute Panzerspähwagen AB43 203(i), reaching a full rate production of 50 StuG and 50 Pz.Sp.Wg. per month.

The Generalinspekteur der Panzertruppen wrote to Reichsminister Speer that he was in favor of continuing the Italian armored vehicle production if it did not interfere with German vehicle production because of the very few raw materials available.

The Generalinspekteur’s note reported that, if the Reichsministerium fuer Rüstung und Kriegsproduktion would approve, the Italian factories would increase, by every means, the production rate of armored vehicle currently on the lines, especially the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i).

This unrealistic production plan was never realized. On 25th April 1945, 2 weeks later, the Italian Partisans started a great insurrection, attacking the last Axis forces in the main cities of northern Italy. Turin, Milan, Novara and Genoa, where the Italian armored fighting vehicles were produced, were freed between 25th to 28th April 1945, capturing the production plants with the help of the workers.

German Modifications

Apart from the new armored plates, mounted only on some Semoventi M43 chassis, other upgrades were done on the Italian semoventi produced for the Germans. These included 4 bigger teeth bolted on the outside of the sprocket wheel, intended to prevent the track slipping off the wheels while driving in muddy or snowy terrain. Another modification was the addition of 3 helmet supports on the roof, 2 on the left side and one on the right, for the crew members when operating with open hatches. The third modification requested by the Germans was to substitute the right roof hatch with one openable in 2 parts for better ventilation of the fighting compartment.

A British light mortar squad near an abandoned Semovente M42M da 75/34 produced for the Germans. Note that the right roof hatch was shorter than the left one. Source: beutepanzer.ru

Other unconfirmed modifications claimed by many sources were:

  • Substituting the Italian radio apparatus with more reliable German-produced ones
  • Replacing the gearbox with one of German origin
  • German-produced Mauser MG34s or MG42s instead of the original Italian anti-aircraft machine guns

The Germans did not usually change the radio apparatus of the Italian tanks and self-propelled guns they used. It is possible the sources refer to occasional changes made by individual crews, such as German intercoms or new batteries and accumulators. The Germans did not modify the powerpacks on the Italian vehicles.

There is no photographic evidence showing the adoption of German machine guns on Italian self-propelled guns. This suggests that these were not widely adopted on Italian vehicles. Most likely, many sources are confusing the machine guns due to the German caliber. In fact, during the German occupation, the factories were ordered to change the caliber of the Italian machine guns and even some rifles to standardize to the German 7.92 x 57 mm Mauser caliber. Many Breda Modello 1938 Italian medium machine guns were modified to fire the Mauser cartridges. This could be considered another German modification of the Semovente M43 da 75/46.

Design

Armor

The armor was both bolted to an internal frame and partially welded (a great innovation for Italian vehicles) and had great thickness compared to Italian standards. The hull armor had 2 angled armored plates with a thickness of 50 mm at 40° on top and 35 mm at 50° on the bottom for the transmission.

The transmission deck plate was 25 mm-thick angled at 78°. It also had 2 brake inspection hatches of the same thickness. The hull side armored plates were 40 mm thick.
The superstructure had a 75 mm thick armor plate angled at 5° frontally, while the gun spherical support was 60 mm thick.

On the casemate’s sides, the 45 mm thick armored plates were angled at 7°, while the rear was protected by a 45 mm thick plate angled at 0°. A plate of 25 mm angled at 15° protected the back of the engine compartment. The roof and floor of the vehicle were 15 mm thick. Unlike its predecessors, the Semovente M43 da 75/46 had three-part side skirts.

The peculiarity of the Semovente M42T was the addition of 25 mm thick spaced armored plates angled at 25° on the front. They had a hatch where the driver port of the M43 was placed. The gun barrel received a 25 mm thick gun shield angled at 25°. This was a great improvement. For all the duration of the war, one of the problems encountered in Italian semoventi was the absence of protection to the spherical support that was sometimes blocked by light arm fire or artillery splinters. On the side, protecting the casemate and the lower part of the fighting compartment, there was a 25 mm spaced armored plate.

A Semovente M43 da 75/34 with its spaced armor plates. In this image, the hatches for the driving port and the gun shield are visible. Source: warthunder.com

Nothing is known about the real efficacy of this spaced armor. At the end of the war, the Italian ballistic armor, like the German one, was produced with poor raw materials and the final result was of bad quality and often broke or split.

Nevertheless, the spaced armor probably guaranteed more chances to survive thanks to the distance between the spaced armor and the casemate’s plate. The total weight of the vehicle was about 15.6 tonnes, 100 kg less than the less-armored Semovente M43 da 105/25.

Hull

On the left front mudguard, there was a support for the jack. On the sides of the superstructure, there were two headlights for night operations. On the rear part, the engine deck had two large-size inspection hatches which could be opened by 45°. Between the two inspection hatches were the sapper tools, including a shovel, a pickaxe, a crowbar, and a track removal system.

Rear of a Carro Armato M15/42. Even if many tools were removed, it was essentially identical to the one of the Semovente M43 da 75/46. Source: masterminiatures.it

The rear of the vehicle had the horizontal radiator cooling grills in the center, the cooling water cap and, on the sides, two fuel caps. The rear had a towing ring in the center and two hooks on the sides, one spare wheel on the left side, and a license plate on the lower left side with a brake light. A smoke grenade box was placed on the rear armored plate, on the right.

On either side of engine deck, on the rear fenders, there were two storage boxes and the mufflers covered by a steel shield to protect them from impacts.

Better view of the Beute Sturmgeschütz M43 mit 75/46 852(i) ready to be delivered at the Ansaldo-Fossati plant. This image allows seeing the turret roof details and bolted armor. Source: forum.warthunder.com

A total of 6 racks for 20-liter cans were placed on the sides of the vehicle, 3 on each spaced armored plate on the sides, just like on other Italian self-propelled guns and tanks. It should be noted, however, that on the Semoventi M43 da 75/46, the cans were not transported because they were never sent to North Africa, and it was not necessary to transport a great amount of fuel during operations in Italy, where it was deployed.

On the inside, starting from the front of the vehicle, was the transmission connected to the braking system, which had two armored inspection hatches. These could be opened from outside by means of two handles, or from the inside by means of a knob located on the right side of the vehicle, which could be used by the gunner. On the left was the driver’s seat, equipped with a fold-down back for easy access. In front, it had two steering tillers, a driving port that could be closed with a lever, and a hyposcope used when the port was closed. The hyposcope had 19 x 36 cm dimensions and a vertical field of view of 30°, from +52° to +82°. On the left was the dashboard and, on the right, the gun breech.

Interior of Semovente M43 da 105/25 prototype. Even if Semovente da 75/46 and Semovente da 105/25 had different main armament and main ammunition racks, they shared the same radio apparatus, dashboard (left) and machine gun maintenance kit and racks (right). Source: fondazioneansaldo.com

Behind the driver was the seat for the loader. The loader had, on the left, the radio apparatus and, above him, one of two armored hatches. In case of an attack from the air, the loader would also have to use the anti-aircraft machine gun. On the right side of the fighting compartment was the gunner’s seat without a backrest. In front of his seat, the gunner had the elevation and traverse handwheels.

On the gunner’s right was the support for the anti-aircraft machine gun when not in use, a maintenance kit, and a fire extinguisher. Behind the support was a wooden rack for ammunition for the secondary armament. In order to prevent the magazines from falling on rough terrain, the rack had a closable curtain. Behind the gunner/commander were the ammunition racks for the main gun. On the rear wall were the engine fan, an engine cooling water tank, and the Magneti Marelli batteries. On the rear side of the superstructure were two pistol ports which could be closed by revolving shutters from the inside. These were used for self-defense and to check the rear side of the vehicle in order to avoid the crew having to expose themselves outside of the vehicle. The transmission shaft ran through the entire fighting compartment, dividing it in half.

How the Semovente M43 da 75/46 would have looked without the spaced armor. It was based on a slightly modified Semovente M43 da 105/25 chassis. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano with author’s modifications

Radio Equipment

The Semovente M43 da 75/46’s radio apparatus was an Apparato Ricetrasmittente Radio Fonica 1 per Carro Armato or Apparato Ricevente RF1CA (English: Tank Audio Radio Receiver Apparatus 1) produced by Magneti Marelli. This was a radiotelephone and radiotelegraph station box of 415 x 208 x 196 mm and a weight of about 18.5 kg. It had 10 watts of power in both voice and telegraphy. It had a small cover that was raised up when the radio was in use.

The Apparato Ricevente RF1CA mounted on Italian semoventi and carri armati. Numbers refer to: 1) audio radio receiver apparatus, 2) power supply, 3) antenna support (early type), 4) accessories, 5) cable that connected the audio radio receiver apparatus with the antenna, 6) cable that connected the audio radio receiver apparatus with the power supply, 7) cable that connected power supply to the batteries, 8) headphones, 9) laryngophone, and 10) fuses. Source: Manuale Apparato Ricevente RF1CA TR7

Operating frequency range was between 27 and 33.4 MHz. It was powered by an AL-1 Dynamotor supplying 9-10 Watts, mounted on the hull’s right side, with a power supply of 12 Volts from NF-12-1-24 batteries produced by Magneti Marelli connected in series. It had a range of 8 km in voice mode and 12 km in telegraph mode. These capabilities were reduced when the self-propelled guns were on the move.

The radio had 2 ranges, Vicino (Eng: Near), with a maximum range of 5 km, and Lontano (Eng: Afar), with a maximum range of 12 km. Even with the Lontano range, in the voice mode it had a range of 8 km.

It was produced from 1940 by the Magneti Marelli company of Sesto San Giovanni, near Milan. and was mounted on all the Italian self-propelled guns and tanks of the M series (except for the Carro Armato M11/39) and the Carro Armato P26/40 heavy tank.

The radio was produced after the Armistice for the Germans, together with manual books in German language. The production of the Apparato Ricevente RF1CA until 1945 also contrasts the hypothesis of the use of German radios on semoventi. After the war, the turning unit of this transceiver was almost entirely copied on the US Army AN/GRR-5 receiver.

On the previous models of semoventi, the antenna radio was mounted on a support that was lowerable thanks to a crank inside the vehicle. The loader had to turn the crank until the 1.8 m antenna was fully raised or fully down. This was a slow operation and the crank occupied space inside the fighting compartment.

From 1942, a new antenna support was mounted on Italian vehicles. The first model equipped with this new antenna was the Semovente M41M da 90/53, while it was introduced in the Semovente M42 da 75/18 later. The new antenna had a 360° lowerable support, meaning that it could be folded in any direction. Usually, a hook on the left side of the front of the casemate permitted it to rest during long drives to avoid it hitting electrical cables or interfering with driving in narrow areas. It seems that, on the prototype and the production Semoventi M43 da 75/46, this support was never mounted and the crew did not have the possibility to lower the antenna.

The different types of antennas and supports mounted on the Italian medium tanks and semoventi. Early type (left) and new type (right), mounted from 1942 on. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

On all the semoventi produced before the Semovente M43 chassis, the antenna support was mounted on the rear left side of the casemate’s roof, while on the Semovente M43 da 105/25, it was moved on the front left side for a different internal arrangement. On the Semovente M43 da 75/46, the antenna radio support was again moved to the rear left side of the roof. To speed up production, Ansaldo-Fossati deployed a single M43 chassis production line. When the chassis was ready, Ansaldo’s workers made a hole on the rear side on the semoventi that would have received spaced armored plates, filling the front left hole with a round armored plate welded on it.

Engine and Transmission

The petrol engine of the Semovente M43 was inherited from previous semoventi M42 and M43 and the Carro Armato M15/42. The new model, the FIAT-SPA 15TB (‘B’ for ‘Benzina’ – Petrol) Modello 1943 petrol, 12-cylinder, V-shaped, water-cooled 11,980 cm³ engine developed 190 hp at 2,400 rpm (some other sources claim a maximum output of 192 hp or even 195 hp).

FIAT-SPA 15TB Modello 1942 petrol engine, radiator, and cooling vents. On the right top is the cooling water tank that was located, on the vehicle, in the fighting compartment. It was divided from the engine by a bulkhead. Source: bnamodel.com

It is not clear if the Germans modified the vehicle in other ways. It seems improbable that they ordered the mounting of German transmissions or other German-produced parts on the semoventi. The engine was designed by Fabbrica Italiana Automobili di Torino or FIAT (English: Italian Automobile Factory of Turin) and produced by one of its subsidiary companies, the Società Piemontese Automobili, or SPA (English: Piedmontese Automobile Company).

Engine and radiator on a Carro Armato M15/42. Even if the Semovente M43 da 75/46 and the Carro Armato M15/42 were different, the engine compartment was only slightly modified. Source: facebook.com Associazione Raggruppamento SPA

The engine ignition system and lighting systems, engine cooling system, and fuel circulation systems were inherited from the previous Semovente M43 da 105/25. In order to start the engine, there was a Magneti Marelli electric starter but also an inertial starter produced by the Turin-based company Onagro. The lever for the inertial starter could be inserted outside the vehicle, on the rear, or from the inside of the fighting compartment. Two crew members needed to turn the crank, reaching about 60 rotations per minute. At that point, the driver could turn the engine button on the dashboard until the first strokes of the engine. The crew members rarely ignited the engine from the inside due to the cramped space, but this could become useful when under enemy artillery fire or in areas in which the enemy could easily ambush dismounted crews.

Ignition crank mounted on the rear of a Carro Armato M15/42. On the Semovente M43 da 75/46, the only difference was the presence of a smoke grenade box on the right. Source: associazioneansaldo.com

On road, the Semovente M43 da 75/46’s maximum speed was 38 km/h, while off-road, the maximum speed was about 15 km/h. It had an on-road range of 180 km and an off-road range similar to the one of Semovente M43 da 105/25, of about 100 km.

On the Carro Armato M15/42, thanks to the increased space in the engine compartment, the fuel tanks were increased to 367 liters in main tanks, plus 40 liters in the reserve tank. This gave a total of 407 liters. On the M43 chassis, the fighting compartment was 20 cm longer, reducing the space in the engine compartment. In other words, the fuel tanks were shortened, decreasing the volume from 407 liters to 316 liters.

This was also likely due to some changes to the engine. The Carro Armato M15/42 and Semovente M42 chassis mounted the FIAT-SPA 15 TB Modello 1942 petrol engine, while the M42T chassis mounted a FIAT-SPA 15TB Modello 1943. This could be simply a wrong official designation or a 1943 development by FIAT and SPA. The modifications are unknown, but it seems that they did not modify the overall performances of the engine. They probably concerned a decrease of the weight of engine or upgraded engine fire extinguisher system due to the extremely flammable petrol. Modifications to the engine weight are plausible due the extremely modest weight of Semovente M43 da 75/46, 15.6 tonnes battle ready, lighter than the Semovente M43 da 105/25 which did not have the spaced armor.

The engine was connected to a transmission produced by FIAT, with 5 forward and one reverse gears. The transmission was mounted frontally. In order to remove it, the transmission deck’s armored plate had to be removed first.

Image of the FIAT gearbox (produced by SPA) mounted on all Italian armored vehicles starting with the Carro Armato M15/42. It was connected to the transmission shaft. Source: Manuale Uso e Manutenzione Carro Armato M15/42 e Derivati

Due to the increased size of the casemate, the rear bulkhead that divided the engine compartment from the fighting compartment was moved 20 cm back. This increased the space occupied by the engine’s flywheel cover inside the fighting compartment, increasing the heat coming from the engine in the crew’s compartment.

The heat and proximity of fuel tanks near ammunition could be a serious danger in case of fire, but during winters, it warmed up the crew members that had to leave at least an upper hatch opened during fighting to ventilate the fighting compartment.

Suspension and Tracks

The Semovente M43 da 75/46’s suspension was a semi-elliptical leaf spring type, as on all vehicles developed from Italian medium tanks. On each side, there were 4 bogies connected to a leaf-spring with 8 doubled rubber road wheels paired on 2 suspension units in total. This suspension type was obsolete and did not allow the vehicle to reach a high top speed. In addition, it was very vulnerable to enemy fire or mines. Due to the lengthening of the hull on the Semoventi M43, one of the 2 suspension units was mounted a few centimeters back.

The tank had 26 cm wide tracks with 86 track links per side, 6 more than the other tanks of the ‘M’ series due to the hull lengthening.

One of the 2 suspension units of a Semovente M41M da 90/53. Each suspension unit was composed of 4 rubber road wheels divided in 2 suspension arms. Source: flikr.com @Chris Streckfus

The drive sprocket wheels were at the front and the idlers, with modified track tension adjusters, at the back, with 3 rubber return rollers on each side. The small surface area of the tracks (about 14,750 cm²) gave a ground pressure of about 1 kg/cm², increasing risk that the vehicle would bog down in soft soils, such as mud or snow.

In a photo taken in 1944 outside the Ansaldo-Fossati plant production line, there were a Semovente M43 da 75/46 and M43 da 105/25 for comparison. The Semovente da 75/46 was equipped with Ostketten (English: Eastern Chains) on the right track. These were probably delivered by the Germans for tests. They were meant to increase surface in contact with the ground and to decrease overall pressure on the ground. Apart from this photo, no other photographic evidence suggests the use of Ostketten on Italian captured armored vehicles.

The Semovente M43 da 75/46 prototype (left) next to a Semovente M43 da 105/25 without side skirts (right). Apart from the main armament and added armor plates, the vehicles were externally identical. The Semovente M43 da 75/46 had the right track equipped with German Ostketten. Source: militaryimages.net

Like the Semovente M43 da 105/35, the M43 da 75/46 was equipped with a side skirt. These were only 4 mm thick and partially protected the sides of the vehicle. Their role was not to protect the semovente from anti-tank rifle rounds or shaped charges ammunition, but to prevent shrapnel from damaging the suspension units and track links. The side skirts had a cut in the back to allow crew to be able to reach the track tension adjuster without dismounting the skirt. Another 3 small holes were made to add lubricant to the return rollers without losing time by removing the side skirt.

Main Armament

The Semovente M43 da 75/46’s main armament was the Cannone da 75/46 Contraerei Modello 1934, an Italian anti-aircraft cannon developed by Ansaldo in 1932 that entered service in 1934. It appeared after an Italian Regio Esercito’s High Command request for a new anti-aircraft cannon in 1929.

Ansaldo and Odero-Terni-Orlando (OTO) not only developed some guns but also tested foreign ones, such as the 80 mm luftvärnskanon m/29 anti-aircraft gun produced by Swedish Bofors. The Bofors gun inspired the Ansaldo design office, which presented the Cannone da 75/46 Contraerei in 1932.

Drawing of the Cannone da 75/46 Contraerei Modello 1934. Source: fondazioneansaldo.com

During trials, the Direzione Superiore del Servizio Tecnico Armi e Munizioni or DSSTAM (English: Higher Directorate of Technical Service Weapons and Ammunition), the branch of the Regio Esercito’s High Command which created artillery design requests and accepted them into service, helped Ansaldo to modify the cannon. This was done to such an extent that some sources even called the cannon the DSTAM-Ansaldo. In 1933, the gun was ready (even if it was only accepted into service in 1934), and the Regio Esercito ordered 100. Ninety-two were delivered by October 1939, while another 240 were to be built in 1940.

A Cannone da 75/46 Cotraerei Modello 1934 in North Africa in November 1940. Source: Istituto Luce via italie1935-45.com

At the start, only the Ansaldo Pozzuoli plant (specialized in artillery production) and the Stabilimento Artiglierie di Cornigliano (English: Artillery Plant of Cornigliano), which was under Ansaldo’s control, produced the cannon. A total of 232 pieces were delivered between 1941 and 1942, while another 4 were delivered in the first 4 months of 1943, together with 108 spare barrels.

OTO and Arsenale Regio Esercito di Piacenza or AREP (English: Royal Army Arsenal of Piacenza) also produced spare parts. OTO delivered a total of 120 cannons by December 1942. The last order of the Regio Esercito’s High Command for 472 Cannoni da 75/46 Contraerei Modello 1934 to be delivered by the end of 1943 was never started due to the Armistice of 8th September.

The Cannone da 75/46 Contraerei of the first batch at the Stabilimento Artiglierie di Cornigliano. Source: fondazioneansaldo.com

When the cannon appeared in the mid-1930s, it was a great artillery piece. It had high initial muzzle velocity due to the use of powerful propellant and barrel length, sustained rate of fire, and large firing arcs thanks to a cross-platform. The gun’s breech had a system to switch between being manually-opened or semiautomatic, with a maximum rate of fire of 15 rounds per minute with a trained crew. Its muzzle velocity was 800 m/s and maximum range was 8,500 m in the anti-aircraft role and 13,000 m against ground targets. The traverse was 360° while the elevation was from 0° to 90°.

Two Cannoni da 75/46 Cotraerei Modello 1934M towed by Pavesi P4 prime movers at the Nettuno shooting range. Source: Ufficio Storico dello Stato Maggiore dell’Esercito via italie1935-45.com
A Cannone da 75/46 Contraerei Modello 1934 with a rangefinder telemeter and Centrale di Tiro Modello 1937 ‘Gala’ deployed by artillerymen of the Nettuno Anti-Aircraft Artillery School. Source: Giuseppe Calò via italie1935-45.com

In July 1943, there were 31 batterie antiaeree da 75/46 (English: 75 mm L/46 anti-aircraft batteries) operational. The Cannone da 75/46 Contraerei Modello 1934 was deployed on all fronts of the war, in the Modello 1934 version, Modello 1934M version (slightly modified), and Modello 1940 static defense version. The majority of the batteries were sent to North Africa. In the Soviet Union, the few groups sent gave great results in the anti-tank role against early variants of Soviet T-34 medium tanks.

A Cannone da 75/46 Contraerei Modello 1934 of the Regio Esercito in the Soviet Union during the winter of 1942-43. Source: Ufficio Storico dello Stato Maggiore dell’Esercito via italie1935-45.com

Although it was a marked improvement over the 75 mm guns of the First World War and it had cutting edge characteristics for the 1930s, the Cannone da 75/46 Contraerei Modello 1934 showed some weaknesses during its use. Rapid wear and tear of cannon’s bore caused its muzzle velocity to drop from 800 m/s to 750 m/s. The Cannone da 75/46 Contraerei Modello 1934 was quickly superseded as a positional piece for territorial anti-aircraft defense as the war continued. It was therefore time to switch to a more powerful weapon, the Cannone da 90/53 Modello 1939.

After the Armistice of 8th September 1943, the anti-aircraft gun was deployed by the Germans, who renamed it 7,5 cm Flugabwehrkanone 264/3 (italienisch) (English: 75 mm Aircraft-Defense Cannon coded 264/3 [italian]) and continued its production. Even the Esercito Nazionale Repubblicano (English: National Republican Army), the Italian Army allied to the Germans, equipped a pair of anti-aircraft units with this cannon. Some guns were also deployed by Italian soldiers in the Allied armies in order to defend Southern Italy from Axis air attacks.

A Cannone da 75/46 Contraerei Modello 1934 of an Italian AA unit during deployment maneuvers after the Armistice. Source: Giuseppe Calò via italie1935-45.com

The Cannone da 75/46 mounted on the semovente was called Kampfwagenkanone 75/46 (English: 75 mm L/46 Tank Cannon) by the Germans. On the semovente mount, the Cannone da 75/46 had an elevation of -10° to +18° and traverse was 17° to either side. The traverse decreased compared to the Semoventi M42M da 75/34 and M43 da 105/25 of 18° due to the presence of new spaced plates.

Semovente M43 da 75/46 sight. Per Alzo da 75/46 Semovente can be read on it. Source: heroesandgeneral.com

The barrel weighed 686 kg, while the gun mounted on the spherical support of the semoventi weighed 810 kg according to German reports. An interesting feature was that the vehicle had the possibility of also being equipped with the Cannone da 105/25 Modello SF just by removing the 75 mm cannon and spherical support with a winch and changing the main gun’s ammunition racks. The difference between the Cannone da 75/46 and Cannone da 105/25 was that the latter weighed just 40 kg more.

The Semoventi M42L armed with the Cannone da 105/25 weighed more than the Semoventi M42T with spaced armor and Cannone da 75/46. This was largely due to weight of 105 mm ammunition. In other words, if the Semovente M43 da 75/46 was equipped with the Cannone da 105/25, its weight would have increased by several hundred kilograms.


 
Rare images of a rare Semovente M42T da 105/25. It was a Cannone da 105/25 mounted on the chassis of a Semovente M43 da 75/46. Source: pinterest.com @lucky01

The Cannone da 105/25 Modello S.F. was developed by Ansaldo and produced by the Stabilimento Artiglierie di Cornigliano. It was developed on the basis of the Obice da 105/23 Modello 1942 a howitzer developed by Ansaldo as a prototype for divisional artillery, together with the Cannone da 105/40 Modello 1943. Due to delays and high costs, only the Cannone da 105/40 Modello 1943 was accepted in service, however it was only adopted from May 1943 and saw limited use. The the tank version of the Obice da 105/23 Modello 1942 was adopted on the Semovente M43 da 105/25 and, after the war, also used in Italian fortifications on the Italo-Yugoslavian border.

The Cannone da 105/25 Modello SF at the Stabilimento Artiglierie di Cornigliano. Source: fondazioneansaldo.com

Inside the semoventi, the Cannone da 105/25 Modello SF had a horizontal traverse of 18° to either side, as well as a depression of -10° and an elevation of +18°. Traverse probably decreased on the Semoventi M42T due to the spaced armor, like the horizontal traverse of other cannons mounted on the same chassis.

The Cannone da 105/25 Modello SF fired the same ammunition as the Cannone da 105/28 Modello 1916, with a maximum muzzle velocity of 500 m/s with armor-piercing rounds. It was capable of piercing a Rolled Homogeneous Armor (RHA) plate of 80 mm at 1,000 m according to German reports.

The Main Gun’s Problems

The Germans proposed to modify the Cannone da 75/46 Contraerei Modello 1934, or as they called it, the 7,5 cm Fliegerabwehrkanone 264/3(i). It is unknown if they finally ordered a modification to the cannons, as planned in December 1943. The really slow production rate of the Cannoni da 75/46 for the Semoventi M43 da 75/46 could be explained by a long and difficult breech modification made in order to permit Panzerabwehrkanone 40 or PaK 40 ammunition to be fired.

The PaK 40 rounds had a length of 714 mm (75 x 714 mm R), while the Cannone da 75/46 Contraerei Modello 1934 round’s cartridge had a length of 580 mm (75 x 580 mm R). In order to fire PaK 40 rounds, Ansaldo had to modify the chamber, if necessary also modify the inner face of the bolt, the extractor, and probably also reinforce the breech and powder chamber if the pressures resulting from firing the PaK 40 ammunition exceed those tolerated by the Cannone da 75/46.

A partially assembled Cannone da 75/46 Contraerei Modello 1934 at the Stabilimento Artiglierie di Cornigliano in 1938. Source: fondazioneansaldo.com

However, the slow rate of delivery of Italian cannons could also be explained by other hypotheses. The first one could be the slow production of spherical supports used to mount the cannons on the semoventi chassis. This does seem an unsatisfactory explanation. In fact, the Italian industry, albeit always failing in the delivery of self-propelled gun spherical supports in large quantities, could probably have fulfilled a request for so few 75 mm cannon mounts.

An image showing off some Semoventi M43 da 105/25 lined up in an Ansaldo-Fossati depot, ready to be delivered. Even if this photo dates before the Armistice, it shows that, even if the Italian industry sometimes failed in the delivery of self-propelled gun spherical mounts, it had an average monthly production that matched the production of the hulls produced in one month by Ansaldo-Fossati with guns from the Stabilimento Artiglierie di Cornigliano. Source: associazioneansaldo.com

The last hypothesis that could explain the low delivery rate of the Cannone da 75/46 is the really low production rate of Cannone da 75/46 Contraerei Modello 1934. It was produced in Piacenza, Pozzuoli, and Stabilimento Artiglierie di Cornigliano, under Ansaldo’s control. After the Armistice of 1943, Pozzuoli was freed by Allied forces in late September, while Arsenale Regio Esercito di Piacenza was converted mainly for vehicle reparation and production of armored improvised vehicles. The artillery production decreased. This meant that the majority of Cannoni da 75/46 production was the responsibility of the Stabilimento Artiglierie di Cornigliano, which remained one of the few Italian artillery producers until 1945.

Main Gun Considerations

The Germans and Ansaldo probably decided to mount the Cannone da 75/46 on the Semovente M42T due to its better anti-tank performance compared to other Italian guns at their disposal.

The choice of mounting a modified anti-aircraft gun proved to be a poor choice for the Germans and it cost them a very low production rate, especially compared to the production rate of Semoventi M42L da 105/25 and Semoventi M42T da 75/34, other last ones produced on the same chassis.

In order to increase the production of better armed Semoventi M42T, the mounting on the Semoventi M42T chassis of the German Panzerabwehrkanone 40 could have been an alternative option. The weight of the vehicle would not have increased by much, as the 7.5 cm KwK40 weighed 750 kg, compared to the 686 kg of the Cannone da 75/46.

Before the Armistice, Italy and Germany signed a contract for the license production of the field version of the PaK 40 in Italy (Italian nomenclature Cannone da 75/43 Modello 1940). The production was not started before September 1943, but some production lines were assembled. It is not known why the Germans did not restart the project earlier instead of adopting the Cannone da 75/46. It would probably have been easier to start delivering German-produced PaK 40 in Italy and then make Italian industry autonomous instead of modifying the Italian anti-aircraft cannon’s production line. After the armistice, OTO produced some spare parts for the PaK 40 for the Germans until the late war.

How the Semovente M43 armed with PaK 40 anti-tank cannon could have looked like. Source: drawingdatabase.com and the-blueprints.com with author modification

Secondary Armament

Secondary armament consisted of a Mitragliatrice Media Breda Modello 1938 (English: Breda Medium Machine Gun Model 1938) produced by Società Italiana Ernesto Breda per Costruzioni Meccaniche (English: Italian Ernesto Breda’s Company for Mechanical Constructions). It was derived from the Mitragliatrice Media Breda Modello 1937, the most modern Italian medium machine gun during the war.

A Mitragliatrice Media Breda Modello 1938 on a Semovente M41 da 75/18 on an earlier anti-aircraft support. Source: pinterest.com

Breda Modello 1938 was its vehicle version, with a shorter and heavier barrel, pistol grip, and top-mounted curved magazine with a capacity of 24 rounds. These modifications were made to ease the use of the machine gun inside vehicles. Breda machine guns fired a particular cartridge developed by Breda especially for machine guns, the 8 x 59 mm RB with a muzzle velocity between 790 m/s and 800 m/s, depending on the round type.

Mitragliatrice Media Breda Modello 1938 with top-curved magazine without anti-aircraft sight. When not in use, it was stored in the left sponson of the self-propelled gun. Source: dandbmilitaria.com

The machine gun was fixed on an anti-aircraft mount attached to a crowbar that offered an increased horizontal traverse for the machine gun in case of an aerial attack. The anti-aircraft supports mounted on the previous model of Italian self-propelled guns barely covered the frontal arc of the vehicles. A similar feature was made on Beute Sturmgeschütz L6 mit 47/32 770(i) (Semovente L40 da 47/32), on which the Germans added a crowbar support for a machine gun to increase the horizontal traverse of the machine gun.

Semovente M43 da 75/46 with a new anti-aircraft support for the Mitragliatrice Media Breda Modello 1938. The vehicle is also equipped with 20 liter can supports on the sides and steel helmet supports for the crew member’s helmets. This particular vehicle was probably the prototype brought to production series status. In fact, this vehicle had the cannon barrel’s counterweight, which was mounted only on the prototype. Source: wikipedia.org

During the German occupation of Northern Italy, the Mitragliatrici Medie Breda Modello 1938 were rechambered for German 7.92 x 57 mm Mauser cartridges, due to the similar dimensions of the bullets: 82.00 mm for the German compared to the 80.44 mm of the Italian cartridge and casing diameter of 11.95 mm compared to the 11.92 of the Italian casings. The 24-round magazine and wooden ammunition racks were left unchanged.

Beginning in 1942, Italian factories started to produce a licensed copy of the German Nebelkerzenabwurfvorrichtung or NKAV (English: Smoke Grenade Dropping Device). It was a smoke grenade system that, through a wire connected to a camshaft, dropped a smoke grenade to the ground. Total capacity was 5 Schnellnebelkerze 39 (English: Quick Smoke Grenade 39) smoke grenades. The grenades had a length of 140 mm, a diameter of 90 mm, and a weight of 1.8 kg. They had a burning time of 4 to 7 minutes, depending on wind and in which area the SPG released the smoke grenades.

The commander had to pull the wire and the camshaft rotated, dropping a smoke grenade.
This system was mounted on the rear of the vehicle, so the smoke screen was created behind the vehicle and not around it, on the front arc.

An unarmored Nebelkerzenabwurfvorrichtung dismounted from a vehicle. Source: Bundesarchiv

The Germans began to stop using this system in 1942 in favor of smoke grenade launchers on the turret, because the grenades fell at the back and the tank had to reverse to hide behind. The Italians, on the other hand, apparently gave no thought to this problem and adopted it in 1942.

A Semovente M43 da 105/25 equipped with Nebelkerzenabwurfvorrichtung mit Schutzmantel (where the Balkenkreuz was painted). Even if they were differently armed and protected, the M43 da 105/25 was similar to the M43 da 75/46. Source: beutepanzer.ru

It seems that the Italians copied the protected variant, called Nebelkerzenabwurfvorrichtung mit Schutzmantel (English: Smoke Grenades Dropping Device with Protective Sheath). It had a rectangular protection, even if the Italian and German protections seem different. It is not known if the Italians also produced the Schnellnebelkerze 39 smoke grenades under license or if the Italian vehicles used the grenades imported from Germany. This smoke system was quickly adopted on all the Italian armored tracked vehicles starting from the Carro Armato M15/42 and on all the semoventi on its chassis. A smaller version appeared even on the Autoblinde AB41 and AB43 medium reconnaissance armored cars.

A cylindrical support for spare smoke grenades was also transported on the vehicle. It was fixed on the rear side of the armored superstructure, behind the engine’s cooling grilles and could transport 5 more smoke grenades.

A Semovente M43 da 75/46 during training. This is the only image of the semovente showing off its rear side. The Nebelkerzenabwurfvorrichtung mit Schutzmantel (red) and the cylindrical support for spare smoke grenades (green) are visible. Source: instagram.com @forza_italiana with highlights by author

Ammunition

Ammunition for the Cannone da 75/46 Contraerei Modello 1934 transported on the vehicle was stored in 2 racks, totalling 42 rounds. One was on the left side of the floor of the fighting compartment and the second one on the floor of the right side of the fighting compartment. The left one was used by the loader as a seat, while the right one was behind the gunner and was openable from the top.

The left rack had the rounds stored in 2 5-round rows and 2 6-round rows for a total of 22 rounds, while the second rack had 2 4-round rows and 2 5-round rows, for a total of 18 rounds.

Cannone da 75/46 Contraerei Modello 1934 Rounds
Name Type Muzzle Velocity Fuze Filler Weight Penetration (RHA angled 30° from vertical)
Perforante da 75/46 APCBC ~ 800 m/s Percussion Model 1909 // 6.2/6.9 kg 70 mm at 500 m
55 mm at 1,500 m
Dirompente da 75/46 HE ? Percussion I.O. 36/40 335 – 345 g of TNT ~ 6.3/6.5 kg //
Notes The gun could fire other three different types of rounds, but these were anti-aircraft rounds not adopted on the Semovente
Cannone da 75/46 Contraerei Modello 1934 anti-aircraft round. Image taken at Cornigliano Artillery Plant. Source: fondazioneansaldo.com

Compared to other semoventi racks, these were under the level of the vehicle’s sponsons and were difficult to hit by enemy rounds that pierced the vehicle’s armor. This problem caused many Semoventi M42M da 75/34 or Semoventi M43 da 105/25 to blow up after penetration.

If the Cannoni da 75/46 Contraerei Modello 1934 were really modified to fire the same ammunition as the PaK 40, it would probably fire all German ammunition for this type of gun.

Ammunition fired by the 7.5 cm Panzerabwehrkanone 40
Name Type Muzzle Velocity Weight Penetration (RHA angled 30° from vertical)
Panzergranate 1939 (PzGr. 39) APCBC-HE-T 790 m/s 6.80 kg 108 mm at 100 m; 80 mm at 1,000 m
Panzergranate 1940 (PzGr. 40) APCR 990 m/s 4.50 kg 143 mm at 100 m; 97 mm at 1,000 m
Sprenggranate 1934 (SprGr. 34) HE 550 m/s 5.64 kg N/A
Hohlladung pattern C grenades. (Gr.38 HL/C) HEAT 450 m/s 4.57 kg 75 mm

Crew

The Semovente M43 da 75/46 had a crew of 3. The driver was positioned on the left of the fighting compartment. On his left was the dashboard and on his right was the gun breech. The commander/gunner was positioned on the right of the vehicle, on the left side of the breech, while the loader/radio operator was sat on the left, behind the driver.

Some German sources state that the Germans preferred to add a fourth crew member behind the gunner, who would load the gun. The loader’s seat would be occupied by the commander/radio operator and the gunner would perform only one function. Obviously, adding a fourth crew member meant reducing the space inside the cramped fighting compartment, which was already cramped with only 3 crew members.

A Beute Sturmgeschütz M43 mit 10,5 cm KwK L/25 853(i) crew posing in front of their vehicle in an Italian depot. Source: beutepanzer.ru

Very little is known about the Semovente M43 da 75/46’s service. Due to their short service, there are no reports about the operational service or German crews opinions.

Major German complaints on other Italian semoventi were about their lack of proper observation sights, insufficient frontal armor, a cramped crew compartment, and (apart from the Semovente M43 da 105/25) main armament not capable of dealing with the most modern enemy tanks. The driving capabilities were never seriously complained about while, whereas for maintenance, complaints depended on a number of factors. If the German unit that deployed Italian semoventi had veteran Italian mechanics or was located in Italy, where Italian military workshops were present, the complaints were much lesser compared to German units that deployed them outside Italy, where the experienced Italian mechanics were few, and there was a general lack of Italian spare parts.

With the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i), in all likelihood, the insufficient armor and main armament’s anti-tank performance complaints were solved.

Operational Use

Not much is known about the Semoventi M43 da 75/46’s service in German hands. Neither Italian nor German sources mention to which German Panzerjäger-Abteilung (English: Tank Destroyer Battalion) the few vehicles produced were assigned to.

The prototype was assigned to a training school in northern Italy that trained German Panzerjäger and German-equipped Italian tank destroyer squads. Infantrymen were also trained to attack enemy tanks and self-propelled guns with anti-tank improvised devices, mines, anti-tank hand grenades, and rocket launchers. Unfortunately, the name of the German training unit is unknown.


 
A Semovente M43 da 75/46 deployed by the Germans to train a Panzerjäger unit in Italy. From the first image, it can be assumed that the vehicle was the prototype due the gun’s counterweight on the barrel’s muzzle. Source: instagram.com @forza_italiana

Some guesses can be made as to which German units used the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i). The 26. Panzer-Division (English: 26th Armored Division), which operated Italian self-propelled guns, created the Jägdpanzer-Abteilung 51 on 17th November 1944. The personnel of the new battalion consisted of veterans from Panzer-Regiment .26 (English: 26th Tank Regiment) and some Sd.Kfz.164 Nashorns from the Schwere Panzerjäger-Abteilung 525 (English: 525th Heavy Tank Destroyer Battalion) were used to equip the 1. Kompagnie (English: 1st Company).

The heavy anti-tank gun platoons of the Panzergrenadier-Regiment 9. and Panzergrenadier-Regiment 67. (English: 9th and 67th Mechanized Infantry Regiments) were used to form the 3. Kompagnie (English: 3rd Company). In November 1944, the unit was operational without the 2. Kompagnie (English: 2nd Company), which was deployed only in January 1945. Some vehicles of the 2. Kompagnie may have been Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i). The 26. Panzer-Division surrendered to the Allied forces in early May 1945 in the Vicenza area, about 200 km east of Parma.

The only unit that for certain deployed the Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) was the 148. Infanterie-Division (English: 148th Infantry Division) that was deployed in Italy after mid-September 1944. On 1st October 1944, it had in its ranks 6 mechanized infantry battalions supported by the 13. Kanonen-Kompanie (English: 13th Cannon Company) and 14. Schwere-Kanonen-Kompanie (English: 14th Heavy Cannon Company). These 6 battalions and 3 companies were divided in 3 regiments: Grenadier-Regiment 281., Grenadier-Regiment 285., and Grenadier-Regiment 286..

The Artillerie-Regiment 1048. (English: 1048th Artillery Regiment) deployed a total of 3 105 mm howitzers groups and 1 150 mm heavy howitzer group with 3 batteries each. It also had Füsilier-Battalion 148. (English: 148th Rifle Battalion), with 4 squadrons, together with many other logistic units, such as the Pioneer-Battalion 1048. (English: 1048th Engineer Battalion) and the Veterinär-Kompanie 148. (English: 148th Veterinary Company). In fact, only 30% of the division was mechanized, the rest of the logistics were towed by horses.

A Semovente M43 da 75/46 captured by the Brazilian troops of the 1st Infantry Regiment “Sampaio” of the Brazilian Expeditionary Force. It was captured in Caorso, near Piacenza in the last days of war. In this image, the right opened split-hatch is visible. It seems to be damaged on the side skirt sections and appliqué side armored plate, but these seem to be more like transport damage than fighting damage. Source: Italian Tanks and Combat Vehicles of World War II

On 3rd December 1944, the Panzerjäger-Abteilung 1048 (English: 1048th Anti-Tank Battalion) was created, composed of Panzerabwehrkanone-Batterie 1. or PaK-Batterie 1. (English: 1st Anti-Tank Battery) with anti-tank cannons, Schwere-Panzerabwehrkanone-Batterie 2. or Schwere-PaK-Batterie 2. (English: 2nd Heavy Anti-Tank Battery) equipped with 8,8 cm PaK 43 anti-tank cannons. On 19th December 1944, it received a platoon of the Festungs-Pantherturm 2. (English: 2nd Fixed Panther Tank Turrets) and then, on 28th December, it also received 6 half-track-mounted 88 mm cannons, quite surely the surviving 8.8 cm Flak 37 (Selbstfahrlafette) auf Schwere Zugkraftwagen 18t (Sd.Kfz.9) (English: 8.8 cm FlaK 18 [Self-Propelled Gun Carriage] on [Sd.Kfz.9] Heavy Traction Vehicle 18 tonnes) formerly belonging to the 26. Panzer-Division that operated in the same areas.

The last company assigned to the Panzerjäger-Abteilung 1048 was the FlaK Kompanie 3. (English: 3rd Anti-Aircraft Cannon Company). After March 1945, the Schwere PaK Batterie 2. was equipped with, as referred to by the original document, 11 7.5 cm Sturmgeschütze. These were in all likelihood of Italian origin, as also claimed by Italian historian Leonardo Sandri in La 148^ Infantrie Division sul Fronte Italiano 1944-1945: Una Documentazione. Eleven of these Beute StuGs is equal to the total production of the entire Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) until January 1945, so it is impossible that all the vehicles were Semoventi M43 da 75/46, some could have been Semoventi M43 da 75/34 or their pre-Armistice version, the Semoventi M42M da 75/34. It could also be a document error. In fact, in many cases, the official German documents referred to “in service” vehicles whilst, in reality, they had not yet been delivered to the unit. In March 1945, the 11 Sturmgeschütz had almost certainly already left the factory but they were still on their way to Panzerjäger-Abteilung 1048.

The Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) probably arrived at the German anti-tank unit between mid-March to early April 1945. They had a really short operative life with the German soldiers.

A Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i) was captured by the soldiers of the 1st Infantry Regiment “Sampaio” of the Força Expedicionária Brasileira or FEB (English: Brazilian Expeditionary Force) in Caorso, 60 km from Parma.

The history behind the capture of this particular vehicle is not clear. It was probably abandoned by Panzerjäger-Abteilung 1048 due to a lack of fuel or mechanical breakdown during the retreat from Bologna, trying to reach the southern shore of the River Po to cross it in the Piacenza area and try to reach northern Italian border to return home before the surrender of the entire 148. Infanterie Division. Another plausible hypothesis was that it was surrendered peacefully by the German soldiers of the Panzerjäger-Abteilung 1048 after various failed attempts at opening a gap in the US and Brazilian encirclement in the Parma and Piacenza areas between 28th April and the morning of 29th April. The unit transferred over 600 wounded Axis soldiers between 13:00 and 14:30 on 21 ambulances to the Mantova Allied hospital and then surrendered to the Allied forces on the afternoon of 29th April 1945.

About 80 pieces of equipment, including 7,5 cm PaK 40, mortars, 105 mm and 150 mm artillery pieces, 8.8 cm half-track-mounted artillery pieces, and Sturmgeschütz, were captured. Together with these, the US and Brazilian forces captured 4,000 horses, 2,500 motor vehicles (trucks, staff cars, cargo half-tracks etc), 1,000 motorcycles, and between 13,579 and 14,779 Axis soldiers.

The only other operational service of the Semovente M43 da 75/46 was in Milan on 25th April 1945. One was captured by the Italian Partisans, probably at the Fonderia Milanese di Acciaio Vanzetti S.A. assembly plant, left abandoned by the German soldiers. This suggests that not all the semoventi in the Vanzetti plant were delivered to the German units.

The Semovente M43 da 75/46 captured in Milan by the Italian Partisans in late April 1945. Source: italiantanktree.files.wordpress.com

The Semovente M43 da 75/46 captured in Milan was ‘graffitied’ by the Partisans, with “W la Libertà” (English: Long Live Freedom) and the acronym “C.L.N.” or Comitato di Liberazione Nazionale (English: National Liberation Committee) written on to avoid friendly fire. It probably had no ammunition and no secondary armament. The Partisans added a 7.7 mm Breda-SAFAT medium machine gun on the roof. It was probably delivered to the Allies after the war ended and scrapped.

Camouflage

The Semoventi M43 da 75/46 produced for the Germans were painted with a single camouflage scheme. It was similar to the Italian Continentale (English: Continental) adopted in mid-1943. The standard Kaki Sahariano (English: Saharan Khaki) monochrome sand camouflage was covered by reddish brown and dark green spots.

Continentale camouflage adopted by the Regio Esercito before the Armistice of 8th September 1943. Source: instagram.com @Forza_Italiana colourized by Johannes Dorn

The Regio Esercito’s Continentale camouflage scheme was upgraded, covering the Italian armored cars, medium tanks, and self-propelled guns with dark green and adding on them reddish brown spots and sand yellow stripes that bordered the reddish brown and dark green spots.

The Semovente M43 da 75/46’s prototype outside the Ansaldo-Fossati plant. In this image, colorized by Johannes Dorn, the 1944 Continentale camouflage is clearly visible. Source: wikipedia.org

As the Semoventi M43 da 75/34 received only this type of 3-tone camouflage, it never received Italian-style camouflage schemes. The prototype, probably assigned to a training school in northern Italy, received the Balkenkreuz, the German tanks’ coat of arms, for identification on the sides and rear, and the number “22” painted on the sides. The other vehicles seem to have been without coats of arms. This was also caused, in all likelihood, by the delivery of the semoventi in the last months of 1944 and early 1945, when German troops were in a shortage of trained crews, fuel, ammunition, and paint and did not waste time painting reconnaissance coat of arms or the unit’s own coats of arms.

Versions

Semovente M43 da 75/34

In 1944, a total of 29 Semoventi M43 da 75/34 were produced for the Germans on the same upgraded and uparmored Semovente M43 da 75/46 chassis. It was essentially a Semovente M43 da 75/46 armed with a shorter and less powerful Cannone da 75/34 Modello SF, already mounted on the Semovente M42M da 75/34. All the rest of the vehicle remained unchanged compared to the Semovente da 75/46.

A Semovente M43 da 75/34 in service with a German unit supporting Italian soldiers of the 1ª Divisione Bersaglieri ‘Italia’ in the Garfagnana area in winter 1944. Source: wikipedia.org

The Semoventi M43 da 75/34, known by the Germans as Beute Sturmgeschütz M43 mit 7,5 cm KwK L/34 851(i), were employed only by the Germans in Italy after late 1944. They supported an unknown German Panzerjäger-Abteilung in the Gothic Line, occasionally operating with Fascist soldiers loyal to Mussolini belonging to the 1ª Divisione Bersaglieri ‘Italia’ (English: 1st Bersaglieri Division).

Many sources place the total number of Semoventi M42M da 75/34 at 174 instead of 145. This is not correct, as the first number also counts the 29 Semoventi M43 da 75/34.

A Semovente M42T chassis was armed with a Cannone da 105/25 Modello SF and tested by the Germans but nothing is known about its fate after the German tests.

Conclusion

The Semovente M43 da 75/46 was the first Italian project that had offensive and defensive characteristics that made it capable of dealing with most of the Allied armored vehicles in the Second World War. This was mainly thanks to the German effort to upgrade some Italian vehicles.

The few vehicles produced and equipped with main guns had short operational lifes and not much is known about their service or their crew’s complaints.

The low delivery rate of the main armament provided by the Cornigliano artillery plant was the greatest problem causing the slow production rate. This forced the Germans to place the finished vehicles in depots awaiting for their main guns, which were delivered with a rate of 1 or 2 per month.

The low gun production rate was not the only criticism of the self-propelled gun. In the same period, the Germans also produced the Semovente M43 da 75/34 with a shorter and less powerful cannon as a stopgap while waiting for the ones armed with 75 mm L/46 guns.
Twenty-nine were built, and while more than those equipped with the 75/46 gun, this was insufficient to even put a dent in the thousands of armored vehicles of the Allied armies.

This low production rate, that was characteristic of the Italian industry during the Second World War, became more pronounced in the last stages of the war due to the scarcity of raw materials, Allied bombardments, and worker’s strikes.

Semovente M43 da 75/46. Illustrations by Godzilla funded by our Patreon Campaign.

Semovente M43 da 75/46 Specification

Size (L-W-H) 5.97 x 2.42 x 1.74 m
Weight, battle ready 15.6 tonnes
Crew 3 (commander/gunner, driver, loader/radio operator)
Engine FIAT-SPA 15TB petrol, 190 hp at 2,400 rpm
Speed 38 km/h
Range 180 km
Armament 1 Cannone da 75/46 Contraerei Modello 1934 with 42 rounds, 1 Mitragliatrice Media Breda Modello 1938 with 504 rounds.
Armor 75 mm + 25 mm front, 45 mm + 25 mm sides and 45 mm rear
Production 1 prototype and 12 vehicles produced

Sources

Gli Autoveicoli da Combattimento dell’Esercito Italiano, Volume Secondo, Tomo II – Nicola Pignato and Filippo Cappellano – Ufficio Storico dello Stato Maggiore dell’Esercito – 2002

Italian Medium Tanks 1939-45; New Vanguard Book 195 – Filippo Cappellani and Pier Paolo Battistelli – Osprey Publishing, 20th December 2012

Carro M – Carri Medi M11/39, M13/40, M14/41, M15/42, Semoventi ed Altri Derivati Volume Primo and Secondo – Antonio Tallillo, Andrea Tallillo and Daniele Guglielmi – Gruppo Modellistico Trentino di Studio e Ricerca Storica, 2012

Panzer tracts No. 19-2 Beute Panzerkampfwagen, British, American, Russian and Italian Tanks Captured from 1940 to 1945 – Thomas L. Jentz and Warner Regenberg – Panzer Tracts – 2008

Andare contro i carri armati. L’evoluzione della difesa controcarro nell’esercito italiano dal 1918 al 1945 – Nicola Pignato e Filippo Cappellano – Udine 2008

Italian Tanks and Combat Vehicles of World War II – Ralph A. Riccio – Mattioli 1885 – 2010

La 148^ Infantrie Division sul Fronte Italiano 1944-1945: Una Documentazione – Leonardo Sandri – published by himself – Milan 2021

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2 replies on “Semovente M43 da 75/46 / Beute Sturmgeschütz M43 mit 7.5 cm KwK L/46 852(i)”

I already commented about this in the page of the M43 105/25, but since this page already hints about the gun issue, I’ll comment here too.
A source by an extremely respected author, Filippo Cappellano’s “Le Artiglierie del Regio Esercito nella Seconda Guerra Mondiale”, Italy, Storia Militare, 1998 (page 265), states that the OTO produced some german 75/46 PaK 40 to be installed on Semoventi M43, as you briefly talk about here.
As you guys wrote, the Regio Esercito adopted the PaK gun in june 1943, exchanging some parts produced by Ansaldo and OTO for complete guns imported by Germany (at least 24, plus some others donated in various fronts; same source as before), with the plan to begin as soon as possible a production under license; needless to say all was stopped by the Armistice in september 1943. However this source states that some guns modified for tank use were produced after the Armistice and mounted on M43 chassis.
Even the game War Thunder follows this clue, having the M43 75/46 use the same gun and ammunitions as the Marder III H; but we all know, and this site more than anyone, that sometimes games can be deceiving and superficial, but it could be interesting to know how they arrived to their conclusion.
In any case Cappellano is a very reliable and renowned author when it comes to historical italian armoured vehicles and artillery; my resources are limited and so I hoped you guys could solve this doubt for this relatively obscure vehicle.
If it could be of help I will gladly send a screen of said pages, but all in italian.

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