In December 1937 the Regio Esercito (Royal Italian Army) authorized the design for the M 13/40. It was to be based upon the M 11/39. Ansaldo delivered the first prototype in October 1939. However, it wasn't accepted until March 1940.
General Caracciolo di Feroleto (head of Inspectorate of Technical Services) supervised the design. Fifteen prototypes were ready by July 1940. Similar chassis to M11/39 but was riveted. Was built from armored plates bolted to a steel frame. The armor had a tendency to crack when hit. After about 150 tanks being produced it had a radio installed and the long mudguards were cut back. In action proved to be unreliable and prone to catching fire.
This was the most widely used tank by the Italians.
Had a radio installed. These were fitted to later production vehicles.
In 1940 Italian crews were given 25 days of training with two hour of driving before going into combat.
The front of the hull was rounded. There was a towing hook placed in the rear, and there were towing pintles in the front and rear.
The driver was located at the front and to the left in the M13/40. The machine gunner was to his right and he also operated the radios.
The turret contained the commander, on the right side, and the loader, on the left side, which was located in the center.
The turret gun slots were open. There was a telescopic gun sight mounted in the turret. The 47 mm gun could be fired by manual or pedal firing. There was a hydraulic system for traversing the turret, with a manual backup. On the turret roof were two periscopes. On each side of the turret were oval pistol ports. The prototype had a pistol port in the rear of the turret, but this was eliminated in the production version. The hatch on the roof was in two pieces.
Some crews removed the power traverse system as it was viewed as unnecessary and took up valuable space.
On each side of the hull superstructure were two circular pistol ports, and in the rear of the superstructure were two more pistol ports.
The suspension was made of four sets of double wheels that were articulated bogies that were then mounted by two assemblies which had semi elliptic leaf springs. The drive sprocket was at the front, the idler at the rear, and three return rollers.
Two 8 mm MGs were in a gimbal mount on the right side of the superstructure.
The 47 mm gun had a muzzle velocity of 2,060 ft/sec. It shot a 3.25 lb AP shell at a velocity of 2,067'/sec.
The engine could be started by and inertia starter or electrically. The power went through the transmission to the drive sprockets in the front. To control the M13/40 a steering and braking gear was used. A reduction gear was placed in the front to reduce the engine revolutions.
An order for 538 tanks was made and production started in June 1940. 22 were produced each month. The production rate of the M13/40 was around 60 - 70 per month.
The 4th Battalion, which had two companies of M13/40s, was deployed to Albania in November 1940.
In January 1941, the 1st Company was almost destroyed in the fighting for the Klisura Castle in the Tepeleni basin in northwest Greece. Mines in the road, Greek gunfire, and the destruction of the bridge over the Desnizes River destroyed four of the M13/40s.
Two tanks of the 2nd Company were lost in the attack on Hill 731 in northern Green in March 1941.
The regime of Prince Paul of Yugoslavia was overthrown on March 27, 1941. On April 6, 1941, Germany invaded Yugoslavia.
The 4th Tank Battalion was sent to the northern Albanian border to support the light tank battalions of the Centauro Armored Division. After the truce talks between the Italians and Yugoslavians broke down, 22 tanks were ordered to cross the Pron River on April 11, 1941. Eleven light tanks and two medium tanks were destroyed. A second wave was sent and eventually the Centauro Armored Division entered Montenegro.
On April 12, 1941, the Italians reached Podgorica.
Five M13/40s of the Littoria Armored Division entered Yugoslavia from the northwest at Sussa on April 12, 1941. They went down the Dalmatian coast and reached Ragusa on April 17, 1941.
Three battalions were sent to Libya in October 1940. There were all lost during the British offensive in western Egypt.
First saw action on December 9, 1940 at Sollum-Halfaya. In service in North Africa, Greece (with battalion of the Centauro), Yugoslavia, and Montenegro.
Over 100 were captured at Beda Fomm and some were used to equip the 6th Royal Tanks and Australian 6th Cavalry. The Australians named the three squadrons that they outfitted Dingo, Rabbit, and Wombat. White kangaroos were painted on the sides to help differentiate them from enemy tanks.
The 7th Battalion of the Ariete Armored Division was the first M13/40 Battalion to attack after the Deutsches Afrika Korps (DAK) arrived on February 12, 1941. It had a HQ company and three tank companies. Each company had a HQ platoon and three platoons with five tanks each. The Ariete also had the 8th, 9th, and 10th battalions with M13/40s. The division received 132 M13/40s by spring 1941.
Also sent to North Africa was the 31st Tank Battalion, Littorio Armored Division, and the 14th Tank Battalion, Centauro Armored Division. The 12th Battalion had its tanks sunk on the was to North Africa. The 11th Tank Battalion, Trieste Motorized Division, was the last to receive the M13/40s. During 1942 most of these tanks were replaced by the M14/41s.
Issued to 2 SS SturmGeschütz detachments and to Panzerabteilung Adria.