Saturday, 19 October 2019

The Tankette's Late Successor

Tank building worldwide made a radical jump forward in the second half of the 1930s and kept up the pace until the start of WWII. The stagnation of the early 30s led to many nations starting the modernization race on even footing. Some nations managed to create designs with great potential, others fell behind. Italy was among the latter. One of the characteristic designs of this era was the L6-40 light tank, which combined progressive design elements with downright archaic solutions.

From a small tank to a light one

The Italians made good use of British tank building experience in the early 1930s. The Carden-Loyd Mk.VI tankette was built under license as the Carro Veloce 29 (CV 29). The design was later radically reformed. That led to the creation of the Carro Veloce 33, the best "clone" of the Mk.VI. The only thing left from the predecessor was the overall concept and layout with a front transmission.

In everything else, it was a progressive and original design. Weighing only 3 tons the tankette had as much armour as light tanks of the era, thanks to which the crew was reliably protected from rifle caliber bullets from the front. The CV 33 also had high mobility. The CV 35 was a continuation of this design with improved armament. The Italians built over 2000 tankettes of all types. In 1938 they were reclassified as Carro L3 light tanks. The CV 33 became the L3-33 and CV 35 - L3-35.

The first variant of the Ansaldo 5 T light tank built in metal. Its ancestry can easily be traced to the CV 35.

The Italian army was saturated with armoured vehicles due to the L3. Sufficiently powerful armament (pair of FIAT machine guns) and thick armour allowed the L3 to carry out missions usually reserved for light tanks. The tank was small, quick, and cheap, and thus attracted attention from foreign buyers. More than a dozen countries used the L3.

Nevertheless, use in combat resulted in a mixed experience. It was quickly discovered that machine guns alone are often not enough against even infantry. The first encounters in Ethiopia resulted in losses of the tankettes. The real trouble began in the fall of 1936 in Spain. A new enemy appeared, a much scarier one than infantry: the Soviet T-26. These tanks had total supremacy over the CV 35 and German PzI Ausf.A. Italians began to arm the L3 with anti-tank rifles, at the same time launching a replacement program. The Italian medium tank program was also expedited.

The second iteration of the Ansaldo 5 T design surrounded by other Italian tanks. The Carro Armato M11-39 prototype nearby shows that the Italians were not looking for an easy way out.

Combat in Italy expedited work on the replacement of the L3. However, Ansaldo's specialists began thinking about further development of small tanks even earlier, in 1935. Italy was carefully watching British development of light and small tanks, especially export models. The British quickly moved from tankettes to two-man light tanks armed with machine guns. These tanks, called Vickers 4-ton, were successful on the export market. This success was noticed in Italy. In 1935 a new light tank was developed on the CV 33 chassis. The tank received a suspension with four road wheels per side in two bogeys and a rotating turret armed with the FIAT Mod.1928 light machine gun.

This version of the light tank was similar to the M11-39 in concept. The idea of one crewman who operated both the cannon in the hull and machineguns in the turret was poor.

This variant of a deep modernization of the L3 did not last long. Even though the maneuverability of fire improved, there were many drawbacks. Experience showed that vehicles of this class needed a more powerful weapon than a machine gun. C.S.M. (Centro Studi Motorizzazione, the organization responsible for development of new military vehicles) reviewed the project and introduced some changes. One of them was a requirement for the 37 mm Cannone da 37/26 and a coaxial Scotti light machine gun.

The change to the chassis was even more substantial. Looks like the Italians learned of the success of the Swedish Landsverk company in developing a torsion bar suspension. Ansaldo's designers radically altered the suspension as a result. There were still four road wheels per side (plus a pair of auxiliary wheels), and they were also grouped into bogeys, but torsion bars were used instead of leaf springs. The design was very original, albeit archaic. Italian engineers were the second after Sweden to use a torsion bar suspension in a tank.

A draft of the final version of the Ansaldo 5 T. This is the same CV 35, but heavier and with a cannon.

The new technical requirements were followed to create a tank known as the Ansaldo 5 T. Its official name was Carro d’assalto Mod.36. This tank was reminiscent of the L3, but this was a fully fledged light tank with a mass of 4.9 tons and with appropriate armament.

The armament was the source of the tank's greatest problem. Trials began in the spring of 1936 and showed that the turret was too small for such a big gun. Before that, on November 19th, 1935, the CSM proposed another layout for the armament. Only the machine guns remained in the turret, the gun was moved into the front plate of the tank. The turret also changed: instead of a design made from several flat plates, a horseshoe shaped plate would be used.

This variant was also not very good. The crew was still composed of two men. The commander, doubling as a loader and gunner for both weapons, would have to turn into a true Figaro. 

The final variant of the Ansaldo 5 T built in metal. It was the most comfortable for the commander, but its characteristics differed little from the CV 35.

Specifications for a tank with a cannon and machine guns in the front plate were ready on June 29th, 1936. This variant of the Carro d'assalto Mod.36 turned out the best. It was tested over the course of two years, but with little success. The tank became heavier than the L3 and its top speed fell to 28.5 kph. The difference in combat effectiveness was not significant. The Cannone da 37/26 was rapidly becoming obsolete. Tanks built by leading tank building nations had enough armour to make it ineffective. Work on the Carro d'assalto Mod.36 hit a dead end.

The first variant of the Carro Armato L6. This vehicle was armed with machine guns only.

The next stage of development of Italian light tanks was an offshoot of work on medium tanks. In November of 1937, FIAT and Ansaldo began working together on request of FIAT director Vittorio Valetta. The requirements for this tank were prepared by the CSM. The 7-10 ton tank would have a crew of three, achieve a top speed of 25 kph, and have a cruising range of 150 km. The armament would consist of either two Breda 8 mm machine guns or one machine gun and one flamethrower.

The CSM put out new requirements for a Carro M da 7 T medium tank in December of 1938. The tank had a mass of about 7 tons, top speed of 35 kph, and enough fuel to drive for 12 hours. The armament also changed: now it consisted of either two Breda machine guns or one machine gun and one 20 mm autocannon. There was also a flamethrower variant. Later the mass of the tank decreased and it was now called Carro M da 6 T. The crew was reduced to two men. The 37 mm Cannone da 37/26 appeared as an armament option.

The reworked vehicle with an enlarged turret and 37 mm gun. It too was later rejected.

The experimental tank that was ready by March 18th, 1940, was anything but a medium tank. FIAT and Ansaldo effectively reworked the Carro d'assalto Mod.36. Only the armour, reaching 30 mm in the front, resembled characteristics of a medium tank. In everything else this was a light tank. The prototype even had purely machine gun armament.

The final prototype, very similar to the production tank. The 20 mm Breda 35 autocannon was clearly too weak by the time the tank was put into production.

The tank was still an improvement over the Carro d'assalto Mod.36. First, it received a 4-cylinder FIAT 18T 4L motor which was also used on SPA 38R trucks. The 68 hp motor allowed the tank to be more mobile than required. The hull of the M6 was reminiscent of the L3, but significantly different. The reworked fighting compartment was roomier. The suspension was different. The auxiliary road wheels were disposed of and the number of return rollers increased to three. The drive sprocket and idler were different as well. The idler was lowered to increase the length of the contact surface. The turret was also a whole new design, and a much roomier one.

The production Carro Armato L 6-40 being loaded onto a trailer. The small mass and a convenient trailer designed especially for this tank allowed it to be carried by ordinary medium trucks.

In June of 1940, in accordance with decree #1400, the Carro M da 6 T was reclassified as a light tank, as any armoured vehicle with a mass of under 8 tons. The tank's new name was Carro Armato L 40. Official correspondence and the instruction manual designated it as Carro Armato L 6-40.

No rush for production

A decision was made in April of 1940 to build 583 Carro Armato L 6-40 tanks. The arrival of the first tanks was expected in May of 1941. However, these deadlines were not met. Work continued, as it was clear that neither the machine gun only variant nor the variant with a 37 mm gun were of any use. The only remaining option was the 20 mm Breda 35 gun. A new enlarged turret was designed. Its perimeter was 30 mm thick and the gun mantlet was 40 mm thick. Several vehicles were developed on the L 40 chassis, including an SPG and a munitions carrier.

Cutaway of the L 6-40. Despite its diminutive size, it was quite roomy inside.

The mass of the L 6-40 reached 6840 kg in the basic configuration and 6880 kg for command tanks with an RF 2 CA radio. The power to weight ratio remained at 10 hp/ton. The top speed was 42 kph on a road and 20-25 kph on dirt roads. This was higher than specified in the initial requirements. The cruising range was also surpassed: instead of 150 km it was 200 km on a highway or 100 off-road.

The Italians created a very decent light tank for the early war period with fairly thick armour for its class. However, the armour of the L 6 was assembled using rivets, same as other Italian tanks. This weakened the effect of the armour when under fire from anti-tank guns.

Progressive torsion bars and archaic bogeys were mixed in the running gear design.

The deadline for new tanks kept slipping. Ansaldo was overloaded with orders for medium tanks and a new factory was needed. In June of 1941 the order for Carro Armato L 6-40 was reduced to 300 units. Production was set up at the main FIAT factory. The hull was supplied by the Terni società per l'industria e l'elettricità spa casting works. Production of the Carro Armato L 6-40 finally began in March of 1942.

Tanks from the second series in use by the occupation group in Nice. In total 428 Carro Armato L 6-40 tanks were built, plus 17 for the Germans. The number 283 that is often quoted only applies to the first production series.

The first series numbered 283 tanks with registration numbers 3808–3814 and 3819–4090. This number is often quoted as the total production run of the Carro Armato L 6-40, but that is not the case. The first series finished in the fall of 1942, but production continued. The tank with number 3896 was converted to the experimental Semovente da 47/32 SPG. The second series began in the fall of 1942 and numbered 68 units with registration numbers 5121–5189. One of these, 5165, was converted to a munitions carrier. 36 tanks of the third series (5203–5239) and fourth series (5453–5470) were also built in 1942. Tanks with registration numbers  5481–5489 and 5502-5508 were built in 1943. In total, 428 tanks were built before Italy exited the war. Two of them were converted into and SPG and a munitions carrier.

A flamethrower variant of the tank that remained a prototype. The different gun mount is noticeable.

It is worth mentioning one other vehicle that was proposed back in 1937, the flamethrower variant of the L 6-40. A decision was made to convert one tank from the pilot batch with serial number 3812 in December of 1941. A new mount was designed to replace the 20 mm cannon and coaxial machine gun. Now the tank was armed with a flamethrower and machine gun. The flamethrower fed from a 200 L tank inside the hull. The tank was converted and trialled in the summer of 1942, but did not enter production.

Late to the fight

The first L 6-40 reached their end users two years after the decision was made to put them in production. This pace was acceptable in peace time, but not in war. The time of light tanks was coming to and end in the spring of 1942. The armour of tanks was becoming too thick for autocannons to penetrate at long distances. For instance, the Breda 35 could penetrate 30 mm of armour only from 300 meters. The mobility of the L 6-40 was not significantly greater than that of Italian medium tanks. The usefulness of the tank was already in question when it entered production.

One of the first L 6-40 tanks, North Africa, 1942. The results of using these tanks in battle were mixed.

Nevertheless, the first L 6-40 began arriving in North Africa in the spring of 1942. The Italians had no other choice. There were simply no other tanks. The M 13/40 and M 14/41 were also not entirely satisfactory for modern war.

The debut of the L 6-40 happened in the summer of 1942 and the results were mixed. The Autoblinda 41 armoured car with the same armament proved much more effective. Considering that the L 6's primary mission was reconnaissance, these tanks were hardly outstanding. Reports stated that the tank needed to get within 300-400 meters of an enemy tank to penetrate its armour, which was suicide in the open desert. Nevertheless, the L 6-40 was actively used in North Africa until the surrender of the German and Italian troops in May of 1943.

Tank from the HQ of the 67th Bersaglieri Battalion, destroyed during Operation Little Saturn near Stalingrad. The tank carried the registration number 4050.

The tank wasn't up to par in North Africa, and it is hard to imagine what tankers thought when they were issued these tanks on the Eastern Front. In the summer of 1942 58 L 6-40 tanks from the 67th Bersaglieri Battalion of the 3rd Cavalry Division Principe Amedeo Duca d'Aosta. It's hard to imagine what the Italian general staff was thinking when they made this move. The weakest Soviet tank that the Italians could have encountered was the T-60, which could not penetrate the L 6-40 from the front, but the L 6-40 could not penetrate it either. The T-70, however, would have no trouble with the Italian tank. An encounter with a T-34 or KV-1 would likewise be predictable.

In addition, by the summer of 1942 the Red Army was saturated with anti-tank rifles, which could penetrate even the front of the Italian tank.

Tank with registration number 3898, NIBT Proving Grounds, 1944. This tank is currently on display at Patriot Park.

Even though the conditions were unfavourable, the Italian tankers got lucky at first. The Red Army was on the defensive for the summer-fall of 1942, which radically increased the survival odds of the L 6-40. The first significant losses were taken in August of 1942 from anti-tank rifles. At least two tanks (3882 and 3889) were captured by the Red Army.

The real nightmare was awaiting the Italian 8th Army in December of 1942. Operation Little Saturn began on December 16th. At this point the 67th battalion numbered 45 tanks. Less than two weeks later nothing was left of them but memories.

The same tank from the side. Markings show that this was the fourth tank of the 1st platoon of the 1st company.

Several of the tanks were captured in fair condition. One of them survived to this day. This was tank #3898 that is currently on display in Patriot Park. Based on existing photographs this was the fourth tank of the 1st platoon of the 1st company. Three tanks of this type were held at the NIBT Proving Grounds at different times. They were referred to as "SPA" or "light tank SPA" due to the brand of the engine. Mobility trials were not held, as these tanks were not interesting. The analysis was limited to composition of a brief list of characteristics, without even noting the speed.

A tank from the fourth series in Yugoslavia. This camouflage was standard for Italian vehicles in the European theatre after 1943.

The tank's use in secondary theatres went better. From 1942 to September 1943 93 of these tanks fought in the Balkans. Most of them (80) saw action in Albania. In mountanous terrain with a shortage of anti-tank weapons to fight them the L 6-40 could shine much harder. The tank was nible and well protected from the front, making it ideal for anti-partisan operations. 13 of these tanks fought on the territory of Yugoslavia.

Panzerkampfwagen L6, German army, early 1945.

FIAT continued to produce the L 6-40 after Italy exited the war and was occupied by the Germans, but under a different name: Pz.Kpfw.L6 2 cm. The Germans ordered 14 tanks. In total 15 regular and 2 command tanks were built. The Germans had little interest in the obsolete light tank, but there were several times more SPGs on its chassis built.

 New and captured vehicles were used in German units both in Italy and in the Balkans. They were used by SS police units, chiefly in Yugoslavia. The L 6-40 was also used by Germany's satellite states. For instance, Croatian infantry units had six of them by December 1944. After the war a small number of L 6-40 tanks returned to Italy. They were also used by police forces sans 20 mm cannon.

L 6-40 in use by police, late 1940s. These tanks were used by Italian police with Breda 38 machine guns instead of 20 mm autocannons until at least 1953.

Intensive use in battle led to only three vehicles surviving to this day. The tank in Patriot Park is in the best condition. One L 6-40 remains in Italy. The tank looks fine from the outside, but is completely empty on the inside. Finally, one tank is located in Albania, in the Gjirokaster fortress. Its condition is far from ideal.

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