WW2 Spanish Prototypes

Carro de Combate de Infantería tipo 1937

Nationalist Spain (1937-1938)
Light Tank – 1 Prototype

The Carro de Combate de Infantería tipo 1937, more commonly known as C.C.I. tipo 1937, was one of many Spanish attempts to create an indigenous tank superior to all the available tanks by cannibalising them. However, sometimes over-enthusiasm and a desire for quick results came at the expense of a well-thought-out design.

The ‘Carro de Combate de Infantería tipo 1937’ also known as the ‘CCI tipo 1937’. This photo shows the vehicle factory-fresh, without a coat of paint – Source: Molina Franco & Manrique García (2009), p. 44

Context – The Spanish Civil War in 1937

In mid-July 1936, a group of Spanish Army officers initiated a coup against the democratically elected government of the Second Spanish Republic. They failed in their initial goals and consequently, the country was divided in a civil war fought between the Republicans (also known as the ‘Loyalists’), and the Nationalists (the ‘Rebels’). Soon enough, foreign powers would become involved providing material and in some cases, troops. Italy and Germany came in support of the Nationalist and airlifted the core of their forces from Spanish North Africa onto the Peninsula, whereas the USSR supported the Republic. The Nationalists, led by General Franco, attempted to take Madrid and end the war in November 1936, but the city resisted.

Map showing the progress of the Spanish Civil War in July 1936, March 1937, March-April 1938, and February 1939. Note the Nationalists are in blue and Republicans in purple – Source: Gifex

By 1937, the Nationalists had the upper hand. Beginning in March that year, they commenced the ‘War in the North’, an operation to take over the Republican positions along the north coast. They would be successful in this, with Bilbao falling on June 19th, Santander on August 25th, and Gijón, the last main Republican holdout in the region, on October 21st.

This northern region of Spain was one of the only industrialized regions in the country and it also had important mineral resources. This area had also produced several armored fighting vehicle (AFV) designs over the years, including the Trubia Serie A, The Bilbao Armored Car, and the Trubia-Naval.

In this context, when Nationalist troops took the North, two unrelated tank projects would emerge, the Verdeja, and the CCI tipo 1937.


After capturing Bilbao and the Vizcaya region in June 1937, the Nationalist wanted to take advantage of the facilities which came to be at their disposal for the purpose of tank production. One of these facilities was the Sociedad Española de Construcción Naval (SECN), located in Sestao, northern Bilbao. Until the city fell, the factory had been building and repairing Trubia-Naval tanks for the Republicans. Nationalist authorities however, declined to continue the production of this tank given how unreliable and deficient it was. They would, though, use the expertise of the factory workers. For this purpose, a Panzer I, a FIAT-Ansaldo CV.33, and a T-26B, the three most common tanks in the conflict, were taken to Sestao to be studied with the goal of creating a new tank based on the best features of each, although it seems no features of the T-26 were actually adapted. A cursory glance at the Trubia-Naval should make it obvious that it also had some influence, with the rear being almost an identical copy and sharing the same engine. The separate Verdeja project which began a year later would commence in a very similar way.

The CCI tipo 1937 resembled the Trubia-Naval in several ways – Source: Artemio Mortera Pérez (2007), p. 66

The design for the new tank was agreed upon at some point in August-September 1937. On September 15th 1937, the Nationalist Army gave a contract to SECN to build an initial series of 30 tanks, soon after, construction of a prototype began.



The tank’s sides consisted of slightly angled plates. To the front, below the turret, to each side were double-hinged-doors for crew access. At the very back of the tank was a ventilation radiator with eight louvres. The rear resembled a Trubia-Naval in appearance. Atop the rear was another radiator to allow the engine fumes to leave the tank. Behind the turret was a hinged hatch to access the engine from the outside. In appearance, the welded turret resembled that of a Renault FT, though the cupola was rather different. The upper frontal plate had a vision slit for the driver on the left and on the right, a position for two machine guns copied from the Italian FIAT CV’s, though on a different side of the vehicle.

Rear view of the CCI tipo 1937, the bit which most resembles the Trubia-Naval – Source: Mortera Pérez (2011), p. 110

Armor was poor overall and was incapable of deflecting 7.92 mm rifle fire. Inferior materials were used for its construction, as initially, chromium nickel steel for the armor was not available. The area where this was produced was still under Republican control. Whilst the exact armor thickness is unspecified, but given the factories experience with AFV production, they would have known that anything under 10mm was totally unsuitable. An educated guess on the armor thickness based on weight and dimensions of the vehicle would indicate that it did not exceed 10-12 mm. The 12mm bottom plate of the CV.33-35 was sufficient enough to withstand 7.92 mm rifle fire, so it can almost certainly be assumed that the armor was of an inferior thickness to this.

Suspension and Tracks

The suspension was copied from the CV, only it was slightly longer. This could have been done by adding links to lengthen the tracks. It consisted of two sets of three bogies and an additional solitary auxiliary wheel at the rear by the idler wheel. There were no return rollers at the top, instead, there was a simple wooden beam holding the track into place.

Side view of the CCI tipo 1937 which shows the the tracks to be almost identical to those of the CV33-35 – Source: Falessi & Pafi


The main gun, the 20 mm gas-operated Italian Breda M-35, was in the turret. The 20 mm Armor-Piercing (AP) round weighed 147 grams and could penetrate up to 40mm of armor at 250m at a 90º angle of impact. This gun had been used in the joint Spanish-Italian FIAT CV.33/35 ‘Breda’ prototype and the very limited production Panzer I ‘Breda’. The idea to equip the CV and the Panzer I with the Breda gun was to give them the capability to engage the Soviet-supplied T-26 of the Republican forces. Initially, there had been plans to equip the CCI tipo 1937 with a 45 mm main gun similar to that of the T-26, but this did not materialize. This was probably rejected as the turret was not big enough to house it and the gun was not available in large enough numbers. Furthermore, the suspension was probably not adequate enough to absorb the gun’s recoil. The frontal machine gun position housed two Hotchkiss Mod. 1914 7.92 mm machine guns which appear to be magazine fed from above.

Frontal-side view of the CCI tipo 1937 showing its 20mm Breda machine gun main armament and mount for two Hotchkiss machine guns – Source: Mortera Pérez (2011), p. 111


The hull was divided into three sections: the driving compartment at the front, the fighting compartment in the center, and the engine compartment in the rear. It is not specified how many crew-members the tank had, but it can be assumed that at least three: a driver, a frontal gunner in charge of the dual 7.92 mm machine guns, and a gunner in charge of loading and firing the main gun who was presumably also the commander. The engine was a 6-cylinder MAN 100 hp truck engine as used in the Trubia-Naval which was readily available in numbers in the factory. It is not known if this was a petrol or diesel engine though. The tank had three forward gears with a maximum speed of 24 km/h, and one reverse giving 5.5 km/h. Other mechanical elements of driving were probably taken from the FIAT CV tank.

Tests and Demise

Initial reactions to the prototype by those testing it, in spite of the feeble armor, were very satisfactory. Even in June 1938, by which point the serious deficiency of the CCI tipo 1937’s armor should have been noted, the template for the Bandera de Carros de Combate de la Legión [Eng. The Spanish Legion’s Tank Division] indicated that the unit was to have 30 CCI tipo 1937’s. However, despite the tank having successfully passed most of the tests with flying colors, including firepower, mobility, and obstacle evasion, the Army, by this point realizing the tank’s clear deficiency in regards to its armor, could simply not accept a tank with such thin armor, and thus rejected it.

Furthermore, the Nationalists had, by this time, captured enough Republican T-26’s to make up a capable tank force for the conditions and circumstances of the Spanish Civil War. A few years later, General Joaquín García Pallasar, an artillery officer and close friend of Franco, who had also been very closely involved with the FIAT CV ‘Breda’ project, wrote his reflections on the CCI tipo 1937 project. Writing in August 1940 for the ‘Ejército‘ magazine, he claimed that the tank had not been properly studied by its creators and they put their will to help and create a tank before taking the time to think how best to build it.

Side view of the CCI tipo 1937 – Source: Molina Franco & Manrique García (2009), p. 45

The experience of the CCI tipo 1937 would not be wasted though. Following the rejection of the CCI tipo 1937, SECN decided to build a lightly armored tank destroyer using a similar, but improved chassis and suspension. The Spanish Army showed no interest in this vehicle. After this, SECN took the gun off and presented it as an artillery tractor which was tested by the Spanish Army, though, with the Spanish Civil War ended and the country in ruins, there was no need for military investment.

The Controversy Over Who Built The Tank

Whilst photographic evidence of the tank being tested clearly shows it at the SECN factory in Sestao, it is important to note that according to Artemio Mortera Pérez, Lucas Molina Franco, and José María Manrrique García (three of the leading historians of AFV use in the Spanish Civil War) some Italian publications claim the tank was built by the Italian company of Ansaldo to be sold to Spain. They do not specify which publications make this claim, making their initial claim not stand as strong. However, some older Italian publications, namely, Cesare Falessi and Benedetto Pafi’s Veicoli da combattimento dell’esercito italiano dal 1939 al 1945, make the claim that the vehicle was built in Ansaldo in 1937 and called Trubia. Regardless, this is patently not true.

Interviewed factory workers are adamant that there was no foreign (German or Italian) contribution to the project. However, Colonel Valentino Babini, the commander in charge of the Raggrupamento Carristi of the Corpo Truppe Volontarie [Eng. Tank Regiment of the Volunteer Troop Corp], writes in his documents of an Italian artillery technician supporting the Spanish engineers building the tank, and highlights the fact that the CCI tipo 1937 copied some features from Italian tanks. This is by no means the only controversy between Italian and Spanish claims surrounding tanks during the Spanish Civil War, with the FIAT CV.33/35 ‘Breda’ being a notable example. This shows that alliances are not always as straightforward as it may seem and that tensions always exist.


The CCI tipo 1937 did not provide Nationalist forces with a significant improvement over the T-26’s they had. Its main armament was sufficient enough at the time to deal with Republican armor (including the Soviet T-26, BA-6 and FAI, and Spanish-built vehicles such as the UNL-35 or AAC-1937), but its speed was disappointing for a light tank, and its armor was simply appalling, being easily penetrated by 7.92mm rifle fire. It was a decent idea in principle, just poorly delivered. Although in most aspects superior to the FIAT CV (overall) and Panzer I (firepower and mobility), it could not compete with the T-26, and when the latter became available in sufficient number to the Nationalists, there was no need for a newer tank.

CCI Tipo 37
Illustration of the ‘Carro de Combate de Infantería tipo 1937’ or ‘CCI tipo 37’, produced by Tank Encyclopedia’s own David Bocquelet (click to enlarge)


Dimensions N/A
Total weight, battle ready 8 tonnes
Crew 3 (Driver, frontal gunner, gunner/loader)
Propulsion 6 cylinder MAN 100 hp
Max speed 24 km/h (14.91 mph)
Armament 1 x 20 mm Italian Breda M-35
2 x 7.92 mm Hotchkiss Mod. 1914 machine guns
Armor Not specified, unlikely to exceed 10-12 mm
Production 1


Artemio Mortera Pérez, Los Carros de Combate “Trubia” (Valladolid: Quirón Ediciones, 1993)
Artemio Mortera Pérez, Los Medios Blindados de la Guerra Civil Española Teatro de Operaciones de Aragón, Cataluña Y Levante 36/39 Parte I (Valladolid: Alcañiz Fresno’s editores, 2011)
Cesare Falessi and Benedetto Pafi, Veicoli da combattimento dell’esercito italiano dal 1939 al 1945 (Bologna: Intyrama Books, 1976)
Joaquín García Pallasar, “Progresos de la Artillería”, Ejército, August 1940
L. Curami and A. Ceva, La Meccanizzazione Dell’esercito Italiano Dalle Origini al 1943 (1994)
Lucas Molina Franco and José Mª Manrique García, Blindados Españoles en el Ejército de Franco (1936-1939) (Valladolid: Galland Books, 2009)

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