After the dismantling of the War Industry Commission of Catalonia, the Subsecretary of Weapons and Ammunitions of Spain contracted Soviet engineers to build a new armoured vehicle.

As they advanced ahead of the infantry they were surrounded and isolated and after some of their machine guns were blocked, they suffered heavy losses.

After the first battle, they gave support in the Rif War, with success during the Alhucemas landing, a decisive victory that led to their return to Spain.

The Sanjuanada of 1926 meant that tanks, usually associated with the artillery officers that participated in the coup d'état, lost the favour of the administration and the projects for national production of armoured vehicles were cancelled.

[4] In Catalonia, after the July 1936 military uprising in Barcelona, the workers decided to assist in the war effort by producing weapons, including tanks.

After the initial chaos and starting from scratch, the War Industry Commission in Catalonia was in charge of managing the production of the new armoured vehicle.

[5] Also, the Italian and German navies controlled most of the naval routes to the Iberian peninsula and because of that, the Soviet Union wasn't able to send resources via sea.

The Spanish sub-secretary of weapons, with the help of Soviet engineers, started the development of a new heavy armoured vehicle in April 1937, taking the BA-6 as a reference.

The most famous vehicle was the AAC-1937, which was based on the chassis of the Chevrolet SD 1937 truck from General Motors Peninsular, produced in Barcelona.