From Tanks Encyclopedia
At the beginning of the 1970s, the Brazilian Army started developing armored vehicles. They would start with wheeled vehicles. After having successfully developed the prototype concepts which would become the EE-9 Cascavel and the EE-11 Urutu, the Brazilians looked to tracked vehicles. Like the previous wheeled vehicle projects, the engineers started small. They first set off remotorizing readily available M3 Stuarts, and then started developing the vehicle that is known as the X1 light tank. The X1 was a modernization of the Stuart which was armed with a low-pressure 90 mm gun and would be developed into an entire family of vehicles.
An attempt to improve the X1 by fixing some of its design flaws was unsuccessful. The X1A1 was developed to improve on the X1, but in the process only got worse. It was too long and too narrow, which made steering a very difficult task. An extensive rebuilding program would have been required to bring the X1A1 to a usable state, something which was simply not worth it. Considering that both the X1 and X1A1 used the now 30 years old M3 Stuart as their basis, some of the flaws would never have been able to be fixed because of the age of the vehicles.
As a result, it was decided that the development of a completely new tank was the way forward. Capitalising on the experiences gained from the X1 and X1A1 projects, the designated X-15 project would use components and design principles from the previous conversions. It would, for example, use the suspension of the X1A1, but also the X1A1’s turret for the first prototype. The resulting tank of the X-15 project would be known as the X1A2 and be the first (and so far only) serially produced tank which was fully designed in Brazil and used in active service.
The X1A2 was produced in two production batches, with the first consisting of 10 vehicles and the second of 14 vehicles. Of these batches, only the first would enter active service, while the second batch mostly ended up as gate guardians and monuments. The first batch X1A2 was officially designated as Viatura Blindada de Combate – Carro de Combate MB-2 (VBC CC Medio Bernardini-2) (English: Armored Fighting Vehicle – Combat Car Medium Bernardini-2), while the second batch was designated as Viatura Blindada de Combate – Carro de Combate MB-2A (VBC CC Medio Bernardini-2A) (English: Armored Fighting Vehicle – Combat Car Medium Bernardini-2A). The reason for this difference was because the second batch used more locally produced components and featured a swing arm for the .50 machine gun, instead of a fixed mount. Interestingly, this swing arm seems to have been incorporated in the X1A2 prototype, but not on the first production batch.
