Feast your eyes on the Bernardini X1A, a heavilly modernized variant of the American M3/M5 light tanks from World War Two.
The X1A was developed as an answer to the Brazilian government's need for more modern tanks on a rather limited budget. It seemed only logical to develop a tank based on equipment that was already available, not to mention that the army was trained in using, and had ample existing infrastructure to support them. The X1A brought a heavily modernized suspension, engine, and unheard of firepower to the Stuart chassis in the form of the DEFA munitions company's 90 millimeter cannon.
In total, 80 X1A's entered service with the Brazilian Army from 1976 to 1978, and were met with enthusiasm by their commanders who appreciated the improved suspension, interior comforts, and excellent firepower of the 90mm gun.
Following the success of the X1A, further developments were made by Bernardini in an effort to improve the vehicle's protection and speed, but the prototype was not cleared for production. The tank's designation, X1A1, was retained in the event of a production order.
Then came the X1A2...
The X1A2 took the improvements of the X1A1 and expanded upon them even further, replacing the last vestiges of the M3/M5 Stuart with totally new components, resulting in a totally new machine. It was, however, perfectly suited to the existing storage, maintenance, and training infrastructure left by it's predecessors, and was readily adopted. However, only a small number were ordered, with 30 vehicles delivered between 1979 and 1983.
In the end, the X1A program came to an unceremonious end when the Brazilian army began to phase out it's light armor, beginning with the few more traditionally modernized M3, M5, and M4 tanks from World War Two, and culminating with the X1A2's, the last of which allegedly saw training action in 1997.
The X1A program was given a spin-off of sorts in 1977 when Brazilian company Avibras proposed a Multiple Launch Rocket System (MLRS) based on the improved chassis of the X1A tank. They were given approval to proceed, and created the Avibras X-40.
The system was only a moderate success, as the missiles themselves proved rather cumbersome for their role, and the X1A was somewhat too small to serve as a proper MLRS platform. A total of 50 X-40's were produced between 1977 and 1979, with Avibras and Bernardini working in tandem to deliver the vehicles. The X-40 remained in service until 1986, when Avibras own "ASTROS-2" MLRS system, based on a more traditional wheeled chassis, superseded the unpopular and ineffective X-40, and they were all retired almost overnight.
The ASTROS-2 remains in service today in an upgraded and modernized form.
Today, the few remaining X1A and X1A2 tanks are on display in various museums and public spaces in Brazil. A few X1A tanks routinely visit military parades, but the exact number of vehicles the Brazilian army has in mothballs is unknown. Only one X-40 is known to remain, as it was seen in a military parade in 2015.
