X1A2

Following the end of WWII, the Brazilian government bought 350 used M3 Light tanks from the United States. As the decades passed, the tank's obsolescence became increasingly obvious. During the 1970s, the local Bernardini vehicle manufacturing company sought to upgrade the fleet of light tanks to modern standards. This produced the "X1A" program, which spawned three noteworthy designs.

The first was the X1A, which emerged in 1973. While the chassis of the M3 Light was retained, the upper hull was completely redesigned. The engine was a diesel Saab-Scania which could output 280 horsepower, and it mounted the rifled 90 mm DEFA D-921F1 (later known as the GIAT F1) gun. This was a low-pressure weapon which could fire HEAT, HESH, and APFSDS ammunition. The tank also received an all new turret and 80 models would be produced. The modernization started in 1975 and ended in 1978.

During 1977, an imitative to further upgrade the X1A had been started. The chassis had been extended to include an additional bogie unit, in order to make room for a new engine, which resulted in the X1A1. While the X1A1 itself had not been accepted into surface, it served as the basis for a third development type: the X1A2.

X1A1. Notice the original front profile of the M3 Light compared to the previous X1A2.

At this point, the X1A2 no longer remotely resembled the tank which it was based on. Rather than being a conversion, the X1A2 was new and wholly produced in Brazil. It featured a new 90 mm Cockerill gun and a new sloped front plate. The estimated weight of 19 metric tons.

The X1A2, as I'm presenting it, is a combination of both the X1A1 and X1A2, while the X1A becomes its own premium vehicle. As with other vehicles like the M113 90V mounting these low-pressure guns, the tank's expected ammunition loadout should be HEAT/HESH/HE. Given this is a Tier VIII tank with a 90 mm, it should be also be expected to have some below average gun handling and characteristics. The X1A2 could probably be best compared to the German HWK 12. 



Guns: 90 mm DEFA D-921F1; 90 mm Cockerill Mk. III

Engines: Saab-Scania D223L (280 hp); Saab-Scania DS-11 (325 hp)

Turrets (Turret Armor (mm)): X1A (??/??/??); X1A2 (??/??/??)

Suspensions/Alternate Hulls, Total Weight (metric tons): X1A1 Carcara (17.23); X1A2 (19)

Hull Armor (mm): 20/??/??

Top Speed: 55 km/h

Crew: 3 (Driver; Gunner; Commander/Radio/Loader)



Parent: M24 Tensa
Children: M41C
See Also: X1A

Sources:

https://www.militaryfactory.com/armor/detail.asp?armor_id=861

http://www.tanks-encyclopedia.com/coldwar/Brazil/Bernardini-X1A.php 

Chant, Christopher. A Compendium of Armaments and Military Hardware (Routledge Revivals), 2014