The Osorio was specifically designed to accommodate Brazil’s limited infrastructure.


Referring to the main battle tank, we must all think of Americans, Russians or Chinese. But you know, Brazilians have built a tank that won both M1 Abrams and Challenger after months of harsh challenges in the desert environment of Saudi Arabia. I am talking about Osorio, which was a main battle tank built by Engesa – a Brazilian private company.

Almost forgotten today, the Osorio was a prototype main battle tank developed by Brazilian arms manufacturer Engesa during the 1980s. The Osorio was named in honour of Manuel Luis Osório, founder of the Brazilian Army’s cavalry branch.

In 1989, Osorio created an almost mythical feat in the worldwide arms manufacturing industry, winning two giants M1 Abrams and Challenger after months of harsh challenges in the desert environment of Saudi Arabia.

It was developed as a privately funded venture by Engesa, with little government support. It was intended to be sold first to Arab and other Third World countries, jump-starting production — and enabling the Brazilian Army to later place its own orders without having to fund development costs. However macro-political events including the Gulf War and American political pressure led to the tank’s demise, and the tank was never acquired by the Brazilian Army.

In 1982 development began in a new venture by Engesa into MBT production for its current export clients, who were having trouble purchasing newer MBT’s built in member country’s of NATO as they were non NATO members (I’m talking about the The Leopard 2).


The Osorio was specifically designed to accommodate Brazil’s limited infrastructure. The combat weight of 43 tonnes was settled upon, as it was within the load capacity of the road bridges and overpasses in Brazil. Likewise, the size constraint into which the Osorio was built allowed it to drive or be transported through Brazil’s existing road and rail tunnels, as well as to fit onto available tank transporters and rail cars.

As this infrastructure was comparable to that of much of the Developing World in the 1980s, it was thought that the Osorio would be ideal for export to these nations.

On the front of the hull and turret, the Osorio tank was equipped with composite armor. This armor was broadly similar to the British Chobham. It has included steel, aluminum, carbon fibers and ceramics. Although the armor of the Osorio was very light, it was extremely powerful and has been rated to defeat any anti-tank projectile above the frontal arc in service in 1986.

Automatic fire suppression and NBC protection systems are available for the vehicle. However it is considered that protection of this tank was inferior to most western MBTs of that time.


The Osório’s survivability concentrated on firepower & speed. The EE-T1 Osorio MBT, intended for Brazilian Army, was armed with a British Ordnance L7A3 105 mm rifled gun, and carries a total of 45 rounds of ammo for it. It fires Armour-piercing fin-stabilized discarding sabot, High-explosive, High-explosive squash head, High-explosive anti-tank warhead, antipersonnel-tracer, White Phosphorus, and canister rounds.

The EE-T2 was intended for export customers and was armed with a more powerful French GIAT G1 120 mm smoothbore gun, but the ammunition is reduced to 38 rounds. It fires Armour-piercing fin-stabilized discarding sabot and High-explosive anti-tank warhead rounds. Both of these guns are fully-stabilized and manually loaded.

The EE-T2 main battle tank has an 80 percent hit probability against the moving target at a range of 2 km.

The EE-T1’s secondary weapons are two 7.62 mm machine guns. One of them was coaxially mounted,, while the other was placed on top of the roof.

The EE-T2 was completed with machine gun coaxial 7.62 mm and anti-aircraft machine guns mounted on the roof of 12.7 mm. The vehicle has a four-man crew including commander, gunner, loader and driver.


Chassis includes 6 bearing and 3 supporting rolls from each side. Tracks were similar to “Leopard 2” main battle tank’s ones, with removable rubber pads. Chassis suspension is hydro pneumatic. First, second and sixth bearing rolls are fitted with spring absorbers. Hull boards and chassis was covered with armored screens, providing additional protection against cumulative rounds.

“Osorio” has good speed and cross-country performance. It reaches 30 km/h in 10 seconds. It manages 30º slopes, 3m wide trenches, 1.15m vertical step. Without preparation it fords 1.2m water obstacles.

The End

Foolishly Engesa had spent over $100 million in the Osório’s development after it passed the field testing with Saudi-Arabia, but not getting the signature on the order sheet. In 1993 Engesa filed for bankruptcy and sadly the Osório never saw production. The Brazilian Army still uses 132 of its original 334 Leopard 1 A5’s and also 91 US M60-A3’s.

Although it just collapsed because of the political pressure of “not fair players” but it has shown that this tank has shown great features and low cost, highly appreciated by world customers.

Learning from this failure, Brazil’s defense industry is applying Osorio’s lessons and technology to other projects.

A series of cult and ambitious products like the Embraer KC-390 transport aircraft, MLRS Astros 2020, nuclear attack submarines, and Avibas cruise missiles … There were first customers to order and pay.

With the strength of diversity, cheap price, relatively high quality and unbounded politics, Brazil is really a big man, a formidable competitor is emerging rapidly among exporting weapons countries in the world.

Thank you for visiting I’m Dung Tran, the person behind all this content. I know some websites are copying my articles. Stop this, or at least respect me by citing the source from Thank you.


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