Cold War Brazil EE-9 Cascavel

EE-9 M4 ET-25

Federative Republic of Brazil (1985)
Wheeled Anti-Aircraft Vehicle – 1 Built

As the Iraq-Iran War was raging on, Iraq was searching for anything which might be able to swing the conflict in its favor. To accomplish this, Iraq sought help from a rising powerhouse in the defense export world to help bring this advantage. The rising Brazilian defense industry had interesting and functional concepts, but most importantly, Iraq could buy its loyalty and heavily fund the industry for it to develop new equipment fully catering to Iraqi requirements.

One of these projects was to fill the requirement of a wheeled anti-aircraft screening vehicle to help cover the Iraqi convoys from Iranian helicopter attacks. Iraqi Army officials contacted the Brazilian company Engesa, which had previously delivered 364 EE-9 Cascavels and 148 EE-11 Urutus, to suggest that the Iraqi Army would be willing to acquire such a vehicle if the company could develop a suitable solution.
As such, Engesa went to work. The company decided that developing a 25 mm autocannon armed turret to be mounted on the EE-9 Cascavel was the way forward, and so, the EE-9 with ET-25 turret was born.

The EE-9 M4 Cascavel armed mounting the ET-25 turret.
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

The EE-9 and Iraq

The story of why the EE-9 Cascavel (English: Rattlesnake) was developed can be traced back to the Second World War. Brazil sent an expeditionary force, known as the ‘Smoking Snakes’, to fight in Italy alongside the Allies. During the Italian campaign, the Brazilian forces were armed with the M8 Greyhound. The Greyhound turned into the most loved vehicle by the Brazilian soldiers, and after WW2, this love would remain embedded in the Brazilian Army.

Soldiers of the Força Expedicionária Brasileira (FEB, Brazilian Expeditionary Force) in Italy.

Although Brazil enjoyed its diplomatic relations with the United States well into the 1970s, the first steps to break free from the United States, from an army materiel point of view, started in 1967. The United States got increasingly involved with the Vietnam War and, as a result, could not supply Brazil with the cheap equipment it once did. As such, it was decided that the Army would try to develop their own armored vehicles.

One of these was the EE-9 Cascavel, which was passed on to Engesa for production after the Army had developed a number of prototypes. Engesa managed to secure an export deal with Libya for 200 EE-9s in 1974 and soon after would receive an order for an additional 200 vehicles. From there, the EE-9 became Engesa’s flagship product, as they would sell it to multiple South American countries as well.

The usage of the EE-9 Cascavel by Libya and its export success managed to get the attention of Iraq. After three weeks of negotiations, Engesa managed to secure the export contract for 364 EE-9s and 148 EE-11s on May 5th 1978. Iraq would be the first to receive a new model of EE-9, known as the EE-9 M4. In contrast to previous models, the EE-9 M4 used an MT-643 transmission which could handle the more powerful Detroit Diesel 6V53 212 hp engine. In addition, the hull featured a number of redesigns like the integration of the headlights in the lower hull plate instead of the installation on top of the upper front plate. The most significant change was the redesigned ET-90 turret, known as ET-90 II, which was able to incorporate night vision sights.

Iraqi EE-9 M4s lined up.
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

This deal started the arms relations between the two countries for the next 13 years. This relation would eventually morph into Iraq becoming virtually the most important customer for the Brazilian defense industry. The start of the Iraq-Iran War in 1980 and the subsequent stalemate would catapult the Brazilian defense industry into its golden age. Systems like the successful ASTROS rocket launcher, the Piranha air-to-air missile, and the EE-T4 Ogum were mostly funded and specifically built to cater to the Iraqi market. An EE-9 for anti-air purposes was also requested by the Iraqi Army.

An Iraqi Astros 2 Multiple Rocket Launcher.

The Anti-Aircraft Cascavel

The Iraq-Iran War saw the most intensive use of helicopters of any conventional war up to that point. Early on, Iraqi tank convoys were attacked and successfully destroyed through the use of TOW and Maverick air-to-surface missile armed AH-1J helicopters. In order to protect these convoys from so-called pop-up attacks, the Iraqi Army sought a vehicle which could act as an anti-helicopter screen and that could immediately engage an enemy helicopter when the convoy was ambushed or when it encountered it. As such, infantry dismounts with surface-to-air missiles and especially expensive and vulnerable surface-to-air missile systems which needed time to be deployed were less suitable for this role.

An Iranian Air Force AH-1J helicopter armed with Maverick missiles.

The requirements and request for the development of such a screening vehicle were supposedly passed on to Engesa by General Amer Rashid at an unknown date. Considering Engesa’s ability to develop prototypes very rapidly (the EE-T4 Ogum prototype was developed and built in just 6 months), it is quite likely that this request was made somewhere in late-1984 to early-1985. In any case, Engesa went to work.

The EE-T4 Ogum.

How the development process exactly went is unknown. It is likely that Engesa looked at the platforms they had available, which were in service with the Iraqi Army, and which were suitable to receive such a role. Engesa likely selected the EE-9 to be used for the anti-aircraft concept as it already drove alongside the armored columns. The Cascavels were used as reconnaissance vehicles and thus were already used to screen the armored columns against potential ground targets. An anti-aircraft EE-9 could still be used in a similar way for reconnaissance but with the emphasis laying on air targets instead.

Turret Designations

Before going into the turrets designed for the 25 mm armed Cascavel, it is perhaps useful to clarify a number of things regarding designation. As far as is known, two ET-25 turrets were made. The first seems to have been converted from the pre-existing ET-90 II turret of the standard EE-9. The second was an actual ET-25 turret which was designed from the ground up.

The first prototype ET-25 turret.
Source: Claudio Agostini

Normally, as with the ET-90 turrets, the first could be designated ET-25 I and the second ET-25 II. Since there is no documentation regarding how Engesa itself designated the turrets, the first turret will be designated in this article as the ET-25 prototype. The second turret will simply be designated ET-25.

The ET-25 turret.
Source: Jane’s Armour and Artillery

Developing the ET-25 Turret

According to earlier sourcing from the Brazilian armored vehicle expert Expedito Carlos Stephani Bastos, the very first prototype turret built by Engesa was suspiciously identical in every way to the T 25 turret from OTO Melara. While there is the extremely remote possibility that Engesa copied the T 25 turret, it seems extremely unlikely. The turret also does not fit the more functional and simplistic design style of the company either. As such, it is very unlikely that this turret was built by Engesa, which seems to be supported by the fact that the turret is omitted from later works of Expedito Carlos Stephani Bastos.

The T 25 turret.
Source: Engesa EE-9 Cascavel 40 anos de combates 1977-2017

There is still a possibility that the T 25 turret influenced the ET-25 turret from Engesa instead. The interior layout seemed to be somewhat similar and the overall shape in the later design stages of the ET-25 turret started to resemble a more functional and simplified version of the T 25. In the early stages, however, Engesa quite simply seemed to have taken the ET-90 turret and adapted it to be armed with the Oerlikon 25 mm KBA autocannon.

A cut-out depression on the right side of the turret was made to facilitate a shell case ejection system, like on the T 25. What does stand out is that while the turret seems to be based on the ET-90 II turret, it does differ in hatch opening concept. From the ET-90 II on, the crew hatch of, for example, the gunner hinged open toward the front, protecting the front of his body when leaving the vehicle. The initial ET-25 prototype turret had both the hatches for the gunner and commander open towards the rear, like in the older ET-90 I design.

The ET-90 II turret.
Source: Engesa Manual

It is interesting to note that the Osorio composite armor variant was developed through the use of an Oerlikon 25 mm autocannon as well. Scale models of the composite armor package were tested by shooting at them with the autocannon to simulate the impact 105 and 120 mm tank rounds at the CTA (Centro Técnico Aeroespacial, Aerospace Technical Center). When this was carried out is unknown, but it seems to have been done before 1985, as the CEO of Engesa claims the composite armor was ready in an interview in 1985. As such, it is a possibility that the 25 mm autocannon used to test the Osorio composite is the same 25 mm which ended up arming the ET-25 turret, as it was already in the country and had no other use. This lines up timetable wise, as the first testing of the ET-25 prototype turret was carried out in April 1985.

The EE-T1 P0 Osorio mock-up with the EE-9 ET-25 prototype in the background in July 1985, when an Iraqi delegation examined both vehicles.
Source: Claudio Agostini

The EE-9 with the ET-25 Prototype

The first picture of an EE-9 mounting a prototype ET-25 turret was taken in April 1985 at the Marambaia proving grounds. According to the ex-Engesa employee Edson Kiyohara, the turret was ready and tested as well at that moment. What is perhaps even more interesting than the ET-25, is the EE-9 it was mounted on. The EE-9 shown in the picture is perhaps the single rarest EE-9 Cascavel to have existed, as it uses wheel hubs with planetary gears.

The EE-9 testbed carrying the prototype ET-25 turret in April 1985.
Source: Edson Kiyohara

No EE-9 in service ever used such a system and it only ended up being used on the EE-11 M7 Urutu versions. The advantage of such systems is that they have much better power and torque transmission efficiencies over conventional designs. Drive shafts suffer only a third of the torque over conventional systems as well.

An EE-11 M7 from the Dubai Police Forces, note the wheel hubs.

In July 1985, the turret was mounted on a standard EE-9 M4 hull. An EE-9 M4 can be distinguished from the other EE-9s due to the engine exhaust being located on the top right rear plate. Only Detroit powered EE-9s had this exhaust placement style and only M4s are known to have mounted Detroit 6V53 engines. While EE-9 M7s could mount such an engine as well due to them also having an MT-643 transmission, they seemingly were never acquired with them. The likely reasons for this ranged from pre-existing logistical structures to increased costs of about US$20,000 per vehicle, with less capital heavy customers being the main buyers of the EE-9 M7.

The EE-9 M4 with the prototype ET-25 turret in July 1985.
Source: Claudio Agostini

The July 1985 Iraqi Delegation

In July 1985, an Iraqi delegation visited the Marambaia proving grounds to receive a presentation of the various projects which Engesa was carrying out for Iraq and other countries at the time. Among the vehicles presented were the prototype ET-25 armed Cascavel on the standard hull, an EE-9 with a pepper pot muzzle brake for the APFSDS test batch, and the EE-T1 P0 Osorio mock-up.

The Iraqi delegation examining the EE-9 with the ET-25 prototype turret, with the EE-9 APFSDS testbed in the rear. Note the muzzle brake of the APFSDS testbed.
Source: Claudio Agostini

The vehicles were shown and some test firing was carried out. The concept was something of a success, as Engesa started designing a brand new 25 mm armed turret from the ground up. It would not be unsurprising if the converted ET-90 turret was a proof of concept to gauge the Iraqi interest in a 25 mm armed Cascavel.

The prototype ET-25 turret test firing for the Iraqi delegation.
Source: Claudio Agostini

Redesigned ET-25

With the seeming enthusiasm secured from the Iraqi delegation, Engesa set off developing a new turret. The turret was smaller in shape and more in line with what was needed to house the 25 mm gun. The turret bustle was reduced in size, as it did not need to store 90 mm ammunition as on the ET-90. and the front tapered off much more heavily due to the much smaller breach of the 25 mm. In addition, a round commander’s cupola was introduced for the commander to have better vision around the vehicle and a searchlight was introduced on the front left side of the turret.

The round commander’s cupola and the searchlight.
Source: Jane’s Armour and Artillery

While the turret was more in line with the needed size to house the 25 mm gun, it was just 50 kg lighter, at 2200 kg, than the ET-90 turret, which weighed 2250 kg. This most likely had to do with the introduction of electric turret drives. As far as is known, no ET-90 turret ever received electric turret drives when they were sold by Engesa. The turret drives would have been heavy and above all, they cost as much as the entire turret itself. For the ET-25 however, electric turret drives were a must to help the crew in dealing with more nimble and faster helicopters.

It is interesting to note that an ex-Engesa employee recalls that the ET-25 turret was a manual turret. According to Jane’s Armour and Artillery, this seems to not be the case, as the ET-25 turret came standard with the electric turret drives. It is, however, possible that the employee referred to the prototype ET-25 turret instead, which does seem to have been a repurposed ET-90 II turret.

From here on, the timeline starts to get hazy. This mainly has to do with a single picture of the EE-9 with the new ET-25 turret being tested in Iraq with an Iraqi paint scheme. This hull could be the same hull as the one with the prototype ET-25, but an ex-Engesa employee remembered that the turret was tested on one of the Iraqi hulls. This last detail of the ex-Engesa employee may hold the potential clue in the timeline.

The ET-25 being tested on an Iraqi EE-9 M4 hull.
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

The course of events seems to have gone as follows. An Iraqi commission visited the Engesa factory in September 1986. During this visit, led by Minister of Military Affairs General Abdul Jabbar Shanshal, the founder of Engesa, José Luiz Whitaker Ribeiro, showed the EE-9 ET-25 to the Iraqi general. The vehicle was presented in a brown and dark green camouflage with the EE-T1 P2 Osorio presented behind the vehicle.

The EE-9 with ET-25 being presented to Iraqi Minister of Military Affairs General Abdul Jabbar Shanshal (right) by Engesa founder José Luiz Whitaker Ribeiro (left).
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

After that, in February 1987, it was presented at the Engesa facilities to a Kuwaiti delegation. Why Kuwait was interested in the vehicle is unknown. The turret was dismounted from the hull but still retained the brown and dark green camouflage. Afterwards, the turret seems to have been sent to Iraq for final trials, where it was mounted on an EE-9 M4 hull from Iraq. It failed to garner enough interest and was sent back to Brazil.

The ET-25 turret presented to the Kuwaiti delegation.
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

A 30 mm armed ET-25?

While researching the EE-9 ET-25, the writer found a number of mistakes in previous sourcing. The Italian turret was one of these, while the other error was a supposed 30 mm armed ET-25. According to Expedito Carlos Stephani Bastos, the new ET-25 turret was armed with a 30 mm gun. Multiple ex-Engesa employees refute this claim however, of which one was present when the delegation from Kuwait came to visit the turret.

In addition, the Jane’s Armour and Artillery book also presented the ET-25 turret and never mentioned an optional possibility to mount a 30 mm autocannon. This would be strange if the 30 mm was actually built as Engesa was known to offer as many options as possible to cater to potential customers. As such, it is very unlikely that a 30 mm armed ET-25 was ever built.

EE-9 ET-25 in Detail

As the EE-9 ET-25 was meant for Iraq and was actually mounted on an EE-9 M4 hull, the writer will write the technical section based on the EE-9 M4 specifications. This does not, however. mean that the ET-25 turret would have been exclusively offered on EE-9 M4 hulls.

The EE-9 ET-25 weighed around 12.5 tonnes (13.8 US tons) combat-loaded. It was an estimated 5.3 m (17.4 feet) long including the gun, as the muzzle brake seems to slightly extend further than the hull, and 5.25 m (17.2 feet) without the gun. It was 2.59 m (8.5 feet) wide, about 2.57 m (8.4 feet) tall to the top of the turret and about 3.2 m (10.5 feet) tall if the ET-50 .50 caliber machine gun mount was counted as well. The EE-9 ET-25 had a crew of three, consisting of the commander/loader (turret left), gunner (turret right), and the driver in the middle front hull.

A rear image of the EE-9 with the prototype ET-25 turret.
Source: Claudio Agostini


The hull of the EE-9 M4 was manufactured from welded bimetal steel plates. The hull also featured two covers which were mounted on the hull above the Boomerang suspension, effectively functioning as mudguards and very minor spaced armor. These mudguards could also have depressions in the middle, as on the Iraqi EE-9 M4s, to stow additional jerrycans.

The front upper hull plate presented 16 mm (0.63 inch) of bimetal armor at an angle of 60º. The sides and rear were 8.5 mm (0.33 inch) thick at varying angles, and the top and bottom hull were 6.5 mm (0.26 inch) thick. The front of the EE-9 was meant to protect from .50 machine gun fire at an unknown range, while the entire vehicle was protected from 7.62 mm AP rounds at 100 m (109 yards), and standard 7.62 mm rounds at 50 m (54 yards).

The average effectiveness of the bimetal plates was about 1.8 times the thickness of an equivalent homogeneous plate against 7.62 mm or 1.5 times the thickness against .50 machine gunfire. This meant that, against .50 machine gun fire, a 16 mm bimetal plate could be used instead of a 25 mm homogenous steel plate. These protection advantages over homogenous plates effectively meant that the Cascavel saved a lot of weight without compromising protection. The outer layer would shatter and blunt the incoming projectile, while the inner layer would relatively move with the bullet, slowing it down and stopping it without shattering.

The EE-9 M4 had two headlights and black-out lights integrated in both sides of the lower front plate. A rearview mirror could be mounted on both sides of the upper front plate. Below the driver’s vision block was a foldable windshield, which the driver could use when driving with an open hatch. The driver had access to 3 periscope sights mounted in a sort of vision block in front of him. The driver’s rotating sliding hatch was part of the top plate and was located behind the vision blocks. These periscopes and other periscopes or sights would not have been active or passive night vision equipment unless the Cascavel was ordered with these devices. The standard periscopes were manufactured by D.F. Vasconcellos.

A frontal view of a Colombian EE-9 M4 showing the headlights, the windscreen, and the 3 periscopes.
Source: Rodolfo Alberto Riascos Rodriguez

A ventilation inlet was installed on both upper hull side plates. These ventilation inlets are recognizable by their frustum shape. A siren was installed behind the ventilation inlet on the right side of the vehicle. The fuel tank cap of the Cascavel was located on the left side, in the middle of the upper side hull plate, with the fuel tank installed on the hull floor. The EE-9 had a large ventilation grille on the rear of the vehicle, reminiscent of the M8, and had a rear light on both sides of the ventilation grill. The engine could be accessed through two large hatches on the hull top rear. The engine exhaust was located on the top right rear plate, as was unique to the EE-9 M4s.

An interior sketch of an EE-9 M4.
Source: EE-9 M4 Manual

The M4 used an adjustable ZF 8062 hydraulic powered steering wheel and had two pedals: the throttle on the right side of the steering wheel, and the brake to the right of the throttle. The gear selector was located to the right of the driver and the hand brake was located to the left. A control panel was located on the front left of the driver for, among other things, the headlights, siren, windshield, the various meters, and interior lighting. To the right was the pressure selector for the central tyre inflation system.


The EE-9 M4 used the Detroit Diesel 6V53N V6 engine which produced 212 hp at 2,800 rpm and 598 Nm at 1,800 rpm. The engine had a total cylinder capacity of 5.212 liters, with a cylinder diameter of 98 mm and a stroke of 114 mm. The M4 Cascavel had a top speed of 95-100 km/h (59 mph) and an operational range of 750 km (466 miles).

It had a turning radius of 8.12 m (8.88 yards) and it could ford a depth of 1 m (3.3 feet). The Cascavel could climb a 65º slope, could climb a vertical obstacle of 0.60 m (2 feet), cross a 1.65 m (5.4 feet) trench, and had a ground clearance of about 0.5 m (1.6 feet). The front-wheel could travel for 0.2 m (0.66 feet), while the rear wheels could travel for 0.9 m (3 feet). It used 12 X 20 run-flat tires with a diameter of 0.5 m (1.6 feet). The EE-9 M2 had a distance between the front axle and rear axle of 3.05 m (10 feet), and a distance of 1.4 m (4.6 feet) between the two rear wheels.

The EE-9 M4 used an automatic Detroit Allison MT-643 transmission with four forward and one reverse gears. The transmission system could handle up to 250 hp and was the only transmission used in the EE-9s which could mount the Detroit 6V53 engine. The M7s would also use this transmission, but they were never paired with a Detroit when they were sold by Engesa.

In addition, the Cascavel used an Engesa 2 speed transfer case, which allowed the Cascavel to be used in reduced and high gear. By putting the Cascavel in reduced gear, horsepower was sacrificed for increased torque, making it more effective in climbing slopes. The vehicle was 6 x 6 driven, of which the rear 4 wheels were part of the Boomerang suspension. The Boomerang suspension, in combination with the Engesa 2 speed transfer case, enabled the Cascavel to cross challenging terrain and provide maximum traction in most situations.

The drivetrain of an EE-9.
Source: Engesa Manual

The power of the engine was distributed to a differential on the front side of the vehicle, and a differential in the rear. The rear differential drove the Boomerang suspension with a single axle, which made the Boomerang suspension such an ingenious design.

In 1969, this suspension was invented by Engesa to enable trucks to transport oil to the refineries through rough terrain with bad infrastructure. With this suspension, the trucks could traverse otherwise untraversable hills for conventional suspension systems, as the wheels would always stay in contact with the ground to provide maximum traction.

The suspension system was a two wheeled-single axle driven suspension. The advantage of the Boomerang suspension was that it could be fitted on existing differentials with a single axle. Normally, this meant that the single axle, designed for the torsion forces of a single wheel, was subjected to the torsion forces of two wheels. Through excellent engineering, half of the torsion forces of the two wheels were mitigated by the suspension system built around the original axle. This design not only enabled the drive of two wheels by a single axle but, with clever usage of gears and bearings on both the axle and tube around the axle, the suspension system can rotate around its axle for 360º. This ability to rotate in extreme angles would enable the vehicles to traverse very difficult terrains and still provide maximum traction, as the suspension system curved with the terrain so that all the wheels were always in contact with the ground.

Exploded view of a Boomerang suspension.
Source: Engesa Manual

The Boomerang suspension used leaf springs for dampening. The two front wheels were used for steering. The wheels on the Boomerang suspension all rotated at the same speed. The front wheels were dampened by large coil springs. The vehicle used hydraulic disc brakes, and was steered with hydraulics as well.

A Central Tyre Inflation System (CTIS) came standard with the M4s. This system would help in obtaining the appropriate traction at various speeds by regulating the tyre pressure. This could help in crossing rough terrain but also save fuel. This was done by the driver through a switch. A Bendix Tu-flo 500 air compressor was used to provide the air flow and pressure for the CTIS.


The EE-9 ET-25 used an all-welded bi-metal steel construction to protect against small arms fire. The armor layout of the ET-25 is unknown, but considering the weight of the turret, it would quite likely be similar to that of the ET-90 II turret. This would mean that the ET-25 would have had 16 mm of bimetal armor at the front and 8 mm at the side, rear and top. This would make sense since the hull had a similar armor layout.

The turret front had a wedge shape with the 25 mm KBA autocannon in the gun mount being located in the middle. A coaxial 7.62 mm machine gun was located to the left of the turret in a separate mounting system which seemed to be slaved to the elevation of the main armament. Two lifting hooks were attached to the front side plates, one on each side of the turret. A main armament slaved search light was mounted on the left front side of the turret and a spent shell case ejection system was located in a depression on the right front side of the turret. The shell election system was further protected by two steel covers. The turret had three electrically operated 81 mm smoke dischargers on each side of the rear side plates.

A side view of the turret, note the two folding covers over the shell case ejection system.
Source: Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020

The commander was located on the left side of the turret and had access to a raised cupola. The cupola was able to receive the ET-50 .50 machine gun mount as well for the commander and had a rear-opening hinge hatch. The commander had access to an unknown 3x day periscope which could be replaced by a 2.7x magnification night periscope. In addition, the commander had access to four 1x magnification periscopes located circularly around the hatch.

The gunner was located on the right and had access to a day/night sight as the main gun sight. The sight type is unspecified, but considering Engesa and Iraq widely used the SS-122 sight on the Cascavels and considering the magnification levels listed, it is quite likely the ET-25 uses an SS-122 sight. The SS-122 sight was an image intensifier sight which provided 10x magnification for the day sight and 9x for the passive night vision channel. The sight mirrors were coupled to the main armament to allow for automatic elevation of the sight mirrors in accordance with the gun elevation.

The SS-122 gunner’s sight.
Source: Jane’s Armour and Artillery

On the ET-25, the sight used an integrated laser rangefinder and offered graticules for air engagements. The turret did not seem to have utilized the SS-123FC fire-control system however, as the turret description does not mention the turret having access to a system providing a moving aiming mark for the sights. As such, target engagement would have had to be done through manual operation of the turret drives and the necessary lead caused by moving helicopters would have had to be estimated by the gunner. This effectively meant that, while the EE-9 ET-25 was to serve as practically the last line of defense of a convoy, it did not have all the potential tools at its disposal to somewhat reliably engage fast moving helicopters.

The turret used an electrically powered traverse and elevation system which was powered by the gunner’s controls. This enabled the ET-25 turret to have a turret traverse speed of 36°/s and an elevation speed of 21°/s. The turret offered a gun depression of -10° and an elevation of +55°. It had a 1.6 m turret diameter, which was the same as the other EE-9 turrets, and had a 0.63 m penetration depth within the hull.


The EE-9 with ET-25 was armed with an Oerlikon 25 mm KBA autocannon. The 25 mm KBA had a total length of 2,888 mm and a barrel length including muzzle brake of 2,173 mm. It had a recoil stroke of 25 to 34 mm and weighed 112 kg in total. The KBA used a double belt feed, allowing for two types of ammunition to be fired and offered multiple firing modes. It could fire in single shot, programmable rapid single shot with a rate of fire of up to 200 rounds per minute and fully automatic with a rate of fire of 600 rounds per minute. The gun was described by an ex-Engesa employee as a work of engineering art.

The Oerlikon 25 mm KBA.

The 25 mm KBA has seen service on a wide array of vehicles including infantry fighting vehicles, reconnaissance vehicles, armored personnel carriers, and anti-aircraft vehicles. Most autocannon based anti-aircraft vehicles used at least multiple cannons and had some form of fire-control system to help track air targets, two things which the ET-25 did not have. In addition, practically all other uses with a single autocannon were on reconnaissance vehicles or infantry fighting vehicles where engaging air targets was a secondary mission, not the main objective, as with the EE-9 ET-25.

The ET-25 had 325 ready-use rounds for the 25 mm autocannon, of which 190 would have been High-Explosive Incendiary rounds and 135 would have been Armor-Piercing Discarding-Sabot ammunition. The latter could penetrate up to 25 mm of steel at 2,000 m at an inclination of 30°. It had an effective firing range of 3,020 m and a maximum firing range of 5,850 m. The APDS ammunition would reach a target at 2,000 m in 1.7 s and the HEI in 3.3 s.

In addition, the ET-25 had 200 ready use rounds for the coaxial 7.62 model F-1 machine gun. It supposedly also had 200 rounds in reserve, which would be somewhat strange, as the standard ET-90 turrets had 2,000 rounds in reserve for the coaxial machine gun, which seems a more likely value. In addition, a .50 machine gun could be mounted, which would likely entail that some 7.62 ammunition boxes would have had to be swapped out for .50 boxes instead. The amount of reserve 25 mm ammunition the EE-9 ET-25 carried is unknown.


In the end, the EE-9 with ET-25 turret failed to get any sales. After testing, Iraq returned the turret to Engesa, where it was supposedly scrapped. The EE-9 ET-25 concept seemed to have mainly suffered from the flaw of being everything and nothing. While the 25 mm KBA was used for anti-aircraft purposes on vehicles, autocannon armed anti-aircraft vehicles usually had multiple autocannons and a fire-control system to help engage the air targets. The ET-25 had neither of these and was already lacking in acting as an anti-aircraft vehicle, especially as a last line of defense. In addition, an ex-Engesa employee recalled the tendency of the Iraqis to make widespread use of heavy machine guns to achieve somewhat similar results.

In addition, vehicles that did use a single 25 mm autocannon were usually either reconnaissance vehicles or infantry fighting vehicles. This issue with using the EE-9 ET-25 as a reconnaissance vehicle was that it was a more expensive 90 mm armed EE-9 which also served as a reconnaissance vehicle.

The autocannon alone was already about US$100,000 in 1988 compared to the US$60,000 for the 90 mm gun. In addition, the turret structure itself was also US$5,000 more expensive than a standard ET-90 turret (US$45,000 compared to US$40,000). Had the buyer requested the turret drives to be installed as well, the turret price would have increased with an additional US$58,000. This would have made a fully outfitted EE-9 ET-25, which would have been somewhat capable of fighting off helicopters, cost about US$361,000 compared to the standard Cascavel at US$258,000 without turret drives.

With regards to serving as an infantry fighting vehicle, the Brazilian Army had already identified in the mid-1970s that the EE-9 Cascavel would be unfit for such use due to its lack of armor. Additionally, it could not transport troops either, turning it into either a fire support vehicle or reconnaissance vehicle. The EE-9 ET-25 would have been outclassed by the more cost-effective 90 mm armed EE-9 in both roles.

Additionally, from 1987 onwards and even before, financial war fatigue had reached the Iraqi government. After 7 years of fighting, stalemate, and being the largest arms importer throughout this period, the Iraqi coffers had started to run dry. In its quest to find new and more arms to tip the scales in its favor, the Iraqi government proceeded spending itself into potential bankruptcy. Among the arms to be bought by the Iraqis were for example Astros 2 rocket ammunition, which ended up being stockpiled by Avibras to then be sold to Saudi Arabia in 1991 and used against Iraq in the Gulf War. It is quite likely that Iraq simply could not afford such a specialized and seemingly not very effective vehicle like the EE-9 ET-25.


The EE-9 ET-25 turned out to be the only EE-9 to receive a different main gun than the original 90 mm gun by Engesa or the initial 37 mm. But for all the goals, it seemed to have failed in actually delivering on those promises. It was a jack-of-all trades vehicle with all the shortcomings a jack-of-all trades tends entail. It lacked the ammunition volume and fire control system to serve as an effective anti-aircraft vehicle, the cost-effectiveness to serve as a reconnaissance vehicle, and the armor and infantry carrying capability to serve as an infantry fighting vehicle.

Why exactly the Iraqis did not decide to buy the vehicle is unknown, but it is a possibility that the Iraqi staff had also recognized these flaws. In addition, Iraq simply could not afford the armament which it once could anymore. In short, the EE-9 ET-25 was, for all intents and purposes, a failure in both concept and sales.

The EE-9 testbed carrying the prototype ET-25 turret in April 1985. Illustrations by the illustrious Godzilla funded by our Patreon Campaign.
EE-9 M4 Cascavel armed mounting the ET-25 turret. Illustrations by the illustrious Godzilla funded by our Patreon Campaign.
The EE-9 M4 with the prototype ET-25 turret in July 1985. Illustrations by the illustrious Godzilla funded by our Patreon Campaign.

Specifications (EE-9 M4 ET-25)

Dimensions (L-W-H) 5.3 (with gun) x 2.59 x 2.57 m (17.4 feet x 8.5 feet x 8.4 feet)
Total weight 12.5 tonnes (13.8 US tons)
Crew 3 (Driver, commander, gunner)
Propulsion Detroit Diesel 6V53 212 hp engine (or OM352A 172 hp engine)
Speed (road) 95-100 km/h (59 mph)
Operational range 750 km (466 miles)
Armament 25 mm KBA autocannon
7.62 mm N model F-1 (coaxial)
Optional .50 machine gun (turret top)
Armor Hull Bimetal
Front 16 mm (0.63 inch)
Side 8 mm (0.32 inch)
Rear 8 mm (0.32 inch)
Top 6.5 mm (0.26 inch)
Floor 6.5 mm (0.26 inch)

ET-25 turret (Estimated)
Front 16 mm (0.63 inch)
Side 8 mm (0.32 inch)
Rear 8 mm (0.32 inch)
Top 8 mm (0.32 inch)
Produced 1

Special thanks to Expedito Carlos Stephani Bastos, the leading expert of Brazilian armored vehicles, Jose Antonio Valls, an Ex-Engesa employee and expert in Engesa vehicles, Paulo Bastos, another leading expert of Brazilian Armored vehicles and the author of the book on Brazilian Stuarts and the website, Adriano Santiago Garcia, a Captain in the Brazilian Army and ex-company commander on the Leopard 1 and ex-lecturer on the Brazilian Armored School, and Guilherme Travassus Silva, a Brazilian with whom I was able to endlessly discuss Brazilian Vehicles and who was always willing to listen to my near endless ability to talk about them.


Engesa EE-9 Cascavel 40 anos de combates 1977-2017 – Expedito Carlos Stephani Bastos
Brazilian Engesa EE-9 Cascavel 6×6 at war 1977-2020 – Expedito Carlos Stephani Bastos
Blindados no Brasil – Expedito Carlos Stephani Bastos
Engesa manuals
Engesa brochures
Dual Harness skin stops armor-piercing projectiles Article of Richard M. Ogórkiewicz

Personal correspondence with Ex-Engesa Employees
Personal correspondence with Expedito Carlos Stephani Bastos
Personal correspondence with Paulo Roberto Bastos Jr.
Personal correspondence with Adriano Santiago Garcia

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