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Cold War Brazilian Wheeled Vehicles Cold War Tunisian Armor

EE-11 Urutu AFSV “Uruvel”

Brazil/Tunisia (1980s)
6×6 Amphibious Fire Support Vehicle – Around 11-12 Built (Including Prototypes)

When Engesa started manufacturing the Cascavel and Urutu in the early 1970s, the idea of a fire support version of the Urutu Armored Personnel Carrier (APC) armed with a 90 mm turret was conceived. Such a vehicle was already mentioned in early catalogs and so, in the late 1970s, the Urutu AFSV (Armored Fire Support Vehicle) came to life, effectively an Urutu 6×6 APC armed with a modified Cascavel turret.

This unpretentious vehicle would even try, but ultimately fail, to compete to become the Light Armored Vehicle (LAV) for the United States Marine Corps (USMC) through a partnership with Bell Aerospace Textron. The prototypes participated in multiple trials around the world, including India and Malaysia, but it would find its only successful sale with the Tunisian National Guard.

A Tunisian Urutu AFSV.
Source: https://www.nairaland.com/1386870/african-militaries-security-services-strictly/1062

The Urutu

The Urutu was Engesa’s troop transport, designed by Engesa and the Brazilian Navy. The vehicle was designed from the ground up to be amphibious, and was approved in 1972 after successful testing in various conditions including open sea, for which it was modified with multiple snorkels, propellers and a wave breaker.

Serial production began in 1973, using the same suspension, engines and transmission as the Cascavel. It managed to achieve large sales in Iraq, Libya and most of South America, but the Urutu would never reach the same success as the Cascavel.

Both the Cascavel and Urutu were upgraded throughout their production runs with different engines, transmissions and brakes, as well as different hull designs. The Urutu was operated by a driver and commander, and could carry 10+2 fully equipped infantrymen.

In addition, it could be equipped with a multitude of different turrets (including Anti-Air). The Urutu AFSVs were made by modifying an existing Urutu hull and mounting a 90 mm armed turret on it. Apart from the turrets, the Urutu could also receive various optional components, like an automatic fire suppression system, amphibious equipment and Nuclear Biological Chemical (NBC) protection, all at the client’s discretion.

Uruvel or Urutu AFSV?

The Urutu AFSV is more commonly known as the Uruvel, combining the designations of the EE-11 Urutu and EE-9 Cascavel into a single word. Although this is practically the most common designation of the Uruvel, no evidence has been found that this designation was in official use with Engesa. Engesa called it the Urutu AFSV in all their brochures and, on the vehicles which were trialed, the Urutu logo with Urutu written underneath is shown. As such, it is very plausible that the Uruvel designations is either an unofficial designation, or was coined at a later point in time.

Picture of the logos of Engesa’s wheeled combat vehicles
Source: Expedito Bastos’ Blindados do Brasil Vol II

The Birth of Urutu AFSV Concept

The Urutu AFSV was mentioned in an early Engesa marketing brochure released around 1973-1974. This brochure illustrated the multiple possible armaments and roles their APC could fulfill, with one of these being “a 90 mm for Light Combat Car Duties”. This was around the time when the first Cascavel with 90 mm gun would be produced, but most likely just before one was finished, as only concept art of this Cascavel was shown in the brochure (at the time, the pre-production Cascavels all had 37mm guns). Therefore, it is an accurate estimate that the Urutu AFSV concept was conceived around 1973-1974, although this “light combat car” would not be finished until between 1975-1981.

Another interesting development in the Urutu AFSV concept is found in a brochure estimated to be released around 1974-1975. An Urutu is presented with multiple turrets, of which one is the French H-90 turret armed with a DEFA 90 mm gun. The first 90 mm turrets installed on Cascavels were these French H-90 turrets, but no Urutu is known to have mounted an H-90 turret.

The position of the turret on the vehicle was not accurately represented in these brochures. It is also worth noting is that the Urutu ASFV shown in the brochure has amphibious equipment, such as the tall snorkels and the anti wave blocks at the side of the roof of the troop compartment, indicating that the concept of the Urutu AFSV was already being developed during the Urutu’s initial prototype stages known as the CRTA.

Picture of the estimated 1974-1975 brochure with a French 90 mm turret showcased.
Source: Engesa Brochure

The Urutu AFSV prototype

Engesa would experiment with multiple turrets on the Urutu and Cascavel during their production runs. It is no surprise that the Urutu AFSV received multiple turrets throughout its development. The earliest Urutu AFSV is estimated to have been built between 1975-1981, but the first Fire Support Urutu might date as early as 1973.

A prototype using a British 76 mm Alvis turret and modified boat-like hull was also built. The design and the experimentation with the boat shape suggest that this vehicle might have been built quite early on, but the exact date of the Alvis Urutu is unknown. The boat-like hull was abandoned after no meaningful improvement in sea-borne performance was encountered. The Alvis turret was tested in arctic conditions in Canada, but it wasn’t developed or marketed further. The Alvis Urutu and Urutu AFSV were marketed separately and thus different concepts.

The Alvis Urutu prototype.
Source: Blindados no Brasil – Expedito Carlos Stephani Bastos

The first Urutu AFSV prototype appeared some time between 1976 and September 1980. It was equipped with an ET-90 I/500 turret in a forward position, near the side doors. This first Urutu AFSV participated in the US Marines Hydracobra competition for a wheeled combat vehicle, but lost to the LAV-25. This particular Urutu AFSV was based on an M2 Urutu which had a manual transmission and was equipped with an ET-90 turret and EC-90 cannon with a 500 mm recoil stroke. In the final evolutions of the Urutu AFSV, the turret would be replaced with a smaller turret and relocated to the middle left. For unclear reasons, the layout was changed, although ex-Engesa employees have pointed out that it most likely had to do with the weight distribution for amphibious operation.

The Urutu AFSV M2 was possibly showcased as a simple proof of concept, while improvements and the new turrets for the low pressure 90 mm and the required 25 mm gun were being prepared for the USMC trials. The hull did not have the final type of headlight internal mounting and seems to have still maintained the original number of firing ports compared to the final version, which only had 6 on either side (4 on the troop compartment, 2 by the side doors).

The early Urutu AFSV (Hydracobra). Note the turret bustle of the ET-90 I turret and the rear hull angle of an M1/M2 hull.
Source: https://www.facebook.com/1429476790683407/posts/1992991320998615/

The Urutu AFSV M5 and M7

The final Urutu AFSV’s used a 90 mm Engesa-produced EC-90 IV cannon with a 300 mm recoil stroke (less than the Cascavel’s 500 mm recoil stroke) in a modified ET-90 turret called ET-90/300. This turret did not have a bustle where for example 6 rounds of ammunition were stowed in the original turret. Documents do mention that the original 500 mm recoil gun and turret could still be installed if the customer desired.

Unlike the early Urutu AFSV, the turret was positioned center-left in the hull, leaving space between the side doors and turret basket. Engesa policy left much of the vehicle characteristics and equipment to the client’s discretion.

Two versions of the Urutu AFSV were made in this new configuration. One was based on the M5 Urutu hull, and the other on the M7 hull. The M5 Urutu AFSV had a center-left mounted ET-90/300 turret and used an OM-352A engine alongside an AT-545 automatic Allison transmission. The M5 Urutu AFSV is known to have been built at some point before December 1981, but it is unknown if the M5 Urutu AFSV was built in time for the LAV competition in the United States, as the Urutu/Hydracobra was already rejected on September 11th 1981.

An Urutu AFSV M5 driving in the Desert.
Source:

The M7 Urutu AFSV used the most modern Urutu AFSV hull Engesa produced. It had the same layout as the M5 and was powered by a more powerful Detroit Diesel DDA 6V53 engine and an automatic MT-643 Allison transmission. But, more importantly, and what sets the M7 hull apart from the other Urutus was the usage of planetary gear wheel hubs. The planetary gears provided better torque transfer, efficiency and lower backlash/inertia from the suspension on other components. This was advantageous as the planetary gear would reduce the wear and tear on the automotive components, giving the vehicle a higher durability and life. Although the price and complexity of the Urutu would increase, the extra durability and performance would most likely make up for the extra costs.

The Urutu AFSV M7 in India.
Source:

The Urutu AFSV in Detail

Overall dimensions were the same as the normal Urutu, with the exception of the height and weight, due to the turret. It was 6.15 m long, 2.59 m wide, and 2.6 m tall, which was about 0.4 m taller than the original Urutu. The weight was 14 tonnes, around 2 tonnes more than the original Urutu. This could change even further depending on the engine used.

It was operated by a crew of three (commander, driver and gunner) plus an additional four soldiers in the back, with enough space for an additional two soldiers seated by the side doors, although these are not counted in some brochures.

Hull

The Urutu AFSV hull was the same as the Urutu’s with no major difference whatsoever except the turret ring, although the choice of engine, transmissions and modifications, such as automatic fire extinguishers, were up to the client’s discretion.

Multiple Urutu AFSV M5s in Tunisia.
Source: https://www.nairaland.com/1386870/african-militaries-security-services-strictly/1062

The Urutu AFSV was armored with 12 mm thick armor at the front and 6 mm on the sides and rear. It used Bimetal steel which offered an improved protection to weight ratio compared to standard steel. The Bimetal armor offered around 1.8 times the effective thickness of an equivalent homogeneous plate against 7.62 mm ammunition, meaning the Urutu AFSV had an effective homogeneous thickness of 21.6 mm at the front and 10.8 mm at the sides and rear against 7.62 mm fire.

The hull was welded and angled at the front and with a minor angle at the sides and rear. The rear angle varied depending on the model, with earlier models having a triangular shape, while the later models had a flat rear. The rear door was operated by the driver or manually by the passengers. All Urutus have two side doors.

The driver was positioned in the front left of the vehicle, next to the engine. The engine was located in a separate compartment. In a brochure of the Urutu, a picture is presented which suggests that there is space for two additional soldiers behind the driver and engine, next to the side doors, although these positions are not mentioned in any other documentation. The turret is positioned on the left middle and, directly behind the turret, are ammunition stowage racks. The 4 soldiers were located in the rear of the vehicle.

The general layout of the Urutu AFSV.
Source: Engesa brochure

The placement of the frontal headlights also varied with the hull version. Early versions had external headlights mounted on the upper front plate, while later versions had hull integrated headlights. Attachment hooks for towing cables were present in the front, sirens could be attached to the front sides of the hull, a stowage point for a towing cable was present in the left side of the vehicle, while, on some versions, the right side was occupied by the exhaust pipe. The Urutu AFSV was fully amphibious, although amphibious equipment such as propellers, rudders and snorkels were optional. A swimming vane operated by the driver was fixed to the top of the frontal hull plate.

It could carry four infantrymen in the back plus another two by the side doors and also featured a bilge pump and a manual backup pump for amphibious operations. The Urutu AFSV also had a single circular hatch on top of the back compartment, alongside a number of firing ports for the soldiers in the back, which varied depending on the hull model. The hull could carry 36 rounds of 90 mm ammunition, although it is unknown if this was standard for every Urutu AFSV model.

An interior shot of the Urutu AFSV and its ammunition stowage racks.
Source: Tecnologia Militar Brasileira

The driver had a steering wheel to steer the vehicle and, depending on the version, would have a brake and gas pedal to the right side of the steering wheel. The gear shift for the automatic transmission was located on his right side and the instrument panel was located on his left side. The driver had 3 periscopes at his disposal, which could be upgraded to day/night periscopes.

An interior shot of the driver’s position in the Urutu.
Source: Adriano Santiago Garcia

Mobility

The Urutu AFSV was offered with 3 main engines in combination with various transmissions, although more options were possible depending on the client’s wishes.

Engine Fuel Horsepower Torque
Mercedes OM352 Diesel 125 at 2,800 rpm 353 Nm at 1,600 rpm (260 ft-lb)
Mercedes OM352A (turbocharged) Diesel 190 at 2,800 rpm 431 Nm at 1,800 rpm (318 ft-lb)
Detroit DDA 6V53 Diesel 210 at 2,800 rpm 598 Nm at 1,800 rpm (441 ft/lb)

The engines were paired with a range of transmissions depending on the Urutu AFSV model. It could have a manual Clark transmission of the Urutu AFSV M2 with 5 forward and 1 reverse gears, an Allison AT-545 automatic transmission of the Urutu AFSV M5 with 4 forward and 1 reverse gears, or an Allison MT-643 automatic transmission of the Urutu AFSV M7 with 4 forward and 1 in reverse gears. Only the MT-643 could be paired with the Detroit engine. In addition, the Urutu AFSV used an Engesa 2 speed transfer case, which allowed the vehicle to be used in reduced and high gear. By putting the Urutu AFSV in reduced gear, it sacrificed horsepower for torque, making it more effective at climbing slopes. The vehicle also offered a power take off function for the propellers through the transfer case.

The Detroit DDA 6V53 Engine.
Source: Blindados no Brasil – Expedito Carlos Stephani Bastos

The Urutu AFSV had a maximum road speed of around 95 km/h and a maximum amphibious speed was around 8 km/h. The floatability of the Urutu AFSV was good enough to enable the vehicle to fire its main gun without sinking due to the imbalance the recoil would create, but the Urutu AFSV was not fit for open sea service. The Urutu AFSV also had a remote tire pressure control system to allow pressure regulation of the tyres from within the vehicle.

Its gradeability was around 60%, with the maximum side slope being 30%. The Urutu AFSV had a ground clearance of 0.375 m and could cross a 0.6 m high vertical obstacle. It had an operational range of 850 km. It could also be airlifted, much like all other versions of the Urutu.

An Urutu AFSV M7 entering a transport plane.
Source: Engesa Brochure

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, would enable the Urutu to cross challenging terrain and provide maximum traction in most situations. 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.

Turret

The turrets can be divided into multiple designations. The main designation refers to the recoil stroke of the gun. A turret with a standard recoil gun, as on the Cascavel for example, was designated as ET-90/500, with the 500 referring to 500 mm recoil stroke. The alternative turret was denominated as ET-90/300 with a 300 mm recoil stroke. Other designations refer to the type of turret used. These are ET-90 I and ET-90 II, which are both turrets designed by Engesa and armed with the EC-90 gun. When one of these turrets is referred to with 300, it means that it is a smaller turret instead of the original Cascavel turret.

The Urutu AFSV had the same turret ring diameter (1,600 mm) as the Cascavel, so the vehicles had interchangeable weapon systems. The first turret installed on a Urutu AFSV prototype was a Cascavel’s ET-90/500 turret mounted in a forward left position equipped with a EC-90 III cannon. Even with this ample weight away from the center of mass the vehicle was fully amphibious, although further details on its sea-borne performance are unavailable.

ET-90 I/500

The ET-90/500 was designed and produced by Engesa in 1975 to replace the French H-90 turrets, so the Cascavels could achieve a higher rate of domestic production. It was made from scratch to be armed with the EC-90 gun, Engesa’s licence produced Cockerill 90 mm low pressure cannon. It had a commander on the left and a gunner on the right side of the turret, and both had 4 periscopes.

The ET-90 I/500 that equipped M3 Cascavels and the early Urutu AFSVs. Note the small droplet hatch at the side that was used to dispose of spent rounds and could be used to fire the commander’s personal guns at surrounding infantry.
Source: Engesa Manual

In some aspects, the turret resembles a H-90 turret, with both sharing the same ring diameter, armament, and layout in some points. The ET-90/500 weighed 2,400 kg and had 16 mm of Bimetal steel armor all-round and 8 mm on-top. It could carry 24 rounds of 90 mm ammunition and had a French F-1 co-axial machine gun. The cannon was fired through a pedal that ignited an electric mechanism in the breech that in turn ignited the primer in the casing. The turret had a handle for elevation and horizontal transverse, with the former also having a trigger for the coaxial machine gun. This turret was used in the Urutu AFSV prototypes but was superseded by the ET-90 2/500 and the ET-90/300.

The ET-90 I bustle rack.
Source: Engesa Manual
ET-90 I turret basket. Notice the ammunition supports behind the crew seats, and the box at the floor of the basket that holds hand grenades.
Source: Engesa Manual

ET-90 II/500

The ET-90 II/500 was first installed on Cascavel M4, becoming standard for all later Cascavels. It shared most characteristics with the earlier ET-90 I, with a few exceptions.
The turret ventilator was relocated to the back of the turret roof, while in the early ET-90, it was mounted in the bustle. The turret height was increased to provide more room and depression for the gun. The turret basket was also redesigned with a slight size increase. Not only was it more comfortable and ergonomic, but the new turret was also capable of receiving modifications such as laser-rangefinders, NVG devices, and drive-motors for traversing the turret. The armor value was the same as the early ET-90, 16 mm all around and 8 mm on-top.

The ET-90 II/500 that debuted in the M4 Cascavel. Note the laser rangefinder and day/night sight for the gunner. This was not standard on all turrets, being left at the client’s discretion.
Source: Engesa Manual

In addition to the overall size increase of the ET-90 II/500 turret, the turret also mounted the Brazilian M971 MAG (FN-MAG licensed copy) as the coaxial machine gun. The gunner’s hatch now opened to the front, being located on the right side of the turret. The bustle rack in the early ET-90 had a double configuration where half of the ammunition was in a revolver-like drum and the rest in rectangular cells. In the ET-90 II, all of the ammunition was stowed in rectangular cells. The ammunition load for both the machine gun and the 90 mm cannon remained the same. It also mounted an improved EC-90 III gun.

The ET-90 II bustle rack, note the equipment and the ventilation pipe.
Source: Engesa Manual

The new turret could also be equipped with a sub-turret for the commander, designated the ET-7,62. The ET-7,62 sub-turret was installed on top of the commander’s hatch to the left of the turret. It had 8 mm all around armor and a universal mount for machine guns or grenade launchers. The machine gun could be fired from within the turret through an electric system using solenoids. The sub-turret could also be equipped with NVG devices and had a dedicated sight for aiming the machine gun remotely.

The ET-90 II turret basket. Note the straight turret basket rods instead of the tapering rods of the ET-90 I turret.
Source: Engesa Manual

ET-90/300

Not much info is available on the ET-90/300 development history, with evidence pointing that two versions of this turret existed, much like its large predecessors from which it was derived. In some images, the gunner’s hatch opens forward, while in others it opens backwards. The ET-90/300 is basically an ET-90/500 without the bustle, eliminating the bustle ammunition rack, which reduced its ammunition capacity from 24 to 12 rounds. The removal of the bustle caused the rearrangement of the ventilator location. The turret weight was reduced to 1,800 kg while maintaining the same performance characteristics as the original ET-90. The elimination of the turret bustle also called for a new gun with a smaller recoil stroke, which was designated EC-90 IV (300 mm recoil, 200 mm less than the original EC-90).

An Urutu AFSV M5 with a center-left positioned ET-90/300 turret.
Source: Brazilian Army

Both versions of the ET-90/300 turret were equipped with 6 smoke launchers on either side of the turret. It had a commander on the left and a gunner on the right side of the turret. The commander’s hatch could mount the ET-7,62 machine gun sub-turret. Both turrets had manual transverse with the option of installing a motor for automatic transverse at the client’s discretion. The turrets had 8 periscopes (4 per crewmen) and a 6x magnification sight for the gunner. The M5 and M7 versions of the Urutu AFSV were equipped with the lighter ET-90/300 turret mounted on a center-left position.

Firepower

The Urutu AFSV was armed with a 90 mm EC-90 IV cannon (36 calibers in length) and had a recoil stroke of 300 mm. As secondary armament, the Urutu AFSV had a Coaxial 7.62×51 M971 (FN MAG) machine gun and a roof-mounted .50 or a 7.62 machine gun mounted on the turret or attached to a ET-7,62 sub-turret. It carried six 76 mm smoke launchers, three on each side of the turret, and stored 12 additional smoke grenades in the turret. The Urutu AFSV carried 12 rounds in the turret, stored in revolver-like drums attached to the floor, plus another 36 rounds in the hull.

Round Capability Effective range Velocity
HEAT (High Explosive Anti Tank) 130 mm (5.1 inch) at 60º from vertical or atleast 250 mm (13.8 inch) flat at any range. 2,000 meters (2,185 yards) 900 m/s
HESH (High Explosive Squash Head) Meant for bunkers, walls, and light vehicles. 2,000 meters (2,185 yards) 800 m/s
HE (High Explosive) Lethal radius of 15 meters (16 yards) 2,000 meters (2,185 yards) 700 m/s
HEAT-TP (High Explosive Anti Tank – Training Projectile) Training projectile 2,000 meters (2,185 yards) 900 m/s
White Phosphorus – Smoke Smoke round 2,000 meters (2,185 yards) 690 m/s

The Urutu AFSV’s firepower was the same as the Cascavel, allowing for the same upgrades, such as laser rangefinders and stabilizers. The Urutu AFSV could be fitted with day/night sights and an electric turret drive as well. The vehicle had a gun elevation of up to 30º and a gun depression of -8º.

The EC-90 Cannon
Source: Engesa Manual

Export Attempts

The first Urutu AFSV prototype participated as a candidate in the trials for the USMC as Bell’s Hydracobra, where it did not pass the initial selection process. Another Urutu AFSV prototype with an Alvis turret and 76 mm gun was tested in the frigid Canadian weather. It seems that the Urutu AFSV and the Hydracobra family were also marketed to Canada, considering the advertisement of the Hydracobra was translated to French.

The United States

Interestingly, the United States would show interest in the Urutu, and indirectly in the Urutu AFSV on two separate occasions. The first was with Bell Aerospace trying to sell the Urutu under the Hydracobra name to the USMC and the Rapid Deployment Force, and later Food Machinery Corporation (FMC) for the same style of Rapid Deployment Forces, special forces, or strategical garrisons.

The Hydracobra

The prototype of the Urutu AFSV appeared as part of a license deal of the Urutu family between Engesa and Bell Aerospace, renaming the Urutu to Hydracobra for the USMC LAV competition in 1980. A version equipped with an ET-90 turret in a forward position, near the side doors, was trialed. The Urutu AFSV fulfilled all of the competition requirements and was submitted. Fortune did not smile at the Hydracobra though, as it did not pass through to the subsequent phases of the competition and was rejected.

A chart showing the various configurations the Urutu/Hydracobra could be built in.
Source: https://www.forte.jor.br/2017/05/24/blindado-urutu-da-engesa-quase-foi-produzido-nos-eua/

The trials demanded a light AFV which could serve for a wide range of roles with full NBC protection, carrying capacity for at least 4 soldiers, amphibious capabilities, light enough to be transported by an CH53 helicopter with a maximum weight of 14 US tons (12.7 tonnes), and had to have the following armaments as an option: 25 mm, 75-105 mm or high velocity gun, Anti-Tank Guided Missile, and mortar. The Urutu would be sold as the Hydracobra through Bell Aerospace. Bell Aerospace would improve the Urutu to United States standards and would subsequently license produce them at Bell’s Wheatfield plant.

The proposed Assault gun and 25 mm turret version of the Urutu/Hydracobra.
Source: Aerospace Technologies of Bell Aircraft Company : a Pictorial History (1935-1985)

FMC

FMC would also attempt to sell the Urutu, and indirectly the Urutu AFSV, around 1985-1986 to the United States. The vehicle was again marketed for some form of Rapid Deployment Force, but also for special forces, such as Delta Force. It was also stated that the vehicles were considered to be sold to the USMC and Army units of the American Armed Forces. The Urutu was trialed in Fort Lewis by the US Army and FMC. After three months of testing in late 1986, FMC would then consider the acquisition of licenses to produce an estimated 200 vehicles, with potentially another 600 for the USMC and the Ranger units of the Army.

Although some sources suggest that the license deals were signed, it seems that the deal and the production for the US Army never actually went through. It already was a very intriguing move by FMC in the first place to try to sell the Urutu again to the United States. The US was already operating the LAV, which could also have been sold to these units as well. It would not be surprising if the United States just wanted to test out the Urutu again to see what it could and could not do, and to maybe sell the Urutu to bind smaller nations to them. In the end, the trials and the license deal never resulted in any physical production by FMC.

Malaysian Trials

The Malaysian Army sought a new armoured vehicle to replace its aging Panhard M3 and V-100 fleet. The SIBMAS, Urutu AFSV and Condor would attempt to obtain the contract. The process towards and the trials themselves would have a number of somewhat questionable occurrences like having no set requirements and eventually set up requirements in the SIBMAS’ favor.

The M5 Urutu AFSV was trialed in Malaysia in 1981, where it performed seaborne firing, (something the engineers thought impossible) and armor tests against small caliber munitions, which it passed without a single penetration.

The Urutu AFSV did not manage to secure a contract in Malaysia which went to the SIBMAS and Condor instead. The decision was met with opposition over the process of the trials, but after a review, the SIBMAS and Condor were still ordered.

Armor test in Malaysia. The armor managed to stop 7.62 and 5.56 AP rounds at 100 meters, and ball rounds at 30 meters.
Source:

Tunisian Service

Tunisia is the only country to operate Urutu AFSVs. but nothing is known about the trials. They received 9 vehicles in 1982 and are used by the Tunisian National Guard for internal security purposes. The Urutu AFSVs in Tunisian service are M5 Urutus equipped with OM-352A engines. These vehicles are used to guard important government buildings in major cities during times of unrest. They were used during the Arab Spring to protect parts of Carthage as passive onlookers.

Thanks to the price tag and the practical characteristics of the vehicle, internal security seems to be its niche. Being capable of intimidating crowds and carrying small numbers of troops around urban environments, as well as dealing with heavy opposition if need be, the Urutu AFSV seems like a perfect vehicle for Gerdameries and rear line security, something similar to the VBC-90s used by the French Mobile Gerdameries.

A Tunisian Urutu AFSV M5 during the Arab Spring.
Source: https://www.nairaland.com/1386870/african-militaries-security-services-strictly/1062

Indian Trials

In 1985, an M7 Urutu AFSV, equipped with planetary gears in the wheels, was tested in India in harsh winter conditions at a high altitude, going as far as swimming in lake Tso Moriri. Its performance was optimal in all weathers and attitudes, although no contracts came out of these trials. It is unknown if any other vehicles were tested and what the Indian Army exactly had in mind for the EE-11 AFSV. The trials remain a bit of a mystery.

The Urutu AFSV M7 in India.
Source: Blindados no Brasil – Expedito Carlos Stephani Bastos

The EE-9 and the EE-11 Versus the Urutu AFSV

The Cascavel and Urutu were designed as ‘sister’ vehicles in the same span of time. The Cascavel was finished before the Urutu and reached more success than the Urutu thanks to its simplicity and tactical value, even though the Urutu was initially thought by Engesa as their most promising product.

The Urutu AFSV was Engesa’s attempt at combining both vehicles, but the compromise seems to have been too much to make it an interesting vehicle. To make a comparison, 3 Urutu AFSVs with Detroit engines were priced at 1.038 million US Dollars in 1988. This meant 3 EC-90 guns and transporting 12 troops to the battlefield. If a nation would instead buy three Cascavels and an Urutu instead, it would have to pay 1.020 million US Dollars for 3 EE-9 Cascavels and 1 EE-11 Urutu, of which the Urutu could transport 11 troops. So for less money, a country could obtain purpose-built equipment or it would spend more for a hybrid vehicle.

This difference in price and the capabilities that purpose-built vehicles bring to the table suggests that the Cascavel-Urutu combination was much more interesting for Armies, as demonstrated by Bolivia, Colombia, or Gabon, while the Urutu AFSV was much more interesting for specialized forces or national guards, like in Tunisia. The overall role the Urutu AFSV seems to market towards is simply much more limited than what the Cascavel and Urutu could deliver for an Army. This is the main reason why it is thought that only Tunisia acquired the Urutu AFSV.

Fate of the Prototypes

It is unknown what happened to most of the prototypes of the EE-11 Urutu AFSV. The M2 Urutu AFSV has most likely either been scrapped or repurposed by Engesa for a different configuration. The Urutu AFSV M5 has either been scrapped, reconfigured, or sold as part of the 9 Urutu AFSV M5’s to Tunisia. The Urutu AFSV M7 returned to Engesa after the India trials, where it remained until Engesa went bankrupt in 1983. After Engesa’s bankruptcy, the Urutu AFSV was passed on to Universal Ltda, a company specialized in overhauling and maintaining Engesa equipment, where it was disassembled in 2001.

Conclusion

The Urutu AFSV is the fire support version of the Urutu APC, armed with a low pressure 90 mm cannon, effectively combining both the Urutu and Cascavel into a single platform. Initially, the Urutu AFSV used a slightly modified ET-90 turret (the same as the Cascavel), but an improved weight balance most likely drove for a redesign with a smaller and repositioned turret of the eventual Urutu AFSV in use today.

It seems that the hybrid nature of the Urutu AFSV also became its undoing. The costs to operate hybrid vehicles compared to purpose-built vehicles simply did not add up for Land Forces to pick the Urutu AFSV over a Cascavel-Urutu combination in conventional units. The Urutu AFSV effectively became more of a niche vehicle, serving in National Guard units instead. The Urutu AFSV was trialed around the world in an attempt to sell it, and although widely marketed, it only managed to secure a single 9 vehicle contract with Tunisia to serve in the Tunisian National Guard. In the end, the Urutu AFSV remains as an interesting concept, attempting to combine the features that made the Cascavel and Urutu great, but ultimately too much of a compromise to be interesting or viable for standard army units.

EE-11 Hydracobra on an M1/M2 hull, illustrated by Ardhya ‘Vesp’ Anargha, funded by our Patreon campaign.
Later Uruvel in Brazilian two tone camo, illustrated by Ardhya ‘Vesp’ Anargha, funded by our Patreon campaign.
EE-11 M5 Engesa export, illustrated by Ardhya ‘Vesp’ Anargha, funded by our Patreon campaign.
EE-11 M5 in Tunisian service, illustrated by Ardhya ‘Vesp’ Anargha, funded by our Patreon campaign.
EE-11 M5 CFN, illustrated by Ardhya ‘Vesp’ Anargha, funded by our Patreon campaign.

Specifications EE-11 Urutu AFSV

Dimensions (L-W-H) 6.15 (20’) , 2.59 (8’) , 2.6 m (8’)
Total weight 14 tonnes (15.43 US tons)
Crew 3 + 4 (possibly 6 extra personnel depending on internal configuration)
Propulsion OM352, OM352A Mercedes Benz engine or Detroit Diesel DDA 6V53
Suspension Boomerang Suspension
Speed (road) Around 95 km/h (59 mph)
Operational range 850 km (528 Miles)
Armament 90 mm EC-90 low pressure cannon
Armor Hull
Front 12 mm (0.5 inch, Bimetal) at 70º
Front (Lower Glacis) 12 mm (0.5 inch, Bimetal) at 30º
Sides 8 mm (0.3 inch, Bimetal)
Rear 8 mm (0.3 inch, Bimetal) at 10º
Turret
16 mm (0.63 inch, Bimetal) allround
8 mm (0.3 inch, Bimetal) top
Produced 11-12 (Including Prototypes)

Sources

Blindados no Brasil – Expedito Carlos Stephani Bastos
Engesa EE-9 Cascavel 40 anos de combates 1977-2017
Engesa’s Marketing Brochures
Engesa’s User and technical manuals for the Urutu and Cascavel
Research and development Title 2 – Hearings on Military Posture and H.R. 5968
LAV-25 – The Marine Corps’ Light Armored Vehicle – James D’Angina
Concept Definition and Evaluation Criteria for the Mobile Protected Weapons System and the Light Armored Vehicle – Terry A. Bresnick, Charles P. Annis, Dennis M. Buede
Kwajalein Hourglass Volume 18
Personal correspondence with Ex-Engesa employees
Engesa pretende atrair compradores para o Urutu, o Cascavel e o Jararaca – 15-3-1981
Brasil deve receber US$ 1,5 bi dos EUA por venda de tecnologia bélica – 17-4-1986
Exército norte-american poderá comprar carro blindado de Engesa – 14-11-1986

Categories
Cold War Brazilian Armor Cold War Brazilian Wheeled Vehicles Has Own Video

VBB-1

Federative Republic of Brazil (1969)
Reconnaissance Vehicle – 1 Prototype Built

Up until 1967, Brazil was dependent on foreign countries for armored vehicles. Throughout and in the aftermath of World War 2, Brazil would receive large numbers of cheap armored vehicles from the United States, including the M3 Stuart and the M4 Sherman, as it had entered the war on the Allied side in 1942. In fact, Brazil had not undertaken any tank design since 1932, and those had only been conversions of tractors and cars into armored vehicles during the revolutions of 1924, 1930, and 1932.

Between 1932 and 1958, the Brazilian Armed Forces created a solid basis of technical institutes from which it could educate technical and research personnel. In turn, these helped the Brazilian automotive industry in developing its own automotive parts and helped in opening laboratories for the manufacturers. In 1967, Brazil set up a plan for the country to become more self-sustaining. The flow of US material had decreased because of its entanglement in the Vietnam War and, after a study, Brazil recognised external dependence on arms suppliers as a serious problem for its political position in South America.

The plan to solve this would be the start of the Brazilian defense industry. The first steps were small, from its first tracked armored vehicle meant for serial production in 1965, called the VETE T-1 A-1 Cutia, to its very first wheeled reconnaissance vehicle with production in mind, designated VBB-1 in 1967. The VBB-1 kickstarted the development of wheeled armored vehicles in Brazil, with the EE-9 Cascavel being the most successful result.

The VBB-1.
Source: https://www.lexicarbrasil.com.br/exercito/

Development

The Viatura Blindada Brasileira 1 (VBB-1), (English: Armored Car of Brazil 1) was developed by the PqRMM/2 (Parque Regional de Motomecanização da 2a Região Militar, Regional Motomecanization Park of the 2nd Military Region), which was a group of Army automotive engineers gathered to study, develop and produce armored vehicles for Brazil. The PqRMM/2 developed its vehicles under the supervision of the Diretoria de Pesquisa e Ensino Técnico do Exército (DPET), (English: Army Directorate of Research and Technical Education). The PqRMM/2 was the birthplace of many of the concepts that resulted in the EE-9 Cascavel and EE-11 Urutu, among others. The first steps of the PqRMM/2, meant to gain experience, was the remotorization of vehicles like the M8 Greyhound and the M2 half-track, which received a diesel engine.

From the experience gained, the PqRMM/2 team initiated the development of a wheeled armored vehicle for reconnaissance. The reason for the PqRMM/2 to develop a wheeled vehicle was because of a study carried out by the Diretoria Geral de Material Bélico (DGMB), (English: General Directorate of War Material), which called for the intensive adoption of wheeled armored vehicles for the Brazilian Army, after having studied wheeled vehicles from various countries. These types of vehicles needed less investment, and were more feasible to develop instead of importing them. The study called for a vehicle like the M8 Greyhound, but simpler.

The reason why the DGMB wanted a vehicle like the M8 Greyhound is because of the experience Brazil had during World War 2 with the vehicle. Brazil sent an expeditionary force, also known as the Smoking Snakes, to fight in Italy alongside the Allies. The Brazilians would operate the M8 during the Italy campaign, and they loved the vehicle. The positive experience with the M8 caused it to be one of the, if not the most impactful vehicles for Brazilian development of armored vehicles. As a result, most of the important wheeled vehicles and the wheeled vehicle program can trace back their roots to the M8 Greyhound during the Italian campaign. The most well known Brazilian vehicle that was based on the M8 Greyhound, albeit heavily improved, was the EE-9 Cascavel.

Early designs

In 1967, the DGMB made a sketch of a 4 x 4 vehicle, armed with a 37 mm cannon which was mounted in a rotating turret. The vehicle needed to have a crew of 3 to 4 members, and was to be sufficiently robust and powerful as the M8, but simpler. This was requested in order not to overburden the PqRMM/2 team more than what they could achieve. The DGMB requirements were passed on to the higher-ups of the Army, which officially collected it under Officia 372, a requirement study for the PqRMM/2 to work from. Further demands were the use of as many off-the-shelf components as possible, in order to profit from the Brazilain automotive industry and to save costs (this would be a common theme for almost all of Brazil’s wheeled vehicles). In addition, the turrets were to be re-used from the obsolete T17 Deerhounds, of which Brazil owned 54 at the time. Finally, the plan was for the chassis to eventually be modified to suit APC, anti-infantry, and anti-air roles.

Sketch of the VBB-1 made by the DGMB in 1967.
Source: Blindados no Brasil

The concept of the 4 x 4 VBB-1 was inspired from the Belgian FN 4RM 62F Auto Blindée. This was one of the vehicles which was studied by the DGMB. Although the VBB-1’s concept was based on the Belgian vehicle, the guns were different. Brazilian doctrine at the time called for the usage of 37 mm guns on reconnaissance vehicles. It can be questioned to some extent if the DGMB might have been stuck in its ways regarding Brazil’s doctrine on the 37 mm, but on the other hand, the VBB-1 was never meant to be groundbreaking or match to its counterparts of the period. Although the concept was based on the Belgian vehicle, the overall design of the VBB-1 seems to have taken most of its inspiration from the M8 Greyhound.

In July 1968, the team led by Lieutenant-Colonel Pedro Cordeiro de Mello, who was the leader of the PqRMM/2, started designing the VBB-1. It would have a 4 man crew and carry spare tires on the sides of its hull. Somewhere around this time, the spare T17 Deerhound turrets got ditched from its development. The reason why is not confirmed by sources. It could be that the development team decided that, while developing a new vehicle with serial production in mind, designing it to mount a turret of which just 57 are available might not be the best decision. It was better to take advantage of the steel foundries and contract a factory to develop turrets. This would give the Brazilian industry experience with turret manufacture and gain another step towards independence. In July of 1986, the first scale model mockup was built. An interesting detail of this model is the complicated raised hull structure towards the turret. Another important detail are the spare tyres mounted on both sides in the middle of the vehicle.

First model of the VBB-1.
Source: Blindados no Brasil

A second model was made, which already simplified the hull construction a bit, and removed the spare tyres in the middle of the first model, replacing them with a continuous side armor plate instead. This was most likely done as the next step within the development of the VBB-1, as the PqRMM/2 had requested the development of so-called bullet-proof tyres, which would theoretically render the spare tyres obsolete in the grand scheme of operations. But it remains unclear if this model was designed with the bullet-proof tyres in mind, or if this model was designed alongside the first model as a proposal.

The model without the spare tyres.
Source: Blindados no Brasil

Development of indigenous run-flat tyres

On June 3rd 1968, Lieutenant-Colonel Mello requested the development of bullet-proof tyres known in Brazil under the acronym P.P.B. (Pneus à Prova de Balas), or run-flat tyres. These tyres were developed by Novatração and would be used for the VBB-1. The selected size of the VBB-1’s tyres was 9.00-20, which was the same size as those of the M8 Greyhound. The tyres were thus interchangeable and the prototypes were extensively tested on the M8’s. The first tyre was developed 3 months after the initial request, and used an outer protective tyre and a separate inner wall. The outer and inner tyre were pushed against the rim lips with an inner rubber ring, also known as a separator. Due to heating issues when used continuously for over 200 km (124 miles), the tyres were rejected.

The next step was a critical development for Novatração. Instead of using an inner tyre, Novatração decided they could use the outer tyre as the inner tyre and the separator ring as a run-flat tyre. This meant that if the outer tyre was punctured, the vehicle could still keep on driving on the separator ring. Another advantage was that crews could now easily field repair any puncturing without the need of removing the wheel from the axle and the outer tyre from the wheel, in order to be able to fix the punctured inner tyre. The new tyre was extensively tested from March 1969 on, and could travel for at least 500 km (311 miles) after it was punctured. Interestingly, the tyre was also tested for a year without any air in the tyre or repairs to the tyre, the tyres held up for 1,200 km (746 miles). The tyres were accepted and delivered in October 1969 to the PqRMM/2. Although the VBB-1 already received its run-flat tyres around March or April of 1969, as a picture dated April 1969, shows a VBB-1 with run-flat tyres.

The VBB-1 tyre on the left and its design by Novatração on the right, note the single outer tyre and the separator around the rim.
Source: Blindados no Brasil

Turret development

Parallel to the development of the tyres was the development of the turret. The initial idea of reusing T17 Deerhound turrets had been ditched, and the PqRMM/2 team opted for a locally produced turret. Sources do suggest that the 37 mm cannons of the T17 Deerhounds were used for the manufacture of the turrets. The new turret was practically a somewhat improved copy of the M8 Greyhound turret. The turret was cast by Fundições Alliperti S/A from SAE 5160 steel, and was further machined by the company Avanzi.

Various gun mantlets were cast by Alliperti and presented on October 25th 1968, along with other components of the turret. A simple gun mantlet with just the main gun hole and a vision hole was selected. This was a simpler gun mantlet than the M8 Greyhound’s mantlet, which was also proposed. Another important difference was that the turret would receive two hatches, instead of an open-top turret like the M8, and it also received a mount for a .50 calibre machine gun in front of the turret hatches. Alliperti produced 8 turrets in total.

Components of the turret and 2 of the proposed gun mantlets. On the left side, an M8 Greyhound like mantlet, and on the right, the simpler mantlet. The simpler mantlet was selected with an extra hole to the side of the 37 mm hole for direct vision purposes.
Source: Ford M-8 Greyhound no Exército Brasileiro

Hull

After the construction of the initial models, work began on building a steel scale model. This steel scale model would start showing clear features from the M8 Greyhound, with the driver and assistant driver’s hatch style being the most notable. The overall shape of the hull, especially the part towards the turret, seems to have been somewhat simplified. A very important detail is the armor values written on the sides of the steel scale model. These values are exactly the same thickness of 3/8 inch (9.5 mm) as the M8 Greyhound’s side armor plates. This might suggest that the overall armor values of the VBB-1 are the same as the M8 Greyhound armor values.

The steel scale model with the armor values written on the plates.
(This picture has been accredited to both the VBR-2 (a 6 x 6 project of the PqRMM/2) and VBB-1 by the writer Expedito Carlos Stehpani Bastos, but after asking the writer himself, he confirmed it was a scale model of the VBB-1, and not the VBR-2.)
Source: Blindados no Brasil

With the initial models and the steel reference scale model completed, work began on the construction of the hull somewhere between July and October 1968. The hull was constructed by the company Trivellato. It reached an advanced stage on October 25th, 1968, when it was photographed. Interestingly, at this point in time, the hull was constructed in accordance with the run-flat tyre concept. However, it is known that the VBB-1, of which a single vehicle was built, was initially delivered as per the spare tyre concept. The first more or less finished vehicle with run-flat tyres was photographed in April 1969, and the first run-flat tyres were made in March 1969. As the hull was initially constructed with the run-flat design, it seems that the PqRMM/2 team decided that it would use the spare tyre concept and cut the side parts of the hull for the spare tyres to be mounted. Somewhere in the early months of 1969, the spare tyre concept vehicle had been delivered, as it was presented to the Army in 1969, and early shooting tests were carried out in 1969, with both vehicles.

Why the PqRMM/2 team decided to cut the sides of the hull for the spare tyres and not wait until the run-flat tyres were delivered, is unknown. It is likely that they wanted to get the vehicle done, and the first set of tyres developed by Novatração did not meet the requirements. They probably weighed the chances of Novatração developing a tyre within specifications and the PqRMM/2 team being able to finish the first concept of the vehicle. With Novatração not having developed a new tyre yet, they went on to develop the spare tyre concept. In addition, an argument can be made that, even though Novatração would have developed a new tyre in time, nothing assured the PqRMM/2 team that that tyre would be significantly better. As converting it back to the run-flat concept would only entail removing the spare tyre mount and welding some extra plates to the side of the hull, the team probably decided that going through with the spare tyre concept was more effective.

The hull which is dated on October 25th 1968. Note the Greyhound tyres.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

The spare tyre concept

When the first version of the VBB-1 with the spare tyres on the side was finished is unknown. It is estimated that it was finished somewhere in between January 1st and March 1969. The reason is because the spare tyre vehicle was presented to the Army in 1969, and shooting tests were carried out with the VBB-1 in this configuration, but in March 1969, the first run-flat tyres were developed and the run-flat concept was first photographed in April 1969.

VBB-1 presented to the Army in 1969.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

Most of the components used for the VBB-1 seem to have been in advanced stages in October 1968. The turret was almost done, the hull was also nearing completion, and the engine was installed in the vehicle as well. Like the VETE T-1 A-1 Cutia before it, and many vehicles after it, the VBB-1 was built with components from numerous private companies. Mercedes-Benz was one of the most important companies involved in the development of early wheeled armored vehicles. Mercedes-Benz Brasil had provided the M8 Greyhounds with new diesel engines, transmissions and differentials during the first stages of the PqRMM/2. For the VBB-1, Mercedes-Benz would again deliver the diesel engine, transmission and a specially developed differential. The differential was an off-center differential which was specially designed by Mercedes-Benz for the VBB-1 project.

Company Component(s)
Mercedes-benz Engine, transmission, differential and other components
Trivellato Hull
Fundições Alliperti S/A Turret
Avanzi Turret
Novatração Run-flat tyres
Engesa Transfer box
Colméia Radiators
MANN Filters
ZF Friedrichshafen Hydraulic steering
DF Vasconcelos Optics
The VBB-1 spare tyre concept.
Source: Blindados no Brasil

The completed VBB-1 with spare tyres was presented to the army in the first quarter of 1969. Almost immediately after it was delivered, the armament and the vehicle were tested. If the tests included anything more than just firing is unclear. It can be expected that it was at least briefly tested and that it performed well enough for the project to carry on. In March 1969, the run-flat tyres from Novatração were finished and, in April 1969, the first picture of the VBB-1 without spare tyres was made.

Firing tests carried out in the first quarter of 1969.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

Run-flat tyre concept

With the development of the run-flat tyres in March 1969, the now finalized VBB-1 was presented in April 1969 in front of the Mercedes-Benz factory in São Paulo. The pride of Mercedes-Benz, or at least their attempt to capitalize on their participation with these Army projects, was shown in the form of a photo album which they had made. This photo album contained pictures of the M8 Greyhound that Mercedes had modernized, and pictures of the VBB-1. Mercedes-Benz Brasil would continue delivering its engines to the rising Brazilian defense industry, which would find their way into the EE-9 Cascavel, EE-11 Urutu, EE-3 Jararaca, and in trucks used for military purposes.

The completed VBB-1 in front of the Mercedes-Benz factory. On the left, a director of Mercedes-Benz Brasil. On the right, Lieutenant-Colonel Pedro Cordeiro de Mello, the leader of the project.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

The VBB-1

The VBB-1 weighed 7 tonnes (7.7 US tons) and was 5 meters (16.4 feet) long, 2.5 meters (8.2 feet) wide, and 2.3 meters (7.55 feet) tall excluding the turret mounted .50 calibre machine gun. Since the VBB-1 was inspired by the M8 Greyhound, its crew was positioned in a similar manner and it is most likely that the crew had the same tasks as in the M8. The VBB-1 was operated by a four-man crew, consisting of the Commander, Gunner, Driver, and Co-driver. The role of loader was most likely carried out by the Commander, like in the M8. The Co-driver would function as a Radio-operator, but if the VBB-1 ever had a radio set installed is unknown.

The VBB-1.
Source: Blindados no Brasil

The hull

The hull was manufactured of steel plates which were welded together. The VBB-1 had a similar style of hull/hatch construction to the M8 Greyhound for the Driver and Co-driver. In a way, the hull can be seen as two parts. A single large and relatively simple bottom hull, and a more complicated structure on top which contains the hatches for the Driver and Co-driver, and on which the turret is mounted.

Picture depicting the simple bottom hull and the more complicated top construction.
Source: Blindados no Brasil

The armor of the VBB-1 is unknown. If the PqRMM/2 team took over the side armor values of the steel mock-up is unknown. However, considering the values of the mock-up, which are the same as the M8 Greyhound, and Brazil’s relationship with the M8, it can be theorized that the armor values of the VBB-1 would be somewhere around the M8’s. The VBB-1’s frontal plate was well angled, at around 60 degrees from vertical. Its sides were flat, but started to angle heavily inwards on the bottom of the hull. The rear armor was practically flat. The more complicated structure of the upper hull used steel plates in complicated and unusual angles, especially on the front part of the hull attached to the sides of the Driver and Co-driver compartment. An interesting pyramid like shape was welded on the left hull side of the vehicle. This was most likely done to protect the spare tyres from frontal fire, and was retained during the conversion to the run-flat concept. It would be probable that this unusual pyramid shape would be either altered or removed altogether if the VBB-1 was ever produced, as its role for the protection of spare tyres was no longer needed and it would have been an overly complicated structure to construct in mass-production.

An example of the complicated angling of steel plates, with this plate being angled inwards, leaving an unusual cavity.
Source: Blindados no Brasil

The driver was positioned on the front left side of the vehicle, and the Co-driver on the right. The turret was located in the middle of the vehicle, and the engine in the rear. The VBB-1 had 2 front lights on both sides, and a black-out light on the left side, next to the front light. On the right side of the hull, the vehicle had a .30 caliber machine gun in a ball mount which was used by the Co-driver. It had a horn and something that resembled an antenna next to the Co-driver’s hatch on the right side of the hull. Behind the horn, the VBB-1 seems to have had pioneer tools. On the rear hull, the VBB-1 had a set of rear lights, including black-out lights.

Mobility

The VBB-1 was powered by a 6-cylinder OM-321 120 hp diesel engine built by Mercedes-Benz. This gave the vehicle a top speed of 90 km/h, with an operational range of 1,200 km (746 miles). It had a turning radius of 7 meters (7.7 yards), and could drive up a 60% slope. The transmission and differential were also produced by Mercedes-Benz, while the transmission box was built by Engesa. The VBB-1 used hydraulic steering.

The OM-321 engine mounted in the VBB-1 in late 1968.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

The vehicle was a 4×4, which meant that every wheel would support, very roughly, about 1.75 tonnes (1.93 US tons). The VBB-1 used 4 run-flat tyres, which were developed and made by Novatração. They were about 1 meter in diameter and used the 9.00 x 20 tyre size, which was also used for the M8 Greyhound.

Turret

The VBB-1 used an altered copy of the M8 Greyhound turret. In contrast to the M8, the VBB-1 turret was not open topped. It had a small plateau on the front side, upon which the mount for the .50 calibre machine gun was installed. Behind, two hatches were installed which folded open to the front. On the sides and the rear, the turret had vision blocks which could fold open if needed. The armor of the turret is unknown. Since it was a copy of the M8 turret, it can be expected that the thicknesses of the armor were potentially the same.

The VBB-1 Turret.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

An important development that the VBB-1 brought was the development and study of armor. Somewhere between 1969 and 1970, the DPET and the Instituto de Pesquisas Tecnológics (IPT) (English: Institute for Technological Research) would test the VBB-1 turret by firing at it with .50 calibre and 37 mm ammunition. The 37 mm cannon was fired at a distance of 500 meters (547 yards) and the .50 calibre at both 250 and 500 meters (273 and 547 yards). The 37 mm and .50 calibre from 500 meters (547 yards) were fired at the front of the turret, and the .50 calibre from 250 meters (274 yards) at the side of the turret. The turret armor managed to withstand both armaments.

The tested turret. Hits from 1. the 37mm cannon, 2. the .50 calibre from 500 meters, and 3. the .50 calibre from 250 meters.
Source: http://www.geocities.ws/militaryzone_portugal/vbb.htm

Armament

The VBB-1 used a 37 mm M6 cannon as main armament, which potentially came from the T17 Deerhound. The 37 mm M6 had a total length of 2.1 meters (6.9 feet) and a bore length of 1.98 meters (6.5 feet). The 37 mm cannon was able to fire the M51 APC round with 53 mm (2.1 inch) of penetration at 455 meters (500 yards) at a 30 degree angle, and 46 mm (1.8 inch) of penetration at 915 meters (1,000 yards) at a 30 degree angle. It could also fire the M74 AP, M63 HE, and M2 canister rounds. In addition to the 37 mm cannon, the VBB-1 mounted a .30 calibre M1919A4 machine gun on the right side of the hull, operated by the Co-driver, and a .50 calibre M2 machine gun on top of the turret. The available ammunition of the VBB-1 is unknown.

Fate

The VBB-1 was extensively tested during 1969 and 1970. It performed in beach trials, mobility trials, and firing tests. The vehicle performed well, but in the end would not be accepted. The reason is because the Brazilian Army wanted a 6×6 vehicle like the M8 Greyhound, and not a 4×4.

From left to right: Beach testing, tests in 1970, mobility test, and shooting tests.
Source: Blindados no Brasil and http://www.geocities.ws/militaryzone_portugal/vbb.htm

Why the PqRMM/2 developed a 4×4 instead of a 6×6 is a mystery. They most likely developed a 4×4 because it was easier and cheaper to build than a 6×6, and thus an excellent vehicle from which to gain experience. The PqRMM/2 briefly considered cutting the VBB-1 and lengthening the hull to create a 6×6 vehicle, but the idea was almost immediately discarded. It was easier and more effective to develop a new vehicle. One of the 8 VBB-1 turrets that were made was briefly used on the CRR prototype, which was a prototype of the EE-9 Cascavel. The VBB-1 is currently used as a gate guardian in front of the Centro Tecnológico do Exército (CTEx) (English: Army Technology Centre). Note that the VBB-1 presented at the CTEx seems to have a different gun than the VBB-1 originally had. It looks like a mock-up on which tubes are screwed together. Considering the state of the VBB-1, it is not unlikely that the 37 mm was removed.

The VBB-1 as a gate guardian at the CTEx. Note the missing vision block on the side of the turret.
Source: https://www.lexicarbrasil.com.br/exercito/

Conclusion

Overall, the VBB-1 seemed to have been a decent vehicle. It performed well in tests, but was outdated from its conception. The VBB-1 did not present anything new and was not better than its counterparts of its time. This is not surprising considering the goal of this project, the lack of experience of the engineers, and taking into account that this was the very first wheeled armored vehicle Brazil had ever developed with serial production in mind.

The Brazilian Army did not want the VBB-1, but a 6×6 instead. The development of the VBB-1 was critical for the future developments of the PqRMM/2 team and the future Brazilian defense industry. Not only did it give the engineers the experience to develop a 6×6 vehicle with a better hull design but, more importantly, it started the development and research of armor and the development of run-flat tyres. The VBB-1 was, most importantly, a vehicle which helped advance the development of Brazilian armored vehicles, and would be the stepping stone towards the famous EE-9 Cascavel and the EE-11 Urutu.

Illustrations

The VBB-1 spare tyre concept. Illustration done by Cut_22.
The VBB-1 run-flat tyre concept. Illustration done by Cut_22.
The VBB-1 as a gate guardian at the CTEx. Illustration done by Cut_22.

Specifications VBB-1

Dimensions (L-W-H) 5 m x 2.5 m x 2.3 m (16.4 feet x 8.2 feet x 7.55 feet)
Total weight 7 tonnes (7.7 US tons)
Crew 4 (Driver, Co-driver, Gunner, Commander)
Propulsion Mercedes-Benz 6-cylinder OM-321 120 hp diesel engine
Speed (road) 90 km/h (56 mph)
Armament .30 caliber machine gun (Hull)
.50 caliber machine gun (Turret top)
37 mm M6 cannon
Armor Unknown, probably somewhere in the region of the M8 Greyhound
Production 1 prototype

Special thanks to Expedito Carlos Stephani Bastos, the leading expert in Brazilian vehicles, please visit his website for further reading on Brazilian vehicles: https://ecsbdefesa.com.br/, 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.

Sources

Personal correspondence with Expedito Carlos Stephani Bastos
Blindados no Brasil – Expedito Carlos Stephani Bastos
Ford M-8 Greyhound no Exército Brasileiro – Expedito Carlos Stephani Bastos
Armored Car – A History of American Wheeled Combat vehicles – R.P. Hunnicutt
Armor Magazine 1973 Jan-Jun
http://www.geocities.ws/militaryzone_portugal/vbb.htm