The ‘Rejected’ Belgian Armored Vehicle That Beat Brazil’s Combat-Proven Tank and Disappeared Forever D

1975, a railway factory in Nivelles, Belgium, not a weapons plant, not a defense contractor with a pedigree in steel and armor, a company that built train carriages. Inside a workshop normally filled with rolling stock, engineers were quietly assembling something very different, a large six-wheeled armored vehicle over 7 m long, nearly 2 and 1/2 m wide with a sealed hull low to the ground and a trim vane folded flat against its nose. It looked purposeful.

It looked capable. It looked, on the surface, like exactly the kind of vehicle a modern army would want. There was only one problem, nobody had asked for it. No army had commissioned it. No government had funded it. No Ministry of Defense anywhere on Earth had signed a requirement document with this machine in mind.

The engineers at BN Constructions Forges et Entereprises Metalliques had built it entirely on their own initiative, with their own money, on a calculated gamble that if they made it real, someone would eventually buy it. They called it the Sibmas, an anagram of the division they had created to build it.

And over the next decade, they would take it to defense exhibitions across three continents, park it beside proven combat vehicles from nations with centuries of arms making tradition, and wait. 20 nations looked at it. 19 said no. One said yes. One army, in one country, placed one order for 186 vehicles. And then the company gave up marketing it entirely.

That single customer was Malaysia. The Sibmas served there for over 40 years. The last of them were retired in January 2023. This is the story of the most commercially unsuccessful armored vehicle of the Cold War era that also refused stubbornly and completely to stop working. To understand why a railway company in Belgium built a six-wheeled amphibious fighting vehicle, you have to go back further, back to a German prototype that the Belgians never quite let die.

In 1968, South Africa was under pressure. The country faced a growing insurgency along its northern border, a hostile international arms embargo tightening every year, and a military doctrine that desperately needed wheeled armored vehicles capable of surviving the vast road poor terrain of Southern Africa, South Africa turned to West Germany, specifically to the engineering firm Büssing, which had been making trucks for military use for decades.

Büssing operated a South African franchise called Springfield Büssing, and through that subsidiary it developed a large 6×6 infantry fighting vehicle on a modified MAN truck chassis. The first prototype appeared in March 1972. They called it the Büffel. The Büffel was trialed against serious competition, including the Brazilian Urutu, the French Berliet VAB 170, and the German UR-416. It won.

South Africa adopted it, handed production to the firm Sandock Austral, and the vehicle entered service as the Ratel, meaning honey badger. Over 1,381 Ratels were eventually built. The vehicle fought in Angola, in Namibia, in the border war that consumed South Africa’s military for 15 years. It became the backbone of one of the most combat-hardened mechanized forces in Africa, but Büssing had sold the original Büffel prototype and its complete development study to someone else, to Belgium, to a railway manufacturer in Nivelles that believed the wheeled armored vehicle market was about to open up across Asia, South America, and the Middle East, and that a capable amphibious low-cost 6×6 fighting vehicle was exactly what newly independent nations would need. The BN engineers took the Büffel concept and rebuilt it from the inside out. The exterior remained strikingly similar to what would become the Ratel, so similar that defense journalists initially assumed the two vehicles were the same machine, and that South Africa had

co-developed the Belgian design. It had not. Under the skin, these were separate vehicles diverging in nearly every mechanical detail. South Africa fitted its Ratel with a Büssing engine and a Renk integrated gearbox and transfer case. BN fitted the SIBMAS with a MAN D2566 6-cylinder turbocharged diesel producing 320 horsepower at 1900 revolutions per minute paired with a ZF automatic transmission.

South Africa built the Ratel for a specific war it was already fighting. Belgium built the Sibmas for a customer it had not yet found. The technical result was formidable. The Sibmas hull was all-welded steel sealed against water entry with a trim vane at the bow that folded down flat during road travel and could be erected by the driver without leaving his seat before entering water.

Two bilge pumps, each capable of shifting 180 L per minute handled any seepage. Twin propellers mounted at the rear and capable of rotating through 360° for steering could drive the vehicle through calm water at 11 km per hour. When approaching a bank, the driver could shift into first gear so that the wheels bit the moment they touched ground while the propellers still pushed from behind.

It was an engineering solution that required no crew action and no complex preparation. On road, the SIBMAS reached 100 km per hour and could travel 1,000 km on a single 400 L fuel load. The engine could be removed through a roof hatch in 30 minutes by two men, a figure the company quoted repeatedly in its marketing materials as evidence of field serviceability.

Run-flat tires meant that a puncture did not strand the vehicle. All six wheels drove and the driver could lock the differentials individually for rough ground. The armor was steel proof against 7.62 mm armor-piercing rounds and shell fragments at combat ranges. It was not protection against cannon fire or heavy anti-tank weapons.

The SIBMAS was designed for the threat environment of colonial policing, insurgency suppression, and conventional infantry support, not for fighting main battle tanks. Nobody who evaluated it ever pretended otherwise. The vehicle the Belgians offered to the world could carry 11 passengers behind its three-man crew.

It could carry them through rivers, across beaches, and over 1,000 km of unpaved road without breaking down. It was amphibious without modification, reliable because it used off-the-shelf truck components, and repairable in the field because those same components were available from MAN dealers across the world.

It should have sold in the hundreds. It did not. BN took the SIBMAS to defense exhibitions throughout the late 1970s. They demonstrated it in tropical conditions in the Philippines, in Malaysia, in the Middle East. They offered it in variants. A basic armored personnel carrier, a fire support vehicle with a 90-mm Cockerill low-pressure gun, an armored recovery vehicle, an anti-tank version with HOT missiles, a twin 20-mm anti-aircraft configuration, a command vehicle, an ambulance.

They had drawings for all of them. Most existed only on paper. The company had declared from the start that it would not begin serial production until an export order created the economy of scale to justify the tooling. So, every demonstration vehicle was a prototype. Every brochure was a promise. No army on earth had ever driven a production SIBMAS because no production SIBMAS yet existed.

This was the fundamental commercial problem. The vehicle was excellent in theory, but arms buyers do not purchase theories. They purchase track records, and the SIBMAS had none. Now, before we get into the procurement battle that nearly destroyed the entire program before a single vehicle was built.

If you are watching this and you have not yet subscribed to British Warfare, hit the button now. It costs nothing. It takes 1 second, and it is how this channel keeps covering stories like this one. Vehicles that the history books skip because they were too obscure, too complicated, or too inconvenient to explain. In 1979, Malaysia launched a major military modernization program called Perista.

The Royal Malaysian Army needed to replace its aging fleet with a modern wheeled armored vehicle capable of operating in the dense jungle terrain of the peninsula and in the riverine environment of Borneo. The requirement was for large numbers, initially estimated at around 1,000 vehicles across multiple variants, the evaluation was chaotic from the beginning.

Officials failed to specify firm technical requirements before inviting contractors to tender. When requirements were eventually issued, they included a combat weight ceiling of 12 tons, a road range of 1,000 km, and full amphibious capability. Then those requirements were quietly altered without formally notifying all competing contractors.

The evaluation period was extended repeatedly. By early 1981, three vehicles had survived the process. The SIBMAS from Belgium, the Engesa EE-11 Urutu from Brazil, and the Radpanzer Condor, also from West Germany. The head-to-head contest that mattered was between the SIBMAS and the Urutu.

On every measure that defense procurement committees are supposed to use, the Urutu should have won. The EE-11 Urutu was in continuous production. Brazil had been making it since 1970. At the time of the Malaysian evaluation, Iraq had several hundred in service, and was using them in the Iran-Iraq War. Libya had nearly 200.

Bolivia, Colombia, Uruguay, Venezuela, Cyprus, and Ecuador had all bought them. By the time production eventually ended in the mid-1990s, 1,719 Urutus would be built for over 20 nations. The vehicle had a combat record spanning three continents. It had been shot at, driven into rivers, and repaired in the field under fire.

Its price per unit was lower than the SIBMAS. It met the weight requirement that the SIBMAS did not, because the SIBMAS in combat configuration weighed closer to 16 and 1/2 tons, well above the original 12-ton ceiling. The SIBMAS, by contrast, had no production history. It had not been shot at.

No military unit anywhere on Earth had operated it in the field. Its weight was above specification. It was more expensive. It was built by a company whose primary expertise was in railway carriages. And yet, the SIBMAS won. In May 1981, the Malaysian Ministry of Defense announced its decision. It would purchase the SIBMAS as a fire support vehicle, primarily configured with the 90 mm Cockerill Mark III gun in a CM902 man turret.

Simultaneously, it would purchase the Condor as its standard armored personnel carrier. The announcement triggered immediate controversy. Critics alleged the fire support specifications had been written around the SIBMAS, but the requirement for a 90 mm gun system in a full amphibious 6×6 hull eliminated the VAB before the vote was taken because no such configuration existed or had been offered for the VAB.

The Malaysian National Investigations Bureau opened a formal inquiry into the procurement. Anti-apartheid campaigners in Britain added a separate accusation, claiming the SIBMAS was effectively a South African Ratel license, which would have put Malaysia in violation of United Nations Security Council Resolution 418, the mandatory arms embargo on South Africa.

The Belgian government formally denied the connection. The lineage was shared, the vehicles were not. The investigation concluded without reversing the decision. In late 1981, Malaysia signed a contract with BN for 186 vehicles. The deal was worth approximately 84 million United States dollars. 162 of the vehicles would be the AFSV90 fire support variant carrying the Cockerill 90 mm gun, a coaxial 7.

62 mm FN MAG machine gun, a roof mounted anti-aircraft machine gun of the same caliber, and eight smoke dischargers on each side of the turret. The remaining 24 would be armored recovery vehicles fitted with a front dozer blade, a rear stabilizer blade, a crane rated to 10,500 kg, and a winch capable of pulling 20,000 kg. No APC variant was ordered.

No ambulance, no command vehicle, just gun vehicles and recovery vehicles. First deliveries arrived in June 1983. Production of the The recovery vehicles followed by The recovery vehicles followed by The entire fleet was delivered on schedule and within budget. The company had built its one and only production run.

In the Royal Malaysian Army, the SIBMAS was assigned to the Royal Armored Corps, spread across several armored regiments equipped with a mix of the new Belgian vehicles and the Condors delivered alongside them. The Army’s intention was to consolidate all SIBMAS into a dedicated armored cavalry regiment structure.

As crews were trained, a process that occupied most of the middle and late 1980s, the vehicles were fitted with air conditioning, a requirement for sustained operations in Malaysia’s tropical climate, and with passive night vision equipment. Crews trained extensively on the river crossing capability, the 90 mm gun system, and the long-range patrol endurance the vehicles’ 1,000 km range made possible.

The integration was harder than expected. The SIBMAS arrived without the deep maintenance and support network that established defense contractors build over years of supplying armies. BN was a railway company. Its engineers understood the vehicle intimately. Its logistical infrastructure for supporting a fleet of 186 armored fighting vehicles spread across multiple Malaysian regiments in a country separated by the South China Sea between its peninsular and its Borneo territories was not the same thing at all. Early in the fleet’s service life, crew shortages slowed the process of qualifying enough operators to run the vehicles at full strength. The Army announced in the mid-1980s that it intended to concentrate all SIBMAS into a single regiment structure. As the training pipeline caught up with the delivery schedule, that consolidation took most of the decade to achieve. Once established in its operational regiments, the of peacetime armored core life.

It participated in annual firepower demonstrations, the events at which the Malaysian Army displayed its capabilities to political leadership, foreign defense attachés, and the domestic press. The 90-mm Cockerill gun performed reliably in these exercises, firing its range of ammunition including the round that became one of its defining selling points, a high explosive round capable of defeating light armored vehicles and fortified positions at ranges up to 1,500 m.

The vehicle’s amphibious capability was demonstrated in river crossing exercises where its ability to move from land to water without 1975, a railway factory in Nivelles, Belgium, not a weapons plant, not a defense contractor with a pedelec on armor, a company that built train car inside a workshop normally filled with rolling stock and quietly assembling something very different.

A large six-wheeled armored vehicle over 7 m long, nearly 12 m wide with a sealed hull low to the ground and a trim vane folded flat against those. It looked purposeful. It looked capable. On the surface, like exactly the kind of vehicle I’d want. There was only one problem. Nobody had asked for it.

No army had commissioned it. No government had funded it. No Ministry of Defense anywhere on Earth had signed a requirement document with it in mind. The engineers at Constructions Ferroviaires et Metalliques had built it entirely on their own initiative, with their own money, on a calculated gamble that if they someone would eventually buy it.

They called it the SIBMAS, an anagram of the division they had created to build it. And over the next would take it to defense exhibitions across three continents, park it beside proven combat vehicles from nations with centuries of arms-making tradition, and wait. 20 nations looked at it. 19 One said yes.

One army in one country placed one order for 186 vehicles. And then the company gave up marketing Italy. That single customer was Malaysia. The SIBMAS served there for over 40 years. The last of them were retired in January 2023. This is the most commercially unsuccessful armored vehicle of the Cold War era that also refused stubbornly and completely to stop work.

To understand why a railway in Belgium built a six-wheeled amphibious fighting vehicle, you have to go back further. Back to a German prototype that the Belgians never die. In 1968, South Africa was under pressure. The country faced a growing insurgency along its northern border. A hostile international arms embargo tightening every year.

A doctrine that desperately needed wheeled armored vehicles capable of surviving the vast road poor terrain of Southern Africa. South Africa turned to West Germany, specifically to the engineering firm Bussing, which had been making trucks for military use for decades. Bussing operated a South African called Springfield Bussing and through that subsidiary a large 6×6 infantry fighting vehicle on a modified MAN truck chassis.

The first prototype launched 1972. They called it the Buffel. The Buffel was trialed against serious competition, including the Brazil, the French Berliet VAB 170, and the German 416. It South Africa adopted it, handed production to the firm Sandock Austral, and the vehicle entered service as the Ratel, meaning honey badger.

Over 1,381 Ratels were eventually built. The vehicle fought in Angola, in Namibia, in the border war that consumed South Africa’s military for 15 years. It became the backbone combat hardened mechanized forces in Africa. But Bussing sold the original Buffel prototype and complete development study to someone else, to Belgium.

To a railway manufacturer in Nivelles, the wheeled armored vehicle market was about to open up across Asia, South America, and the Middle East, and that a capable amphibious 6×6 fighting vehicle was exactly what newly independent nations would need. The BN engineers took the Buffel concept and rebuilt it from the inside out.

The exterior remained strikingly similar to what would become the Ratel, so similar that defense journalists initially assumed the two vehicles were the same machine, and that South Africa had co-developed the Belgian design. It had not. Under the skin, these vehicles diverging in nearly every detail.

South Africa fitted its Ratel with a Bussing engine and a Renk integrated gearbox and transfer case. It fitted the SIBMAS with a MAN 2566 six-cylinder turbocharged diesel producing 320 horsepower at 1,900 revolutions per minute. Paired with a ZF automatic transmission. South Africa built it for a specific war it was already fighting.

Belgium built the SIBMAS for a customer it had not yet found. The technical result was formidable. The SIBMAS hull was all-welded steel sealed against water entry, with a trim vane at the bow that folded down flat during road travel, and could be erected by the driver without leaving his seat before entering water.

Two bilge pumps, each capable of shifting 180 L per minute average. Twin propellers mounted at the rear and capable of rotating through 360 steering could drive the vehicle through calm water at 11 km/h. When approaching the driver could shift into first gear so that the wheels bit the moment they touched ground while the still pushed from behind.

Engineering solution that required no crew action and no complex operation. On road, the SIBMAS reached 100 km/h and could travel 1,000 km on a single 400 L fuel load. The engine could be removed through a roof hatch in 30 minutes by two men, a figure the company quoted repeatedly in its marketing materials as evidence of field service ability.

Run-flat tires punctured did not strand the vehicle. All six wheels move and the driver could lock the differentials individually. The armor was steel proof against 7.62 mm armor-piercing rounds and shell fragments at combat. It was not protection against cannon fire or heavy anti-tank weapons.

SIBMAS was designed for the threat environment of colonial policing, insurgency, sub-conventional infantry support, not for fighting main battle tanks. Nobody who evaluated it ever pretended otherwise. The vehicle the belt of the world could carry 11 passengers behind its three-man crew. It could carry them through rivers, across beaches, and over 1,000 km of unpaved raking down.

It was amphibious without modification, reliable because it used off-the-shelf truck components, parable in the field because those same components were available from MAN dealers across the world. It should have sold its It did not. BN took the SIBMAS to defense exhibitions throughout the late 1970s.

They demonstrated it in tropical conditions in the Philippines, in Malaysia, in the Middle East. They offered it in variants, a basic armored personnel carrier, fire support vehicle with a 90-mm Cockerill low-pressure gun, an armored recovery an anti-tank version with HOT missiles, a twin 20-mm anti-aircraft configuration, a command vehicle, an ambu- They had drawings of them.

Most existed only on paper. The company had declared from the start that it would not begin serial until an export order created the economy of the tooling. So, every demonstration vehicle was a prototype. Every brochure was a promise. No army on earth had ever driven a production SIBMAS because no production SIBMAS yet existed.

This was the fundamental commercial problem. Vehicle was excellent in theory, but arms buyers do not purchase they purchase track records, and the SIBMAS had none. Now, before we get to the procurement battle that nearly destroyed the entire program before a single vehicle was built.

If you are watching this and you have not yet subscribed to War Stories, hit the button now. It costs nothing. It takes 1 second, and it is how this channel keeps covering stories like this one. Vehicles that the histories they were too obscure, too complicated, or too inconvenient to explain. In 1979, Malaysia launched a major military modernization program called Perista.

The Malaysian army needed to replace its aging fleet with a modern wheeled armored vehicle capable of operating in the dense jungle terrain of the peninsula and in the riverine environment of Borneo. The requirement was for large numbers, initially estimated at around 1,000 vehicles across variants. The evaluation was chaotic from the beginning.

Officials failed to specify firm technical requirements to invite contractors to tender. When eventually issued, they included a combat weight ceiling of 12 tons, range of 1,000 km, and full amphibious capability. Then those requirements were quietly without formally notifying all competing contractors.

The evaluation period was extended repeatedly. By early 1981, three vehicles had survived the process. The SIBMAS from Belgium, the Engesa EE-11 Urutu, and the Radpanzer Condor, also from West Germany. The head-to-head contest that mattered was between the SIBMAS and the Urutu. On every measure that defense procurement committees are supposed to use, the Urutu should have won.

The Engesa Urutu was in continuous production. Brazil kicking it since 1970. At the time of the Malaysian evaluation, Iraq had several hundred in service using them in the Iran-Iraq War. Libya had nearly 200. Bolivia, Colombia, Uruguay, Venezuela, Cyprus, and Ecuador had all bought them.

When production eventually ended in the mid-90s, 1,700 Urutus would be built for over 20 nations. The vehicle had a combat record spanning three continents. It had been shot at, driven into rivers, and repaired in the field under fire. Its per unit was lower than the SIBMAS. It met the weight requirement that the SIBMAS did not because the SIBMAS in combat configuration weighed closer to 16 and 1/2 tons well above the original 12-ton ceiling.

The SIBMAS, by contrast, had no production history. It had not been shot at. No military unit anywhere on Earth had operated it in the field. Its weight was above specification. It was more expensive. It was built by a company whose primary expertise was in railway carriages. Yet, the SIBMAS won. In May 1981, the Malaysian Ministry of Defense announced its decision.

It would purchase the SIBMAS as a fire support vehicle primarily configured with the 90-mm Cockerill in a CM902 mount turret. Simultaneously, it would purchase the Condor as its standard armored personnel carrier. The announcement triggered immediate controversy.