Alfa Pioneered An Incombustible Fuel Tank But It Never Got The Chance To Save Lives

It was a brisk 8 degrees in Le Mans on Sunday the 30^th of March, 1969, and Lucien Bianchi was testing Alfa Romeo’s new T33 prototype in preparation for that year’s 24 Hours of Le Mans. The new Quadrifoglio clocked over 190mph over the final crest on the Hunaudières when the car spun out and hit a telegraph pole. The Belgian, winner of the 1968 event alongside Pedro Rodriguez, was tragically killed as the car erupted into flames. When word of the accident reached the head of Alfa Romeo’s racing division, Carlo Chiti, he was devastated. 

Carlo Chiti was a legend in motorsport, joining Alfa Romeo in 1952 and designing the beautiful 3000 CM before moving to Ferrari and designing the 246 and 156 Sharknose championship winning cars.He was the man who convinced Ingegnere Ferrari to put the horse behind the cart — or, to put the engines behind the drivers rather than in front of them. 

After leaving Ferrari for the short-lived breakaway ATS team in 1962, he then returned to Alfa Romeo in 1963 upon the formation of their new motorsports division, Autodelta. As an engineer, he was a genius; as a team principal, he was known for his short fuse; and as a man, he cared deeply for everyone around him, to the point that drivers often said he was an uncle to them. In fact, he cared so deeply for his ‘nephews’ that after Bianchi’s death, he began researching a way to stop cars from setting on fire during accidents.

Contemporary fire safety solutions in racing focused on mitigation; equipment such as fire extinguishers and mandatory fireproof clothing focus could protect the driver once a fire had started, but Chiti, ever the innovator, wanted to completely remove the chance for a fire to start. 

There are three main ways of fighting a fire:you can use water to cool it; carbon dioxide  to suffocate it; or foam to mechanically separate the fuel. However, in the late 1960s, there had been a rise in halogenated hydrocarbons being used to chemically separate the fuel.These materials reacted with the elements required for the combustion to occur, thus removing them and rendering the fuel inert. There were already some chemical extinguishant systems in existence, but the main issue with this solution was that, as it was a pressurised system, any accident which damaged the system would stop the extinguishant from being released, something that was common with the unpredictable forces of a car accident. There was also the issue that, again, for it to work a fire must already have started. Chiti would not stand for this – there had to be a way to inert the fuel before it set alight. 

At the time, racing fuel tank designs were single fuel cells with a rubber polymer bag inside which itself contained a plastic foam which would expand inside the tank in the event of an accident to avoid it exploding; however this foam did not and was not designed to prevent fire. The concept that Autodelta devised was to store equal measures of fuel and chemical extinguishant, in this case Fluobrene, in separate adjacent containers .As a result, in the event of an accident, the walls separating the liquids would break and the liquids would mix. As they mixed, the Floubrene reacted with the fuel and changed its chemical composition, rendering it non-flammable. 

Chiti’s method had several advantages – most notably the reduced points of failure,as it was a passive system and required no electronic or mechanical device to activate it. Additionally, by stopping the fuel in the fuel tank from setting fire rather than spraying key areas of the car with extinguishant, it stopped a fire from ever starting and meant the car did not need to be on fire in order to be effective.

The first prototype of the tank was a matrix of square-tube cells arranged vertically in a cube inside an aluminium tank – like square breadsticks inside a box. The space between the outside of the cells and the inside of the tank was filled with 8mm of anti-slosh foam soaked with the extinguishant. The outside layer of cells was then also filled with anti-slosh foam soaked in the extinguishant, while the inside cells were filled with fuel. As a result, nothing could breach the fuel tank without first breaching the Fluobrene, and the fuel could leak out of the tank without first mixing with the substance that could extinguish it. The design also had provisions for the tubes carrying the fuel to the engine – they were all inside other tubes filled with Fluobrene. 

The second prototype tank utilised innovations in synthetic materials to become dual bag variants – with the two tanks being flexible bags rather than aluminium walls. The bags offered even greater protection than the aluminium and, as they were flexible like in today’s Formula 1 cars, were much more practical for real-world use. 

The testing programme for this new tank was extensive – and Autodelta were so confident in their design that it was directly compared to an FIA style tank with double the mandated wall thickness. The engineers wanted the experiments to answer 5 main questions: how the tank operates in real-world conditions; what causes an FIA tank to ignite; which chemical extinguishant to use; the ideal volume of extinguishant to use; and if there was tank layout which was mass-producible without compromising on the security of the design.

The experiments covered every eventuality, from dropping each tank 20 metres onto concrete, to piercing both tanks with a 1000°C degree metal lance, to blowing up each tank with 20g of dynamite. Each had the same outcome – the FIA tank either leaked or ignited while the Autodelta tank passed every single test.

The results of these tests were clear: Autodelta’s new design was able to completely eliminate fuel fires. Even when small flames were elicited from areas of spilled fuel, footage from the tests showed they were extinguished once the Fluobrene mixed with the fuel. Chiti had discovered something brilliant.

However, there were more tests to complete. To ensure it was the Fluobrene stopping the flames as to some other factor, such as the construction of the tank, Autodelta acquired three Formula Monza cars, two Formula 3 cars, and an Alfa Romeo road car in order to crash test them at Monza. The cars’ normal tanks were encased in Fluobrene. When they underwent crash testing, engineers could confirm that the Fluobrene was the preventative factor.

Of course, the new design wasn’t perfect – the addition of the Fluobrene carried a large weight penalty – the first-generation prototype was around 66kg heavier but by the end of the development process Autodelta’s engineers had lowered that to around 25 kilos more than the FIA standard tank per 60 litres of fuel. Furthermore, as it also utilised a groundbreaking new tank design, which would require new construction techniques, alongside the extinguishant at the forefront of chemical engineering, which would itself be expensive to manufacture at scale, the cost for teams would be higher than the more traditional FIA design. With F1 cars in the early 1970s only weighing around 550kg – and teams always unwilling to spend money on anything other than performance – the opposition from other teams was strong.

The work was progressing well but, unfortunately, motorsport was about to provide several more examples of why such research was so necessary when on the 10^{th of} January 1971 Ignazio Giunti was killed in a Ferrari 512M at the 1000km of Buenos Aires when his car struck the stricken Matra of Jean-Pierre Beltoise and somersaulted through the air before catching fire upon impact. The Autodelta design was first patented on the 15^th of June 1971 in Italy, just over five months later

Less than a month later, on the 11^th of July, Pedro Rodriguez – a two-time F1 winner and Lucien Bianchi’s teammate for their 1968 Le Mans victory – was killed when a tyre came off his car at the Norisring, sending him into a wall and bursting into flames. Depressingly, it was in another Ferrari 312M. His death sent shockwaves across Mexico and the racing world, and he remained Mexico’s most successful racing driver for over 50 years, when Sergio Perez hit the racing scene.

On the 24^th of October that year, Jo Siffert, two-time Grand Prix winner for BRM, would lose his life at Brands Hatch during a non-championship F1 race when his rear suspension broke, pitching him into the barrier. Once again, the car burst into flames. Siffert, having fractured his leg, was unable to extract himself from the car. The marshals attempted to extinguish the fire and reach him but, shamefully, the extinguishers they had been provided with did not work. If they had he would surely have survived the accident.

Two days after Siffert’s death, Carlo Chiti presented the safety tank to the racing world at Bologna. Members of the press, other team bosses, and many drivers including the newly-crowned 1971 World Champion and safety activist Jackie Stewart were all invited to an explanation of the concept and a demonstration of its effectiveness – live examples of the explosive and red-hot lance tests. Stewart was reportedly thrilled with the results, and the effectiveness of the concept was clear to all. Obviously, November was too late in the year for the tank to be mandated for 1972, as its size and weight would have required all of the F1 and non-Autodelta sportscar manufacturers to make heavy modifications for their 1972 cars, but Chiti was keen on a 1973 introduction.

So keen was he that Autodelta’s new Alfa Romeo 33TT3 raced the 1972 World Sportscar Championship with the safety tank, in order to prove its credentials in race conditions and to pressure the FIA, F1’s regulatory body, into approving it for discussion at the 1972 World Motorsport Council in April. The new model also used a new steel tubular frame chassis – lighter than the conventional monocoque chassis – to make it stiffer, stronger, and safer in the event of an accident. Empty of fuel the lightest of their three cars was still 40 kilos heavier than the Ferraris, but there was also a privately owned 1971 Alfa T33/3 with the FIA standard fuel tank. 

Their qualifying went surprisingly well with Rolf Stommelen qualifying a safety-tank equipped car 2^nd, only 0.31 behind Ronnie Peterson’s Ferrari and well ahead of the standard tank Alfa. The pace difference was more apparent in the 168-lap race, but their biggest failing was reliability and operational issues. Two of the cars failed to make half-distance, while the third safety-tank car, driven by Vic Eflord and Helmut Marko, had to stop at the end of lap one to have a screwdriver removed from the cockpit and spent the rest of the race plagued by technical gremlins. In the end, the standard-tank Alfa finished six laps behind the race-winning Peterson Ferrari with the Elford/Marko car a further two laps behind them. 

Not an ideal start to its racing life for the safety tank, but the problems with the car were far more than the extra weight from the tank. Reliability was poor, and drivers really struggled with the new tubular chassis, finding it too stiff and difficult to drive. 

Chiti and his crew continued the experiment in Daytona in 1972, where the 24-hour race had been shortened to six, with Autodelta bringing 4 tubular-chassis cars equipped with the safety tank. This was immediately ruined during the Roar, the build-up to the event, when de Adamich suffered a puncture, hit the wall, and wrote off the chassis. Notably, it didn’t set fire, but there’s no indication it would have if it was using a standard tank.  Alfa was down to three cars.

Things got worse in qualifying when Nanni Galli suffered a puncture, hit the wall, and wrote off a second chassis . Autodelta had considered the fact that someone else might suffer a puncture, hit the wall, and write off a chassis after the Roar incident and had brought a 1971 chassis along for the race week just in case. It didn’t help, though: the qualifying pace was abysmal. Ferrari locked out the top 4 on the grid, and were a full 2.5 seconds ahead of the fastest Alfa Romeo. 

The race was a similarly dismal affair: one car barely made half-distance, one finished 24 laps down, and the least-troubled car was still 4 laps behind the Ferraris on pace (although that was still good enough for 3^rd).

Chiti returned from Daytona knowing something about the car needed to change. The problems with the chassis and the suspension were too fundamental to quickly alter, so the safety tank was removed as a way to quickly lessen the weight disadvantage. The drivers were consulted, and all apart from de Adamich wanted the tank gone. In a car with so many issues, the tank was to Autodelta what cocaine was to eels – another problem they didn’t need. 

There were some small victories, though. The safety tank had been proven to work in a race scenario, so Chiti had evidence to give to the World Motorsport Council when pursuing its implementation in motorsport, and the issues with the weight would be solved when it was made mandatory, so they still deemed the project a success. No Alfa Romeo drivers were killed in the rest of the 1972 season, but Ferrari went on to win every race of the 1972 World Sportscar Championship.

Chiti wasn’t content to sit back and wait for the FIA to act, though; in preparation for adapting the design to single-seater chassis, Autodelta decided that Formula Italia- a new junior series in Italy akin to Formula Ford – would run the safety tank as mandatory. From the outside it seemed successful – no drivers were killed in accidents in Formula Italia – but the safety tank was abandoned after only one season. With the design adapted for the unique stresses and demand of a single-seater chassis for the first-time, new limitations were exposed: the vibrations from the track and the engine would cause the partitions between the Fluobrene and the fuel to break unexpectedly, causing the car to stop and requiring a lengthy stripping and cleaning process on the engine and fuel system to remove any remnants of Fluobrene. 

With more time and more interest in the project, these issues could surely have been solved, but the FIA rejected the design for 1973.  It did make positive steps in mitigating the risks of fire in the future by mandating in-car extinguisher systems and a way to pipe air into drivers’ helmets alongside a massive overhaul of marshals’ equipment and protocols. It wasn’t Chiti’s incombustible fuel tank, but it was something.

Chiti was not deterred by his design’s rejection – the needless deaths of drivers across the world were his motivation. Autodelta’s design was patented in the United States on April the 16^th 1974. He later made a presentation to the Society of Automotive Engineers in March 1977, sharing their findings and hoping to gain academic support for their concept and expand the scope of his research, potentially adapting it for use in passenger cars.

But the Fluobrene inerting liquid would never catch on – fuel tank fires were considered statistically insignificant in road cars for any legislation to pass, and the sport’s governing body would never budge on the design, despite the human cost. 

In retrospect, it’s clear that the Fluobrene design included one major flaw:  Fluobrene, like Freon, is one of the Chlorofluorocarbon (CFC) that massively depleted the Ozone layer.Even though Fluobrene’s use in motorsport would have been low comparative its use worldwide, it still would have contributed to the depletion and would have required a large increase in their production. CFCs like Fluobrene were banned in 1989 under the Montreal Protocol and have mostly been replaced by less damaging (but still damaging) Hydrofluorocarbons in the years since. 

While this project may technically have been a failure, it should be remembered as another example of Carlo Chiti’s pioneering genius. The concept of a tank that is completely non-combustible still seems impossible today, but it was real and it worked over half a century ago. If anything, it was another example of Chiti being held back by those around him – as with Ingegnere Ferrari’s reluctance to move to a rear-engined car. Once Chiti was allowed to work as he wanted, he produced the Ferrari 161 that won the 1961 World Championship in the hands of Phil HIll. 

After this saga, Chiti would design the Alfa Romeo 33TT12, which would win the 1975 World Sportscar Championship. He then oversaw Autodelta’s transition into F1, via an engine programme which powered the Brabham BT46B ‘Fancar’. The works Alfa Romeo squad adapted quickly in their first two full seasons to earn a pole position and podium with Bruno Giacomelli. 

Chiti’s engineering expertise are evident, but one element of his character that should not go unnoticed was his heart. Speak to anyone who drove for him and they will tell you how much they respected him. His tough attitude towards on-track performance extended to his drivers, which they expected, but the love he had for them was clear too. In victory and in grief, he was there for them – they considered him an uncle and he considered them his sons. 

His caring nature is perhaps best-exemplified through his actions at the 1000km Buenos Aires one year. When a stray dog ran onto the circuit, Chiti leapt into action running onto the circuit to rescue it. He took it back to the Autodelta factory where he built a kennel for it, and soon many other local stray dogs, out of old pieces of T33. Chiti adopted them, put them in his cars, and finally they were safe.