Today, drivers no longer need to worry about Formula 1 fuel tank safety, but the safety innovations that allowed for this sense of security are crucial for continuing the sport. Historically, F1 drivers were deeply concerned with fire safety concerns and the overall efficacy of metal tanks. Eventually, manufacturers replaced these fuel tanks with malleable bag-style tanks renowned for being much lighter and safer.
Unfortunately, the road to this safety milestone in Formula 1 is paved with several lost lives due to ignition from tank ruptures. Drivers lost to fatal vehicle crashes include such beloved names as Lorenzo Bandini, Roger Williamson, Stuart Lewis Evans, and Piers Courage. Other F1 greats, like Niki Lauda and Clay Regazzoni, would have lost their lives during tank rupture incidents without the intervention of fellow competitors and safety marshals. Even today, Jackie Stewart recounts with dread the feeling of being trapped in his BRM and soaked in fuel after a nasty crash, a situation so precarious that the whole scene could have gone up in flames any second.
Another development besides fuel bags that saved lives on the track was fireproof race suits. Before using fireproof suits was the norm, F1 drivers frequently refused to wear safety harnesses for fear of being trapped in their vehicles in the event of a fire. Vehicular design advancements that assuaged fire fears began with McLaren’s introduction of the 1981 MP4, which featured a carbon fibre monocoque with tanks placed inside the tub to ensure that they remained intact. Other teams followed suit shortly after.
The Progression from Metal to Rubber Tanks
In the 1950s, Formula 1 fuel tanks were comprised of aluminum cases seated behind the cockpit. The lines fueling the engine were aligned forward, past the driver, to reach the engine. Like Lancia’s D50s, some designs deviated from this standard to seat the pannier tanks on the sides of the cockpit instead, which improved handling by ensuring a consistent weight at the vehicle’s tail. However, the caveat was that the driver had to worry about potential tank failures on either side of him. The advent of rear-engine F1 cars moved tanks to the front, seating them above the driver’s legs.
Malleable rubber bag tanks were first introduced in Jaguar’s C-type racing sportscars in the early 1950s. This then-unconventional design’s main advantage was that it was less likely to get pierced on impact or chafed by attachment straps or chassis tubes.
These prototypal bag tanks were initially housed inside aluminium tanks for safety’s sake. Still, they posed some concerns that were eventually addressed by Aero Tec Laboratories (ATL), an American firm, in the 1970s. ATL, led by former F1 racer Peter Regna, created a revolutionary safety measure for these tanks that prevented fuel from pouring out of the tank even after a pipe rupture. In short, when a major impact occurs, the frangible components of the fuel line snap at specific points and the couplings, which are also breakable, automatically close, thereby sealing the bag.
Another stroke of genius pioneered by ATL was a reinforced fuel safety cell that was less prone to punctures. In recent decades, advancements have focused mostly on the bag itself to ensure a more durable vessel for fuel, leading today’s fuel tanks to be composed of a weave of polyurethane and Kevlar.
Before the rules on fuel tank location and size were standardized, other design optimization attempts included the placement of small fuel cells distributed strategically around the cockpit. Typically, this meant one was above the driver’s legs, and two were seated in the back on each side of him. Today, however, Formula 1 regulations are quite clear that fuel tanks should be stored in the monocoque rear to ensure driver safety and maintain consistency and fairness in competing vehicles’ design. As a result, many Formula 1 innovations focus on more subtle design and structural elements while improving safety functions.
Formula 1 Fuel Tanks Today
Bag tanks are the antithesis of the sleekness and elegance in geometry and implementation often associated with automotive engineering. These tanks are oddly-shaped for seating in the back end of the monocoque and ribbed to keep the over 30 sections of the tank intact. However, this space-saving and safety-driven design can hold a whopping 30 gallons, or 110 liters or kilograms of fuel, the maximum allowed for a race.
The tank is wide at the base and tapers off at around neck height on any given driver. The end of the bag extrudes forward from the rear end of the monocoque. This design ensures a better fit in the car and keeps fuel stored in such a way that the vehicle maintains a low center of gravity. The tank is fitted to the driver’s seat and the tub using studs that keep it upright.
Another factor that keeps fuel seated low in the car is the use of baffles. This pair of rubber shelves keeps the fuel from moving too much in the tank while cornering or making other tricky maneuvers that can affect the car’s handling. Another benefit of this unique design is that it ensures easier delivery to the engine than a conventional tank.
Two openings can be found at the back of the bag tank: one on top for the fuel lines and one on the bottom for the mechanical pump. The former is a frangible, self-sealing coupling directly to the fuel line; the latter, meanwhile, collects and pressurizes fuel from the collector on the bottom of the tank for expedient travel up to the fuel lines. Pit crews use holes on either shoulder to fill the bag tank. This design may sound unusual to accommodate pit garages on either side of the vehicle.
All in all, like many Formula 1 parts and design choices, the design of the modern fuel tank is tailored specifically for the sport to maximize safety, optimize space usage, and maintain a certain level of flexibility and adaptability during races. Many designers prefer the elegance of a tall, thin tank for the sake of efficiency, but this type of design is not ideal for an F1 vehicle.
How A Formula 1 Fuel Tank Works
This video explains how a Formula 1 fuel tank is designed, and how it works.