In the chaos of a crash, surrounded by debris and extreme tension, Formula 1 relies on highly advanced and complex machinery that requires equally sophisticated safety systems. The sport has developed multiple intervention protocols designed to ensure rapid and safe responses, especially when considering the risks associated with hybrid power units and high-voltage battery systems.
There are details that often escape even the most attentive eye. Yet it is precisely in these hidden elements that a crucial part of modern Formula 1 safety engineering is found.
An incident that occurred during yesterday’s Miami Grand Prix, which saw Pierre Gasly’s car overturn and remain awkwardly perched on the barriers, helps highlight one of these lesser-known features: small visual indicators and control elements positioned near the main pillar of the Halo. These are designed to provide marshals with immediate information and control in the event of a serious accident.
These are not simple indicators, but essential tools engineered to allow immediate and safe intervention by marshals under extreme conditions. When a car comes to a stop after an impact and the driver is unable to act, every second becomes critical.
Neutral override and hybrid system safety indicators
The first system, associated with a red LED and a red “N” letter on a white background, is linked to the so-called Neutral Override. This is not just an electronic command: in the event of hydraulic pressure loss, it activates a mechanical bypass that physically separates the internal combustion engine and the MGU-K from the transmission.
In other words, it allows the drivetrain to be disengaged, preventing a locked system from making it impossible to move the car without causing further damage.
The second element is the yellow indicator featuring a lightning symbol. This is not a control input, but a warning system. The high-visibility ERS LED displays the status of the high-voltage hybrid system.
It is designed to remain active even after the car has been shut down (for at least 15 minutes), indicating to marshals whether the system is electrically safe or not. The presence of the high-voltage symbol, in accordance with ISO standards, immediately highlights the risk level, which in modern power units can reach nearly 1000 volts.
If the LED is green, the chassis is electrically safe. If it is red, marshals must activate the Kill Switch before intervening.
Fire suppression and emergency shutdown systems
The third component is the white switch marked with a white “+” symbol on a red background, known as the extinguisher and Kill Switch. This is a critical emergency command.
Once activated, it triggers two simultaneous critical sequences: it rapidly discharges the fire-extinguishing chemical into nozzles located in the cockpit and around the power unit area, and it activates the emergency shutdown protocol of the ERS (Energy Recovery System).
It also physically opens the high-voltage contacts inside the Energy Store battery pack, isolating it and safely discharging residual energy stored in the inverters and cables.
It is important to distinguish these systems from other devices present on the car. External handles marked with the letter “E”, for example, represent the master switch and allow marshals to cut ignition, fuel pumps, and main electrical systems.
Similarly, the car is equipped with an impact light connected to the ADR system, which communicates the severity of a crash to rescue personnel, integrating data from onboard sensors and the driver’s biometric systems.
This is not only about protecting the driver, but also about safeguarding trackside personnel, who often operate in extremely dangerous conditions with very small margins for error, enabling rapid and standardized intervention in line with technical regulations.
What happens if F1 batteries catch fire?
One of the most frequently asked questions is what happens if the batteries catch fire. The onboard fire suppression systems in an F1 car are not designed to fully extinguish a lithium-ion cell fire.
In the event of mechanical damage, a chain reaction known as thermal runaway can occur. This is a self-sustaining process that generates heat and can release oxygen, making conventional extinguishing agents ineffective at suppressing the flames.
For this reason, Formula 1’s primary approach is not immediate fire suppression, but battery isolation. The Energy Store is engineered with heat-resistant structures designed to contain the phenomenon, prevent propagation, and give the driver enough time to safely evacuate the car.
In the event of a real fire, the most effective response comes from outside the car: prolonged high-volume water cooling applied by marshals. It is the removal of heat that is the only truly effective method to interrupt the reaction and bring the system back to a safe condition.
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