Romain Grosjean’s fiery crash at the Bahrain Grand Prix registered a peak force equivalent to 67Gs, the FIA’s investigation into the accident found.
Motor racing’s governing body has published its full report on the accident and the areas of safety it must improve. Grosjean miraculously escaped after his Haas car hit a barrier, split apart and caught fire.
The investigation determined Grosjean hit the barrier at 192 kmh at a estimated yaw of 22 degrees.
The French driver spent 27 seconds inside the car. He has already described the terrifying experience and how he was convinced he was going to die.
Explaining the way the car was able to split in two and catch fire, the report said: “The car suffered extensive damage during the impact including separation of the power train assembly from the survival cell.
“The fuel tank inspection hatch on the left-hand side of the chassis was dislodged and the engine fuel supply connection was torn from the fuel tank ‘safety bladder’; both providing primary paths for the escape of fuel from the tank.
“The driver safety equipment including helmet, HANS and safety harness as well as the survival cell, seat, headrest and Halo frontal cockpit protection performed according to their specifications in protecting the driver’s survival space and managing the forces applied to the driver during the impact.
“The high voltage Energy Recovery System (ERS) battery was significantly damaged, with some parts of the ERS battery assembly remaining with the powertrain and others remaining attached to the survival cell.
“Fire was ignited during the final moments of the barrier impact, starting from the rear of the survival cell and progressing forwards towards the driver as the fire grew.”
“The resting position of the survival cell, relative to the upper rail of the barrier significantly restricted the path for driver egress. Due to damage to the survival cell and a number of components within the cockpit environment, Romain Grosjean’s left foot was initially trapped as the car came to rest.
“The driver was able to free his foot by withdrawing it from his racing boot leaving the boot in the entrapped position in the car and then moved both the dislodged headrest and steering wheel to egress the car.”
The FIA has committed to a list of safety priorities in the wake of the accident. The governing body is continuing to evaluate the survival cell of cars, as well as rear view mirrors and headrest assembly, given the way Grosjean struggled to immediately free himself from the cockpit.
The failure modes of the power unit mounting will also be investigated.
Grosjean sustained burns to his hands but is signed up to race in IndyCar for Dale Coyne this year.
The report said the medical car arrived at the scene within 11 seconds of the accident. This response time was achieved partly due to the fact the safety car driver took a short cut across Turn 1.