Romain Grosjean was going 192 kph (119 mph) when he hit a metal crash barrier and his car exploded into a fireball around him at the Bahrain Grand Prix.
The impact was estimated at 67 Gs, a force equivalent to 67 times his body weight. By comparison, heavy braking in an F1 car produces about 6 Gs.
The findings came from an investigation into the horror crash last November by governing body the FIA that concluded on Friday, and will be presented to the drivers commission on Tuesday.
The French driver made an astonishing escape from the raging furnace.
Grosjean’s Haas car sliced in half after penetrating the barrier and quickly caught fire. He was trapped inside the cockpit for 27 seconds before scrambling out, yanking his jammed foot out of his racing boot in order to do so.
He suffered only minor burns to the back of his hands and a sprained left ankle, and was discharged from hospital soon after.
The crash happened on the opening lap when the right rear wheel of his car clipped the left front wheel of Russian driver Daniil Kvyat’s AlphaTauri, when attempting to pass from the left to right-hand side of the Sakhir track.
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 … providing primary paths for the escape of fuel, the FIA said in a statement. 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.
The ring-shaped halo device at the front of Grosjean’s cockpit protected his head by withstanding the huge impact, and he credited it with saving his life.
Then, dealing with the shock of a ferocious crash while a fire threatened to burn him alive, Grosjean was faced with another problem.
Romain Grosjeans left foot was initially trapped as the car came to rest, the FIA said. 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 (leave) the car.
After his release from hospital Grosjean went to meet the three medical crew FIA doctor Ian Roberts, medical car driver Alan van der Merwe, and a local doctor who reacted so swiftly to help him.
They arrived at the scene in a medical car in just 11 seconds by cutting a corner due to local circuit knowledge and pre-planning, the FIA said.
Ian Roberts went immediately to the scene of the incident and instructed a marshal to operate the dry powder extinguisher around the cockpit where he identified Romain Grosjean, the FIA said. Alan van der Merwe retrieved a fire extinguisher from the rear of the car whilst the local doctor prepared the trauma bag.
It proved to be Grosjean’s last race in F1 since he was without a seat for 2021, and he has switched to the IndyCar series with Dale Coyne Racing.