Lewis Hamilton’s disqualification at the Chinese Grand Prix, explained

Why was Lewis Hamilton disqualified at the Chinese Grand Prix?

Lewis Hamilton’s second race weekend as a Ferrari driver began with pole position, and a win, in the F1 Sprint race at the Chinese Grand Prix.

It ended with a disqualification in the Grand Prix itself, dropping Hamilton out of the points after he finished sixth.

Following the race, technical delegates performed their customary post-race inspections of cars, which included a measurement of the thickness of the skid plate underneath Hamilton’s SF-25. According to a report from Jo Bauer, the FIA F1 Technical Delegate:

The rearmost skid was measured according to the team’s legality documents submission in accordance with TD039 L, item 1.2 b) i). Measurements were taken along the stiffness-compliant area at three different points of the periphery (inner arc). The recorded measurement were 8.6 mm (LHS), 8.6 mm (car centerline) and 8.5 mm (RHS).

As this is less than the 9 mm minimum thickness required by TR Article 3.5.9 e), I am referring this matter to the stewards for their consideration.

Document 80, the Technical Delegate report, can be read in full here:

The referral to the race stewards resulted in a hearing at the Chinese Grand Prix, which was conducted at 6:48 p.m. local time. During the hearing, which was attended by Hamilton himself according to the report, the driver ”confirmed that the measurement is correct and that all required procedures were performed correctly. The team also acknowledged that there were no mitigating circumstances and that it was a genuine error by the team.”

According to race officials, the standard penalty for a breach of Article 3.5.9 of the FIA Formula 1 Technical Regulations is disqualification.

Here is the decision in full:

The disqualification mirrors what happened to Hamilton at the 2023 United States Grand Prix. That afternoon in Austin Hamilton finished second and Charles Leclerc — his current Ferrari teammate — finished sixth.

But both were disqualified when post-race inspections uncovered that the plank was not in compliance with the Technical Regulations.

F1 cars have these planks, or “skid blocks,” on the floors of the car in part as a safety element added in the wake of Ayrton Senna’s tragic death. They serve a two-fold purpose: First to protect the chassis from damage when the car’s floor touches the track surface at high speeds and second, to act as a safety gauge. They can help measure whether the cars are running too low, or too close, to the track surface.

Article 3.5.9 of the F1 Technical Regulations governs the “Plank Assembly.” Specifically, the section that Hamilton was noted to have violated is Article 3.5.9(e), which reads as follows:

The thickness of the plank assembly measured normal to the lower surface must be 10mm ± 0.2mm and must be uniform when new. A minimum thickness of 9mm will be accepted due to wear, and conformity to this provision will be checked at the peripheries of the designated holes.

As you can see, the thickness of the plank is required to be 10 millimeters. F1’s regulations allow for one millimeter to be worn down throughout a race weekend due to wear and tear. Anything more than that, and the car will have been deemed to violate the Regulations.

Having run afoul of this Regulation, Hamilton has now been disqualified.

Ferrari released a brief statement, noting that the team “misjudged the consumption by a small margin:”

till, that is not enough to avoid the disqualification.