Pirelli investigates Silverstone blowouts that caused last-lap chaos for Hamilton

Debris from Raikkonen wing may be to blame, claims Isola Softer tyres for second race at track will increase pit stops

Pirelli will today announce the findings of its “360-degree investigation” into what caused a series of dramatic tyre failures at the end of Sunday’s British Grand Prix.

Lewis Hamilton, Mercedes’ sixtime world champion, eventually won his home race for a record seventh time. But only after he completed the final lap on three wheels, his front-left tyre having punctured with around 2.4 miles remaining.

It was an extraordinary display of skill and feel from Hamilton, under intense pressure from the Red Bull of Max Verstappen, who closed from 30 seconds back to within six seconds by the finish.

Hamilton said afterwards that his “heart nearly stopped”. But if he was worried, he did not show it.

In-car footage released by F1 yesterday revealed fascinating radio communications between the 35-year-old and his Mercedes race engineer, Peter Bonnington, showing how focused and calm both remained while the chaos unfolded all around them.

The late drama did, however, raise plenty of questions about Pirelli’s tyres. Hamilton was one of three drivers to suffer a front-left failure in the final three laps, along with Mercedes team-mate Valtteri Bottas and Mclaren’s Carlos Sainz Jnr. Both Hamilton and Mclaren team principal Andreas Seidl said they had “no warning” of the “sudden death” of the tyre.

After the race, Red Bull reported that Verstappen’s tyres had also been “right on the limit” when they decided to pit him with two laps remaining, so that he could go for a fastest-lap bonus point.

Mario Isola, Pirelli’s Formula One tyre chief, speculated that debris left by Kimi Raikkonen’s Alfa Romeo, which suffered a late frontwing failure, might have caused the problems.

The fact that there were safety cars early in the race meant virtually every driver dived into the pits and then tried to make their tyres last until the finish, well beyond Pirelli’s recommended limit.

“It could be high wear,” Isola said. “Tyres with 38 laps or more on this circuit are quite worn, but I’m not saying that the wear is the cause of the issue. It can be debris, because we had the pieces of the front wing of Kimi that were on track, but also some other debris.

“We don’t want to exclude anything. We want to analyse everything 360 degrees.” Teams are anxious to know of any safety concerns because F1 returns

Cool head: Lewis Hamilton, with the help of race engineer Peter Bonnington (below), survives the last lap on three wheels

to the high-speed Silverstone track this weekend for the 70th Anniversary Grand Prix. Pirelli is planning to bring a range of softer tyres to the second Silverstone race, which should wear more quickly, necessitating more pit stops.

It is not the first time Pirelli has found itself in hot water following a British GP. In 2013, Hamilton lost the lead due to tyre failure, while Felipe Massa, Jean-eric Vergne and Sergio Perez all suffered separate blowouts.

Following an inquest, Pirelli concluded that several factors had contributed to those tyre failures including under-inflation, extreme camber angles, aggressive kerbing and rear tyre-swapping – which has since been outlawed.

The rear-tyre compounds were altered for the German GP that followed that race, with a new compound subsequently introduced for the remainder of the 2013 season.

It remains to be seen whether similar drastic action is required this year.