Lewis Hamilton fastest in German Grand Prix first practice

Lewis Hamilton picked up on Friday morning where he left off at Silverstone when he set the fastest time in opening free practice for the German Grand Prix at the Nurburgring.

Six days after his sensational pole lap at the British Grand Prix, the 28-year-old Briton steered his Mercedes car to a fastest lap in 1min 31.754sec -- and without any hint of a tyre failure -- in the first session of the weekend.

On a mild and dry morning in the Eifel, Hamilton was two-tenths of a second ahead of his Mercedes team-mate German Nico Rosberg, who won last Sunday's race.

The Mercedes pair were a full second clear of their nearest rival, Australian Mark Webber of Red Bull, who continued to show a new lease of life after announcing his intention to move to sportscar racing at the end of the season.

Webber was third ahead of German Adrian Sutil of Force India.

Finland's Kimi Raikkonen of Lotus was fifth and Brazilian Felipe Massa of Ferrari in sixth, despite completing only 18 laps during a troubled morning for the Italian team.

Rivals Mercedes did 24 laps, while two-time champion Spaniard Fernando Alonso failed to complete a lap due to suspected electrical problems.

Briton Jenson Button, the 2009 champion, was seventh for McLaren ahead of defending triple world champion and current series leader German Sebastian Vettel in the second Red Bull.

Vettel has never won on home soil and is keen to make his 30th win one to celebrate on Sunday if he can achieve it in front of a German crowd.

The session was the first to be run using the new Kevlar-belted tyres from Pirelli, introduced by the Italian suppliers following last weekend's spectacular events at Silverstone where four drivers suffered high-speed blowouts during the race.

In a move to endorse Pirelli's switch of tyres on safety grounds, the sport's ruling body on Friday morning announced it was imposing a ban on tyre swapping and strict limits on tyre pressures and cambers.

In a note that was sent to all the teams, the International Motoring Federation (FIA) race director Charlie Whiting said: "For safety reasons, we have been asked by Pirelli to ensure that the tyres on all cars are run under the conditions listed below.

"It will be the responsibility of each team to satisfy the FIA technical delegate that the cars comply with the following requirements at all times."

This move from the FIA came after Pirelli wrote to motor racing's governing body on Thursday requesting that teams are limited in how they exploit the rubber, because that was viewed as a contributing factor in the Silverstone failures.

Whiting added in his note: "Front and rear tyres must be used on the side of the car for which they were originally designated (meaning no swapping from side-to-side.)"

Amid this flurry of guidelines, and following a threat late on Friday from the drivers that they would pull out this weekend if there was any repeat of the tyre problems, Pirelli motorsport chief Paul Hembery conceded that the failures at Silverstone were their responsibility.

"We allowed the teams to invert the tyres when we shouldn't have done," he said. "With the cars going much quicker this year that creates different loads.

"With the inverted tyres you create a weakness point, and that was the issue. There were secondary issues, which have been mentioned, but I don't want to take away from the fact it was our responsibility.

"Going forward, though, there are things we need to be much more rigid on, and that's where we are at."

The chairman of the Grand Prix Drivers' Association, Pedro de la Rosa, praised Pirelli's moves to address the issue, saying safety was paramount.

But he warned that drivers would meet to discuss their next move if there were problems with tyres during qualifying and the race itself.