Bottas sets British GP practice pace as Vettel tries F1's shield

Bottas used the soft compound Pirelli tyres to clock a 1m29.106s at an overcast Silverstone, 0.078 seconds quicker than Mercedes team-mate Lewis Hamilton.

Championship leader Vettel, who was sixth fastest, headed out of the garage at the start of the session with the screen, which extends along the car's nose in front of the driver, attached to his Ferrari.

He completed a single installation lap and then returned to the garage where Ferrari removed the device and switched attention to its weekend programme.

The medium compound - the hardest tyre available this weekend - was the rubber of choice for the early installation laps before Kimi Raikkonen fitted the super-softs and set the first time of the session with a 1m32.533s.

He traded quickest laps with the Red Bulls of Daniel Ricciardo and Max Verstappen, with Verstappen coming out on top initially.

Mercedes then sent Bottas out and he went quickest on the soft tyres with a 1m30.788s.

Hamilton lapped three tenths faster with his first real effort on the softs but his team-mate responded immediately to become the first driver to dip into the 1m29s.

Bottas continued to improve, gradually bringing his time down to a 1m29.106s, quicker than last year's pole position time of 1m29.287s.

Red Bull emerged as Mercedes' closest challenger, with Verstappen and Ricciardo third and fourth quickest respectively, but both their laps were set on the super-softs.

Raikkonen was the leading Ferrari in fifth, 1.031s off the pace but four tenths quicker than team-mate Vettel, who spun at Becketts and flatspotted his tyres.

Fernando Alonso, running the more-powerful 'spec 3' Honda engine in his McLaren again this weekend, was eighth quickest on the super-softs, a tenth behind Toro Rosso's Daniil Kvyat.

Felipe Massa, whose Williams team adopted a split approach with its upgrades after a troubled Austrian GP by running different configurations on his and Lance Stroll's cars, was ninth.

Stoffel Vandoorne made it two McLarens in the top 10, just half-a-tenth slower than team-mate Alonso.

Antonio Giovinazzi borrowed Kevin Magnussen's Haas and set the 17th quickest time, nearly half-a-second off team-mate Romain Grosjean.

Jolyon Palmer missed much of the opening part of the session with his Renault up on stands in the garage, but the team eventually got him back out and he ended up 18th quickest after 16 laps.

PRACTICE ONE RESULTS: