Airborne gravel blamed for Hulkenberg's Barcelona retirement

June 15 : Audi have blamed airborne gravel for Formula One driver Nico Hulkenberg's Barcelona-Catalunya Grand Prix retirement.

The German veteran coasted into the pit lane and retired from Sunday's race when his car suddenly lost power.

The team later revealed it had nothing to do with reliability, with Hulkenberg saying stones thrown up by Liam Lawson's Racing Bulls car had hit an emergency electrical cutoff switch on the Audi behind.

"Liam ran slightly wide ahead of me and put a wheel into the gravel at Turn 12, which kicked up a lot of stones. Some of them hit our car and appear to have triggered the emergency safety switch, causing a complete shutdown of the system," explained Hulkenberg.

"Everything switched off instantly and that was the end of our race."

Hulkenberg had started in the top 10 for the first time this season and had been hopeful of converting that into points. Lawson ultimately ended up eighth.

Racing director Allan McNish confirmed the safety fire switch had taken a hit, triggering an automatic function designed to shut the car down in an emergency.