Heidfeld's fire caused by overheating exhausts
1 August 2011 – Initial investigations at Renault indicate that a long pit-stop was the cause of the fire which took Nick Heidfeld out of Sunday’s Hungarian Grand Prix. After retiring on the exit of the pit lane, the German’s car then gave out a small explosion, expected to have been trigged as cold extinguisher foam contacted with a hot gas canister.
Although Technical Director James Allison is yet to publish a full report into the incident, it is highly expected that the issue began when one of the wheel nuts forced a lengthy stop - with normal procedure requiring the driver to maintain 18,000rpm as full throttle is applied with the pit lane speed limiter active.
As mechanics attended to the wheel problem, the car remained stationary for around 10 to 12 seconds as opposed to the usual three or four; this caused the forward-pointing exhausts to overheat and in-turn the bodywork caught fire.
The subsequent explosion of the left sidepod occurred as the cold fire extinguisher foam came into to contact with the aforementioned small gas canister, which all cars carry in order to feed the pneumatic valve system of the engine.
It has been confirmed by the Hungaroring that a marshal – hit by flying debris as the sidepod exploded – suffered no more than bruising to the leg.
Renault are expected to authenticate an official explanation on Monday evening.
The Renault fire can be viewed at GPUpdate TV