In-depth investigation: The Heidfeld fire explained
4 August 2011 – The Hungarian Grand Prix brought a fourth McLaren victory in Jenson Button’s 200th Formula 1 start, although the race might best be remembered for the spectacular fire which took out Nick Heidfeld. Following a thorough investigation, Renault Technical Director James Allison talks us through the dramatic moment.
“First of all, we ran a slightly different engine mapping strategy in qualifying, which produced hotter than normal exhausts. We believe that this elevated temperatures and caused a preliminary crack in the exhaust pipe. We presume that the crack then propagated during the laps to the pit-stop - this was not evident to us as we believe that the failure occurred upstream of the place where we have a temperature sensor.
“We believe that Nick then came in with a partially failed exhaust. This pit-stop took longer than normal and the engine was left at high rpm for 6.3 seconds, waiting for the tyre change to be completed; under these conditions, a lot of excess fuel always ends up in the exhausts and their temperature rises at around 100°C (212°F) per second. This temperature rise was enough to finish off the partially failed pipe and to start a moderate fire under the bodywork.”
Allison went on to confirm that, as reported by GPUpdate.net on Monday, the subsequent explosion of the left sidepod was a failed and overheating air canister which is normally used to supply the engine’s pneumatic valve system. The Enstone-based team is now submitting a report to F1 governing body the FIA.
The Hungaroring fire was Heidfeld’s second of the season, having also suffered a blaze during third practice for the Spanish Grand Prix of May.
- The Renault fire can be viewed at GPUpdate TV
Heidfeld’s fire caused by overheating exhausts