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.
“As with most accidents, several incidents combined to cause the fire that Nick suffered in Hungary,” Allison explains.
“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 incident was highly undesirable, as it has caused us to write off a chassis,” Allison began to sum up. “We will take steps prior to the next race to reduce the likelihood of a further fire and to ensure that the air bottle cannot overheat. We are in touch with the FIA, both to provide them with a full report of the incident and also to explain to them the actions we are taking to prevent a reoccurrence.”
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