The last two weekends have both provided me with interesting opportunities to reflect on the vagaries of endurance racing. I spent the Easter weekend at Spa-Francorchamps for Creventic’s “12-hour” race: the sum of two parts of 3h 48m and 8h 48m meant it was only 11h 37m 32.882s in total, but in some ways that is not important.
Then, this last weekend I was at Silverstone for the Citroen C1 24-hour challenge, a remarkable race with 99 starters and which 11 different cars led overall at one point or another. What the two races had in common was that on both occasions the likely-looking winner was beaten in the closing stages by a faster car closing from behind. At Spa, the Herberth Porsche of Robert Renauer, Ralf Bohn and Daniel Alleman had been leading for most of the second part of the race, as the Scuderia Praha Ferrari of Matteo Malucelli, Josef Král and Jiří Písařík got the rough end of the “code-60 lottery” and fell back to be more than a minute and half behind with just under two hours to go.
With twenty minutes remaining, the gap was down to fifteen seconds, but Herberth had also managed to get themselves onto a slightly better fuel strategy, such that their final stop should have been around four seconds quicker. Even Matteo Malucelli wouldn’t have been able to close the gap in the remaining three laps. Or so we thought. The “tag” that is registered on the fuel pump had timed out while Ralf Bohn was trundling down the kilometre-long pit lane, and when the Herberth refuelling crew went to put the pump nozzle into the fuel filler on the Porsche’s bonnet, the pump did not provide any fuel. Resetting the pump was done quickly, but not quickly enough, and the stop was more than eight seconds longer than the stop for the Ferrari – the gap was gone and the lead changed.
At Silverstone, we had a classic example of what I call “The Squeeze” – where the leader is caught between a faster car closing the gap from behind and the end of the race that is just a little bit too far away.
The Circuit Pro team in car number 385, Simon Harrison, Patrick Watts and Tim Hartland had been in the lead of the race since around 7am, and had slowly drawn away from the rest of the field. By the time Tim Hartland took over at the wheel for his final stint, at 10:45am, there was a one-lap gap back to the number 321 Old Hat-entered car of Dan Bruce, Tony Hutchings, Callum Hutchings and James Keepin and two laps back to the very rapid number 347 McAttack entry of Joe Wiggin, Declan McDonnell and Simon Walker-Hansell.
The race had started at 5:30pm on Saturday, after a full day of BARC-organised racing – crucially, the green light had been shown at 17:31:29, so Hartland’s job was to be quick, stay out of trouble, and drive for 2h 10m. Tight, for a full tank of 35 litres fuel for a Citroen C1, but certainly feasible, bearing in mind that the car was under no pressure. That would give Patrick Watts and Simon Harrison similar length stints and allow the team to get to the end of the race with just two more stops.
All the competition would certainly need three more stops, meaning that the Circuit Pro team’s lead was all the more secure. Hartland duly brought the car back in at 1pm after a 43-lap stint, and Patrick Watts went back out with (one assumes) a full tank of fuel, a lap’s lead over the rest of the field, and a pit stop in hand. A safety car period just before 2pm gave Joe Wiggin in the McAttack car the chance to refuel cheaply, but of course that also gave Watts the chance to save fuel.
The turning point came when Patrick Watts brought the Circuit Pro car in for its final stop at 3:14pm after a stint of 39 laps – four laps less than Tim Hartland had done, and leaving Simon Harrison needing to stay out for 2h 15m to get to the end of the 24 hours. By the time Harrison had got away, the McAttack car had gone through into the lead, but had a pit stop still to make. Ten laps later, Joe Wiggin was in, to hand over to Simon Walker-Hansell.
For the McAttack team, the chase was now on: the gap at the end of Walker-Hansell’s first flying lap was 1m 54s, but he was lapping between one and two seconds per lap quicker. I would love to know the amount of information that the Circuit Pro team had at their disposal at this point – later this year, I am hoping to catch up with Simon Harrison, and he will probably be willing to discuss things, but for now this is mere speculation (or informed guesswork). Poor old Simon probably didn’t have much to go on from the driving seat either – team radio was banned, mobile phones not allowed: the only means of communication was via the pit board. I heard after the event that some teams had their car radio tuned into the commentary on Silverstone Radio, and apparently, it was helpful.
Anyway, from the comfort of the commentary box, I was able to simulate the progress of Simon Walker-Hansell in the McAttack car, and assuming an average lap time of 3m 03s, it seemed that he would get to the end of lap 405 at a race elapsed time of 24h 00m 29s
To win the race, therefore, Simon Harrison would have to complete 405 laps before 24h 00m 29s, but after 24h 00m, or have to go onto an extra lap. The extra lap would mean a stint of 44 laps. The car’s longest stint in dry conditions had been 43 laps. Circuit Pro’s dilemma: Pit to get more fuel? Or stay out and try to conserve fuel? Wait for a Safety Car? That could be disastrous, as it would likely as not cause the gap to close significantly.
Calculators out again: The time lost in pit lane at the speed limit of 40km/h: 40s. Driver out and in: 15s. They would probably only need two more litres of fuel; still that would take 15s. Total time lost: 1m 10s. So if Circuit Pro would have called Harrison in for the “splash and dash”, it would have reduced the gap from 1m 54s to around 45s at best. At that point in the race, assuming there were no Safety Cars (there weren’t), there were 30 laps remaining. With Harrison flat out, could Walker-Hansell close the gap at a rate of 1.5s per lap?
Looking at Harrison’s lap times, it is not easy to work out at whether he was trying to save fuel early in his stint. His first flying lap was lap 364, then laps 383, 390 and 395 were the car’s three fastest laps of the race – so it is clear from those that his main concern was speed. From lap 397 onwards, though, he hardly got within two seconds of his best lap. By this time, the gap back to Walker-Hansell was less than a minute, so Harrison’s options were limited. Actually, he had no option, he had to stay out. He was between a rock and a hard place. He didn’t have time to stop for fuel anymore, but he needed to stretch the fuel to do 44 laps in the stint. Or hope that Simon Walker-Hansell would just slow down a bit. He was feeling the Squeeze.
Rather than averaging 3m 03s, the McAttack car was doing 3m 02.2s – meaning that Walker-Hansell was on schedule to cross the line after 405 laps at 24h 00m 03s. If Circuit Pro was aware of that, the pit board would surely have been telling Harrison to push on. He appeared out of Luffield at the end of his 405th lap with 15s still on the clock. He slowed, expecting the chequered flag to be put out. The man holding the flag stood resolutely watching his stop-watch in one hand, the flag still furled in the other. Ten-nine-eight, the seconds were ticking down and Harrison accepted the inevitable and went onto another lap, despite it already being 17:31, according to his on-board clock. Did they know the race had started nearly 90s after the appointed time? Behind, Walker-Hansell had closed to within seven seconds of the leader, and crossed the line with 24h 00m 00.084s elapsed.
Lap 406, Simon Harrison’s C1 coughed as it exited Stowe, and Simon Walker-Hansell pounced. The car that had started at the very back of the grid, had then lost five minutes in the pits at the end of lap one, had managed to take the lead on the very last lap, and win by just 7.219s.
Who says endurance racing isn’t exciting?
Then, this last weekend I was at Silverstone for the Citroen C1 24-hour challenge, a remarkable race with 99 starters and which 11 different cars led overall at one point or another. What the two races had in common was that on both occasions the likely-looking winner was beaten in the closing stages by a faster car closing from behind. At Spa, the Herberth Porsche of Robert Renauer, Ralf Bohn and Daniel Alleman had been leading for most of the second part of the race, as the Scuderia Praha Ferrari of Matteo Malucelli, Josef Král and Jiří Písařík got the rough end of the “code-60 lottery” and fell back to be more than a minute and half behind with just under two hours to go.
With twenty minutes remaining, the gap was down to fifteen seconds, but Herberth had also managed to get themselves onto a slightly better fuel strategy, such that their final stop should have been around four seconds quicker. Even Matteo Malucelli wouldn’t have been able to close the gap in the remaining three laps. Or so we thought. The “tag” that is registered on the fuel pump had timed out while Ralf Bohn was trundling down the kilometre-long pit lane, and when the Herberth refuelling crew went to put the pump nozzle into the fuel filler on the Porsche’s bonnet, the pump did not provide any fuel. Resetting the pump was done quickly, but not quickly enough, and the stop was more than eight seconds longer than the stop for the Ferrari – the gap was gone and the lead changed.
At Silverstone, we had a classic example of what I call “The Squeeze” – where the leader is caught between a faster car closing the gap from behind and the end of the race that is just a little bit too far away.
The Circuit Pro team in car number 385, Simon Harrison, Patrick Watts and Tim Hartland had been in the lead of the race since around 7am, and had slowly drawn away from the rest of the field. By the time Tim Hartland took over at the wheel for his final stint, at 10:45am, there was a one-lap gap back to the number 321 Old Hat-entered car of Dan Bruce, Tony Hutchings, Callum Hutchings and James Keepin and two laps back to the very rapid number 347 McAttack entry of Joe Wiggin, Declan McDonnell and Simon Walker-Hansell.
The race had started at 5:30pm on Saturday, after a full day of BARC-organised racing – crucially, the green light had been shown at 17:31:29, so Hartland’s job was to be quick, stay out of trouble, and drive for 2h 10m. Tight, for a full tank of 35 litres fuel for a Citroen C1, but certainly feasible, bearing in mind that the car was under no pressure. That would give Patrick Watts and Simon Harrison similar length stints and allow the team to get to the end of the race with just two more stops.
All the competition would certainly need three more stops, meaning that the Circuit Pro team’s lead was all the more secure. Hartland duly brought the car back in at 1pm after a 43-lap stint, and Patrick Watts went back out with (one assumes) a full tank of fuel, a lap’s lead over the rest of the field, and a pit stop in hand. A safety car period just before 2pm gave Joe Wiggin in the McAttack car the chance to refuel cheaply, but of course that also gave Watts the chance to save fuel.
The turning point came when Patrick Watts brought the Circuit Pro car in for its final stop at 3:14pm after a stint of 39 laps – four laps less than Tim Hartland had done, and leaving Simon Harrison needing to stay out for 2h 15m to get to the end of the 24 hours. By the time Harrison had got away, the McAttack car had gone through into the lead, but had a pit stop still to make. Ten laps later, Joe Wiggin was in, to hand over to Simon Walker-Hansell.
For the McAttack team, the chase was now on: the gap at the end of Walker-Hansell’s first flying lap was 1m 54s, but he was lapping between one and two seconds per lap quicker. I would love to know the amount of information that the Circuit Pro team had at their disposal at this point – later this year, I am hoping to catch up with Simon Harrison, and he will probably be willing to discuss things, but for now this is mere speculation (or informed guesswork). Poor old Simon probably didn’t have much to go on from the driving seat either – team radio was banned, mobile phones not allowed: the only means of communication was via the pit board. I heard after the event that some teams had their car radio tuned into the commentary on Silverstone Radio, and apparently, it was helpful.
Anyway, from the comfort of the commentary box, I was able to simulate the progress of Simon Walker-Hansell in the McAttack car, and assuming an average lap time of 3m 03s, it seemed that he would get to the end of lap 405 at a race elapsed time of 24h 00m 29s
To win the race, therefore, Simon Harrison would have to complete 405 laps before 24h 00m 29s, but after 24h 00m, or have to go onto an extra lap. The extra lap would mean a stint of 44 laps. The car’s longest stint in dry conditions had been 43 laps. Circuit Pro’s dilemma: Pit to get more fuel? Or stay out and try to conserve fuel? Wait for a Safety Car? That could be disastrous, as it would likely as not cause the gap to close significantly.
Calculators out again: The time lost in pit lane at the speed limit of 40km/h: 40s. Driver out and in: 15s. They would probably only need two more litres of fuel; still that would take 15s. Total time lost: 1m 10s. So if Circuit Pro would have called Harrison in for the “splash and dash”, it would have reduced the gap from 1m 54s to around 45s at best. At that point in the race, assuming there were no Safety Cars (there weren’t), there were 30 laps remaining. With Harrison flat out, could Walker-Hansell close the gap at a rate of 1.5s per lap?
Looking at Harrison’s lap times, it is not easy to work out at whether he was trying to save fuel early in his stint. His first flying lap was lap 364, then laps 383, 390 and 395 were the car’s three fastest laps of the race – so it is clear from those that his main concern was speed. From lap 397 onwards, though, he hardly got within two seconds of his best lap. By this time, the gap back to Walker-Hansell was less than a minute, so Harrison’s options were limited. Actually, he had no option, he had to stay out. He was between a rock and a hard place. He didn’t have time to stop for fuel anymore, but he needed to stretch the fuel to do 44 laps in the stint. Or hope that Simon Walker-Hansell would just slow down a bit. He was feeling the Squeeze.
Rather than averaging 3m 03s, the McAttack car was doing 3m 02.2s – meaning that Walker-Hansell was on schedule to cross the line after 405 laps at 24h 00m 03s. If Circuit Pro was aware of that, the pit board would surely have been telling Harrison to push on. He appeared out of Luffield at the end of his 405th lap with 15s still on the clock. He slowed, expecting the chequered flag to be put out. The man holding the flag stood resolutely watching his stop-watch in one hand, the flag still furled in the other. Ten-nine-eight, the seconds were ticking down and Harrison accepted the inevitable and went onto another lap, despite it already being 17:31, according to his on-board clock. Did they know the race had started nearly 90s after the appointed time? Behind, Walker-Hansell had closed to within seven seconds of the leader, and crossed the line with 24h 00m 00.084s elapsed.
Lap 406, Simon Harrison’s C1 coughed as it exited Stowe, and Simon Walker-Hansell pounced. The car that had started at the very back of the grid, had then lost five minutes in the pits at the end of lap one, had managed to take the lead on the very last lap, and win by just 7.219s.
Who says endurance racing isn’t exciting?
