‘Precisely. But, at 22.61.44 – without, if you remember, any sign of Remy touching the dial on the steering wheel – the hydraulic valve is suddenly activated with near-maximum force.’
‘Which means?’
‘Her rear wheels had started to rotate at slightly different speeds, because she’d started rounding the corner. At the moment the wisp of smoke appeared, the differential was fully locked, the clutch having been slammed shut.’
‘Forcing both rear wheels – suddenly – to rotate at exactly the same speed, presumably?’
‘Correct. The right rear adjusting the most – suddenly under-rotating – hence the wisp of smoke from the tyre. Normally on a corner, with the weight shifting to the outside, the outside wheel is loaded – so it would be the inside one that would change speed. But here, the inside wheel was still on the clean part of the track, while the outside one was on the dirty – with less grip – so it was the outside wheel that adjusted this time.’
Straker was shaking his head. ‘You know, Remy did mention that she felt a jolt … maybe the right rear locking-up was something to do with it?’
‘Very possibly.’
‘What does all this locking-up mean?’ asked McMahon.
‘Well, Sandy, two things. First, at that precise moment, the car will have been destabilized by the momentary lock-up in one rear wheel – and, second, because the rear axle was now effectively “fixed”, it would immediately show much more resistance to turn.’
Straker suddenly looked dark.
He was about to speak, when Backhouse held up his hand.
‘But that's not all…’ The race engineer triggered the footage again. In slow motion, he let it run on beyond Sabatino's two steering attempts.
‘After Remy realizes she's not going to turn in time, we come to the brakes,’ said Backhouse. Moving his hand to point at another set of data, he said: ‘This is the reading from sensors measuring the pressure on the brake pedal; as you can see – there – she's just hit the brakes … pretty hard.’
‘Presumably not an unexpected reaction, under the circumstances?’ offered McMahon.
‘Absolutely not,’ replied Backhouse. He paused the film.
Straker said. ‘Everything all right, Andy?’
The race engineer looked troubled. ‘I need to show you something else, something strange.’
‘Go on?’
‘I need to explain what would be considered normal, though, before you can see the significance of this for yourself.’
The other two nodded.
‘Let me give you the big picture. I can always go into more detail afterwards, if you want me to?’
Both Straker and McMahon nodded again.
‘Okay, under the current Formula – the rules – F1 cars have to run hybrid engines and their size is relatively small. The quid pro quo is that we are permitted to augment the power of the engine by “recycling” some of the energy it produces. In fact, to be competitive we have to do this. Recycling is done by connecting a generator to the engine – an Energy Recovery System – called MGU-K…’ Having said that Backhouse put his hand straight up in apology, indicating some of the detail was not essential to their understanding. ‘This device generates electricity, which can then be stored in batteries on the car for subsequent use; that stored electricity is actually fed back through the same generator – turning it into an electric motor – to assist the engine during subsequent acceleration.
‘But, the process of generating that electricity takes considerable effort, producing significant reverse torque – sorry – resistance. It would seriously slow the engine down – and the car – if we used the generator all the time; it would kill performance. However, we make a virtue of the resistance it does create while generating electricity – when we want to slow the car down. Instead of losing energy that would otherwise be lost as heat in the brakes, we “harvest” some of that energy for recycling by engaging the generator; and we use the resistance that it creates, then, as part of the braking system. But the car-slowing attribute provided by the harvesting only works on the drive train – the back wheels. Are you with me so far?
‘I now need to explain how this interacts with the brakes. The brakes on an F1 car – front and back – are operated by fairly conventional hydraulics. But to make the most of the useful deceleration characteristics of the energy recovery generator, we end up trying to combine these two very different braking systems – both with very different variables – and expect them to work at the same time. To manage all this and get the most out of both for the drivers, we have to have a smart add-on to the cars’ existing engine management system – to fine-tune the different contributors to the braking process.’
Backhouse looked at the others and thought he had probably given them enough background. ‘So, with that rough outline in mind, what we should expect to see during deceleration is Remy hitting the brake pedal. Immediately after that, we should see the hydraulic-operated front brakes respond. Then, depending on a number of factors – the brake balance front-to-rear, the temperatures in the front discs, the response of the car, and a whole load of other things – the smart add-on to the ECU, the car's computer, should activate the energy recovery generator to start harvesting, which would also contribute to slowing the car down. Finally, as a balancing item, so to speak, we would then expect to see the hydraulic system on the rear brakes kick in, particularly given how fiercely we might expect her to be trying to decelerate at this point.’
‘So what happened at Turn Eleven, Andy?’ asked Straker.
Backhouse now looked like a man in mourning. ‘Remy did hit the brake pedal, as I showed you before – as measured by the pressure recorded on the pedal itself. But if you look over here,’ he said pointing to a different set of numbers, ‘her front brakes didn’t respond: the hydraulic valves stay completely closed – inactive. Most bafflingly, the ERS generator did not cut in, either. And finally, as shown here, there was no fill-in or backup braking from the hydraulics on the rears.’
‘Meaning her brakes didn’t work?’ said McMahon
The race engineer shook his head.
‘At all?’
Backhouse's eyes conveyed his answer.
‘So, if I’ve followed you,’ said Straker, ‘during this extremely short period into the corner, the overall hydraulic pressure across the car remained constant. One hydraulic valve, though – in the steering – stayed inactive, causing the steering wheel to be heavier than expected, as shown in the torque spike on the steering column. At almost the same time, the hydraulic valve within the differential on the rear axle – which should have stayed partially activated – activated fully, without any instruction from Remy, locking that axle which would not only lock-up the outside wheel but also cause the car to behave like it wanted to run on in a straight line. And, at the crucial moment, the three elements of the braking system, if I’ve understood you correctly – the hydraulics in front, the energy recovery generator and the hydraulics on the rears – all failed to activate, meaning, effectively, that she had no brakes?’
The race engineer shook his head in agreement.
‘None of which should have been expected or intended.’
‘Fuck, no,’ said Backhouse. ‘At that speed, even the slightest unexpected happening on the car will have a disproportionate effect, throwing the balance and control for the driver.’
‘Christ,’ said Straker. ‘How did those valves and systems get to do each of those things?’
Backhouse replied: ‘Cars can fail at any time – components can fail – drivers can make mistakes, so one shouldn’t rule out a “normal” failure of some kind. But, all of these elements are unconnected. For them to behave like this – with things “going in different directions” at the same moment – is almost impossible by themselves. Mathematically, the probability of them doing that randomly – in that sequence – is so remote as to be dismissed.’
‘So are you saying that these valves and systems were instructed to do those things?’
Backhouse nodded. He paused. ‘They would have to have been.’
