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Bloodhound: how do you stop a 1000mph car?
Ollie Kew straps in for the first test of the land speed record car’s parachute brakes… in a 542bhp Jag
The world’s fastest man isn’t best pleased.
Andy Green has just marched into the canteen at ex-RAF base Bentwaters, scowled at the queue around the drinks fridge and tutted: “Who decided to put the fridge in the narrowest part of the room?” That’s attention to detail for you.
It’s about the only time a wide grin ever leaves the rangy Wing Commander’s face, despite today being the D-Day for his 1000mph company car’s brakes. Talk about a stiff upper lip.Of course, with our peerless record of driving very fast down runways (ahem), TG is naturally happy to help test the braking system for the Bloodhound SSC, the new land speed record project aiming for the world’s first four-figure speedo reading in 2017.
Bloodhound will use disc brakes below 200mph, and perforated airbrakes to initially slow its charge. But a good old-fashioned parachute will still handle the lion’s share of the stopping.
And before the chute is packed into the back of a giant firework with Andy Green strapped to the pointy end, the release mechanism needs testing. We need a fast car.
Somehow, this has led to me strapping myself into a stickered up Jaguar F-type R Coupe with an ominous metal canister sticking through its back window like a badly packed camping stove. Jaguar’s now an official partner in the Bloodhound project - the very engine that powers this 542bhp V8 Jag will be used as a the fuel pump for the record car’s rocket motor. That’s right: Bloodhound’s fuel pump makes 542bhp.
Jaguar is also providing the reconnaissance vehicles for the attempt, just as it did back in 1997 when Andy Green drove Thrust SSC through the sound barrier at Black Rock Desert, Nevada. Straight into the record books too, scoring a searing 763mph average. The F-type R is Jag’s fastest current model, up for 62mph in 3.9 seconds and a modest top whack of, erm, 186mph. Should be brisk enough for firing parachutes out the back, anyhow.
Doubtless you’re scoffing about now.
“Parachutes have been around for decades,” you’re snorting. “They daily bring skydivers safely back to Earth and restrain dragsters time after time without complaint. Why are you bothering to test this one?”
It’s a harsh lesson learned from the last time an outright land speed record was set. Thrust SSC made several unsuccessful attempts on the record because it overshot its stopping point at the end of one supersonic run. The rules state your car must complete two runs in opposite directions within one hour, so people don’t employ cheeky slope and massive tailwind to crank up their result.
Thrust SSC’s electronic release mechanism was decimated by the heat and vibration you’d expect from smashing Mach 1 in a dust bowl. The parachutes were a weak link. With Bloodhound targeting a 35 per cent higher v-max, this time there’ll be no room to coast to a stop if the chutes don’t obey Andy’s command.
A simple cable-operated mechanical mechanism is supposed to make the parachutes behave this time. It’s a remarkably elegant solution, and tinier than you might expect.
Andy explains: “The two-metre diameter parachute is identical to what Richard [Noble] used on Thrust 2 in 1983. It just so happens - spookily - that a two-metre chute is the perfect size for us.”
Andy also points out something remarkable about the small puffs of dust released from the parachutes as the Jag barrels past at 150mph on another test run.
“That’s Black Rock [Desert] dust,” he says airily.
Eh? “These are the actual parachutes that stopped Thrust SSC?”
“Yes,” replies Green in his typical ‘why are you remotely impressed by that’ matter-of-fact tone. “That’s the great thing about parachutes. As long as you store them properly - a cool, dry, dark place to preserve the nylon - they’ll last for years…”
So, with the dusty but apparently hard-as-nails chute rammed into the deployment canister, the release mechanism armed, and the Jag topped up with a couple of thimbles of fuel (a full tank could upset the weight balance when the ‘chute tensions), it’s time to peel off down Bentwaters’ gritty 1.7-mile tarmac.
I spin the car 180 degrees at the runway limit and aim the nose back down the airstrip. Various warning lights are blinking on the dashboard, as if the car’s electronic brain knows the body’s been hacked about, and the car’s up to no good.
Heat-haze melts the surface into shimmers a few hundred yards ahead, so the braking point - marked by a bush the team have planted at the runway edge - isn’t visible. Meanwhile, the pit team warns about speed over the radio. A vicious crosswind has swept in. I’m not being a wuss here - it’s the sort of gust you could lean into to take the weight off your feet.
The Bloodhound guys are worried about how much the gale will disrupt the parachute. Theoretically, the Jag will just about crack 180mph down here, but this is a severely expensive piece of equipment that can’t be risked. I’m asked to aim for a 130-140mph maximum as we pass the marker-bush.
No problem. The F-type might be lugging along the weight of a roll cage and parachute gubbins, but its interior has been largely stripped. Besides, you could unfurl the chute at the start line and the R Coupe would still leap off the line like a train. A smoky, coal-fired train at that.
0-100mph is dealt with in around nine seconds, and I’m passing 135mph so early I have to lift off just before the car reaches its deciduous braking point.
Leaving my left hand clamped around the F-type’s podgy steering wheel, my right hand grips the fabric rip-cord - taped to the roll bar - like a child holding a balloon at a fairground. I feel ridiculous. Here goes nothing. Three, two, one… pull.
Nothing happens. In a split-second, I take my eyes off the road and look at the pull-cord. I’ve pulled it the requisite two inches as briefed. Maybe I broke it? Maybe the parachute’s malfunctioned? Should I hit the brake pedal?
In the time it’s taken my brain to run through that little sequence of panic, behind me, the Jag has grown a twenty-foot tail. The little ‘drogue ‘chute’, a sort of sidekick to the main event, is ejected from its heatproof jacket via the spring-loaded release.
It grabs hold of the 135mph headwind, and pulls out the main chute, which releases cleanly from the holster. The whole caboodle tensions, and meanwhile back in the cockpit, I’m trying not to headbutt the steering wheel.
As soon as the ‘thwack’ of deceleration has hit, it’s over. It’s actually a great lesson in how pathetic regular human reaction times are. I am, it turns out, an awfully regular human. As my chest compresses into the belts, I instinctively tense my stomach, take a gulp of air and hold it there, like a boxer expecting a gut punch.
But by the time I’ve actually sent that signal from brain to lungs, the initial moment of deceleration is long gone, and the Jag is coasting to a steady stop. At 50mph, I jettison the parachute(via another lever pinched from a rally car handbrake) to stop it dragging on the rutted runway. Somewhere along the way, I’ve remembered to breathe back out. Phew.
The Jag completes in excess of 20 runs during the test day at Bentwaters. Every single time, the parachute release performs faultlessly. The team are understandably chuffed.
The key thing to remember here is that I’ve experienced around 1G of deceleration for a fraction of a second. I lost about 20mph when the parachute first inflated. That’s child’s play.
When Bloodhound’s parachutes first burst into the desert air at 685mph, Andy Green will be subjected to 3G - equivalent to losing 60mph a second. Imagine driving along in your car at 60mph, then stopping from that speed in just one second.
That’s how it’ll feel for Andy - and for a hell of a lot longer. Several seconds, in fact. The parachute straps will be handling a 13.5 tonne load. Ouch.
And, when - on the Hakskeen Pan - Bloodhound is stopped at the Turnaround Team at the end of its first run, the chutes will be repacked, the car spun around, and it’ll set off to do it all over again.
“We don’t know how the car will handle as it decelerates,” Green admits. “That’s one of the things we’re just going to have to find out.”
At least this time, he can be confident his parachutes will be on form. With just a little help from TG.
NB: Due to delays with parts manufacture and an impeller bearing failure, Bloodhound has pushed back its tested schedule. The Newquay Airport tests will now take place in November 2015 rather than August, and early desert running won’t kick off until spring 2016. As Andy Green explains: “You can’t build a 1000mph car with 3000 bespoke components without expecting a few delays. I’ve been working with the guys on this project for eight years already…”