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Andy Green and Bloodhound

2014-04-16 08:06

PROUD MOMENT: Andy Green and the Bloodhound SSC get ready for action in 2015 in the Northen Cape, South Africa. Image: Andy Green


Former land speed record holder and leader of the heads Bloodhound Supersonic Car Project will celebrate the 30th anniversary of his epic record on October 4th 2013. In 1983, Noble piloted his Thrust2 to a then world record speed of 1019.47km/h in the Nevada Desert.

LONDON, England - A British team is developing a car that will be capable of reaching 1000mp/h - 1610km/h. Powered by a rocket Eurofighter-Typhoon jet engine the vehicle will try to crack the world land-speed record.

The Bloodhound will run on Hakskeen Pan in the Northern Cape, South Africa, in 2015 and 2016.
Wing Commander Andy Green, the current world land-speed record holder, is writing this diary for Wheels24 about his experiences working on the Bloodhound project and the team's efforts to inspire international interest in science and engineering.


The Bloodhound SSC is the ultimate kit car, with around 3500 bespoke components, plus fasteners (including 15 000 rivets in the rear chassis alone). Of course, that doesn’t stop me greeting the team with a helpful "Hi guys – have you finished it yet?". Not just yet, is the answer, but we’re still on track to run in South Africa in 2015.

A key part of running a speed record car is being able to stop it, as discussed in last month’s update. Bloodhound will have a huge amount of energy at 1609km/h. To put that in perspective, a 70-tonne high-speed train moving at 124mph - 201km/h has about 560 Mega Joules of energy – 100 fewer than our car. It’s enough energy to boil more than 300 000 kettles, so it’s a safe bet that we can’t stop Bloodhound with wheel brakes alone.

Our engineer has calculated about 52% of the Bloodhound's energy will be absorbed by aerodynamic drag 36% by the airbrakes (and/or drag chutes) and 11% will be dissipated by the vehicle’s rolling resistance. That makes 99%. The remaining 1% will be absorbed by the wheel brakes.


For the runway tests, the Bloodhound will have brakes on all four wheels, with dual circuits, to give it plenty of stopping power and redundancy. The runway at Newquay in Cornwall, England is 2.7km long, huge until you’re doing 320km/h in a six-ton car. We’ll be using carbon/carbon brakes, the same as those used by aircraft and high-performance race cars, to give us the best braking performance on the runway.

When we get to South Africa the brakes will be less important, as they are only doing 1% of the work. There’s no point in getting 99% of the braking done and then trundling off the end of Hakskeen Pan at 80km/h. The wheel brakes will shorten the stopping distance by about half a kilometre and they will also let me slow the car to walking speed, turn it through 180 degrees and stop right next to the turn round crew. The speed record regulations require a run in both directions within one hour so turning round and stopping in exactly the right place is a key part of it.
There is a problem with wheel brakes on the desert. We won’t need to use them at 1000mph, but they will still be along for the ride, at more than 10 000rpm (that’s 170 revolutions per second). We tested a carbon fibre brake disc at 10% above this spin speed, to give us a safety margin. The disc exploded. This carbon disc was one of the best in the world the same specification the RAF’s
Typhoon jets use. We already knew that no jet fighter has ever flown at 1000mph at ground level and now we know their brakes won’t survive it either. We need another solution.


The proposed alternative is an unusual one using steel discs. No one uses steel for brake discs in extreme applications. Steel doesn’t absorb as much energy as carbon and it can be damaged by the extreme heat that race car brakes experience. Steel does have one key advantage for us though – it’s stronger than a carbon disc. Steel will survive the extreme loads at 100mph, but the question is, will it survive exposure to 1% of the Bloodhound's huge amount of energy?

To test the steel brake discs we went to AP Racing where the rest of Bloodhound’s brake assembly has been made. We cranked their rig up as fast as it could go which equates to around 258km/h for Bloodhound. The test team did 10 full stops from maximum speed on the same steel disc. Maximum temperature on the disc was around 1100 degrees Celsius, about the same inside a volcano.

To get into the cockpit I will climb down through an oval canopy hatch. This area is subject to very low pressure at supersonic speeds, as the air accelerates over the cockpit, and this low pressure will try to tear the cockpit hatch off the car.


The front suspension is also coming along well. Each upper section was machined from a forged block of aerospace-grade aluminium measuring the size of a coffee table and weighing 300kg. After 180 hours of machining we’re left with an upper suspension piece now weighing 18kg with 280kg of material to be recycled.
This phase of Bloodhound’s engineering is all about details. Any mistakes we make now will cost us dear, when we get to the desert in South Africa. If we’re going to have a world-class engineering adventure and push the boundaries of physics at 1609km/h and do it all safely, then we need to get the details right first time. It’s a fascinating process to watch, as it all starts to come together.

More from Andy Green in May.


2019-04-23 16:41

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