Bloodhound SSC and the quest for the supersonic

A world-record racing run that will take just seconds has been almost 10 years in the making.
9 May, 2017
One day soon, the Bloodhound SSC will streak across the Kalahari Desert in South Africa in hopes of traveling at more than 1,600 kilometers per hour.
It all started in 2008 at the Science Museum in London. Richard Noble, Andy Green and the Bloodhound team announced a plan to crush the Outright World Land Speed Record, and at the same time inspire STEM education and a new generation of scientists and engineers.

Green is himself the current record holder, after driving the ThrustSSC – a twin turbofan jet-powered car – a blistering 1227.985 kmh across the required one mile in October 1997. It was the first supersonic record too at Mach 1.016, and Green is joined by Noble in holding current or previous records for driving the world's fastest cars.
Images: Andy Green, Bloodhound SSC Tail, and Richard Noble (Paul Gravestock/Flickr)
In 2011, the first parts of the car moved from the 3D computer models to the machining and building process in Britain. There are thousands of components, made of titanium (as is the case with the outer skin) and carbon composites, among others – and then there is all of the aluminium in the vehicle.

To achieve a new goal, the Bloodhound was painstakingly built from materials that could take the heat. For the wheels, that's meant an aerospace-grade aluminium alloy that removes the need for any tires.

The wheels also need to withstand 50,000 radial "g" at the rims. These wheels are just under a meter in diameter and weigh around 95 kilograms, and are designed to spin 175 times per second.
Images: Engine, Bloodhound Staff (Simon Longworth, Flickr); Cutaway (Paul Gravestock, Flickr)
"If you imagine spokes of a wheel coming to the center, it is the focal point of the high stress and it is also where the wheel is thickest, so we needed to find an alloy where we could get the heat treatment," said Bloodhound lead engineer Conor La Grue in an interview with Engineering Materials.

Just building the Bloodhound wheels is a process that has involved 20 different companies and about 100 processes. Other vehicle components, such as the tail fin, also are made of aluminium. A key consideration in building the fin is how close it is to the jet engine that sits directly below its base. The Eurofighter-Typhoon engine, powered by a rocket, generates 1,500C of heat at full power, which – according to Green – is hotter than molten lava inside a volcano. The importance of this detail is, like all other aspects of the engineering, seen as part of the whole as scientists put the power puzzle together.
Bloodhound recently announced that its record-setting run has been pushed back until 2018 pending more funding, but in the meantime the project's other goal of attracting youth to careers in science and technology continues. Almost 100,000 children have participated in Bloodhound-led learning in the past year, building mini-rocket cars and connecting with the project through their schools and communities.

It's not just STEM either: One lesson on Hakskeen, the dry lakebed chosen for the run in South Africa, looks at facts and figures about the geology of the site – it's effectively smoother than a pool table – and what it takes to make it ready. Soon, it will be time for the Bloodhound's big adventure.