Mark Chapman - chief engineer, Bloodhound SSC
Quick thinking: The chief engineer of the Bloodhound SSC faces the challenge of making a car travel at 1,000mph… safely.
Building the fastest car in the world would be a demanding job at the best of times. But taking on the role of chief engineer mid-way through the project, when you’ve never been involved in any sort of car-design project, adds new meaning to the word ’demanding’.
For Mark Chapman, the chief engineer role represents the highest point in a varied career. ’To be honest, I have a low boredom threshold. If I’d spent my whole career at Rolls-Royce I might have been very good at turbines or compressors, but the thought of sitting down for the next 20 years at the same desk doesn’t fill me with glee. I’ve had a lot of different jobs and this is the icing on the cake really.’
Most of Chapman’s experience has been in aerospace, although he started out designing weapons systems for submarines. ’I was in a special projects division of what is now Babcock and I got a lot of experience around submarines, nuclear power and aerospace. The project doing CFD analysis of sewage works was pushing the limit of what can be called fluid dynamics, though.’
“I have a low boredom threshold. I’ve had a lot of different jobs, and this one is the icing on the cake”
By 2000, Chapman had moved to Ricardo Aerospace and it was there that he first came into contact with Richard Noble, former land speed-record holder and director of both Thrust SSC, the first (and so far only) car to break the sound barrier, and of its successor, Bloodhound SSC. At the time, Noble was developing an all-carbon light aircraft that could act as a point-to-point air taxi, utilising small landing fields; this is now being flown as the Farnborough Aircraft F1 Kestrel. ’I was responsible for engine integration and cockpit ergonomics, among other things,’ Chapman said.
Several other jobs later – including spells working on the lift system for the vertical take-off variant of the Lightning II Joint Strike Fighter – Chapman found a strange phone message on his answering machine. ’It was all rather obscure, from a chap called John Piper, who I didn’t know, saying that a mutual acquaintance had suggested that I might be interested in a unique vehicle-based project and asking me to meet him in a pub in Bristol,’ explained Chapman. (Bloodhound’s headquarters, known as ’the dog house’, is just down the road.)
To unravel this cryptic invitation, Chapman googled John Piper and found he was a hugely experienced motorsport engineer and a veteran of many Formula 1 teams. Most notably, however, he had been engineering director for JCB DieselMax,a car that broke the land speed-record for diesel-powered cars while being driven by Thrust SSC pilot Andy Green – who Chapman discovered had been involved with a Richard Noble project.
That bit of deduction proved to be correct and Piper showed Chapman an initial scheme for the Bloodhound SSC car. Bloodhound was designed to shatter the world land speed-record, raising it from Thrust SSC’s 763mph (1,228km/hr) to more than 1,000mph (1,610km/hr). It has a dual engine: a jet, the prototype of the Eurofighter Typhoon engine, and a rocket. However, this wasn’t immediately clear.
’I saw that it had a jet in it and a funny tube on the top of that that I originally thought was a parachute can,’ he recalled. ’There was a funny V12 engine in it, so I asked what that was. “That’s for the rocket,” John said. “What rocket?” That’s when I realised what I was getting into.’
Piper was, until recently, engineering director for Bloodhound, but kept up his interest in F1 and has now decided to devote more of his time to motorsport while retaining a role as engineering consultant. In a reshuffle of the team, Chapman has now taken on the new role of chief engineer. It is the start of a new phase for the design of the car, he explained.
’Up until now, the car design has been split between myself and Brian Coombs; his background is in motorsport, with Red Bull racing and in Le Mans prototypes, so we’ve divvied the car up. The bits that look like a car were Brian’s: wheels, suspension, chassis, brake package, steering and so on. The bits that looked like a plane were mine: I’ve been looking at jet and rocket integration, the external shape of the car, airbrakes, fins, winglets and stability. But we are trying to be less compartmentalised. We are trying to solve everything by computational analysis, because with the way we are funded and the timescale, we are having to cut down on testing.’
“When we switched the rocket to underneath the jet, a lot of the aerodynamics we thought would work, suddenly wouldn’t. The shape of the rear of the car had to be quite different.”
The previous philosophy was to take several different solutions to each problem as far as possible before deciding on which route to take on the car itself, Chapman explained. However, this led to long development cycles. ’For example, we were trying to make the rocket housing as light as possible, because the rocket has been getting bigger. That would have meant many test firings, because we were using carbon fibre and we had to be sure it wouldn’t rupture. Instead, we’ll now use a metal housing, which may add four or five kilos to the car, but we know it won’t burst.’
The result has been a subtle repositioning of the team’s philosophy. ’We were going to make the best 1,000mph car in the world,’ Chapman said. ’And with more funding, we would have been able to. But that’s now not possible. What we are going to make is a car that will do 1,000mph and do it safely.’
Ask Mark Chapman
Want to know anything about designing and building a 1000mph car? Curious about what it’s like to work on a landspeed record project? Email us at email@example.com, and we’ll put the best of your questions to Mark. He’ll answer them on our website shortly.
Mark Chapman Biography
Bloodhound SSC Project
1992 BEng in Aeronautical Engineering, Bath University
Varied work with Babcock, including submarine weapons systems and CFD on sewage-works components
Principal engineer for Ricardo Aerospace, including forward section of air taxi with Richard Noble; initial design on Joint Strike Fighter
Boeing Propulsion Systems, Seattle
Rolls-Royce, working on JSF STOVL take-off system
2008 Joins Bloodhound SSC project full-time
2010 Takes on chief-engineer position at Bloodhound
Q&A Resolving problems facing the Bloodhound SSC
What engineering issues have you recently faced?
For the past six months my head has barely risen above my CAD station. In the initial stages of development, we worked with a configuration that had the rocket engine above the jet engine and we’d got to the point where we knew how to work that car, aerodynamically. The rocket had steadily been getting bigger and we were working to get the weight down, but then we started looking at the forces we’d need on the control surfaces. We found that in the situations where you were turning the rocket on and off, the control surfaces had to work really hard, and that gave us a problem with failure cases.
Was that connected with the engine positions?
When the rocket engine was on, it generated a downward force towards the front of the car, so to counteract that, the front control surfaces had to generate a small amount of lift. But in a case where the front hydraulics failed, the first thing you’d want to do would be to turn the rocket off, to slow the car down. That would remove the downforce and the risk was that the lift from the front surfaces would flip the car up. It was difficult to imagine a way the system could fail safely.
Why does changing from rocket-over-jet to jet-over-rocket help with this?
With the jet-over-rocket configuration, the engines are actually positioned on either side of the centre of thrust, which is a much more stable configuration. The car was more stable and easier to control. But we had understood the aerodynamics of the rocket-over-engine configuration – we had stabilised it transonically and supersonically. When we flipped the positions, a lot of the aerodynamics that we thought would work suddenly wouldn’t. The shape of the rear of the car had to be quite different.
How have you managed the redesign?
We’re relying heavily on our simulation systems and Matlab to analyse the data and find what works. In the 18 months we were working with rocket-over-jet, we did maybe 12 or 13 CFD runs. In three months where we were working on jet-over-rocket, we did 120 runs and that gave us an equation for a car that works. It’s given us a shape we wouldn’t have predicted; team aerodynamicist Ron Ayers took a look and said he’d never have picked that shape. It’s been so successful we are looking at rolling out this analysis technique to other parts of the car design.