Cockpit of BLOODHOUND SSC revealed
The cockpit of BLOODHOUND SSC, the 1,000m/h land speed racing car, was unveiled last week in Bristol, UK. The state-of-the-art carbon fibre monocoque has been tailored to the needs of driver Andy Green and will be his supersonic office during record attempts in the South African desert in 2015 and 2016.
Hand crafted by URT Group using five different types of carbon fibre weave and two different resins, the monocoque has taken more than 10,000 hours to design and manufacture. Sandwiched between the layers of carbon fibre are three different thicknesses of aluminium honeycomb core, which provide additional strength. At its thickest point, the monocoque is comprised of 13 individual layers but measures just 25mm in cross section.
The structure weighs 200kg and bolts directly to the metallic rear chassis carrying the jet, rocket and racing car engine. The carbon front section will have to endure peak aerodynamic loads of up to three tonnes per square metre at 1,000m/h as well the considerable forces generated by the front wheels and suspension. It will also carry ballistic armour to protect the driver should a stone be thrown up by the front wheels at very high speeds.
The roof of the cockpit has been designed to create a series of shockwaves that will channel the air into the Eurojet EJ200 jet engine. If supersonic air reaches the jet engine fan blades, the airflow will break down and the engine will ‘choke’. This can generate huge changes in pressure that could damage both the jet engine and car, hence BLOODHOUND SSC using shockwaves over the canopy to slow the airflow from over 1,000m/h to just 600m/h in a distance of around one metre. Deflecting winds travelling five times faster than a hurricane will, however, cause additional noise and vibration to be transmitted into the cockpit.
The sound levels expected in and around BLOODHOUND SSC are being carefully evaluated. The cockpit is positioned in front of three incredibly loud motors: the jet, a cluster of hybrid rockets and the racing car engine that drives the rocket’s oxidiser pump. Collectively they will generate a noise level estimated at 140dB. Much of the noise will be directed backwards, away from the driver, and above 750m/h the car will out-run its own sound waves. However, the Project’s engineers still anticipate that shockwave and jet intake noise levels may produce over 120dB inside the cockpit. Andy will wear an in-ear communications system specially made by Ultimate Ear to protect his hearing and to ensure that he can communicate with mission control.
BLOODHOUND has a highly specialised windscreen custom-made by PPA Group from acrylic. The plastic is heated, stretched and then two layers are bonded together to create a 25mm section, thicker than a fighter jet’s windscreen and sufficient to withstand an impact with a 1kg bird at 900m/h. Due to the oblique angle the windscreen is set at, the driver will in fact be looking through 50mm of curved plastic. The key challenge has therefore been to make the screen robust while maintaining absolute visual clarity.
Green has drawn on his experience of flying fast jets and driving World Land Speed Record winners Thrust SSC and JCB Dieselmax to design the dashboard and cockpit layout. Good ergonomics are vital given that BLOODHOUND SSC will cover a mile in 3.6 seconds, or 150m in the blink of an eye.
The central screen shows the speed in miles per hour and Mach number, calculated by GPS, plus jet engine and rocket outputs. Dynamic speed indicators help Green to judge when to fire the rocket and deploy the braking systems. Wheel loads are also given prominence. BLOODHOUND does not use aerodynamic downforce, as a Formula 1 car does, while lift at the nose or rear axle must also be avoided at all costs. The need to carefully balance forces throughout its 1000m/h speed range is one of the major reasons why shaping the Car has taken 30 design-years.
The left-hand screen shows hydraulic pressures and temperatures in the braking and airbrake systems, while the one to Green’s right provides information about the three engines, including temperatures, pressures and fuel levels. Together, the EJ200 jet engine and Nammo hybrid rockets produce around 210kN of thrust, equivalent to 135,000 thrust hp, or 180 F1 cars, and Green will monitor their status at key points during each run.
BLOODHOUND’s dash also features two precision-engineered analogue Rolex instruments: a chronograph with built-in stopwatch, and a speedometer graduated up to 1,100m/h. The speedometer is a vital back-up to allow the car to be stopped safely should the digital dashboard fail, while the chronograph will help to time the start-up and cool-down of the jet, and help to monitor the performance of other systems. Tested to withstand the severe vibration at 1,000m/h and the desert heat, these bespoke Rolex instruments are unique to BLOODHOUND SSC.
Green enters his office via a carbon fibre hatch, 500mm in diameter, just below the jet air intake. At full power, the EJ200 fan sucks in 65 m3 of air per second, so the hatch will be fastened using latches able to withstand loads of 2.5kN to prevent it from getting ingested into the engine.
The instrument panels have been coated with a special non-reflective grey paint to provide the optimum background colour against which to see the gauges and controls, while the cockpit walls are white to maximise the available light in the cockpit. The car also has interior lights, as BLOODHOUND SSC will often be prepared before dawn, when the desert will still be dark and temperatures around freezing. During the day ambient temperatures will approach 40ºC though BLOODHOUND SSC will most likely not run in conditions above 25ºC as the metallic sections of the car will get too hot for the team to handle and the jet engine is inefficient when burning hot, less dense air. Cockpit temperature is still expected to approach exceed 35ºC, so external air conditioning will be used to cool it prior to each run, though this is primarily for the comfort of the electronics, not the driver.
Green will keep BLOODHOUND SSC on course using a bespoke 3D printed titanium steering wheel, shaped to his hands and finger reach. Buttons on the front control the EMCOM radio, airbrakes and parachutes, while triggers on the rear of the handgrips prime and fire the rockets. BLOODHOUND engineers developed several design evolutions of the wheel, the last of which was finalised for manufacture by Cambridge Design Partnership. BLOODHOUND has a conventional steering rack with a 30:1 ratio though its long wheelbase makes for a very large turning circle: 240 metres, compared with 10 metres for a typical family hatchback.
BLOODHOUND SSC has pedals like a regular car, though once again, they are custom designed for Green. The right-hand pedal throttles the EJ200 jet engine and will be used to start the car moving. The left pedal controls the wheel brakes and will be used to slow the car at speeds below 200m/h. The wheel brakes will only contribute about 1% of the total braking effort, reducing the stopping distance by around half a mile. Braking speed is critical, as using the wheel brakes above 200m/h will exceed their energy capacity and set fire to them.
During a 1000m/h run, BLOODHOUND SSC will cover 12m in 2 minutes, exerting an acceleration force of almost 2G and peak deceleration force of 3G on Greem. This long-duration G force is another experience unique to BLOODHOUND: an F1 driver may experience higher G forces, but they only do so for a few seconds at a time. Green will be sat in a carbon fibre seat, moulded to his body shape by Real Equip, and manufactured by URT Group. This seat installation will provide unparalleled levels of support and safety for the driver, who will be angled back and strapped in using a Willans five point harness. Green will also wear a Pro Ultra HANS device, to protect his neck from sudden, violent movements or decelerations, and an Arai helmet.
The cockpit also carries a Camlock air supply, feeding clean breathing air to Green through the ‘Adom’ mask used by RAF Typhoon pilots. This full-face race spec helmet, mated to a jet fighter-style breathing system, is again unique to BLOODHOUND and combines the best driver protection features from both motorsport and aerospace. A Willans fire suppression system has also been specified, which will douse the cockpit in foam should built-in infrared sensors detect naked flames.
Driver safety has been the prime design and engineering objective throughout BLOODHOUND’S gestation and the team has worked closely with motor racing’s governing world body, the Fédération Internationale de L’Automobile to create the best safety cell in the history of motor sport.