Automotive Design
the T.25 as a compact, lightweight city car (Fig. 2). The T.25 is a three-seater with a rear-mounted three-cylinder petrol engine. Having subsequently teamed up with Zytek Automotive, a UK-based company with extensive experience in electric and hybrid vehicle powertrains, an electric version of the car has been designed, known as the T.27.
Pure electric
Based on the T.25, the T.27 is a pure electric vehicle using a 25 kW motor and 12 kWh lithium-ion batteries. Recycled materials are incorporated within the innovative composite panels that add stiffness and integrity to the ‘exoframe’ primary structure. However, one of the most important aspects of the design of the T.25 and T.27 is Gordon Murray Design’s low-energy iStream manufacturing process, which utilises a monocoque but with body panels that are attached mechanically in order to reduce assembly time and complexity, and minimise the cost of accident repairs. Thanks to the simplified assembly process, the
manufacturing plant can be one-fifth of the size of a conventional factory, which could reduce capital investment in the assembly plant by approximately 80 per cent. Yet the flexibility of this assembly process means that the same factory could be used to manufacture different variants or models - even the T.25 and T.27 could be built concurrently. Gordon Murray Design also says that the iStream process is a complete re-think on high-volume materials, as well as the manufacturing process, and will lead to a significant reduction in CO2
emissions over the lifecycle of the vehicles produced
using it. According to the company, the iStream composite monocoque brings Formula One technology to mass- production vehicles, with significantly higher specific energy absorption rates compared with conventional bodied cars. Far from being a design exercise, the T.27 is well on the way
EEC 40 per cent offset deformable barrier front high-speed impact and the T.27 passed with zero cabin intrusion (Fig.3). This result is an endorsement for the iStream manufacturing system that delivers reduced weight and cost without compromising safety.
Concept cars
While Riversimple and Gordon Murray Design are making progress towards production-ready vehicles, Swiss company Rinspeed is continuing to create concept cars that are perhaps less likely to make it into production. For example, the 2009 Rinspeed iChange concept was described as the world’s first car whose body adapts to the number of passengers on board (Fig. 4). For Rinspeed boss Rinderknecht, the vehicle is more than just a clever concept car: “The iChange is a symbol for the fundamental changes the auto industry undergoes worldwide. And it is clear that only those companies will survive that have innovative answers for the demands of a new automotive era.” In seconds a streamlined one-seater sports car transforms
into a comfortable car with ample room for three - achieved at the press of a button that causes the rear end of the car to pop up. And the reason for this transformation stems from the
basic idea behind the iChange, which is that the energy demand of a vehicle depends mostly on its weight, the type of engine it uses and its aerodynamic properties. The extremely lightweight car weighs only 1050 kg, with power coming from an electric motor and a choice of battery packs, one for short- range and the other for long-range journeys; the pop-up rear end means the car’s aerodynamic properties are adapted to suit the number of vehicle occupants. While other cars are encumbered by exteriors that can accommodate up to seven passengers even if they are only transporting a driver, the iChange’s adaptive body means that the lone driver is conveyed in a teardrop-shaped car that offers optimal aerodynamic properties and, therefore, minimised energy consumption. If more than one person needs to be transported, the expanding rear provides room for two passengers. As a result of the increased weight and the altered aerodynamics, the energy consumption increases - but only when passengers are carried. More recently the same company has announced the
Rinspeed Bamboo. Many interior components are made from bamboo fibres, but the four-seater, open-top Bamboo sets out to awaken the longing for sun, summer, lightness and easiness - and the desire to be at the beach. Neither the Bamboo nor the iChange are likely to go
Fig. 4. Rinspeed’s iChange concept features pop-up rear bodywork so that the aerodynamics can be adapted to suit the number of occupants.
to being ready for production. In January 2011 Gordon Murray Design announced that the T.27 had been subjected to its first crash tests at the MIRA (Motor Industry Research Association) facilities. The crash test was the mandatory
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on sale imminently, but it is a real possibility that the urban cars from Riversimple and Gordon Murray Design could be on the road soon. And although the major automotive manufacturers will continue to unveil concept cars that attempt to address our future needs, these companies are so intimately involved with conventional production methods and business models that they are, in truth, unlikely to present us with a step change that can make a major difference to the way we perceive and procure personal mobility. Let us hope, therefore, that the independent design
houses find the right formula in terms of customer appeal, commercial success and sustainability. l
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