Lightweight Electric/Hybrid Vehicle Design

Introduction xxi
gains made in the decade 1985–1995 were lost by making engines powerful enough, in the US, to
drive at twice the speed limit on the open road. Obviously the situation is worsened if conventional
heavyweight steel construction is used and the tare weight of cars rises with the increasing
proliferation of on-board gadgetry. While ‘supercar’ construction has shown how structure weight
can be reduced, advanced technology could also be used to reduce the 10% of engine power used
in powering ‘accessories’ such as power steering, heating, lighting and in-car entertainment.
The imperative for power steering is removed by the ultra-light construction of the ‘supercar’,
provided steering and handling dynamics are properly designed. In EV supercars, wheel motors
might provide for ABS and ASR without further weight penalty. High intensity headlamp
technology can considerable reduce power demand as can the use of fibre-optic systems which
provide multiple illumination from a single light source. Light-emitting diode marker lamps can
also save energy and experts believe that the energy consumption of air-conditioning systems
could be reduced by 90%, if properly designed, and used in cars with sandwich panel roofs, heatreflecting
windows and solar-powered ventilation fans. But none of this compares with the savings
made by high strength composite construction which has the potential to bring down average car
weight from 3000 to 1000 lb. It is reported that many of the 2000 or so lightweight EVs operating
in Switzerland already weigh only 575 lb without batteries.
The ability to achieve net shape and finish colour from the mould in polymer composite
construction is important in offsetting the higher cost of high strength composites over steel. But
also the cost of steel is only 15% of the conventional structure cost, the remainder being taken up
in forming, fabrication and finishing. Around half the cost is taken up by painting. The cheaper
tooling required for polymer composites is also important in making small-scale production a
feasible proposition, alongside direct sales from the factory of ‘made-to-order’ cars. A number of
these factors would help to remove the high mark-up to the customer of the factory price which is
typical of conventional car sales and distribution.
0.3 Lean production, enterprise structures and networking
Lean production has grown out of post-Fordist ‘flexible specialization’ which has led to growing
specialization of products, with a new emphasis on style and/or quality. The differentiated products
require shorter production runs and more flexible production units, according to Clarke 2 . The
flexibility is made possible by new technologies, the emerging economic structure being based on
computerization and other microchip hardware. Rapid gains in productivity are made through full
automation and computerized stock control within a system that allows more efficient small batch
production. Automatic machine tools can be reprogrammed very quickly to produce small quantities
of much more specialized products for particular market niches. Economies are set to be no longer
dominated by competition between hierarchically organized corporations and open to those
dominated by cooperation between networks of small and interrelated companies.
Lean enterprises are seen as groups of individuals, functions, and legally separate but operationally
synchronized companies that create, sell, and service a family of products, according to Womack
et al 3 . This is similar to the Japanese ‘keiretsu’ concept of large, loose groupings of companies with
shareholding connections. They cooperate both technically and in sharing market information and
the result is an array of business units competing in vertically and horizontally links with other
companies within a single project. A trading company with well-developed worldwide networks is
usually at the centre of the operation and can feed back vital market trends to the production companies.
Of almost equal importance is the involvement of international banking corporations who can provide
a source of industrial finance. Changes in legislation are required by European countries to make a
similar system of common shareholdings plus private ownership acceptable to company law.