Lightweight Electric/Hybrid Vehicle Design

Introduction xvii
With the high volume builders, already under pressure from overcapacity, their main attention is
likely to be focused on retaining markets for current design vehicles, without the ‘distraction’ of
radical redesigns. The ambitious, imaginative and high technology specialist has thus much to
gain from an informed innovative approach and could benefit from a reported longer-term trend
when drive systems will be manufactured by huge global producers and vehicle manufacturing
will tend towards a regional basis of skilled body shops catering for local markets.
0.2.5 EV AS PART OF A WIDER TRANSPORTATION SYSTEM
The ‘physical’ design package for an electric vehicle will result from a much larger ‘design package
of affecting factors’ which encompasses vehicle operational category, manufacturing systems/
techniques, marketing and distribution. Packages for industrial trucks and specialist delivery vehicles
are already established but those for passenger-car variants much less so. It has been suggested
that the first substantial sales of electric cars might well be to electricity generating companies in
the public utilities sector, who would rent them to railway operators for end-use by rail travellers.
Such people would purchase their hire with return travel tickets to destination stations at which
EVs would be parked in forecourts for the use of travellers. Other potential customers might be
city-centre car hire fleets, taxicab operators in fossil-fuel exhaust-free zones or local authorities
setting up city-centre car pools.
One of the most imaginative EV applications is the lightweight mini-tram, Fig. 0.2, as exhibited
at the Birmingham ElectriCity event in 1993. This is a vehicle that runs on low cost tracks which
can be laid on an ordinary road surface without further foundation. The vehicle can travel up to 50
km/h and is a flywheel-assist hybrid machine having its batteries recharged via low voltage
conductor rails positioned at intervals around the track. Each car weighs just over 3 tonnes unladen
and can carry 14 seated and 11 standing passengers. A 5 km route, including rails, can be constructed,
to include five trams, ten stops and four charge points, at a cost of just £1 million. It seems an ideal
solution to the problem of congested cities that have roadways that date back to pre-automobile
days, with the mini-trams able to transport both passengers and goods in potential ‘pedestrian
precincts’ that would be spoilt by the operation of conventional omnibuses and tramcars. The
proposal serves well to illustrate the opportunities for electric vehicles, given some imaginative
lateral thinking.
Since launch, larger vehicles have been produced and entered service. The one seen at Bristol
Docks (Fig. 0.2, right) has a steel frame with GRP body panels and weighs 13 tonnes, compared
with the smallest railcar which weighs 48 tonnes. There are four production variants on offer,
carrying 30, 35 or 50 passengers, and a twin-car variant of the latter. Use of continuously variable
transmission now ensures the flywheels run at constant speed; a third rail at stations is used for
taking in electricity for ‘charging up’ the flywheel. A 2-minute recharge would be required for the
Fig. 0.2 Parry flywheel-electric hybrid rail bus.