APPENDIX A
PROPOSED FUEL CELL POWERED ULTRA LIGHT RAIL
TRAM
by James Skinner, Bristol Electric Railbus
Ltd
Government's targets for reducing and eliminating
toxic pollution, carbon emissions and traffic congestion in urban
areas can only be met by introducing an improved system of public
transport to replace the diesel bus. Such a system needs to have
the following characteristics:
1. Zero carbon dioxide and toxic emissions.
2. Popularity with the public, to encourage
modal shift from cars.
3. Ability to operate in pedestrianised areas
without worrying pedestrians.
The system best able to provide a combination
of all these elements is Ultra Light Rail (ULR), using fuel cell
powered light trams.
ZERO EMISSIONS
Standard production fuel cells are now sufficiently
well developed to provide a feasible source for the power required
for a tram. Weight, size and energy density are not such crucial
issues for a tram as they are in designing a car. The duty cycle
of a tram can normally be expected to be less demanding and more
predictable than a car or even a bus, so a light tram can benefit
from fuel cell technology long before it becomes commercially
or technically practical for cars or buses. Using only existing
proven and reliable technology it is now possible to build a prototype
fuel cell powered tram. The existing CUTE fuel cell buses (three
of which are currently running satisfactorily in London on the
25 route) have already shown that fuel cells are a practical alternative
technically, but not commercially (see below under affordability).
The only emissions from a fuel cell tram will be water. The hydrogen
fuel can either be a by-product of existing industrial activity
or produced by electrolysis of water, using electricity from renewable
sources.
POPULARITY
Market studies all over the world have established
that the public greatly prefer trams to buses and that consequently
trams, unlike buses, achieve a high degree of success in attracting
travellers out of their cars into public transport. This is confirmed
by the greater modal shift achieved by new tram systems replacing
bus systems. A further important confirmation of this popularity
is provided by the fact that tram tracks can raise adjacent property
values far more than a bus route. Introducing fuel cell buses
is only commercially practical if the operator is subsidised by
Government, because a fuel cell powered bus appears to the public
to be no different from any other bus but in fact costs very much
more. This means that patronage will be no higher than for a diesel
bus and fares will be the same. By introducing a ULR tram, with
its low infrastructure cost, public demand for trams can be met
economically, because the energy efficiency of the tram drastically
reduces the size and cost of the fuel cell. The extra cost of
the fuel cell can anyway be more than covered by the savings made
on the reduced infrastructure specifications.
PEDESTRIANISATION
City centres need to be made accessible, attractive
and free from pollution if the notorious do-nut effect is to be
avoided—empty centres and suburbs spreading further into
the countryside. Pedestrianising central areas allows shoppers
to roam unmolested by cars and buses. This creates a stronger
sense of community, especially in smaller towns, which huge out-of-town
shopping estates, surrounded by acres of car parks, cannot hope
to achieve. Towns like Zurich and many others have proved that
shoppers do not mind the predictable path of even large conventional
trams in pedestrianised streets, where a bus would be unacceptable.
In smaller towns bus-sized trams can be even less obtrusive. In
high-value, heavily populated central shopping areas like Oxford
Street in London a continuous shuttle service can be supplied
free to shoppers, analogous to free elevators in tall buildings,
at an affordably low cost.
NOISE
Accelerating internal combustion engines cause
intrusively high levels of noise in towns. Fuel cells and electric
motors are virtually soundless. The electrical energy storage
system of the tram allows for smooth, fast, noiseless acceleration.
Well-planned routes can minimise wheel noise by avoiding sharp
turns. Narrow gauge tracks of a metre or less can also reduce
the minimum turning radius. Well-laid tracks can reduce wheel
noise to very low levels, as demonstrated on many new Continental
heavy train routes.
AFFORDABILITY
High cost is the principal factor limiting the
introduction of trams to replace urban diesel buses. ULR has been
developed with the specific aim of overcoming this constraint.
The reasons why installing and operating a ULR system costs so
much less than a conventional tram and competes in cost with diesel
bus systems are numerous and include:
— Design—ULR vehicles are designed
like buses that are adapted to run on rails in the road. Conventional
trams are designed like railway trains, only slightly adapted
to run on roads. ULR trams are thus lighter than conventional
trams, with important consequences for the design and cost of
the infrastructure and the drive train of the vehicles.
— Infrastructure—on-board power
supply in ULR trams eliminates the need for overhead wires and
thus avoids the need to earth high voltage currents through the
rails. The low weight of the ULR tram requires only light rail,
which can be easily moved and replaced by temporary track if sub-surface
work on services needs to be done. This makes it unnecessary to
build a deep substructure or move the services under the road—two
of the main causes of the high cost of conventional trams.
— Energy efficiency—the rolling
resistance of steel wheels on steel rails is much less than for
rubber tyres on tarmac road, reducing the energy needed for a
tram to one third that of a bus. The energy requirement is further
reduced by the hybrid drive train, whether it be fuel cell/electric
or diesel/gas/electric, which enables the prime energy source
to run steadily at optimum level, keeping the energy storage system
charged to meet the energy demand of the vehicle. Regenerative
braking is used to recover energy that would otherwise be wasted
and feed it back into the electrical energy storage system. The
consequent reduction in the power specification of the tram brings
big savings both on the cost of the hybrid fuel cell or diesel
electric drive train and also on the cost of fuel. Fuel will become
an increasingly significant cost factor with hydrogen and also
with fossil fuels as prices increase and Government diesel fuel
subsidy for buses (currently £360 million pa) is phased out.
— Durability—the normal life
of a tram is 30+ years compared with 8-13 years for a bus. This
reduces the amortisation cost dramatically.
— Patronage—the popularity of
trams leads to higher patronage levels and increased revenue.
— Permanence—tram tracks laid
in the road demonstrate a commitment by the local authority to
long-term operation of a reliable, comfortable and attractive
public transport service. The importance of this commitment is
reflected in the uplift in land values for properties adjacent
to newly installed tram routes. New tram systems can be funded
by capturing this uplift in value for the public benefit.
In their report on light rail, published in
April 2004, the National Audit Office recommended that grant funding
should be made available for innovative forms of light rail, which
are currently excluded from the many Government new vehicle grant
schemes for buses for no apparent reason. The development, testing
and demonstration of a fuel cell powered Ultra Light Rail tram
should be given the highest possible priority as it offers the
prospect of meeting Government's environmental transport targets
at an affordable cost.
February 2005
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