Urban transport


24th June 2015

The future of passenger transport in Leicester

It took a bunch of designers to help me find out that a tram system for Leicester will be a non-starter. The designers came up with a schematic for how a possible tramway system might look in Leicester and posted it on social media sites. There were a lot comments about the idea, both for and against. ‘The Future of The Tram in Leicester’ evoked a debate; but it was one that I had seen before. The local paper had run a story on the subject when proposals were put forward in November 2008. The news report suggested that even a basic tram system would cost in the order of £300 million (at 2008 prices.)

Public transport is an important driven for the local economy. Leicester sits within a catchment area of about two million people. Those people can go to Nottingham, Derby, Loughborough, Lincoln or they can go to Leicester. Destination choice is important for jobs, commerce, entertainment, the arts and all the other key aspects of life and economic activity. It is easy to think that the private car is the answer to everything; but, with an ageing population its importance is declining. An increasing proportion of the population will become dependent on public transport. Public transport is, I would argue, a key driver in the economy of cities but it often placed too low down on the priorities of people who plan urban areas.

The trams idea did however get me thinking about what the city might develop to replace its present public transport system – the bus. If buses need replacing. Leicester is a relatively small and compact urban area. What it needs is a way of moving large quantities of people around from the outer suburbs to the inner city. The personalised transport unit – the car – as we know it, cannot last for ever; unless they are all converted to run on electricity. Fossil fuels will not last forever.

The main objection to the tram is that it mixes cars and pedestrians. The next objection is that it just could not work given the physical layout of the buildings and the streets as they are today in Leicester. Trams might work in Nottingham, Manchester or Sheffield, though some local people have disagreed that they are all that wonderful.

What kind of transport system would work given the layout of Leicester’s inner city? A variety of options have already been tried in various cities in this country.

Could we go underground? London, Tyne and Wear, Liverpool and Glasgow has underground with their passenger transport systems. Would this work in Leicester? To answer this we have to look at the geology of what the city stands on. Even with a favourable geological sub-strata, the cost of building an underground system would be prohibitive, in today’s climate of public funding.

Could we go up? That might be a more viable solution. Put your light passenger transportation system on stilts. That presents an option which avoids mixing conventional traffic and pedestrians with a transit system.

The way to go is the Automated People Mover (APM) similar to the elevated monorail systems that run on a single track (as opposed to the twin rails of conventional trains.) Some monorail system are suspended beneath the track and others ride on top of it (straddle-beam and suspended monorails.) To make such systems work, there are a lot of requirements.

Two requirements must be met: the infrastructure costs and the running costs. To build a raised system you have to be able to place the stilts (or piers) in a way that will not interfere with the existing road system. Neither must the resulting structures interfere with light; they must not put existing buildings into their shadow. This suggests some kind of piers that place the trackways in the middle of existing roads using supports that are placed either side of the system on the pedestrian walkways – the pavements. This suggests a shape like an arc, although in wider thoroughfares single piers could be used.

The tracks, if we can call them that, must not be heavy. That means we have to rethink the kind of vehicles that will run on them. The units that run on the raised system must be light enough. That means doing away with two things: wheels and engines. These weigh too much. The wheel is an archaic device for allowing vehicles to be moved along without too much friction. Engines are heavy items; if we can remove them from the wagons, that makes the passenger units much lighter.

A motive method should be electric. There is no point in designing a transit system based on fossil fuels. So out goes anything to do with diesel (a) because that requires heavy engines and (b) because it is a fossil fuel. The future of transport is not about wheels or fossil fuels.

Linear induction does away with wheels and runs on electricity. A maglev (magnetic levitation) system propels wagons (carriages) without the need to have engines to pull them – the movement is caused by magnets on the trackway itself and the carriages float above the tracks – hence no need for wheels. The single beam track carries the electricity supply without the need for cables and is light enough to be supported on single piers. Such systems are also very quiet – no noisy engines, no rumbling wheels and no noisy suspensions. They glide quietly along. People can be moved either in carriages about the size of a conventional single-decker bus or in small units about the size of a conventional large taxi or minibus. The trackways are light enough to require only single pillar support piers.

The carriages must be light. They must be made of materials that are tough, hard-wearing and light. Systems like these require very little maintenance. Units of up to 100 seats should be sturdy enough and light enough to float above the tracks (about one centimetre) above the trackways even when fully loaded with passengers and luggage.

Another advantage of the maglev system is that only the section on which a ‘train’ is running needs to be powered. There is no need to run the carriages at high speeds. Most journeys are going to be over short distances. Between the outer suburbs and the inner city stops, the longest distances are of the order of three to four miles at most. Conventional diesel-powered buses stop every few yards. Most of the energy consumed by transport is speeding up and slowing down. The one thing buses do well is their ability to stop every few yards. This is another reason why the construction of the carriages must be made from very lightweight materials to reduce the energy needed for acceleration.

Having this kind of system is possible because we now have the computing power to run the motors. maglev requires microchip technology that runs at very high processor speeds. That is a feature of how linear induction works. There is constant real-time interplay between sensors and the control mechanisms.

There will have to be two tracks: one for each direction of travel, so that carriages can turn round and go back. It assumes that there will be twin tracks, one for each direction of travel – in bound and out bound – unless it is possible to run the whole thing on loops. This would require routes where single tracks only are needed but where there is in-bound and out-bound directions of travel. Unless each track has only one set of carriages which turn round at the terminus and then travel back.

Would such a system need signalling to avoid carriages running into each other on the same section of track? In a twin track system, carriages pass each other on separate tracks. It should be impossible for two carriages to run in opposite directions on the same track simply because the linear induction would make this impossible – the induction allows only forward motion. Hence the need for a second track to allow carriages travel back in the same direction and to pass carriages coming the other way. In high-speed systems, the tracks have to be far enough apart to prevent air pressure problems when two trains pass each other. Or, the carriages have to be designed to funnel pressurised air away from the gap between passing carriages. But, in an short-journey urban system – a relatively slow-moving system – this would not be a problem.

When we think about the dense inner city environment, we have more problems in designing the supports than we would have on the long, wide thoroughfares of arterial routes. The tracks could be supported, at least in narrow streets, from the buildings on either side. Attach the supports to the walls of buildings – this kind of low-weight engineering should make that possible.

The tracks would need to stand at least as high above street level as a double-decker bus or as high as the tallest van or lorry. Even if the tracks can be placed in the middle of the thoroughfare, would there be enough clearance either wide of the trackway to allow large, high-sided vehicles to run on conventional roads?

To visualise the system, I imagined what the system would look like on some of the existing arterial routes, like London Road, Welford Road, Saffron Lane, Melton Road, Narborough Road, etc. Many of these existing arterial routes are quite wide.

Even in Narborough Road, there is probably enough width to place the trackways in the middle and allow enough clearance either side for conventional vehicles. Some bridges might have to be removed. Pretty much all the Victorian railway tracks have been removed throughout the city; so, there are no disused railway that could be used. One criterion for this kind of system is that it should not require the demolition of buildings. It should be fitted into the existing layout of buildings.

It would be necessary to build the supports from metal (or other strong materials) rather than from concrete. The supporting piers should be constructed from new materials that can take the weight, not rust or deteriorate over time and which can be thin enough not to get in the way of pedestrians. At some points the tracks would have to span wide sections – where the route crosses road junctions for example. I think all this will be possible with good engineering design. Concrete is relatively expensive and has a shorter life-span than new materials based on carbon fibre or plastic materials. Many of the flyovers that were supported on concrete piers have had to be demolished because the materials degraded with age.

Carriages with wheels running on rails are heavy and require concrete trackways and piers to support their weight. Linear induction tracks are much lighter and hence do not need rails (there are no wheels) and would look more like the trackways of rides at funfairs and amusement parks. Wheel-less carriages floating silently on single tracks raised above the level of existing traffic and powered by electricity – this is what I see as being the future of urban passenger transport. Makes the conventional twin-rail tram look archaic.

Trevor Locke

Trevor Locke has a masters degree in Urban Policy Studies

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