Changing Trains

An interesting article by Michael Meacher in Monday’s Daily Telegraph looked at global energy consumption, and suggested that the world has already used up half of its identified oil reserves. And whereas the first half lasted 145 years, such is the rate of consumption that we will get through the rest in just 40.

So where will that leave the railway industry? After more than 100 years of reliance on steam, the majority of rail operators today use diesel traction. Trials with alternative technologies are negligible. A prototype biogas-fuelled railcar unveiled in Sweden last year attracted interest, and US investors are looking at growing crops for biodiesel. Next month East Japan Railway plans to put into operation a three-car multiple-unit powered by fuel cells.

There has been a lot of talk about fuel cells, particularly if the rail industry can piggyback on developments in the automotive market. Fuel cells offer potential benefits in terms of reduced emissions at the point of use. But as with biodiesel there are questions about the energy needed to generate the fuel in the first place. Writing in the August 2005 issue of Railway Gazette International, traction expert Professor Roger Kemp explained that the use of fuel cells was less efficient, in terms of power losses, than conventional electrification.

Fuel is really only a means of storing and transferring energy to the point where it is needed. Given that the recent steep oil price increases are not likely to be the last, perhaps more railways need to revisit the idea of electrification. Today electric operation is mainly restricted to Europe and parts of Asia. And only in Russia and China are there big programmes of railway electrification: Chinese Railways is currently wiring around 5 000 km a year. Electric traction also offers the prospect of sustainable generation: trains in Japan and Sweden and trams in Calgary are driven by wind power, and Swiss railways have has long relied on hydroelectricity thanks to the mountainous terrain.

Since early electrification schemes were abandoned in the 1950s and 1970s, North America's freight railways have been the bastion of efficient high-power diesel operation. Pressure from the railways has seen loco builders squeezing more and more fuel efficiency out of their engine designs, with spin-off benefits for operators in other parts of the world. Common wisdom says the high fixed costs of electrification do not sit well with the long straggling transcontinental main lines.

Recent electrification proposals in the USA have been driven mainly by concerns over air pollution in urban regions such as the Los Angeles basin or the Texas chemical belt. But in operating terms short regional electrified networks are inefficient, forcing extra loco changes and requiring the wiring up of a dense network of low-density feeder routes.

In terms of global energy consumption, perhaps we should look at the other end of the spectrum – at those long straggling main lines. Over the past two decades, the Class I railroads have concentrated more and more traffic onto a few high-capacity corridors. Add in the FRA requirement for trains to be inspected every 1 600 km, and a possible strategy emerges.

Electrifying the trunk lines from the West Coast to the Midwest in ‘chunks’ of 800 or 1 600 km, corresponding to crew change or inspection division points, would minimise the impact of loco changes on utilisation. The long distances and the need to minimise the supply infrastructure suggest 50 kV – as on South Africa’s Orex iron ore line – or at least 2 x 25 kV autotransformer feeding. Overhead electrification would have to provide clearance for double-stack intermodal under the wires, but this is being pioneered in Russia and should not be insurmountable.