Electric shock

The amount of the UK’s railways that is electrified is well behind the rest of Europe. Rod Smith believes we need to get current.

George Stephenson said in 1847, ‘I have credit of being the inventor of the locomotive, and it is true I have done something to improve the action of steam for that purpose. But I tell you, young man, I shall not live to see it, but you may, when electricity will be the great motive power of the world.’ (letter to The Times, 4 April 1912).

One hundred and fifty-seven years since this prediction was made, and more than 100 years after the first electrification schemes of steam railways in the UK, it is sobering to examine what little progress has been made towards electrifying our railways.

We are well behind other European countries, with — at 30 per cent — only a slightly higher proportion of our routes electrified than India and China. China has 3.6 times more kilometres of electrified route than Britain, and India three times more. Bear in mind, too, that about one third of our electrified route is the third rail DC system, south of London.

Exactly 100 years ago this system was described as ‘already an obsolete device, discarded in the latest types of electric railway. In 10 years’ time there will probably be no “live rail” left… It is an engineering blunder.’ (letter to The Times, 8 October 1904, from Prof Silvanus P Thompson).

The technical advantages of modern electrification based on high-voltage AC are well rehearsed and include better acceleration, greater availability of vehicles, easier and cheaper maintenance, greater safety, and less engine vibration and noise.

In 1981 British Rail and the Department of Transport produced a report (Review of Mainline Electrification) that concluded that even on purely commercial grounds not only was ‘a substantial programme of railway electrification financially worthwhile’ but that the more extensive and faster options would be better propositions than the more modest ones.

It also suggested that the most cost-effective way to electrify would be a rolling programme whereby a team of experts would work on a whole series of lines sequentially (when one line is completed it moves to the next) as this would optimise resources and expertise, plus give industry the long-term order book that creates economic stability.

What this report suggested is known as the ‘network effect’: the more lines electrified the more it would be financially advantageous to electrify even more lines. This is because it would enable more trains to run through services without needing a change of motive power en route, and help avoid the wasteful situation whereby diesel trains run on electrified railways because small sections of the journey involve using non-electrified lines.

A further major advantage of electrification is energy efficiency and reduced pollution. Given the limitations of supply of hydrocarbon fuels just around the corner, we should seriously question the need to build diesel trains that will have a life of 40-plus years. Renewable fuels used to produce electricity could run our trains. Energy could be recycled through regenerative braking systems and the advantages of distributed traction through modern lightweight motors could be obtained.

The time has come for another strategic review of the possibilities of further extensive electrification of our railway system. The initial costs will be small compared with the longer-term benefits and the huge environmental improvements brought to an important component of our country’s transport system.

Prof Rod Smith is head of mechanical engineering at Imperial College.

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