Electrical components and applications for rail systems

Rail transport has been an integral part of economic and industrial life in most countries for almost two centuries (Box A) (see table 6 , page 14). After nearly a century as the only means of mass land transport, its physiognomy is undergoing profound change. Electricity has been, and still is, one of the main driving forces behind this development, thanks to the decisive advantages it brings to the railroads:

• In terms of energy efficiency, it ranks first by its very design: friction energy on contact with the wheel-rail is the lowest, and electric traction further enhances this result;

• with regard to the environment, it respects – thanks to the use of electric power – perfect integration, whether in urban areas or on long-distance lines.

In this context, it is interesting to analyze the main components – or vectors – of what we should call the "railway system". This approach can be transposed to any other transport system: air, sea or road.

Each of its components makes use of the applications of electricity, and this is the analysis proposed in this article, after giving a few historical landmarks.

At the same time, all aspects of the railroad benefited from electricity: car air-conditioning, light signalling, motorization of points, etc.

The transport industry is evolving in such a way that there is competition at every level. In this context, the strengths and weaknesses of each are decisive. After holding a monopoly in both passenger and freight transport until the 1960s, the railroads moved into niches corresponding to their strengths:

• High-speed rail has been developed in Europe and the United States, and is currently being planned in Asia and Australia;

• urban transport in the form of metros, suburban networks and tramways, to relieve congestion in cities and alleviate infrastructure saturation and air pollution caused by cars;

• freight transport complements other transport systems and avoids the risks associated with road transport, in terms of saturation, safety and pollution.

These three major areas call on electrotechnical and electronic technologies, as profitability imperatives bring energy and sustainable development aspects into play.