Wagons for all types of rail system are increasingly being manufactured using large aluminium profiles. Corrosion resistance and energy saving thanks to low weight result in economic efficiency compared with conventional steel construction.
Aluminium has been used in railway carriages and trams since the 1920s:
- It was first used for handles, rods and pelmets, then for roofs and finally for the skeleton and walls of railway carriage bodies and for the tanks of tank wagons.
- Bulk freight wagons with aluminium loading hoppers for grain, coal and ores were introduced in the 1930s, especially in North America and Australia.
- At the beginning of the 1950s, the superstructures of the carriages of the London Underground were made on a large scale from aluminium sheet and riveted to steel undercarriages.
- In Germany in the 1960s, there was a changeover to welding the whole railway carriage (undercarriage and superstructure) from aluminium sheet and aluminium profiles, for example for underground railways in Berlin, Munich and Nuremberg.
- Thanks to the possibility of extrusion and automatic welding, self-supporting carriage bodies made from large profiles up to 30 metres long have been manufactured since the beginning of the 1970s; they have been used for new underground and local railways, as well for high-speed trains (for example the ICE) all over the world since the end of the 1980s. Longitudinal stiffening of the profiles ensures a high degree of impact safety and stiffness of the carriage body.
- The parts of freight wagons, especially those for bulk goods, that have to be operated by hand, like tailboards, are also made from large profiles.
The main reason for the increasing use of aluminium in rail vehicles is its superior overall economic efficiency, which results from the sum of capital expenditure and operating costs. The capital expenditure for aluminium carriages is usually higher. However, this is more than compensated for over the total operating period, which is at least 30 years on average, by the high corrosion resistance and reduced weight, which leads to lower maintenance costs and energy savings. Construction with aluminium saves up to 50 per cent weight compared with the conventional methods of construction. The resultant lower operating power required compensates for the higher energy requirement for the extraction of aluminium after only a few years. The energy saving is particularly pronounced with underground and local trains that have to accelerate frequently.
Today some 60 per cent of all passenger train carriage bodies are made from aluminium.