The renovation of the Zollamt bridge in Austria will use PU composite sleepers

Railway sleepers made out of fibre reinforced PU have been installed as part of the renovation of the Zollamt bridge in Vienna, Austria, believed to be the first time such technology has been used in Europe.

The pultruded sleepers are made by Japan’s Sekisui Chemical in Eslon Neo Lumber FFU, a composite of long glass fibres and Bayer’s Baydur 60 polyurethane. Sekisui Chemical has sold the product for over 20 years in construction applications in the Asian market; it has been used in Japan for the sleepers on bridges and tunnels carrying the Shinkansen high speed train.

Michael Schwittlinsky from Sekisui Chemical Germany said the composite is particularly suited as a more weather-resistant alternative to wood for sleepers on bridges due to the “temperature changes, UV radiation and in particular the permanent moisture in the air”. Lighter in weight than either wood and concrete sleepers, the polyurethane sleeper can ensure static limits will not be exceeded when renovating tracks on older bridges.

Plastic railway sleepers have also been used in the USA. In 2001, German plastics machinery manufacturer Berstorff and PolySum Technologies developed a process for producing railway sleepers made from waste HDPE packaging and inorganic filler.