A GROUP of Austrian companies unveiled a frame sleeper design for ballasted track. It consists of a prestressed frame shaped like an H with two crossbars. These form a continuous longitudinal beam supporting the rails.
Known as the RS95, the frame sleeper doubles the bearing surface, so halving the load on the ballast. A resilient layer forming the base of the frame sleeper should significantly reduce transmission of noise and vibration. The greater bearing surface should also increase transverse rigidity.
During the second week of June a 150m trial section of track with frame sleepers was to be installed on the Himberg - Gramatneusiedl section of Austrian Federal Railways’ line from Wien to Parndorf. This will be followed by installation in September of a 1·5 km trial section in Kärnten, and next year German Railway is to accept a 20 km test section.
Although initial costs may be up to 25% higher than conventional sleepers, major savings are anticipated in maintenance, with lower wear of the ballast.
Companies involved are SSL Stahlbetonstellenwerk, Semperit, Getzner-Werkstoffe, Vossloh-Werke and PORR Allgem Baugesellschaft. The project was supported by Austrian Federal Railways, and development work was carried out by the Technical University of Graz.
