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RTR 4/2010 16 (track 1), had been jointed sections with a length of 60 m, a “54 E2” rail profile and an “R 320 Cr” grade of steel on wooden sleepers. The wear had been so intense that the rails had needed grinding every 2–3 years and replacing every 4-5 years. In the course of the replacement work, the 60-metre rail sections were continuously welded and safety caps were placed on all the sleepers. The rails laid on track 2 had the “54 E2” profile and were made of the “R 350 HT” grade of steel, whereas those laid on the experimental track (track 1) were in 60-metre lengths and made of various different grades of steel from the manufacturers Voestalpine and Corus (recently renamed Tata Steel Europe). The “Westbahn” railway line between Vienna and Salzburg is more than 150 years old and is the most important eastwest link in Austria. It is a constituent part of the Trans-European Network (TEN) and at the same time the most heavily-trafficked line in the whole network of the Austrian Federal Railways (ÖBB). With nearly 360 trains a day (counting both directions) and a load of around 30 million gross tonnes passing over each track each year, this line is extremely demanding in terms of both operations and maintenance of the infrastructure. It is, in particular, on the first forty kilometres of the line at the Vienna end, known as the “Wienerwald section” that there are tight curves in the track with radii as small as 270 m, permitting maximum speeds of only 70 km/h. The outlay on maintaining the permanent way over this section of the line is very considerably higher than on the other parts of it. 1 Test section on a mainline track In June 2003, the ÖBB laid tracks from various suppliers with high mechanical properties, including a Brinell hardness of 350 HB and more, in a tight curve as an experiment and then observed the development of rail wear and the formation of rail corrugations over a period of five years. The Railway Institute at the University of Innsbruck was appointed to accompany the experiment by making measurements throughout, by presenting the results in graphic form and by interpreting them. The halt of Eichgraben/Altlengbach lies on a right-hand curve extending over about one kilometre on the double-track railway line from Vienna to St. Pölten and Salzburg (km 28.921 – 29.843) with a radius of 280 m, a cant of 160 mm and a maximum permitted speed of 75 km/h (Fig. 1). It was the eastbound Salzburg–Vienna track (track 1) that was chosen for the experiment. At this location, the line climbs with a gradient of approximately 10‰. The daily load on the track is around 80000 gross tonnes, comprised 55% of freight trains and 45% of passenger trains. The older tracks in use before the relaying operations in 2002 (track 2) and 2003 Hard rails in tight curves The combination of increasing loads on tracks, high tractive forces and limited maintenance budgets is forcing railway infrastructure managers to optimise the wheel/rail inter face still fur ther. The use of hard materials for rails might be one way of contributing to extending the service life of rails laid in tight curves. Head of permanent-way technical division ÖBB Infrastruktur Bau AG, Vienna bernhard.knoll@oebb.at Dipl.-Ing. Dr. techn. Bernhard Knoll Professor University of Innsbruck, Railway and public-transport section guenter.prager@uibk.ac.at Ao. Univ.-Prof. Dipl.-Ing. Dr. techn. Günter Prager Professor emeritus University of Innsbruck, Railway and public-transport section erich.kopp@uibk.ac.at Em. Univ.-Prof. Dr.-Ing. Erich Kopp Fig. 1: Experimental curve on the Salzburg-St. Pölten-Vienna line. Radius 280 m, cant 160 mm, maximum speed 75 km/h. This track is used predominantly by eastbound traffic (Source: the authors)

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