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RTR 4/2010 21 Hard steel for every type of point „ Fig. 2: Cogidur crossing for withstanding wheel-set loads of 35 tonnes parts touching one another, even after a long period of service. Cogidur has also shown its suitability for applications other than points too. One example of this comes from the public-transport operation in Augsburg, where the material was tested in an expansion joint on a tram track in 2008, when the Ulrichsbrücke was rebuilt (Fig. 3). That was so successful that Vossloh Laeis has now received a follow-on order for the next bridge to be rebuilt. 180 millimetres entirely in Cogidur, the profiles were cut with precise dimensions from the metal plates and welded edgeways into the point (Fig. 2). Vossloh Laeis manufactured a total of eight flat-grooved Cogidur crossings for a scissors crossover which entered service in Helsinki in June 2009. The big challenge in this project was to equip all the crossings with insulating joints – in other words, to manufacture the joint gaps of only four millimetres so accurately that there was no risk of the metal on municipal railways, can subsequently be worked into the switch blades and crossings with great accuracy. In order to arrive at a rail height of 180 millimetres, the manufacturer decided from the very outset to employ a composite rail structure. In the case of point crossings, the upper layer of 80-millimetre-thick Cogidur plate has a backing layer of 100-millimetre-thick rolled structural steel under it. This is a favourably priced structure, which has become established as the standard solution. In the case of switch blades, the upper part is made of 100-millimetre-thick Cogidur and the lower part of 80-millimetrethick structural steel. The first points made of Cogidur were delivered to the municipal transport operations in the cities of Berlin and Augsburg in 2001. It became clear in only a very short period of time that they were subject to less wear than the points used beforehand. Cogidur was therefore specified as the standard material for heavily trafficked points on the municipal networks of those two cities. Numerous other cities followed their example, not only in Germany, but also in the Netherlands (Fig. 1), Finland, the United Kingdom and Canada. The additional costs of acquiring the Cogidur points are more than offset by a longer service life after laying and less expenditure on maintenance. In Berlin, by way of example, no maintenance jobs have so far been necessary after a period of eight years. Rotterdam carried out the experiment of laying two points, a normal one and one made of Cogidur, at the same time for comparative purposes. The result of this was that the normal point had to be lifted again after two years, whereas the Cogidur point is still working reliably. All-in-all, those customers who have Cogidur points in use report on a service life of between two and four times that of conventional points. 3 Tailor-made manufactures Using composite rails, a low-cost and extremely durable standard point construction has been developed. The manufacturer has also ventured successfully into the production of special designs to meet customer wishes. For the city of Vancouver it manufactured approximately a hundred crossings with a height of 160 millimetres, including an integrated wing rail, made entirely of Cogidur rather than of two different materials. Points capable of carrying axle loads of up to 35 tonnes were manufactured for the steelworks in Dillingen (Saarland, Germany) and the open-cast lignite mine near Niederaussem (to the west of Cologne). In order to achieve a height of Fig. 3: Cogidur expansion joint for the tram track across Ulrichsbrücke in Augsburg

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