First prefabricated tram turnout installed in Bytom

Quick installation of concrete turnout blocks and the option to efficiently replace just the steel turnout structure are the main advantages offered by the CONTRACK technology, which was used for the first time in the modernized tracks in Bytom thanks to Tramwaje Śląskie.

A prefabricate, integrating a concrete substructure and pavement with the steel structure of a single tram turnout with a ZT-116-3200 R50 switch, was installed in the first half of April this year at the intersection of Powstańców Śląskich and Piekarska streets in Bytom, as part of the latter’s major alteration. The first logistics and construction works, which were at the same time prototype works, lasted about a week, although the target time for final installation of such a prefabricate is expected to be 48–72 hours.

Installation of tram turnouts as part systems integrated with vehicular traffic has so far depended on a lengthy construction process. Its initial steps consisted in pouring the concrete substructure, followed by turnout anchoring and welding, completed by pouring the top concrete slab. Due to the bonding time of each concrete layer (which takes 28 days), this took many weeks, requiring a complete closure of entire intersection parts. Moreover, replacing worn-out steel turnout parts as part of this solution involved repeating the most time-consuming part of the process – replacing the top layer and repeated concrete bonding.

“At the stage of conceptual works, we relied on experiences from the railway sector, where we have been transporting, unloading and installing finished turnout blocks for years. Another important contribution came from the many years of observations related to the development of technology of tram concrete slabs integrated with straight track section,” lists Małgorzata Urbanek, KZN Bieżanów Group Project Manager working on the CONTRACK project. “This constituted the grounds for our innovative concept of concrete blocks integrated with tram turnouts. Such a prefabricate can be used like a finished ‘block’ or ‘puzzle piece’ in the construction process, significantly reducing the time of installing the finished component into the road and maintaining high initial quality of the structure,” adds Urbanek.

As with railway turnouts, there are three blocks of switch, closure rails and frog. The turnout structure, switch drive, dewatering boxes and electric heater systems are installed in dedicated concrete slabs and then the whole thing is finally integrated using specialized construction chemicals. Depending on the customer’s guidelines, integration can take place at the manufacturer’s plant or at the target installation site. During the first works executed in Bytom, the final integration of the previously prepared and tested prefabricate took place at the construction site.

“Our solution also allows for removing the worn-out part of the steel turnout structure without disturbing the concrete block. This is especially important when comparing the durability of a concrete pavement, which is calculated to be at least 30 years, and the operational prospect of the turnout, calculated to be about 10 years. This provides tremendous opportunities for maintenance work and quick, ‘weekend’ replacement of the steel part made of such prefabricate,” emphasizes Małgorzata Urbanek. “What’s more, in the case of works performed in Bytom, the technology used allows for preserving the continuity of tram permanent ways and enables the contractor to maintain vehicular traffic at the intersection,” emphasizes the Project Manager.  

The CONTRACK technological concept (from English “concrete” and “track”), developed by the KZN Bieżanów Group, met with immediate response from the market. Letters of intent have been signed with both Tramwaje Śląskie and the City of Kraków Road Authority, while other infrastructure managers have expressed their keen interest in the solution. “Each interruption of tram traffic results not only in measurable financial loss for the company, but above all significant congestions for passengers, leading to their dissatisfaction and often abandoning tram transport. CONTRACK technology is expected to allow for significant shortening of the installation process and the subsequent turnout service times as well. This long-awaited solution may soon become the standard, although today it is an innovation,” says Jacek Kaminiorz, Technical and Operations Director of Tramwaje Śląskie S.A., and adds, “We try to open up to modern solutions in our investments. Recently, we became the first tram company in Poland to commission an energy storage facility. Now we will be testing another innovation from the KZN Group. We hope that this solution will work out well.”

“Choosing Tramwaje Śląskie was a natural consequence of good environment for innovation. As part of this pavement-related cooperation, the KZN Bieżanów Group previously managed to build an innovative monoblock tram switch in Zabrze,” concludes the manufacturer.