Bytom - The first prefabricated tram switch built

The precast element integrating the substructure and concrete surface with the steel structure of the ZT-116-3200 R50 single tram turnout with a switch was installed in the first half of April of this year at the intersection of Powstańców Śląskich and Piekarska Streets in Bytom, as part of a thorough reconstruction of the latter. The initial, prototype logistics and construction work lasted about a week, although the target time for the final installation of such a precast element is expected to be within 48-72 hours.

Until now, installing tram turnouts as part of integrated road traffic systems has been dependent on a lengthy construction process. It began with pouring the concrete base, followed by anchoring and welding the turnout, and finally pouring the top concrete slab. Due to the 28-day curing time of each concrete layer, this took weeks, resulting in complete closure of sections of the intersection. Furthermore, replacing worn steel turnout components in this solution required repeating the most time-consuming part of the process: replacing the top layer and re-curing the concrete. 

"During our conceptual work, we drew on our experience in the railway sector, where we have been transporting, unloading, and installing prefabricated turnout blocks for years. Long-term observations related to the development of tram concrete slab technology integrated with straight track were also crucial," explains Małgorzata Urbanek, CONTRACK project manager on behalf of the KZN Bieżanów Group. "Our innovative concept of concrete blocks integrated with tram turnouts was based on this. This prefabricated element can be used like a ready-made "block" or "puzzle" in the construction process, significantly reducing the time required to install the finished element in the roadway and maintaining the high initial quality of the structure," adds Urbanek. 

As with railway turnouts, we are dealing with three blocks: a switch, connecting rails, and a crossing. The turnout structure, switch drive, drainage boxes, and electric heater installations are installed in specially prepared concrete slabs, and then the entire assembly is finally integrated using specialized construction chemicals. Depending on the client's guidelines, integration can take place at the manufacturer's premises or at the final installation site. During the first project in Bytom, the final integration of the previously prepared and tested prefabricated element took place on the construction site. 

"Our solution also allows for the removal of worn-out steel sections of the turnout structure without damaging the concrete block. This is particularly important when you compare the durability of the concrete surface, which is expected to last at least 30 years, with the turnout's expected operational life of approximately 10 years. This opens up enormous possibilities for maintenance work and quick, weekend replacement of the steel section in such a prefabricated element," emphasizes Małgorzata Urbanek. "Furthermore, in the case of the work performed in Bytom, the technology used allows for the continuity of the tramway structure and allows the contractor to maintain vehicular traffic at the intersection," emphasizes the project manager.  

The CONTRACK technology concept (from the English words concrete and track), developed by the KZN Bieżanów Group, met with immediate market response. Letters of intent were signed with both Tramwaje Śląskie and the Krakow City Road Authority, and other infrastructure managers expressed their keen interest in the solution. "Any interruption in tram service not only represents a tangible financial loss for the company, but above all, significant disruptions for passengers, resulting in their dissatisfaction and often even abandonment of tram service. CONTRACK technology is designed to significantly shorten the turnout installation process and subsequent maintenance. This long-awaited solution may soon become the norm, although today it is an innovation," says Jacek Kaminiorz, Technical and Operations Director at Tramwaje Śląskie SA, adding: "We strive to embrace modern solutions in our investments. We recently became the first tram company in Poland to commission an energy storage facility." Now we're testing another innovation from the KZN Group. We hope this solution proves successful.  

The choice of Tramwaje Śląskie was a natural consequence of the favorable climate for innovation. As part of this surface-related collaboration, the KZN Bieżanów Group successfully installed an innovative monoblock tram switch in Zabrze, the manufacturer summarizes.