COMPREHENSIVE MODERNISATION OF THE RAILWAY LINE IN DAXLANDEN

THE PROJECT AND ITS REQUIREMENT

In 2024, Karlsruhe Public Transport, the City Utilities and the City Civil Engineering Department launched a regeneration project comprising a range of measures to maintain and renew the transport and utility infrastructure. The project included the installation of new tracks and turnouts for the tram line, construction of barrier-free stops, renewal of overhead lines, and a roughly 2.6 km-long green track designed to improve the microclimate and reduce noise pollution in the neighbourhood.
 
The existing facilities were among the oldest in the city, so they needed to be modernised, including the section of the tram line. The entire construction section spanned a track length of around 4,750 metres. Around 2,800 metres of these were covered with asphalt within the road space, and around 2,650 metres were laid as green track. Vibration protection has also been installed in the town centre at the points of greatest stress along this section of the route.

THE SOLUTION

The task included reducing vibration and structure-borne noise levels inside the buildings. A lightweight full surface supported mass-spring system was installed in the track bed for this purpose. A Calenberg USM 2020 elastic track bed mat, dimensioned to meet the site conditions, was laid on the sub-base. The USM Type 2020 is ideally suited to protecting local residents against vibrations and structure-borne noise from passing trams, due to its tuning frequency of f ≤ 20 Hz.
At the points of greatest stress on this track section, around 2200 m² of USM Type 2020 were installed in the protected area and USM Type 3000 in the transition area. The elastic Cisador 35, 20 mm wide, was installed as a vertical bearing covering approx. 600 m² to ensure vibration protection along the sides of the system.
 
A mass-spring system effectively reduces the generation of vibrations. According to KVB, a system of this type has not yet been installed in Karlsruhe.