Darmstadt’s new Lichtwiese Tram Line – A Plus for the Whole City

At the end of April 2022, Darmstadt’s Technical University (TU) officially launched their new tram line after a two-and-a-half-year construction period: this line goes to Lichtwiese campus on around 1.3 kilometres of new tracks, connecting the campus to the city centre and the main railway station – a rail infrastructure for the coming century.
By Sigrid Riewe-Scholz

This improvement to the public transport connection was planned by transport provider HEAG mobilo GmbH and the city of Darmstadt, and in close cooperation with TU Darmstadt. “HANNING & KAHL’s task was to produce three different control systems: single-track safety protection, the point controller and a level-crossing controller. All of these should function as autonomously as possible“, explained HANNING & KAHL Project Manager Thomas Klein adding:“We rigorously implemented this specification, and all systems function independently.“ 

To ensure optimum operations at all times, the point controller – at the request of HEAG mobile  – does not allow any runs in the event of a malfunction on the single-line track segment. The point controller assesses whether there is still enough space in the turning loop. If HEAG mobilo had not decided on this function, too many trams could be sent in the direction of the loop which would mean that one tram would have to reverse out of the loop.

Mastering challenges together
As the technical university has a highly-sensitive measuring system, it is vital that the rail traffic does not cause any vibrations. To prevent any impact, track construction is based on a heavy-mass spring system. This system decouples the body of the rail mechanically from the surrounding premises. Impressive result: outside of the heavy-mass spring system no vibrations are felt when trams cross. This meant that HANNING & KAHL had to specify all blocking circuits, frequency coupling coils, point machines and signals long in advance because this system does not allow any subsequent changes.

“On completion of the project I would like to mention the customer’s extremely constructive participation in finding solutions for a controller“, Klein praises the cooperation between the partners.  Lichtwiesenbahn proves that enhancements and optimisations of the rail system can greatly reduce emissions, noise and fine dust and help ensure efficient, environmentally sound and climate-friendly public transport.

Components of the Signalling Installations
- Three point controllers for Lichtwiese tram wye
- Signalling installation in three control cabinets on the line 
- Safe route management as per the explanatory report for tram and road traffic
- Signals
- Vehicle-detection elements/Track-free report 
- Track-occupation displays
- Key switches 
- Cables 
- “Operate & Observe“ for OCC managers/dispatchers