Modernisation of Depot 3 in Graz: New Shunting Route Control for Greater Capacity and Operational Stability
The comprehensive modernisation of the line infrastructure in Graz started back in 2021 with the “Maintenance Graz Linien” project. This was launched in the context of the plan to relieve congestion in the city centre as well as the procurement of 15 new, 34-metre-long Flexity trams. The historic Depot 3 in the north west of Graz needed to be expanded to support future operations with longer vehicles and shorter headways. Once the adaptation measures have been completed, it will be possible to park up to 60 trams there in the future. By Jörg Grote
Comprehensive operational plans were drawn up for this in 2022 and 2023. These included new entrances from Eggenberger Strasse, additional sidings and a new, standalone point controller implemented intentionally without an interface to the existing relay technology. The historic relay installation, including control panel and cabinet, is continuing to operate unchanged.
The construction work for the eastward expansion of the depot began in 2024. In addition to preparatory measures, such as utility relocation works, tree felling and noise control planning, the primary focus was on improving operational performance and modernising the infrastructure. The project has resulted in six new sidings with additional track connections, a total of eleven new points, a new tram wash facility as well as upgraded workshop and overhead line equipment. At the same time, there has been extensive track and overhead line rehabilitation work within the depot to significantly improve operational stability when vehicles are entering and leaving.
The new five-way shunting route control is a key element of the expansion. It controls the incoming routes via the new point systems at Eggenberger Strasse. The additional main line points enabling rapid entry into the depot from both directions are especially important here. Further sets of points then route the vehicles to the six new destination tracks. The point machines being used are of the 61.1 series.
The main line points installed in 2025 are based technically on the tried-and-tested Graz standard design using HN-P control technology from HANNING & KAHL. This is complemented by advanced point position, track occupancy and route status message feedback for the signalling installation and the new shunting route control. Safety is maintained through two independent systems using mass detection and track circuit technology.
The shunting route control in trial operation since March 2025 was developed through intensive technical co-ordination. The aim was to achieve particularly high availability while ensuring a clear alignment with the proven processes of the relay control already in place.
The system differentiates between three operating modes. In standard operation, routes are organised via a dispatcher in what is known as the Operate & Observe mode. This can be done directly at Depot 3 or centrally via the Citycom WAN. An additional operator station is provided on the eastern outer wall of the workshop as a fall-back. In following-train operation, a route already set can automatically be used by subsequent vehicles. Finally, automatic operation enables fully automatic route setting depending on the detected vehicle types, which are identified via the HCS-V communication system and automatically assigned to the six destination tracks.
The technology that makes up the new shunting route control is distributed across two aluminium outdoor cabinets as well as an additional heating control cabinet with ConnAct® integration. The displays indicate the set route and respective destination track to the drivers. After the points have been safely locked, the drivers then run on sight. Occupied tracks are automatically detected and locked for further route setting.