As part of the Lausanne Morges Agglomeration Project (PALM), Transports publics de la région lausannoise (tl) is constructing a new tram line in the western part of Lausanne. This initial line will connect Villars-Ste-Croix to the city centre, providing the residents of western Lausanne with a viable alternative to car travel. The project aims to improve quality of life in Lausanne by reducing road traffic and noise pollution. Enotrac was responsible for conducting the risk analysis for the tram maintenance garage/workshop in Lausanne.
About the project
Transports publics de la région lausannoise (tl) is constructing a tramway line in the west of Lausanne, serving 16 stops between Lausanne-Flon and Villars-Ste-Croix. The line will operate a fleet of a dozen modern trams with full accessibility for passengers with reduced mobility. As a flagship project for the region, the tramway offers a sustainable alternative to individual private car use and promises to improve the quality of life of the residents living along this route, particularly in terms of noise and air pollution. To support operations, a new maintenance and servicing facility (Garage-Atelier, GAT) is being built near Perrelet, adjacent to the existing tl bus depot. The GAT will be connected to the main tram line via a bridge over the SBB railway tracks. Enotrac was commissioned to carry out the risk analysis for the GAT.
Our contribution
Enotrac collaborated with Geste to carry out the risk analysis for the maintenance and servicing facility (Garage-Atelier, GAT) of the future Lausanne tramway. The methodology followed the Common Safety Method (CSM), and an established risk matrix used since 2012 for this project was applied.
The study focused on the GAT during its commercial operation phase. Initially, Enotrac and Geste developed a definition of the system and its scope. Thirteen subject-matter experts contributed to this process, providing expertise in a wide range of subjects including
- Overhead contact line systems
- Track design
- Architecture
- Depot operations
- Railway signalling
- Depot maintenance and equipment
- Civil engineering
These experts participated in a dedicated hazard identification workshop based on the system definition. They were able to contribute their expertise and identify the system’s hazards. A key challenge in the analysis was the coordination across these diverse technical domains, especially due to the high number of interfaces involved in GAT operations.
Following the hazard identification workshop, Enotrac and Geste assessed the risks of the 81 hazardous situations that had been identified. To mitigate the risks, no fewer than 110 mitigation measures were defined and exported.
As part of the analysis, the Safety Integrity Level (SIL) required for the main PLC controlling the GAT’s equipment was determined in accordance with IEC 61508.
All findings and mitigation strategies were formally documented as part of the final risk analysis deliverables.
Facts and Figures
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Customer
tl
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Duration of the project
March 2023- August 2023
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Location of the project
Lausanne
Our services in the project
