Sometimes, everything really does come together at once. The largest manhole covers by surface area ever developed and installed by ACO Passavant Detego are a perfect showcase of our multidisciplinary expertise.
The client: Luxtram, the public tramway operator in Luxembourg City.
The challenge: oversized floor access covers with multiple special requirements.
The timing: tight—and it became even tighter during spring 2020, when the project was in full swing.
This project highlights our ability to deliver custom-engineered solutions under pressure, combining precision, performance, and flexibility to meet complex infrastructure demands.
To reduce car traffic in the city center, Luxembourg has made public transportation free for everyone since February 2020. In addition, the Grand Duchy is investing €2 billion in expanding and modernizing its public transport system. A key part of this initiative is the deployment of electric trams that operate without overhead lines. These trams recharge their batteries in seconds during station stops, requiring high-performance transformers—which, along with their infrastructure, needed to be installed underground to preserve the urban landscape. ACO Passavant Detego was commissioned to develop the custom transformer access covers. The design had to meet strict technical requirements while blending seamlessly into the surrounding architecture, ensuring both functionality and aesthetic integration.
Large transformer covers with special requirements – custom engineering for Luxtram
When it comes to infrastructure, sometimes standard solutions just aren’t enough. For the Luxtram project in Luxembourg, ACO Passavant Detego was tasked with developing custom transformer access covers—the largest we’ve ever produced by surface area.
Oversized covers for key locations
A total of five custom manhole covers were required, two of which shared the same design. These included:
- The largest cover (3 × 19 meters) at Luxembourg Central Station
- The second-largest at Place des Metz
- One cover at Place de Paris
- Two identical covers at the Hamilius and Place de Paris tram stops
More than just size: Meeting complex requirements
Beyond their dimensions, these covers had to meet multiple technical and architectural demands:
- Rainwater-tight and thermally insulated
- Heavy-duty load-bearing, suitable for truck traffic
- Automated opening mechanisms for frequent pedestrian access
- Minimal visible metal for a discreet appearance
- Pavable surfaces to blend seamlessly into the urban environment
From concept to completion – under pressure
Following our proposal in spring 2019, the project was commissioned in October 2019, with construction scheduled to begin in April 2020 and completion by December 2020. Tight timelines are nothing new in construction—but few anticipated the added challenge of the COVID-19 pandemic, which brought restrictions on mobility and supply chains.
Despite these hurdles, the project stands as a testament to our ability to deliver tailored, high-performance solutions under demanding conditions.
Custom manhole covers and two-shift production: Delivering excellence during challenging times
Successfully navigating the first phase of the COVID-19 pandemic was made possible thanks to the strong collaboration with our clients and the dedication of our team at ACO Passavant Detego. Complex challenges like the Luxtram project continue to drive us to deliver top performance.
Operating in a two-shift system, we not only developed the perfect solution for Luxtram, but also managed to meet the needs of all our other customers during a turbulent year.
Precision Manufacturing and On-Site Installation
For the Luxembourg covers, countless individual components were welded, bent, and laser-cut. Given the scale of the project, our team handled the installation on-site to ensure precision and quality.
Seamless Collaboration and Architectural Integration
Once the covers were installed and approved, other trades immediately began paving over the covers, allowing them to blend almost invisibly into the surrounding anthracite-colored stonework. The result: a technically advanced solution that is visually unobtrusive and architecturally harmonious.
On time and on point: Custom Manhole covers for Luxtram delivered as scheduled
At ACO Passavant Detego, meeting deadlines is always a top priority—especially when it comes to complex infrastructure projects. In this case, it was a particular success: the handover of our custom manhole covers was completed on schedule in December 2020, just in time for the opening of the new tram line before Christmas.
Engineered for performance and durability
The exceptional size of these covers required equally exceptional materials. As expected, our manufacturing standards ensure that the covers withstand daily operational loads without compromise. Regular maintenance checks conducted in Luxembourg continue to confirm their long-term reliability.
Seamless integration into urban architecture
What makes this project truly stand out is how discreetly the covers blend into their surroundings. As requested by the client, minimal metal is visible on the surface. By using natural stone finishes, we met the high design standards and architectural requirements—especially at Place des Metz, where the second-largest cover was installed. The result: a technically advanced solution that visually disappears into the cityscape.