Case

Innovative LED conversion for Göteborgs Spårvägar

Together Tech's collaboration with Gothenburg's Spårvägar shows the way for sustainable and efficient lighting solutions

During the summer of 2023, Together Tech started a project in collaboration with Göteborg Spårvägar to convert the interior lighting on the M32 trams from conventional fluorescent tubes to LED. Driven by new legal requirements, the project is an important step in the direction of more modern and energy-efficient public transport solutions.

Project start and first test tram

Together Tech's approach was to find a simple and resource-efficient solution. It turned out that the fixtures were still serviceable and could be reused, and instead we developed an electrical conversion. In November 2023, the team rebuilt a test tram to determine the best technical solution. After agreeing with the customer on the exact specifications, the rebuild was carried out and thoroughly tested. The team carried out measurements on every seat in the test tram and the installation met the strict requirements for passenger traffic, including light intensity and color temperature. The results from the test tram gave the green light to continue with the remaining 61 trams in the spring of 2024.

Challenges and successes

The project included dismantling the existing lighting, installation and commissioning of the new LED lighting and cleaning the fixtures. Despite logistical challenges and material delays, Together Tech managed to get the installation underway in mid-April 2024. The project was completed before midsummer 2024, exceeding the client's expectations. The work was carried out by a dedicated team of approx. 20 people in total, who were involved periodically and also included the partner Fas Elektriska in Partille.

- One of the biggest challenges was getting access to the trams, which were in traffic during the course of the project. High demands were placed on planning and cooperation between the customer and the project team, which worked very smoothly and without disrupting the tram traffic, says Jan Persson, Together Tech's project manager, who with an experienced hand has driven the project to completion even ahead of schedule.

The image shows the light intensity of the existing solution, before the conversion.

Technical solutions and energy savings

A technical challenge was to replace the old 220-volt fluorescent tubes, which used a ballast to invert to 24 volts direct current. This was solved by developing a simple circuit board, which proved to be both faster and more cost-effective than using traditional cabling.

- The new LED lighting saves energy and provides an experience of improved light intensity in the carriages. At the same time, conformity is achieved with the newer M33 trams, which creates uniformity and strengthens the impression of a modern tram fleet, says Bo Johansson, Head of Technology at Gothenburg's Spårvägar.

The image shows the light intensity with the new LED installation.

Positive experiences and lessons learned

Project manager Jan Persson highlights the positive experience of working closely together with colleagues in an environment that stands out a little from everyday work at computers, which created a strong team spirit.

- Together Tech has solved technology development, planning and logistics in an efficient way and has shown great willingness to adapt to our needs. They have not only modernized the lighting of the trams, but also demonstrated the strength of cooperation and innovative technology. Together we pave the way for a brighter and more sustainable future, adds Mikael Sandgren, Vehicle Development Engineer at Gothenburg's Railways.

Björn Aiff, Business Unit Manager at Together Tech, sums it all up in conclusion.

- Our overall solution, from product development to installation, creates added value for customers and provides a clear environmental benefit, while at the same time strengthening teamwork and learning across several technology areas. A win-win-win!