Helsinki tram services to see daily cancellations after power upgrade

By admin On Sep 17, 2025

Older tram. Photo: Sami Perttilä / Helsinki City Transport Oy

Helsinki’s central tram network will experience daily service cancellations over the coming week due to damage caused by a recent increase in overhead line voltage.

Helsinki City Transport (Kaupunkiliikenne Oy), the capital region’s transport operator, confirmed on Wednesday that while most of the tram fleet remains operational, the number of vehicles available for weekday service is still slightly below normal.

The disruption stems from a voltage change carried out overnight between 13 and 14 September. The upgrade increased the overhead DC voltage from 600 to 750 volts, causing inverter failures in several older trams. Inverters convert direct current into alternating current and are essential for the tram’s electrical systems.

Antti Nousiainen, head of asset management at Kaupunkiliikenne, said additional spare parts are expected soon.

“We will receive more replacement parts next week. As soon as they arrive, we will be able to restore several trams to service quickly,” Nousiainen said.

Despite repair work progressing, not all older tram units have returned to operation. This has led to reduced rolling stock availability and, as a result, daily cancellations are expected throughout the week.

Kaupunkiliikenne said it regrets the inconvenience to passengers and is working to minimise the impact. Real-time updates on service disruptions are available on the Helsinki Regional Transport Authority (HSL) website.

The voltage upgrade was part of a broader plan to modernise tram infrastructure and improve system efficiency. The newest tram models in Helsinki are compatible with the higher voltage, but the ageing articulated units have shown vulnerabilities under the updated conditions.

There are no changes to the overall timetable, but passengers are advised to check for updated service information before travelling.

Source: www.helsinkitimes.fi