As of 2010, there are four tram depots/workshops in Helsinki; HKL-maintained depots in Töölö, Vallila and Koskela, and a Bombardier Transportation-maintained workshop at Pasilan konepaja.

The Töölö depot houses trams running on lines 4 and 10, as well as some of those on line 5, approximately one third of the whole rolling stock.
The Helsinki tram museum is located next to the Töölö depot.
Between 1948 and 1974 the Töölö depot also housed the trolleybuses used on Helsinki's sole trolleybus line.

The Vallila depot houses repair-, paint- and rebuilding facilities, and administrative functions.

The Koskela depot is the largest tram depot in Helsinki.
It houses approximately two thirds of trams in the city, and contains training facilities.
The Koskela depot is linked to the main Helsinki tram network by a long section of double track that is not used by passenger-serving trams.

The Pasilan konepaja tram workshop was established in mid-2008 by Bombardier transportation as a repair shop for the Helsinki Variotrams, the maintenance of which became Bombardier's responsibility in May 2008.
The workshop takes up a part of the former VR Group electric locomotive workshop at Pasilan konepaja.
As of August 2008, the workshop does not have a permanent link to the tram network (although tracks run just outside the depot doors); instead, portable tracks are used to run the trams to and from the workshop.

Planning process is under way (as of November 2017) for a new tram depot in Ruskeasuo region next to current bus depot and to reconstruct the Koskela depot.
There were plans earlier to excavate an underground tram depot in the base rock below the existing Vallila depot and adjacent city blocks, but this was calculated to be too expensive.
As of 2010, there are four tram depots/workshops in Helsinki; HKL-maintained depots in Töölö, Vallila and Koskela, and a Bombardier Transportation-maintained workshop at Pasilan konepaja.
The Töölö depot houses trams running on lines 4 and 10, as well as some of those on line 5, approximately one third of the whole rolling stock. The Helsinki tram museum is located next to the Töölö depot. Between 1948 and 1974 the Töölö depot also housed the trolleybuses used on Helsinki's sole trolleybus line.
The Vallila depot houses repair-, paint- and rebuilding facilities, and administrative functions.
The Koskela depot is the largest tram depot in Helsinki. It houses approximately two thirds of trams in the city, and contains training facilities. The Koskela depot is linked to the main Helsinki tram network by a long section of double track that is not used by passenger-serving trams.
The Pasilan konepaja tram workshop was established in mid-2008 by Bombardier transportation as a repair shop for the Helsinki Variotrams, the maintenance of which became Bombardier's responsibility in May 2008. The workshop takes up a part of the former VR Group electric locomotive workshop at Pasilan konepaja. As of August 2008, the workshop does not have a permanent link to the tram network (although tracks run just outside the depot doors); instead, portable tracks are used to run the trams to and from the workshop.
Planning process is under way (as of November 2017) for a new tram depot in Ruskeasuo region next to current bus depot and to reconstruct the Koskela depot. There were plans earlier to excavate an underground tram depot in the base rock below the existing Vallila depot and adjacent city blocks, but this was calculated to be too expensive.
Helsinki tram network