The Helsinki metro system was opened for traffic in 1982, first as just one line linking the city center and Itäkeskus (East Center). Subsequently the line has been lenghthened towards the east as two branches, one to the suburb of Vuosaari and another to Mellunmäki. A new line towards the west (Helsinki city center - Matinkylä in the neighbouring town Espoo) is under construction, was supposed to be opened in 2016 but as this text is being written in the summer of 2017 there is still no sign of a working metro in Espoo. Rail gauge is 1524mm and the trains get their DC 750V electricity from a third rail by the side. This is the first series, class M100 train built by Strömberg in the 1980s. Picture at Siilitie station 1.4.2014 by Ilkka Siissalo

First generation Helsinki Metro unit 119 in Itäkeskus July 30 1997. Metro opened in Helsinki 15 years earlier. Metro uses 750 V DC from third rail. Photo by Kimmo Kotimäki. Uploaded Aug 12, 1997

Second generation Helsinki Metro unit in Kulosaari in 2009. These trains are built by Bombardier. Public domain picture by Wikimedia commons user "Yaropolk".

Second generation Helsinki Metro train 221 at Siilitie station 1.6.2016. Photo by Ilkka Siissalo.

A third generation of metro trains for Helsinki was taken into use during early 2017. This picture shows one of the brand new class M300 trains in full speed by the Roihupelto metro depot during its test runs. The trains are built in Spain by CAF. Picture at Roihupelto depot 17.8.2016 by Ilkka Siissalo.

A closeup of the brand new M300 class train no 14. Picture at Roihupelto depot 17.8.2016 by Ilkka Siissalo.