The Sm2 is a class of electric multiple units in use by VR in its commuter rail traffic in southern Finland. Fifty Sm2 units were built between 1975 and 1981 by Valmet in Tampere. Since the withdrawal of the older Sm1 units, the Sm2 units are the oldest multiple units in use in Finland.
All Sm2 units were completely renovated between 2002 and 2011. Only the bodywork and the technics remained mostly untouched. Many of the changes are visible to the passengers, including a different type of seat and modern toilets. Between 2018 and 2024, all remaining operational units were refreshed, with new moquette and a new livery consisting of a white bodyside with a green lower band, except for units 90 and 91, which remains in their vintage red livery.
Technical information
Like the Sm1, each Sm2 unit consists of two cars: the Sm2 is the motored car of the multiple unit, while the other car, the driving trailer, is a part of the Eioc class.
The units are numbered from 51 to 00. The individual carriages are 6051 to 6100 for the Sm2 motor car and 6251 to 6300 for the Eioc driving trailer.
The train can be driven from both ends, which is a major advantage compared to locomotive-pulled trains in commuter traffic. Sm2s can be coupled together with Sm1s forming trains of at most six units (12 cars), but the length of the commuter train platforms limits the maximum length to five in commercial traffic.