VR Class Sm2

The Sm2 is a class of electric multiple units in use by the VR Group in commuter traffic in the Helsinki area. 50 Sm2 units were built between 1975 and 1981 by Valmet airplane factory in Tampere. The electric systems were built by Strömberg in Pitäjänmäki, Helsinki. The Sm2 units have undergone a complete renovation in the 2000s, during which the trains were essentially rebuilt. Only the bodywork and the technics remained mostly untouched. Many of the changes are visible to the passengers, including a different type of seat, modern toilets and a new livery.

To the outside the most significant difference in the appearance of Sm1 and Sm2 units are the corrugations designed to support the structure on the sides of the Sm1 unit. They don't exist in the more modern Sm2. Sm2 units can be coupled together with Sm1 units (but not with Sm4 or Sm5 units), forming trains of at most six units (12 cars), but the length of the commuter train platforms limits the maximum length to five units in commercial traffic. Naturally, the full length trains can be seen in the depot traffic in the mornings and evenings.

Like the Sm1, each Sm2 unit consists of two cars: the Sm2 is actually the motored carriage of the multiple unit, while the other car, the driving trailer, is a part of the Eioc class. The train can be driven from both ends.

The maximum speed of the train is 120 km/h (75 mph). The bodywork is made of aluminium, as opposed to steel in Sm1. The bogies are better and the Sm2 units have air suspension instead of steel suspension. The Sm2 units are numbered between 6051/6251 and 6100/6300 (the number of Sm2 unit / the Eioc carriage)