VR Class Sm4
| Industry | Rail transport |
|---|---|
| Founded | 1995 |
| Headquarters | Helsinki , Finland |
| Products | Commuter rail services, including Sm4 EMU trains |
The Sm4 electric multiple unit (EMU) serves as a low-floor train model utilized by VR Group for commuter rail operations. The initial procurement included ten units that commenced service in 1999, with a subsequent delivery of 20 additional units completed by 2005. Produced by the Spanish manufacturer CAF and based on a design originally developed by Alstom Ferroviaria (previously Fiat Ferroviaria), the Sm4 is commonly referred to by the nickname pupu (‘bunny’).
Features
An Sm4 set is composed of two motorized cars, each equipped with its own pantograph. These trains employ regenerative braking technology, enabling a reduction in electrical energy usage by as much as 30%. Capable of reaching speeds up to , the Sm4 offers passengers a quiet and smooth travel experience. Amenities include air conditioning, CCTV surveillance, and digital displays providing route information. The design features partially low-floor sections, ensuring all entry points align with platform height, and includes accessible restroom facilities. Bicycle storage areas are positioned adjacent to the driver cabs.
To accommodate varying passenger volumes, up to five Sm4 units can be coupled together. During peak travel times, it is common to operate two or more units in tandem, increasing capacity without adding extra trips.
Routes
Engineered for longer-distance commuter journeys, the Sm4 has replaced older Sm1 and Sm2 models on routes connecting Helsinki with Riihimäki and Lahti. It also services the lines between Tampere and Riihimäki as well as Riihimäki to Kouvola. Initially deployed on shorter routes with frequent stops due to a shortage of appropriate low-floor trains, the Sm4 has since been completely superseded on HSL commuter rail lines by the more modern Sm5 low-floor trains as of November 2009.