VR was searching a diesel motor car to be used on low traffic regional services on non-electrified tracks years after the last of the earlier diesel motor car series had been decommissioned by the end of the 1980s, and diesel locomotive pulled passenger trains had been found to be uneconomical for small-demand services. VR had earlier experimented with converting an old unpowered passenger car into a diesel motor car, but the prototype was never put to service and VR ultimately decided to acquire all-new cars. After a failed purchase, 16 Dm12 units with 20 options were finally ordered from the Czech manufacturer ČKD Vagonka, now Škoda Vagonka, in 2001, at a price of 160 million FIM. The first unit arrived to Finland earlier than expected, on, after being tested in the Czech republic. VR was able to start traffic using the first unit between Joensuu and Pieksämäki on. After a month and a half of usage without problems, it was serviced in June 2005, including a change of seats and modifications to the air intake. The second unit was delivered in August 2005 and followed the first between Joensuu and Pieksämäki. More units soon followed, and they were used between Joensuu and Nurmes. At the end of the year, VR had received 11 units, nine of which were serving passengers. The units were delivered to VR in 2004–2006, entering commercial service in 2005. The units are used in regional and feeder services mostly in Eastern and Central Finland, but also on the Karjaa-Hanko route near the coast of the Gulf of Finland. The Dm12 is currently the only diesel motor car in Finland. All Dm12 units were withdrawn from service on after two fires in short succession, in Punkaharju on, and Keuruu on. The multiple units have been temporarily replaced with trains pulled with diesel locomotives or buses. The fires were a result of a fuel leak, which caused fuel to spill on the hot engine. The units are being re-entered in service during June 2012 after the faulty fuel lines are replaced. The nicknames for the Dm12 are Peräkylän Pendolino, "Viidakkopendolino" Skoda and Demari.
Specifications
At a maximum, three Dm12 units can be coupled into a train to increase capacity. Each car has two passenger compartments, two entrance vestibules and a driver's cabin at each end of the car. The driver cabins have air conditioning. There are two places for wheelchair-using passengers, the unit has lifting platforms for wheelchair access and the toilet is designed to be accessible to the disabled. The heating of the passenger compartments uses waste heat from the diesel engines.
Livery
Dm12 units are painted in a distinctive red-gray colouring on a white background. As of June 2012, the two oldest units, 4401 and 4402, have been painted according to VR's white-green paintscheme.
