The VR Class Ds1 Also known as "Puumotti" (Roughly translated to Wood Cubic meter "motti" being a means to measure wood volume) was the first railbus of the Finnish State Railways.

The Ds1 was built by the Pasila workshop, but the automotive parts including the engine were supplied by the Swedish company DEVA.

The vehicle consisted of a motor room, a luggage compartment, and a 3rd class passenger compartment bare on a wooden bench seating.

The Finnish State Railways started ordering Diesel multiple units and railcars, as road transport began to compete with rail passenger services.

The use of steam locomotives on quiet railway lines would have been inappropriate, and the associated costs would have been too high.