The VR Class Hr11 was the first class of line-haul diesel locomotives used by Valtionrautatiet (Finnish State Railways). Only five units were built, all delivered by

Valmet Valmet Oyj is a Finnish company and a developer and supplier of technologies, automation systems and services for the pulp, paper and energy industries. Valmet has over 200 years of history as an industrial operator. Formerly owned by the S ...

in 1955. The

Maybach Maybach (, ) is a German luxury car brand that exists today as a part of Mercedes-Benz. The original company was founded in 1909 by Wilhelm Maybach and his son Karl Maybach, originally as a subsidiary of ''Luftschiffbau Zeppelin GmbH'', and ...

diesel engines used in the locomotives proved highly unreliable, resulting in a complete overhaul of the engine-transmission system in 1956–58, but this did not solve all of the reliability problems. The Hr11 series was withdrawn from service in 1972.

History

VR (Finnish Railways) started a modernization project in the early fifties. VR had a small amount of diesel and gasoline-powered railcars since the 1920s, but in 1952 VR had only steam locomotives. Modern aluminum-carriage diesel powered express multiple units (Dm3 and Dm4) were introduced in 1952. Related to these orders, VR ordered in 1952 five passenger train diesel locomotives with hydraulic transmission from

Oy, Tampere. The locomotives were delivered in 1955.

Technology

The locomotives had originally two six-cylinder Maybach MD320 diesel engines driving each their own Maybach

Mekydro A torque converter is a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power ...

K64B hydraulic-mechanical gearbox. The engines and transmission were placed in the bogies. The engine-transmission units proved to be very unreliable, and in 1956–58 a complete overhaul was done. Among other improvements, the engines were fitted with turbochargers, which increased the power from 450 hp to 600 hp, but simultaneously lowered the RPM from 1700 to 1500 r/min. The new engine designation was Maybach MD325. The gearboxes were changed to another type, Mekydro KL64. After the upgrade, the engines were reasonably reliable, but the reliability of the Maybach Mekydros did not improve significantly.

Operation

The locomotives carried a gray livery, with wine-red broad stripes. The gray color and sleek looks earned it the nickname ''Lentävä susi'' (Flying Wolf). They pulled mainly passenger trains between Tampere, Helsinki and Turku. All units were abandoned in 1972.

Preservation

No 1950 is stored at the

Finnish Railway Museum The Finnish Railway Museum ( fi, Suomen Rautatiemuseo) is located in Hyvinkää, Finland. It was founded in 1898 and located in Helsinki. The museum was moved to Hyvinkää in 1974. The museum is on the original station and yard site of the Han ...

References

External links