VR Class Dv12
Encyclopedia
The Dv12 is the standard Finnish
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

 medium-weight diesel-hydraulic road locomotive operated by VR
VR Group
VR or VR Group is a state-owned railway company in Finland. Formerly known as Suomen Valtion Rautatiet until 1922 and Valtionrautatiet / Statsjärnvägarna until 1995...

. As all the main lines of Finnish railway network have been electrificied, the locomotive is designated mostly to unelectrified, less frequently used side lines. Occasionally it may still pull cargo trains on main lines. It has also been put in service as a shunter, replacing older classes Dv15 and Dv16 as they were retired. A total of 192 locomotives were built by Lokomo and Valmet between the years 1963 and 1984. As of 2011, the oldest Dv12 units are 48 years old.

Technical information

The Dv12 is a general purpose locomotive which was designed for both passenger and cargo train use. Its 1000 kW power is somewhat low by current standards, but it is capable of multiple-unit operation with only one train crew and doublets and triplets are common. It has a low axle load of 15.6 tonnes, which makes it very well suited for branch lines that allow only smaller axle loads. All the axles are interconnected with shafts and universal joints to the Voith L 216 rs hydraulic transmission. Because all axles must rotate at the same speed, the individual slipping of axles is impossible. This translates into a very good tractive effort for a 62 tonne locomotive. The main engine is a Finnish-built Tampella SACM MGO V16 BSHR Diesel with two Brown Boveri-VTR 200 M turbochargers.

The Dv12 has two speed ranges, 85 km/h (52.8 mph) for cargo use and 125 km/h (77.7 mph) for passenger use. This mechanical gear can only be switched with the locomotive at standstill.

Sr12

Between 1965 and 1972, 60 slightly heavier variants of the Sv12 were built. These were assimilated in the same series when their nomenclature changed to Dv12.

Sv1

Dv12 number 2501 was modified between 1978 and 1980 to run on electricity instead of diesel, becoming class Sv1 number 3201. The locomotive was used first in freight traffic, later in passenger trains between Helsinki and Imatra. The Sv1 was used to test three-phase
Three-phase electric power
Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...

 alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

 electrical engines; the results were used when developing class Dr16
VR Class Dr16
The Dr16 is a class of diesel-electric locomotives used by VR . The 23 locomotives have a single, off-centre cab and are currently VR's most powerful diesel locomotives. Their nickname is "Iso Vaalee"...

. The electrical components were delivered by Strömberg
Stromberg
-People:*Lyndon Stromberg, American sculptor and designer*Karl Stromberg, the villain in the James Bond film The Spy Who Loved Me*Joseph R. Stromberg, historian with the Ludwig von Mises Institute*Glenn Strömberg, Swedish soccer player...

, which was also involved in the Dr16 project. The locomotive was painted yellow with black stripes, a colour scheme known from another short-lived prototype, the Dr15.

In 1984, after four years of testing, the Sv1 was refitted with a diesel engine, returning to its original nomenclature and number. Number 3201 is nowadays used on an Sr2 class
VR Class Sr2
The Sr2 is a class of electric locomotives of the VR Group. They were built by SLM / ABB and later by Adtranz and finally Bombardier Transportation and assembled by Transtech Oy...

locomotive. As of 2011, Dv12 number 2501 is still in use.

Retirement and future development

In 2009, VR abandoned some of the older units of 2700 series Dv12s. The company plans to purchase new diesel locomotives during the 2010s.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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