In service 1988- Constructed 1988-2005 Refurbishment 2011- | Manufacturer LHB, ABB Entered service 1988 Number built 126 units | |
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The Type DT4 is a four-car electric multiple unit train built for the Hamburg U-Bahn. It was first introduced in 1988 and is currently the second newest type of subway trains in Hamburg.
Description
The development of the DT4 began in 1986. Initially, the work was based on the experience gained in the DT3-DAT with modern three-phase electric engines, but the new trains would have a more futuristic design, reduced noise, increased safety and greater economy than the older trains. The first unit was completed on 30 May 1988, the passenger service began on 17 October of that year. The four-car DT4s are units that run on six bogies. The second and fifth are unpowered bogies similar to Jacob bogies. The body was created in lightweight steel. For a single car, two door pairs on each side have been installed, there is no transition between the cars.
By 2005, a total of 126 units were delivered in six series of development. The sixth series ("DT4.6") uses a different propulsion type and therefore cannot be coupled with the other series.
The Class DT4 was the first subway type in the world equipped with an internal sprinkler system.
Beginning in 2011, the DT4 trains are being refurbished. They receive a newer interior appearance, similar to the interior of a DT5 train. One car of the unit 140 was refurbished for testing purposes in summer 2010, in 2011 the regular refurbishment started.
Between 2012 and 2014 the propulsions of ten units of the second series were replaced by the newer type from the sixth series, technically converting them into DT4.6 units and being coupled only with them since then. The conversion was done to receive urgently needed spare parts for the propulsions of the first and second series which are rare to find on the market as they are almost 30 years old.