Hamburg U-Bahn Type DT4

The Type DT4 is a four-car electric multiple unit (EMU) train type operated by the Hamburger Hochbahn AG on the Hamburg U-Bahn system since 1988.

HHA-Baureihe DT4
A DT4 train at Überseequartier station in May 2013
In service	1988–
Manufacturer	LHB, ABB
Constructed	1988–2005
Refurbished	2011–
Number built	126 units
Number in service	126 units
Fleet numbers	101–226
Capacity	182 seated
Operators	Hamburger Hochbahn AG
Depots	Farmsen, Barmbek, Billstedt
Lines served	U1, U2, U4
Specifications
Train length	60.28 m (197 ft 9 in)[1]
Width	2.58 m (8 ft 6 in)[1]
Height	3.32 m (10 ft 11 in)[1]
Doors	2 pairs per side (per car)
Maximum speed	80 km/h (50 mph)
Weight	76.8 t (75.6 long tons; 84.7 short tons)[1]
Traction system	Three-phase asynchronous (two motors per powered bogie)
Power output	1,000 kW (1,340 hp)
Electric system(s)	750 V DC third rail
Current collector(s)	Contact shoe
UIC classification	Bo′2′Bo′+Bo′2′Bo′
Braking system(s)	Dynamic main brakes, automatic air brakes
Safety system(s)	Sifa
Track gauge	1,435 mm (4 ft 8+1⁄2 in)

Formation

Every DT4 unit consists of four cars, which are formed as two articulated half-sets with two cars each. The cars don't have gangways, but feature windows in the car ends.^[2]

Interior

The interior consists of transverse seating bays.^[2] Widescreen passenger information displays are to be fitted to the whole DT4 fleet, with works scheduled to be completed in 2022.^[3]

• 
  Interior view DT4.1 and DT4.2
• 
  Interior view DT4.3 and DT4.4
• 
  Interior with passenger information display in September 2008
• 
  Interior of a refurbished train in August 2015

Technical specifications

The trains have steel car bodies and a three-phase propulsion system.^[2] Thyristor inverters are used in the DT4.1 and DT4.2 trains, and the DT4.3 through DT4.5 trains use GTO-pulse inverters.^[2] The DT4.56 and DT4.6 trains use IGBT-pulse inverters.^[2]

Each four-car set has four powered bogies and two non-motored bogies. The powered bogies are equipped with water cooled three-phase asynchronous motors.^[2]

History

The development of the DT4 began in 1986, and the first unit was completed on May 30, 1988.^{[citation needed]} Passenger service began on October 17 of the same year.^{[citation needed]}

The DT4 trains are being refurbished since 2011.^{[citation needed]} They receive a newer interior appearance, similar to the interior of the DT5 trains. One car of set 140 was refurbished for testing purposes in summer 2010.^{[citation needed]} Regular refurbishment started in 2011.^{[citation needed]}