DB class 474

DB class 474/874
Series 474
Number:	224 railcars (ET) 70 intermediate cars (EM) (474.1 + 2) 42 intermediate cars (EM) (474.3)
Manufacturer:	Traction equipment: Adtranz , now Bombardier Mech component: LHB , now Alstom Transport Germany
Year of construction (s):	1996-2001 2006
Axis formula :	Bo'Bo '+ 2'2' + Bo'Bo '
Gauge :	1435 mm ( standard gauge )
Length over coupling:	65,560 mm
Height:	3,720 mm
Width:	3,008 mm
Trunnion Distance:	16,190 mm (ET) 13,280 mm (EM)
Bogie axle base:	2,300 mm (ET) 1,800 mm (EM)
Empty mass:	100 t (474.1) 094 t (474.2) 106 t (474.3)
Top speed:	100 km / h
Hourly output :	920 kW (1250 hp)
Acceleration:	1.0 m / s²
Braking delay:	0.7 m / s² (E-brake) 1.2 m / s² (rapid braking)
Driving wheel diameter:	855/780 mm
Impeller diameter:	680/610 mm (474.1 + 2) 850/770 mm (474.3)
Power system :	1200 V DC (474.3 additional 15 kV 16.7 Hz AC)
Power transmission:	Lateral busbar coated from the side (474.3 additionally through overhead contact line )
Number of traction motors:	8 × 1TB 1713-0JA02
Coupling type:	Scharfenberg coupling
Seats:	208
Standing room:	306
Floor height:	1,035 mm
Classes :	1st / 2nd, since 2000 only 2nd

The class 474/874 is an electric multiple unit specially designed for the Hamburg S-Bahn network.

history

The first series of 45 vehicles was ordered from Linke-Hofmann-Busch in 1994 as the consortium leader of the Linke-Hofmann-Busch consortium (mechanical part) and the then ABB Henschel AG (electrical and control technology) in Salzgitter and delivered from 1996. In 1997 he was presented to the press. The second series of 58 vehicles was ordered in 1996 and delivered to the Hamburg-Ohlsdorf depot by 2001 .

technology

The series 474 represents a generation change in the vehicles of the Hamburg S-Bahn . As before, power is fed in via a busbar that is coated on the side and is attached to the side of the track . The vehicles are supplied with direct current of the voltage level 1,200 V via this busbar . For the first time, liquid-cooled three-phase asynchronous machines , which are connected to the axes via a two-stage gearbox, are used as drives . To operate the asynchronous liquid-cooled be on DC power GTO - inverter used. The vehicles of the 474 series are approved for a top speed of 100 km / h. In contrast to the previous 472 series , the intermediate car is again non-motorized, as was common before the 472 series. The railcars are consistently controlled by computers, which replaced the conventional control system that had previously prevailed in the older Hamburg series 470 and 472. The control data are no longer transmitted via individual lines, but via serial bus systems (vehicle bus is DVB, train bus is WTB ). It is therefore not possible to drive the vehicles of the older series with those of the 474 series in mixed units. Like their predecessor models, the vehicles are equipped with a Scharfenberg coupling, which is designed in such a way that there is a mechanical coupling option (e.g. for towing operations) with the previous model series via an adapter coupling.

In 1997 and 1998 there were significant problems with the vehicles. After strong vibrations, there were inadequacies in the ventilation, the door opening mechanism and the engine, which led to an acceptance stop. The press attributed this to ordering without testing prototypes.

Multi-system version 47 4.3

The 474.3 series was put into operation in 2006 and 2007. These two-system vehicles are made up of nine new vehicles and 33 conversions of existing vehicles of the second series. The vehicles are also equipped for catenary operation with 15 kV 16.7 Hz traction current . The intermediate cars have a pantograph for the overhead line as well as all the high-voltage equipment. They also have four-quadrant controllers that generate the direct current required for driving from the down-transformed alternating current of the contact wire. This means that the braking energy can also be fed back into the traction power network. The 15 kV pantograph in the 474.3 series is referred to exclusively as a pantograph to distinguish it from the side pantographs for direct current operation .

As planned, the class 474.3 multiple units have been in use since December 2007 as S3 from Pinneberg via the City Tunnel and the Niederelbebahn to the Stade S-Bahn terminus . Here they have replaced the regional trains previously operated with locomotives . From the former S-Bahn terminus Hamburg-Neugraben, power is supplied via the overhead line.

474 plus

This is the name under which S-Bahn Hamburg GmbH is modernizing all of the 474 series vehicles. The vehicles are fundamentally refurbished. Passages are created between the individual cars and new passenger information systems are installed. A multi-purpose area will be set up in the middle car and the door area will be provided with a new anti-trap safety edge and a light grille. The vehicles will also be repainted. Originally, the trains should also be equipped with air conditioning. The 4012 train was presented to the press as the first prototype for the conversions in July 2011 at the Ohlsdorf depot. The modernization of the remaining vehicles was initially expected to begin in 2012. However, due to technical difficulties (including an excessively high weight of the air conditioning system) the conversion prototype was not approved. Some trial components were then removed again.

The replacement of the seat cushions began in autumn 2009. These increase seating comfort and are intended to make vandalism more difficult.

The conversion in series would have cost a good million euros per train. The financing of this project, however, was not clarified. Talks were held here with the states of Hamburg, Lower Saxony and Schleswig-Holstein. In media reports from mid-2013 it was said that the beginning could be delayed until the first units of the DB class 490 are delivered. In fact, the series delivery of the modernized “474 Plus” began in February 2016, and a train is finished at the Neumünster repair shop around every six weeks .

The overall aim of the project is to improve the quality and thus increase the number of passengers.

For technical reasons and to avoid a new approval procedure, the installation of an air conditioning system was not included in the further planning. On Friday, January 9, 2015, the reconstruction prototype 4012, with the air conditioning removed, was presented as the first modernized series train that went into operation immediately. All remaining 111 trains will also be converted accordingly by 2021 for 70 million euros. The work will be carried out in accordance with the transport contract between Hamburg and DB Regio (parent company of S-Bahn Hamburg GmbH), which will apply from 2018.

Half of the planned conversions were carried out in May 2019, so that the modernization of the entire fleet will be completed by 2021.