DR Class 250

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Baureihe 155
Technical data
Class number	155
Put into service	1974
Retired	In active service
Number built	273
Manufacturers	LEW Henningsdorf
Wheel arrangement	Co'Co'
Maximum speed	75 mph / 120 km/h
Gauge	1435 mm
Length from buffer to buffer	19,600 mm
Service weight	123.0 tons
Number of motors	6
Power at rail	5,400 kW
Tractive effort	480 kN
Safety systems	Sifa / PZB / LZB
Brakes	Knorr airbrake, electric brake

The DB AG Class 155 (before 1992 DR Class 250) is a German electric locomotive used on freight trains. Nicknamed "Electric Container" or "Powercontainer" it was the most powerful locomotive in the former GDR and with about 200 units today still remained indispensable for Railion Deutschland, the railway cargo carrier of Deutsche Bahn.

[edit] History

In the middle of the 1960s it became apparent, that the engine classes 211 and 242, which began to be built in 1961, were not powerful enough. So DR decided to build a new 6-axled electric locomotive suitable for all classes of traffic. In 1974 3 prototypes wer built by LEW Henningsdorf, the leading builder of railway locomotives in the GDR. A series of 270 locos were delivered between 1977 and 1984. Their main application was for heavy cargo trains and the fast "Städteexpress"-trains (comparable with InterCity).

After the reunification of Germany railway traffic in East Germany slumped. The locos were renumbered as class 155 and many of them were operated in West Germany. After DBAG was restructured the class were assigned to DB Cargo (now Railion) for freight services. The 155s can be seen throughout Germany heading all kinds of freight trains. Since 1998 some locomotives have been cannibalised.

[edit] Construction

The locos have two 3-axled bogies. Each axle is powered by an one-phase series-wound AC motor. The torque is tranfserred by a double-sided spur gear to the wheels. Two scissor shaped pantographs collect the current of 15 kV / 16.67 Hz from the catenary. Recently many of these pick-ups have been by modern single-arm pantographs during refit.

The core of the electric system is the 3-blade main transformer with oil-cooling. The control unit has 30 power notches, semi-automatic in opeartion. The settings are thyristor controlled, which was a novelty for series locomotives in the GDR. All units are equipped with an catenary-current-controlled electric brake. The safety equipment in the driver's cab has an electronic deadman's brake (Sifa), "punctiform" automatic train controls (complying with with the new regulations (software version PZB 90)), and train radio equipment with GSM-R communication. Relatively recently computers were added for the electronic timetable EBuLa.

Some of the later models have been equipped with LZB System. These can be used to haul heavy and fast container cargo trains on the German high-speed network.