Baureihe (Class) 420 ("Olympia EMU") was conceived as a mass-transit EMU to serve on Munich's new S-Bahn system (introduced with the 1972 Olympic Games, thus the name). The amazing number of 480 units were built from 1969 through 1997, and, though successors exist, the 420 still is the backbone of Deutsche Bahn's (to be correct: DB Regio's) S-Bahn services at Frankfurt/Main, Munich and Stuttgart.
Its concept was revolutionary at its time: weight-saving aluminium superstructure; all axles driven (and thus dynamically brakable!); thyristor-controlled motors; automatic bumper coupling for MUing units together; many doors for quick passenger exchange -- all this made for an incredible success story.
Technical fact sheet:
- Concept: Bo'Bo'+Bo'Bo'+Bo'Bo' layout (three-car articulated EMU, two two-axle bogies per car, all axles driven); up to three units can be MUed together (one unit = "short train"; two units = "full train"; three units = "long train")
- Power: 2,400 kW sustained at 72 km/h
- Traction: 180 kN maximum
- Top speed: 120 km/h
- Total weight: 138 tonnes or 129 tonnes, depending on date built
- Length: 67.4 m
- Distance between axles in bogie: 2.5 m
- Distance between bogies (end cars): 16.5 m
- Distance between bogies (middle car): 14 m
- Diameter of driven wheels: 85 cm
- Seats: 192 second-class (Munich); 184 second-class (Munich AirPortLine); 175 second-class + 17 first-class (Frankfurt, Stuttgart)
- Doors: 12 per side