Baureihe (Class) 612 ("RegioSwinger") is Deutsche Bahn's flagship diesel motor unit (DMU). It was built by ADtranz and uses tilting train technology which makes it a godsend for non-electrified auxiliary lines with steep grades, lots of curves and low to medium traffic. In fact it has tightened the timetable immensely on many lines where it is in service.
612's downside is its questionable reliability -- the active tilting system caused problems for years on end, which is especially annoying because without tilting, a delay of about 20 minutes is the consequence on a typical connection. By now, however, DB seem to have mastered their problems with this high-tech beast.
I often ride 612s (on the Nahe line which connects Saarbrücken with Frankfurt/Main) and I've come to like them quite a bit. They're beautiful, comfortable, air-conditioned vehicles like most new MUs, but what makes riding them a real thrill (especially through beautiful landscapes) is the feeling of speed they give you when making tight curves at full tilt, diesels roaring. It's fun overtaking cars with a 612 :)
Technical fact sheet:
- Concept: 2'B'+B'2' (two-part articulated diesel motor unit, two two-axled bogies and one diesel engine per half-train, the engine driving the inner bogie by means of a fluid transmission); up to four units can be MU'd together; active tilting for better performance in curves
- Power: 1,118 kW (two 12-cylinder Cummins diesels of 559 kW each)
- Top speed: 160 km/h
- Total weight: 104 tonnes (13 tonnes per axle)
- Length: 51.75 m
- Width: 2.85 m
- Height: 4.20 m
- Reach: ca. 1,500 km (on 2,600 litres of diesel fuel)
- Tilting: "neicontrol-e" active tilting technology; maximum tilt is 8°
- Seats: 23 first class, 112 second class, 13 folding seats (which makes for a maximum capacity of 592 passengers in a four-unit consist)