Bombardier RegioSwinger
| Company type | Train model |
|---|---|
| Industry | Rail transport |
| Predecessor | DB Class 611 |
| Founded | 1998 |
| Headquarters | Germany |
| Products | Diesel multiple unit trains |
| Parent | Adtranz, Bombardier Transportation |
The RegioSwinger represents a tilting train diesel multiple unit (DMU) engineered specifically for rapid regional transport on routes lacking electrification.
Development and service
Originally produced by Adtranz in Hennigsdorf and subsequently by Bombardier Transportation, the RegioSwinger is operated in Germany by Deutsche Bahn under the designation class 612.
In 2004, Croatia introduced eight units known as HŽ 7123 or InterCity Nagibni (ICN), primarily servicing the mountainous Zagreb–Split corridor to shorten travel duration and enhance passenger experience. These trains, colloquially called nagibni (swinger), are also assigned to other Croatian lines depending on demand. Nonetheless, safety issues emerged after a fatal derailment near Rudine in 2009 and a collision in 2006, resulting in the withdrawal of two units and potential reductions in service due to a constrained fleet.
The class 612 was developed as a replacement for the troublesome DB Class 611, incorporating an improved electric tilting system known as Neicontrol-E. Introduced from 1998 onward, early operational challenges included wheelset fractures discovered in 2004, which necessitated disabling the tilting function temporarily and reducing speeds, causing timetable disruptions. Starting in 2005, molybdenum-reinforced axles were fitted, allowing tilting capabilities to be reinstated. Currently, class 612 remains integral to DB’s high-speed regional operations on non-electrified tracks.
After axle failures grounded the ICE TD class 605 fleet in 2003, class 612 units took over the Dresden–Munich service to preserve travel times. Sixteen of these were repainted in ICE colors as class 612.4; however, tilting was again deactivated following recurrence of similar technical faults.
Technical information
Both passenger and driver areas feature full air conditioning. Each class 612 trainset comprises two powered coaches equipped with Cummins QSK-19 diesel engines, with power transmitted via hydraulic drive systems. Up to four trainsets can be linked using the Scharfenberg coupler, while onboard computer systems automatically handle trainset configurations.
The braking arrangement includes pneumatic brakes, hydraulic braking mechanisms, and an electro-magnetic eddy current brake. The maximum permissible tilt angle is 8°.
Accidents
On July 24, 2009, a Class 612 unit derailed near Rudine on Croatia’s Zagreb-Split line, causing six fatalities and injuring 55 of the 119 passengers aboard. The derailment was attributed to slippery conditions caused by improperly applied fire retardant on a steep downhill segment, which impaired braking efficiency and led to excessive speeds beyond safe limits.
This track section had undergone reconstruction in 2005, and the train had passed inspection just two days prior to the accident. The event renewed discussions about whether these trains are appropriate for local operating environments. Investigations highlighted the recent application of a new "aqueous based resin liquid penetrate" TG-300 fire retardant as a probable factor.
Comfort
- Travelers have reported that seating on Class 612 trains is uncomfortably firm for extended journeys.
- In Germany, these trains carry the nickname Wackel-Dackel (wobbling Dachshund) owing to their characteristic motion.
- The tilting system may induce motion sickness among certain passengers.