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Multiple traction control system, intelligent drive and tamping in Y-steel sleepers

Maintaining lines with so-called Y-steel sleepers is a particular challenge. Meeting it takes tamping machines that can deal with alternating rail fastening positions. The UNIMAT 09-4x4/4S Y-DYNAMIC can – and it offers much more.

UNIMAT 09-4x4/4S Y-DYNAMIC „Bernhard“

In the spring of 2018, DB Bahnbau, responsible for infrastructure maintenance in the Deutsche Bahn AG group, put a new universal tamping machine from Plasser & Theurer into operation. As the name UNIMAT 09-4x4/4S Y-DYNAMIC shows, the machine can be operated in continuous working action on lines with Y-steel sleepers. Called “Bernhard” by DB Bahnbau, the new Unimat is a highly universal machine. It is the first machine to combine the Y-sleeper tamping feature with continuous working action and a new dynamic track stabiliser. Despite the additional features, the axle load of the Unimat does not exceed 20 t, ensuring its suitability for line category C2. And where there is “Bernhard”, “Bianca” is close: The tamping machine and the ballast regulating machine form a strong team. 

USP 2000 C2 “Bianca”

The new USP 2000 C2 universal ballast regulating machine works independently, quickly and carefully behind the tamping machine. Moreover, “Bianca” is part of a special duo: During transfer travel, the two machines are controlled from the driver's control desk in the front machine – using an additional function in the P-IC control. The machines are also fitted with a new on-board unit providing access to the electronic drivers’ timetable sheet of Deutsche Bahn AG, called “EBuLa”. If a timetable of the infrastructure manager is available, the machine can be operated independently in the railway network. Equipped with a GSM-R receiver and the EBuLa on-board unit, track maintenance machines can access the same data as locomotives and other trains. This is a major advantage as modern machines, such as “Bernhard & Bianca”, mostly travel under own power.

Tamping alternating Y-sleepers

The Unimat 09-4x4/4S Y-DYNAMIC is a specialist for maintaining turnouts and tracks with Y-steel sleepers. This type of track is characterised by curved sleepers, forming an alternating Y. The rail fastenings are placed at regular intervals, but not in a parallel position. To maintain such tracks, the four tamping tine pairs can be displaced longitudinally. Travelling and working on track sections with conventional sleepers is possible at any time. Fitted with the SmartALC, the machine uses the DRP to document its work in a measuring graph which can be sent online immediately. 

Veritably variable: the track stabiliser

The dynamic track stabiliser installed in the rear part of the machine is another further development: The impact force acting horizontally on the track is variable. This makes it possible to control track settling more accurately and improves the homogeneous, durable track geometry quality following tamping. This is a particular benefit before and after fixed structures and during the frequent stop-and-go on the work site. In densely built-up areas, the lower impact force reduces the propagation of the vibrations beyond the track area. 

Intelligent drive for eco-friendly operation

Bernhard’s special feature for transfer travel under own power: PlasserMotionDrive. The intelligent drive system uses drive blending to provide the power needed. The machine starts with hydrostatic support. As the speed increases, the hydrodynamic drive takes over, showing its advantages. This improves acceleration and saves fuel. On lines with steep gradient, the second driving bogie is activated. New hollow shaft axles at the wheelsets facilitate regular inspection during machine maintenance.

Operated across Germany

DB Bahnbau Gruppe GmbH was presented with the machines in Königsborn, Germany. Operated all across Germany, the machines are primarily used in the north and east of the country. Eight machine operators and eight service technicians were trained at Plasser & Theurer in Linz, to ensure that “Bernhard” and “Bianca” form an efficient team at all times.