Stabili­sation

The dynamic stabilisation of the track is an essential factor in track maintenance.

Dynamic stabilisation of the track is a successful method developed by Plasser & Theurer for optimum track maintenance.

There is scarcely another method in the track laying and track maintenance sector that has been investigated by railways and research institutes as intensively as dynamic track stabilisation. The findings from these wide-ranging tests have contributed towards further optimisation of the technique. Today the dynamic track stabiliser is an established feature in the machine fleets of railways and contracting firms all over the world.

Stabilisation unit
Stabilisation unit
© Plasser&Theurer

The aim:

The aim of dynamic track stabilisation is to achieve improved anchoring of the track skeleton in the ballast bed. After dynamic stabilisation, the condition of the track offers greater operating safety and enables travel at the maximum line speed, particularly on newly laid track or after full track maintenance.

As a result, speed restrictions can be avoided and stoppages completely reduced. In addition, due to the dynamic track stabilisation, the geometrically correct position of the track is available for a longer period of time, the quality reserve of the track rises. The systematic use of this procedure during renovation, new track laying ballast bed cleaning, and track maintenance gives savings in the operating area and a favourable cost/benefit calculation of the complete track maintenance.

The principle:

The dynamic track stabiliser sets the track in horizontal oscillations whilst applying a static vertical load at the same time. This causes the ballast stones to re-arrange their position, with the result that the track is lowered and "rubbed" into the ballast bed.

Schematic representation of the stabilisation unit
Schematic representation of the stabilisation unit
© Plasser&Theurer

Mode of operation:

When maintenance is performed using a tamping machine, the track is levelled, lifted, lined and tamped. The tamping machine consolidates the ballast underneath the sleepers in the area of the tamping zones.

The subsequent dynamic stabilisation produces a homogeneous ballast structure. The vibration in the ballast in conjunction with the static load causes the pieces of ballast to be pushed closer together. A force-free reorganisation of the pieces of ballast is the result. The number of cavities is reduced, the ballast stones show, instead of single points of contact, a larger number of contact surfaces and edges. Also, between sleepers and ballast stones the number of contact surfaces increases significantly.

This homogenisation of the ballast bed raises the durability of the track maintenance. The overall larger frictional surface between sleepers and ballast produces a larger resistance to lateral displacement both for the loaded, as well as for the unloaded track. In contrast to other conventional methods of ballast treatment there is a spatial consolidation with a completely altered ballast structure. A new bearing support is produced for the sleeper, while retaining or even improving the perfect track geometry, wider areas of the ballast bed take over the transmission of the forces. The resistance to longitudinal displacement is raised too.

During the work, the dynamic lateral displacement resistance can be measured and recorded without requiring an additional work step. The same applies to all other essential parameters for the track geometry.

The advantages:

  • Homogeneous, spatial consolidation of the entire ballast bed.
  • Increase of the resistance to lateral displacement.
  • Protection of the ballast material before rubbing by the dynamic settlement of the Ballast stones.
  • Reduction of the danger of track buckling.
  • Durability of accurate track geometry over a longer period, raising the quality reserve of the track.
  • Extension of the maintenance intervals.
  • Great savings in the sectors track maintenance and operational hindrance costs when the technique is applied regularly.
  • Dynamic stabilisation raises the safety and helps to lower costs.

Stabiliser DGS 62N 1
Stabiliser DGS 62N 1
© Plasser&Theurer
  • Dynamic track stabiliser in standard railway vehicle design.
  • Two stabilisation units, arranged between the two bogies.
  • Four-track rollers and two pressure rollers per unit acting as clamps.
  • Synchronous-action out of balance oscillator to produce the horizontal oscillation directed crosswise to the track axis (0-42 Hz).
  • Hydraulic cylinders to apply the vertical load (max. 356 kN).
  • Proportional levelling system for an automatic tailor-made settlement.
  • Two noise insulated cabs each with a driver's control desk.
  • In one of the two cabs the operating and control elements for use when working are clearly arranged.
  • Between the two cabs the side of the machine can be covered if required.
  • With additional measuring trailers, as well as a multi-channel recorder, it is possible to record up to six track parameters (option).

Stabiliser DGS61N 10
Stabiliser DGS61N 10
© Plasser&Theurer
  • Dynamic track stabiliser with one stabilising unit positioned between the bogies.
  • Four track rollers and two pressing rollers acting as a clamp for clamping the track skeleton.
  • Vibration frequency variable from 0 - 42 Hz, max. load 178 kN.
  • Cabs with driver's desks, one with controls DGS 61 N.

Stabiliser AFM 2000
Stabiliser AFM 2000
© Plasser&Theurer

Stabiliser KSP 2002
Stabiliser KSP 2002
© Plasser&Theurer

Stabiliser KSP 2002
Stabiliser KSP 2002
© Plasser&Theurer

Stabiliser VDM1000
Stabiliser VDM1000
© Plasser&Theurer

Stabiliser PVT800
Stabiliser PVT800
© Plasser&Theurer

You can find suitable specialist literature to the topic here:

The Basic Principles of Mechanised Track Maintenance

The Basic Principles of Mechanised Track Maintenance

This book is dedicated to the many people involved in the day to day planning and performance of track maintenance activities. Providing a practical approach to everyday challenges in mechanised track maintenance, it is not just intended as a theoretical approach to the track system. 
Railways aim at transporting people and freight safely, rapidly, regularly, comfortably and on time from one place to another. This book is directed to track infrastructure departments contributing to the above objective by ensuring the track infrastructure’s reliability, availability, maintainability and safety – denoted by the acronym RAMS. Regular, effective and affordable track maintenance enable RAMS to be achieved.