Ballast fouling caused by day-to-day operation must be cleaned regularly. The technologically correct method is of crucial importance.

The technologies developed by Plasser & Theurer fulfil all key requirements: precise cut of the formation, sustainable cleaning quality, accurate re-placing of the clean ballast and exact positioning of the track.

Using a scraper chain, the ballast can be cleaned without dismantling the track. Then it is cleaned in a large vibrating screen with several screen layers. This helps to achieve optimum quality of the cleaned ballast. The ballast excavating chain also prepares the right foundation for the new ballast bed. The clean ballast is returned to the track directly behind the excavating chain. The waste is conveyed to the front of the machine and usually transferred to a spoil conveyor and transport system.

To meet different local requirements, ballast cleaning machines are individually specified, which is key for their cost-efficiency.

Expert tip

Only thorough cleaning over the whole ballast bed width will achieve the desired cleaning result. It is not enough to clean the ballast bed shoulders only.


The continuous-action removal of the track bed material and the required feed rate demand enormous tractive effort.

Machines have to meet the following requirements:

  • high advance rates for utilisation of short intervals between trains,
  • high cleaning quality,
  • re-use of the bulk of the ballast, a cost-intensive resource,
  • versatile use of the machine systems.

Plasser & Theurer cleaning machines meet all these requirements perfectly.

We build ballast cleaning machines in all sizes and output categories, with one, two or three screening units. We also offer additional solutions to enhance the machine functionality, e.g. for the supply of new ballast, additional cleaning of smudgy and viscous fouling or the integration of dynamic track stabilisation. Moreover, we offer systems for trackless ballast bed cleaning, for cleaning of turnouts and for selective cleaning.

A wide range of additional equipment can be used to enhance the functionality of basic machines and to adapt to the respective requirements.

Six decades of experience in ballast bed cleaning show:

  • Excavation of the entire ballast bed – if fouled humps of ballast remain at the ballast bed shoulder, drainage will be affected later on.
  • Ballast excavation with a straight cut to produce a formation with the correct lateral crossfall and a uniform course in longitudinal direction of the track.
  • Full depth ballast excavation under the sleepers – highest fouling level is in the lowermost area.
  • Partial cleaning (for example shoulder cleaning) normally has little success – a large proportion of the ballast attrition occurs in the area underneath the sleepers.
  • Cleaning in vibrating screen units specifically developed for track ballast – ensures that only few fines remain and as much reusable ballast as possible is retrieved.
  • Conveying of segregated spoil to the front – the cleaned track is not fouled by material falling down.
  • Uniform reballasting with precise adjustment of track level – the track is best prepared for tamping after cleaning.

We recognised the need for ballast bed cleaning machines early on – following first trials in the late 1950s, our first fully hydraulic ballast cleaning machine, the RM 61, went into operation in 1963.