Ballast clearing machine

Published on 16 April 2008

This is a self-propelled machine fitted with devices that lift the track and tools that remove the ballast.

Excavator of an mechanical undercutter (picture by ETF)

Undercutter-screener :

Self-propelled machine installed on bogies, first equipped with elements able to lift the track but also equipped with tools which, under the raised track, can take the poluted ballast off the roadbed and proceed to its screening, consign grading elements are reset in the track.

Nowdays, modern machines perform numerous functions and this is thanks to the different hydraulic developments that this material can perform:

- the gutting of the zone which is under the track with only one passage with a depth reaching 30cm and a breadth reaching 8ml.
- the clearing ballast from the track thanks to the add of new ballast.
- the ballast screening excavated thanks to sieves held horizontally by hydraulic jacks.
- the reset of the ballast which has been screened by hydraulic-controlled conveyor and deflector.
- the perfect leveling of the ballast course which has been screened by a trail groomer.
- the waste disposal or of all the gutting products thanks to a carpet placed at the front of the machine or thanks to a direct blast to the embankment, or even more by loading the wagons placed at the front of the machine.
- the compaction of the railhead after re-ballasting the track with new ballast.
- the sweeping of surplus ballast on the rails in order to throw it to the left or to the right of the track, depending on the situation of the track bench.

Measuring devices can provide all geometric datas concerning works which have been realized to the driving staff, including different measure systems and control of the gutting depth and of the batter given to the roadbed. These systems are electromechanical, with a laser beam or with automatic control on some machines equipped with a computer.

An electronic recorder permits the imediate control concerning the quality of work which has been done, it records the gutting depth, the batter of the roadbed and the value of the track subsidence after working on it.