The tamping unit, which is equipped with sensors, “senses” the condition of the ballast during the tamping process, i.e. the degree of ballast fouling.
Stereo cameras measure the distance from the machine to the measuring points when the machine is travelling along the track.
Plasser ReferencedTrackGeometry: In conjunction with the inertial measurement unit (IMU), the fixed-point measuring system determines the absolute track geometry with high accuracy.
We as developers are very pleased and proud to see that our latest technologies are enthusiastically received by others. This was also the case in autumn 2022, when our test vehicle, a fully electric Unimat 09-4x4/4S E³, was able to demonstrate its capabilities under field conditions in Sweden as part of Shift2Rail.
In the run-up, we were able to upgrade the machine’s measuring system. After the approval of our machine was finally extended to Sweden, this meant one thing: “Sweden, here we come!”
Sweden already set an example in terms of climate protection in 1991 by introducing a carbon tax. The country shows great interest in environmentally friendly drive systems; therefore, our electrically powered E³ machine was a major hit. Equally, the electrically powered tamping units emit far less noise, which was a pleasant surprise.
The deployment on eight selected line sections demonstrated to the participating companies the potential that modern sensor technology offers for the further development of maintenance strategies. The machine demonstrated what a complete end-to-end process looks like in practice – from pre-measuring to semi-automatic maintenance to post-measuring and creation of the acceptance report. The focus was on detecting the condition of the ballast and the fixed-point measuring system.
The “sensing” tamping tines detect the condition of the ballast more or less while tamping takes place (the operating principle is explained in more detail here). The data provided supplements and updates existing records and can be verified through trial excavations of the ballast.
The track geometry measuring system allows the track to be surveyed at much higher speeds than before using the tamping machine itself. The combination of the fixed-point measuring system and the inertial measurement unit (IMU) determines both the relative and absolute track geometry. This increased accuracy has an especially high impact on high-speed lines. We were able to present and discuss the results directly afterwards.
Apart from the technologies demonstrated, this project was also a highlight in other respects: the teamwork was exceptional. Preparation, machine transport, construction site logistics – everything went smoothly. Therefore, once again a big thank you to everyone who supported us: Trafikverket, Infranord, and TMC. This shows how important and effective collaboration between companies, authorities, and technology partners can be in order to develop and implement innovative solutions for the railway industry.
It's fun doing projects like this together – everyone sees how this technology can be used directly in the field and everyone enjoys it.
Bernhard Antony, Head of Technology Centre Purkersdorf, Plasser & Theurer
