You may have already seen one of them: every day, Infrabel engineering trains travel all over the country. Their mission? To maintain the tracks and to ensure that rail traffic can travel in complete safety. One of these devices is the switch tamper – a machine that literally puts trains back on the right track.
Measuring the gradient ratio
Normally, the tracks are level and don’t show too much unevenness. The switch tamper is used to measure the gradient ratio of the tracks.
If the measurement shows that the tracks aren’t completely level – even if the difference is just three millimetres – the switch tamper puts them back into the correct position.
Ballast compactor
First, the tracks are lifted or their direction is changed so that the switch tamper’s compactor can quickly compact the ballast under the sleeper.
This ensures that the track remains in its new position, and that the values fall back within the permitted limits or tolerances. The track is once again declared completely operable.
(Source: Infrabel)