Similar to pebbles, but larger, angular, sharp-edged and cubically broken, “ballasts” are especially preferred by engineers on railways due to the advantages of both their shape and size.
Although these stones, which are made of basalt, granite, syenite, porphyry or hard limestone, do not seem to have such an important task, they actually have tasks that make train journeys safer.
With this machine you see, new stones are poured and compacted at regular intervals.
Ballasts; It prevents direct contact of the rails with the soil and prevents decay that may occur due to mud and frost. They prevent the train load from passing into soft soil, so that the ground does not collapse and there are no slopes on the tracks. The frequency of stones is higher on high-speed train lines.
There are various layers under the rails and the ballasts support these layers.
The integrity of the line actually starts from the base. Thanks to its downward slope, the possibility of water collection on the rails is reduced, and the drainage of the water becomes easier. Otherwise the rails would rust, the soil would loosen and the boards would rot. Sometimes an elastic mat is also placed in the lower ballast layer and under the ballast.
Thanks to these stones, no plants can grow on the rails.
Otherwise, the roots of the plants will slowly move the rails as they grow, which can even cause the train to derail. In addition, since there is vibration on the rails, it is difficult to grow plants in this area. In order to guarantee the work, spraying is also done from time to time for this reason.
If the railway passes through wetlands, plants that absorb water, such as eucalyptus, are planted on the edges, thus preventing the rails from deteriorating due to water. In fact, there was a train accident in our country in the past years due to the destruction caused by water. Unfortunately, many people lost their lives due to this “negligence”.
Pointed and angular stones also ensure that the rails and connections remain narrow and straight.
If they were smooth and slippery like the stones on the beaches, they would slide over each other due to the vibrations of the trains. Stones that hold together with their rough edges can stay where they are. This ensures that the rails remain intact – with the help of, of course, large nails, metal clips and boards.
Sources: Science ABC, Wikipedia, Dergipark, insapedia