If you notice, you will see the railroad tracks covered with a layer of rock below. Have you ever wondered why?
Railways are a basic element in railway transport, helping to guide trains to run without much concern for steering as other means of transport.
A rail line consists of two lines running parallel to each other placed on horizontal bars called sleepers.
The sleepers have a role to fix the rails, while at the same time transmitting pressure from the rail to the ground below. Sleepers are put on a layer of rubble. Why?
The rails are being maintained, adding stones - (Photo: Cooma Monaro Railway).
When a train passes, the railroad will be under great pressure because trains can have a total mass of tens of thousands of tons.
Therefore, in order to ensure that the pressure is evenly transmitted downwards while keeping the track stable under the load of the running vessel, a ballast layer is required to further support the sleepers.
In addition, this layer of stone is spread underneath and around the sleepers, creating a frictional force, contributing to fixing sleepers when there is a train passing.
Without this layer of rock, the railroad track is ground, when the train has a large volume running through, it is very likely that the track is deformed or subsided, threatening to flip the ship.
This rubble also helps to drain water. When rain, rainwater will easily flow through the gap between the stones escaping, limit the amount of water remaining on the tracks and contribute to protecting the soil below.
Rubble also helps to limit plant growth around the tracks - which makes the soil under the tracks become weaker .
However, in many places, people still do not know the role of this layer of stone, many have brought stones to use for the family's own activities.
The rails are called slabs (English: ballast) , derived from the fact that they are used to crush sailboats.
In most countries around the world, these layers of stone are regularly maintained.
The thickness of the stone layers depends on the size of the sleepers and the distance between the sleepers, as well as the number of trains running on the tracks.
Usually the thickness of a three-layer stone layer is not less than 150mm, while high-speed tracks may even need up to 500mm of rock.
An insufficient amount of ice can overload the underlying soil layer, causing the track to bend or sink to the ground. The stone layer below 300mm can cause potential vibrations to damage the nearby houses or buildings.
Because the three-layer stone plays a very important role in operating the railway system, in most countries around the world, these layers of stone are regularly maintained.
In many cases, they can be renewed or renewed using a variety of methods such as using limbs, specialized machines or through biotechnology.