Ever Wondered What The Stones Alongside Railway Tracks Are For?

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If you have ever walked along railway tracks you will have noticed the tracks lie among rocks.

There is a reason for everything. You might wonder why things are done or built a certain way for as long as you can remember but you just don’t know why. There are many advances in technology and engineering which have changed certain structures. But if something has proven to be the best option and solution, no engineer is going to argue to change it. Trains for example have evolved from the steam locomotive to the futuristic high-speed machines we know today. Yet the train tracks used presently have not changed much in the last 200 years. The United States certainly knows what it is doing when it comes to rail transportation. The British magazine, The Economist, recognizes this country’s industry as, “the best in the world.” Hence, why change is a good thing.These broken stones are called ballast or track ballast. The rocks help to keep the tracks securely in place.

Jacob Z

It's not an easy task keeping the tracks in place either. Tracks can change from heat expansion, ground movement, and vibrations.

Precipitation and changing weather can also impact the structure.


The ballast protects the tracks from all the mentioned elements.

The thick bed of stones also prevents weed, plants, and other vegetation from growing under the tracks.


Tracks have to support trains weighing hundreds of thousands of pounds all at once.

Engineers two centuries ago realized they needed to build a steady foundation.


First the ballast are laid, followed by the laying of wooden beams, with more rocks are poured over.

This ballast seals the tracks in place by not allowing them to slide everywhere. Finally the steel rails are laid, anchored to sleepers to hold them down.


The ballast also prevent the rails from getting flooded and moved by the water.

It may seem that the tracks have a lot of loose rocks. In reality the rocks are tightly packed when laid.

Weeds may be abundant in the area but they have no chance to grow on the actual tracks.

The rocks are purposely crushed to be jagged and irregular in shape. They work as an interlocking mechanism.

Ian Sane

Ballast do begin to get crushed over a period of time.

New ballast are then dumped on the tracks with a ballast tamping machine. Trains have to pass slowly for a period of time until the rocks settle in place.

Andi Campbell-Jones

The word "ballast" has ties to the sea.

It is a nautical term applied to the stones used to stabilize ships.