Trains have been one of the most pivotal pieces of technology to ever be produced by mankind.
They have been in use for well over 200 years, and their prevalence as a form of transportation isn’t going to diminish any time soon. Of course, trains have evolved quite a bit over the years to accommodate new technologies, and modern trains scarcely resemble their ancient ancestors.
Bullet trains and magnetic trains of the future look like science fiction materials brought to life, and they will become much more common as their costs come down.
If you are a frequent train rider, you might have noticed that almost all tracks are supported by broken rocks similar to dense gravel.
Those rocks may seem like an insufficient foundation, but they actually provide the most support for the highest value. The rocks that form the foundation are called ballast, and they are responsible for keeping the track firmly in place.
Tracks are formed by first laying a single layer of ballast before laying the wooden ties and the track. A second layer of ballast fills in the gaps.
Once a few trains have driven over new tracks slowly to settle the ballast, the foundation is much more protective against tremors, heat and cold variation, and growing flora than any other type of foundation for the price.
You might expect a solid concrete foundation would function better, but the disconnected nature of the ballast allows it to absorb much more vibration without affecting the tracks.