| At first glance, the construction of a railroad track | | | | the ballast that fills the railroad bed helps water to |
| looks simple, like you could just throw down some | | | | run downhill, away from the tracks. The ballast |
| gravel, lay some railroad ties across it, and set | | | | itself also aids with drainage; it's a common use |
| the long metal tracks on top of that. But it's really | | | | for aggregates in many different situations. |
| a very complex work of engineering, scientifically | | | | Because small pieces of stone don't fit seamlessly |
| determined to be the best construction for safely | | | | together, water can drain through the stones, |
| supporting the tons of material and passengers | | | | away from the tracks, and into the ground or |
| that are transported by rail every year. One of | | | | other place designed for it. Railway ballast is |
| the most important ingredients in railway | | | | essential for making sure that tracks don't flood |
| construction is railroad ballast. | | | | during rain or other bad weather. |
| Ballast is the gravel that forms the foundation of | | | | 4. Resists vegetation growth. Long stretches of |
| the railroad track. It's made up of aggregates, or | | | | railroad tracks are built through areas that aren't |
| different kinds of rocks and stones crushed to a | | | | built up or settled. In such places, you can clear |
| precise size and density. After a century and a | | | | the land, but the land immediately starts to take |
| half of expermentation in railway track design, | | | | back what you've claimed. It first does this |
| engineers have established 5 major reasons why | | | | through the growth of small weeds, plants and |
| railroads use ballast. | | | | wild grass in the cleared areas. Railway ballast is |
| 1. Grounding. A railroad bed is deeper than it looks, | | | | packed tightly and deeply, and extends far |
| since if you're looking at it, you only see the top. | | | | enough out past the track itself that this |
| But it goes several inches deeper than that, and | | | | vegetation finds no place to plant itself, thus |
| the dug out bed is filled with ballast. The gravel as | | | | delaying the overgrowth of the tracks. |
| a whole unit acts to ground the entire structure | | | | 5. Facilitates maintenance. For all the reasons listed |
| solidly into the ground. This way, neither the | | | | above, track ballast helps keep railroad tracks |
| ballast nor the tracks have any leeway for | | | | strong and secure. Because the tracks resist so |
| movement. | | | | many of the potential difficulties, it makes it much |
| 2. Raising. During the railroad track construction, | | | | easier for railroad personnel to keep the tracks |
| track ballast is poured not only to fill up the hole | | | | maintained. |
| created to be the road bed, but higher than that, | | | | Without aggregate ballast, there would be no |
| so that the rails are actually lifted above ground | | | | railroads. There would just be no way to keep |
| level. This height will level out over several years, | | | | the tracks safe and secure under all the weight |
| but it helps with drainage, and it makes it so that | | | | they're expected to bear. It's hard to imagine the |
| the ballast doesn't wear away as quickly. | | | | history of our country without this versatile |
| 3. Drainage. As mentioned above, the hill made of | | | | resource! |
