Why Are There Stones Along Railway Tracks?

The crushed stones that line railroad tracks are collectively called track ballast. More specifically, the track ballast constitutes the trackbed upon which sleepers or railroad ties are laid. As you may have seen, these stones are packed below, between and around the railroad ties. The thickness of the track ballast usually ranges between 25-30 cm, and varies depending on certain conditions pertaining to the geographical location of the railway track.

Track ballast usually consists of crushed rocks or stone, but in some cases, less suitable alternatives, like burnt clay, are also used. However, it’s important to understand that you can’t just throw a bunch of rocks on a railroad and be done with it. As mentioned, the stones in the track ballast have a characteristic shape, size and texture. Their surface is not smooth and their edges are jagged, and for good reason. These rocks interlock with each other and therefore stay in place. If you replace them with circular or smooth rocks, they would slide over each other and compromise the strength of the track ballast. As you might imagine, this can have catastrophic results.

#science #animation #trackballast #track #ballast

Intro - 0:00
What is track ballast? - 0:37
7 reasons behind why there are stones on railway tracks - 2:03
Maintenance of track ballast - 4:47

References

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[Scienceabc]

Hello, everyone! We are aware of the mistake of using the word "dampening" instead of "damping." Unfortunately, YouTube does not allow you to make corrections, so please bear with us.

[renakunisaki]

Can't believe the amount of genius engineering that went into a pile of rocks.

[timfagan]

I used to work in a quarry, making track ballast.
The rocks we were getting out of the ground was called blue stone. It's very hard. There was a lot of science that went into making it, we was only allowed to have 4 broken faces on the rocks, so they locked into each other. But the faces of the rocks were only allowed to have 3% chipping damage. Else it made the rocks weak and they wouldn't do their job properly. And when your stacking it off the end of a conveyer belt, then it goes into the loader bucket then into the truck, it's very hard to keep this 3%. But we managed to do it. Also, little fact seen as alot of people don't know this, rocks can die. They become useless and have zero strength in them. It's called Saprolite. And is caused by the elements decomposing the rock, and they lose mineral structural strength. You can pretty much crush it into a gritty powder in your hand!
Also just to kind of give you an idea, how how well that stuff locks together,
Sand has an angel of repose of 32⁰ in a conical shape, when falling off a conveyer belt from height, before it collapses on its self and starts making a cone again.
And 35⁰ when wet.
Railway Ballast has an angle of repose, in a conical cone. Of 38.7⁰ from its weight alone, so it shows how well that stuff locks together, and is used for railway tracks!
Incredible science!

[XverXDriveX]

It's incredible how many things we take for granted. When you stop and think about pretty much anything, everything is pretty complexe, in reality. It just blows my mind. Fascinating video.

[michaelvd]

As a train driver myself, I love seeing so many people in the comments that are interested to learn more about how these things work. Thank you for creating this informative video, it's very useful for educational purposes!

[johnarmstrong]

I have an 80+ year old friend that once told me about how his father used to make a living constantly replacing railroad rocks for the railways. Apparently it was a big industry in certain backwoods areas. When they came up with this new rock, it completely ended the need and they all had to find new jobs.

[vishnumarichi]

1. 2:21 Holds the sleepers in place.
2. 2:34 Load distribution
3. 2:52 Vibration Damping
4. 3:14 Drainage
5. 3:37 Prevents vegetation on the tracks
6. 4:02 Noise Absorption
7. 4:24 Minimizes Thermal Expansion

[Randy.E.R]

This is one of those things I never thought to ask, but am glad I learned the answer.

I was born and raised in a railroad town in the beautiful Southern California desert. The town of 3000 people existed because of the railroad, NOT the two highways as so many people believe. There was a time in the early 1900s when the town had a few hundred people, four saloons, and some hotels across the street from the railroad. I have pictures from that era. Imagine the stories that could be told from those days.

Growing up there in the 1970s and 1980s I can remember the Southern Pacific and Santa Fe railroads screaming through town. It never got old. When we were kids we would wait for the caboose to pass by and holler for water. The would often toss cartons of ice cold water out the window to us. Most would bust when they hit the ground, but a few would survive. I wish I had saved one.

When I moved away in the 1990s, I moved to a town with no trains. It was hard to sleep at night without the sound of trains. Its unbelievable that the sound of trains were what put me to sleep at night. Especially the whistling of the turbochargers on an idling engine. There was something soothing about it.

What does my comment have to do with rail ballast? Nothing; I am getting old and love to tell stories 😹

[SB-qmwg]

Another reason is sparks... the steel rusts and the train's rims kick sparks off the lines creating fires. The rocks stop vegetation. I've seen several rail line fires in dry months

[DataSmithy]

One benefit that you may have missed: due to the good drainage a railroad beds they act as floating foundations, preventing heaving during freezing weather. This is sort of the same feature as your benefit number 4, good drainage, but applies during freezing weather.

[itsbusyish]

As a former conductor I can say the sole purpose of these rocks is to be piled at an angle to allow the rail workers to roll their ankle every 10 feet.

[timeforbeans]

I found this video completely fascinating, and humbling to me personally. Thank you
As a 20 year USA railroad worker myself, you hit the Spike on the head.
I have always hated ballast! BLAH...it is so big and jagged, tears up my boots.
I hate ballast every year I have to buy new boots because of the ballast.
But what you said in your video is all true.
And I love it!
🤩

[mildredpierce]

It’s fascinating how complex trains and the railroad systems are yet someone came up with all this stuff. Brilliant.

[wlockuz]

I pass by these kind of stone on a rail track at least once a day and never have I stopped to think what thoughts went behind them. What really amazes me is how simple of a solution this is to multiple problems thats are completely of different nature.

[tainadelcaribe]

The things we take for granted, like some rocks! Love learning how things work and the reasoning behind designs. Awesome, clear, concise video!

[reckszkingzactivitiesrkat.]

I love content like this because you learn so much about different things around you that you overlook everyday 👏🏾.

[mec]

This video has given me a ballast perspective. Thanks.

[kevinblatter]

I live near a Diabase gravel quarry and they explained to me once what makes good railroad ballast. Your video goes considerably more into detail. Thank you.

[BlackKnightsCommander]

I always knew about the vegetation, vibration and drainage benefits but I never thought about the others. This was very informative

[Justin]

I gave this a thumbs up for making a video that could have been stretched to 10 minutes, but wasn't and presented all the information clearly. Thank you and very cool to learn about!