Every year, companies that own railroad track spend millions maintaining ballast, the crushed rock underneath railroad ties and steel rails. New research may help to extend the useful life of ballast, with the aim ofsaving time, money and the need to quarry new rock.
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Research could boost durability and cut the costs of railroad tracks across U.S. From the University of Kansas, this is Research Matters. I’m Brendan Lynch.
Every year, companies that own railroad track spend millions maintaining ballast, the crushed rock underneath railroad ties and steel rails. Now, KU research may help to extend the useful life of ballast, with the aim of saving time, money and the need to quarry new rock.
Bob Parsons: Ballast helps to redistribute the load from the trains. Ballast is composed of large rock, but over time it gets contaminated from finer particles from rock dust, natural dust and coal dust from coal trains. And you have the soils from underneath coming up. So the fine particles fit between the larger stones of the ballast and contaminate it.
Bob Parsons, professor of civil, environmental and architectural engineering at KU is studying the promise of making ballast more durable using “geogrid,” a type of platic netting typically employed in reinforcement of soil.
Parsons: It’s a netting made of triangles, the ballast is placed on top of the geogrid. It will help with the rock breaking down, and help lock the ballast into place and keep it from moving. By providing a framework, and making it more rigid and fixed and stronger in general, it prevents the ballast from breaking down into smaller particles.
With nearly 150,000 miles of freight railroad track crisscrossing the U.S., improvements to the resilience of ballast could result in huge cost savings by avoiding a laborious process called “undercutting.”
Parsons: Undercutting is a significant maintenance action where a railroad will lift up the track and a chainsaw-like device will saw out the upper layer of ballast. That ballast is run thorough a sieve where the fines are taken out, so you have just the larger pieces left, and that’s recycled and put back on the track.
For more on railroad ballast, log on to Research Matters dot KU dot EDU. For the University of Kansas, I’m Brendan Lynch.
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Research could boost durability, cut cost of railroad tracks across U.S.