Understanding the Types of Rocks Used on Railroad Tracks

Have you ever wondered what type of rocks are present on railroad tracks? These stones play a crucial role in the stability and smooth operation of trains. Let's explore the different types of rocks used, the reasons behind their selection, and the process that ensures their effectiveness.

What Are Ballast Stones and Their Functionality?

Ballast stones are specially selected rocks that form the bed on which railroad tracks are laid. These rocks serve as a foundation, helping the tracks remain stable and level under the immense weight and force exerted by trains. As trains vibrate the ground, the ballast stones interlock with each other, providing a strong and stable base.

What Are the Common Types of Ballast Stones?

Over the years, I have witnessed a variety of ballast stones being used in different regions based on availability and suitability. While some areas use crushed slag near steel mills, others simply use the rock available from nearby quarries. Sometimes, the most accessible and cost-effective material is utilized.

Granite in Florida

In Florida, the ballast stones used on railroad tracks are predominantly granite. Interestingly, Florida does not possess a bedrock, necessitating the import of these stones from other areas. The granite is chosen for its hardness and durability, ensuring that the railroad tracks can withstand the heavy loads and frequent vibrations of passing trains.

Selection Criteria for Ballast Stones

Ballast stones are carefully selected based on specific criteria to ensure their suitability for supporting railroad tracks. These stones are usually hard and angular, capable of withstanding the immense weight and providing a long-lasting foundation.

Common Types of Hard Stones Used as Ballast

Granite: This is one of the most common types of ballast stones due to its hardness and stability. Basalt: Another igneous rock that is exceptionally hard and can be used as an alternative to granite. Metamorphic Rocks: In rare cases, metamorphic rocks such as quartz and marble have been used, though these are less common due to their less durable nature.

Other Types of Rocks and Temporary Solutions

While granite and basalt are the preferred choice for their hardness and durability, there are instances where other types of rocks are used. When very hard rocks are not available, other materials are used on a temporary basis until more suitable rocks can be brought in. These temporary solutions include sands, gravels, and even crushed concrete.

Conclusion

The stones used on railroad tracks, known as ballast, are chosen based on their ability to provide a strong, stable foundation. Whether it's granite, basalt, or another type of rock, these materials are crucial in ensuring the safety and efficiency of train operations. Understanding the types of rocks used on railroad tracks and their selection criteria can help us appreciate the engineering and science behind modern transportation infrastructure.