One Of The Most Demanding Applications For Aggregate: Railroad Ballast


Over 200,000 miles of railroad track cover the United States. Today’s trains can exert a force of 100 psi (pounds per square inch) when passing over track – and those tracks must be able to withstand that constant force. That is where railroad ballast comes into play.Railroad ballast is one of the most demanding applications for aggregate, or crushed stone.

What is railroad ballast?

Railroad Ballast, otherwise known as railway or railroad ballast is an aggregate formed from crushed stones such as granite and other smaller materials such as clay. Primarily utility and construction companies use railway ballast to provide a level base for rails and sleepers. Railroad ties, or sleepers, are the rectangular support piece kept perpendicular to the tracks. Track ballast forms the track bed upon which railroad ties (sleepers) are laid. It is packed between, below, and around the ties. Ballast bears the load from the railroad ties and holds the track in place as the trains roll over it. The term “ballast” comes from a nautical term for the stones used to stabilize a ship. 

What type of aggregate makes up railroad ballast?

A specific type of stone must be used for railroad ballast. If the stones are too smooth, such as river rock, the pebbles would roll over or slide against one another when a train passes. In order to provide support to the tracks, stones with angular edges must be used. The angular nature of rail ballast allows the stone to lock in place. Resource’s railway ballast is tested to high standards to make sure it is strong enough to resist damage or abrasion and prevent movement. We understand how important it is to use high-quality rail ballast for safety and maintenance purposes.

Other functions of railroad ballast

Apart from holding the railway lines in place and providing support for heavy trains, here are the other functions of railroad ballast:1. Ballast keeps vegetation from growing on railway tracks which could weaken the ground on which the railway lines run.2. Ballast also keeps water from reaching the track on a regular basis and softening the ground. Therefore, the stone around tracks is always sloped downward, away from the tracks. It also allows proper drainage beneath or around the tracks to ensure standing water does not gather on the tracks.

RESOURCE Delivers

Our team of experts in construction and railroad aggregates has over 20 years of experience and many of our materials are pre-approved by the Washington Metropolitan Area Transit Authority (WMATA). We're here to help you select the ideal solution for your specific project specifications and goals.


Industry Highlight (source: ForbesThere are approximately 689,974,000 railroad ties in the United States, supporting 212,000 miles of railroad track. Old ties are recycled for use in landscaping, turned into pellet fuel, or burned in co-generation plants to provide electricity.