Ballast cleaner

[3][4] The advantage of ballast cleaning is that it can be done by an on-track machine without removing the rail and sleepers, and it is therefore cheaper than a total excavation.

[3][5] Early automated cleaners used vacuum pressure built by a steam locomotive to suck ballast up from the track to feed it into the sifting grates.

[5] More fully automated ballast cleaners were developed in the early- to mid-20th century by several companies including Speno[7] and Pullman-Standard;[8] a version of Pullman-Standard's machine was demonstrated in 1949 that was estimated to save railroad companies about $1,000 per mile of track on their maintenance ($12,806 in 2023).

A conveyor then moves the ballast into the cleaner, where it gets forced through a mesh by a shaking chamber.

This process can be done in short sections, meaning that track life can be considerably extended with the minimum of disruption.