Southern Pacific Undercutter and Its Maintenance-Of-Way Crew at Indio, California

Description

Maintenance of the ballast layer directly below the ties is an essential part of a healthy track structure, as ballast degrades over time and becomes increasingly fouled reducing its ability to drain, provide adequate load bearing support, and withstand vertical, lateral, and longitudinal forces. Southern Pacific used specially trained crews who operated undercutter equipment to restore ballast that had become fouled.

The excavated material could either be fully discarded or screened and returned to the track, with only the finer parts of the ballast not being recycled.