For nearly five decades, the Southern Pacific Railroad utilized two massive roundhouses at its railyard near downtown Tracy. The roundhouses were constructed to service and repair steam locomotives at Tracy, which was a major waypoint on the SP during the first half of the Twentieth Century.
In the mid-1950s, the Southern Pacific began the complete phase-out of steam locomotives, replacing their entire fleet with more reliable diesel-electric locomotives, which required substantially less maintenance.
At the same time, the SP chose to reduce and relocate its facilities in downtown Tracy, moving its storage yard farther east of town – on the far side of the Eleventh Street overpass, spanning the area east nearly to Banta. (The relocated yard opened in 1961.)
With the relocation, down came the roundhouses and up grew a simple “shed” near the SP’s new depot at the foot of Sixth Street near MacArthur, providing just enough space to service one or two diesel locomotives at a time. A refueling dock and sanding station – essential to provide additional traction for heavy trains heading over the Altamont – were also constructed.
The diesel facility remained in use into the 1990s, after which it was shut down. Subsequently, its windows were covered with plywood sheets, its huge doors were sealed shut, and the rails leading up to it were torn out.
Special thanks to Robert J. Zenk for generously providing the photos of the Southern Pacific’s Tracy Yard at the top of this page (1979, in black and white) and below (1966, in color).