A Southern Pacific S-12 Class 0-6-0 switcher, #1258 is on display diagonally opposite the Amtrak Depot in downtown Martinez, CA. Outshopped in 1921, it is one of six of this class built in the SP's Los Angeles shops (#1257-#1262). A further thirty-two were built at the SP’s Sacramento shops (#1247-#1256 & #1263-#1284). The SP bought or built a total of four hundred and sixty-four 0-6-0 switchers between 1867 and 1926.
The 0-6-0 dominated switching duties on US railroads from the late 1880s right up to WWI, although increasingly heavy freight loads had, by then, already brought more orders for
0-8-0 switchers. At the same time, older main and branch
line engines were often relegated to yard duty, either
as-built or after their leading and trailing trucks had been removed.
The small size of the 0-6-0 made it an ideal choice for municipalities that wanted to preserve something of their railroad heritage without the demands made by maintaining larger, heavier power. As a result, a number of Southern Pacific examples have survived. You can see some of these on the SP S-10 #1237 page of this website, the SP S-10 #1298, the SP S-14 #1293 and the Travel Town pages.