Southern Pacific Railroad

The Tehachapi Pass Railroad Line was cut through solid and decomposed granite by about 3,000 Chinese laborers using nothing more than picks, shovels, horse drawn carts, and blasting powder. This line, which rises from the San Joaquin Valley and through the Tehachapi Mountains, originally included 18 tunnels, ten bridges and several water towers to accommodate the steam locomotives. Completed in less than two years, it was part of the final line of the first railroad to connect San Francisco with Los Angeles.

The articulated wheel-base steam locomotive represents the final phase of steam locomotive development in size and power. The cab-in-front feature was widely used by the Southern Pacific Railroad beginning in 1909 to alleviate smoke and heat problems for locomotive personnel en route through tunnels and snow sheds. This locomotive, built by the Baldwin Locomotive Works, operated between 1944 and 1956 before being displaced by a diesel-electric locomotive.

This inertia dynamometer is used to test railroad wheels under controlled conditions that can greatly exceed normal service. It is the first and only railroad dynamometer to test track wheels using vertical and lateral loads, as well as thermal braking loads, at the wheel rim. It can also test railway car and locomotive axles.