ASARCO 2

This industrial switching locomotive was originally constructed as a 12-ton diesel-mechanical unit for American Smelting & Refining Company (ASARCo) Engine No. 2, serving the company's Selby, California smelter complexm, one of the San Francisco Bay Area's major heavy industrial facilities processing precious and base metals. During its service life, ASARCo modified the locomotive by adding two tons of steel plate ballast and installing upgraded mechanical systems, ultimately increasing its capacity to 14 tons with a General Motors 4-71 diesel engine and hydraulic transmission.

Following the refinery's closure in 1971, the locomotive was sold to M. Lummus Company of Richmond, California, a railroad equipment dealer and contractor. In 1973, Marriott Corporation acquired it for construction of the narrow-gauge railroad at California's Great America theme park in Santa Clara. After assisting with track construction, it served as the park's backup locomotive until retirement to a siding in 1984.

The Society for the Preservation of Carter Railroad Resources discovered the idle locomotive at Great America in 1996. The theme park donated the unit, delivering it to the museum the following day. Initial restoration efforts proved challenging due to equipment limitations and vandalism damage, leading to the locomotive's sale to a private owner who commissioned Brooks Locomotive Works to perform a complete rebuild.

In 2004, the fully rebuilt locomotive was shipped to Kauai Plantation Railway in Lihue, Hawaii, where it became their first locomotive, operating as No. 10 and assisting with that line's construction. Deemed too small for regular operations, it was replaced with larger locomotives and returned to California in 2010, joining Roaring Camp & Big Trees Railroad. However, age and exposure to Hawaii's salt air had rendered it unfit for service, and it was sold to a private California owner in 2013.

When SPCRR sought a larger locomotive for operations, a museum member who had performed early restoration work pursued reacquisition. A private collector purchased the locomotive in 2015 and leased it to SPCRR, with the unit arriving at Ardenwood Historic Farm on September 1, 2015. Between 2016 and 2025, SPCRR volunteers undertook comprehensive rebuilding including installation of a newer diesel engine and addition of air brake systems to meet modern passenger train safety requirements.

The locomotive entered public passenger service on October 26, 2025, representing a major milestone for SPCRR railroad operations. This veteran industrial switcher now runs regularly in passenger service, having successfully transitioned from Bay Area heavy industry to historical railway operations, a journey spanning eight decades and three states.