Promontory Locomotive Project

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The legacy of the transcontinental railroad, constructed between 1862 and 1869, can be found at Golden Spike National Historic Site. The race to complete the railroad ended in a symbolic event when the locomotives representing the West's Central Pacific (Jupiter) and the East's Union Pacific (119) met at Promontory Summit, Utah on May 10, 1869 where ceremonial spikes were driven into ties at the famous "Golden Spike Ceremony". The advancement in rail accessibility soon heralded a new direction of commerce, communications, transportation, politics, and military conquest on the western frontier of the continental United States.

In 1976, the United States Congress authorized funding for and directed the National Park Service (NPS) to design, build and operate replicas of the two famous locomotives as part of a plan to recreate the scene of the historic event. The Jupiter and 119 were both originally 4-4-0 locomotives, involving four leading wheels, four drive wheels, and no trailing wheels. Designed specifically for use on American railroads, the 4-4-0 was the most common locomotive in use during the Civil War and the transcontinental railroad construction era, and therefore became known as the American Standard.

No original plans or blueprints were, or have been found, for either steam engine in the railroads' or manufacturers' archives. A team at O'Connor Engineering Laboratories spent over ten years researching the locomotives and designing the replicas as they appeared in photographs in 1869. Several key figures in the railroad research field were involved in the process of creating the 789 drawings produced for reconstructing the two locomotives. Using information known at that time, O'Connor Engineering Service constructed the two engines in Costa Mesa, California, between 1976 and 1979. These original pencil drawings are part of the Technical Information Center’s (TIC) collection, with sheets spanning up to 15 feet in continuous uncut length down to 8.5 x 11 detail sheets of the smallest components. This collection represents the park service’s continued preservation of our history of human ingenuity, tenacity and perseverance in monumental construction and capturing those efforts for posterity.