Promontory Summit, Utah is where the Golden Spike was driven in celebration of the completion of the First Transcontinental Railroad. Two locomotives are featured in the famous photo of the event: Central Pacific #60 (Jupiter) and Union Pacific #119.
In 1974, the National Park Service had approached O'Connor Engineering Laboratories of Costa Mesa, California, to construct exact, full-size replicas of the Jupiter and Union Pacific 119. As was the case with the engines themselves, no drawings or plans of the engines survived, necessitating entirely new drawings to be produced based mostly on photos of the engines as well as research done on similar engines built around the same time.
The replicas were completed in 1979, and began operations on May 10 of that year, 110 years after the original Golden Spike ceremony, and continue to make demonstration runs.
The drawings produced by O'Connor Engineering Laboratories are in the public domain, as they were produced with public funds. You can download a complete set of plans for both locomotives here:
- Promontory Locomotive Project, Sheets 1-281 (PDF)
- Promontory Locomotive Project, Sheets 282-786 (PDF)