The locomotives and rolling stock are using knuckle-type couplers which did not begin wide use until the 1890's. In the 1860's era setting of this movie, the couplers in use would have been link and pin. This anachronism is understandable as the safety issue would have prohibited the use of the era appropriate link and pin couplers.
The Central Pacific steam engine used in the sequence of the 10 mile day was a coal burner, evident by the straight pipe smokestack. All Central Pacific steam engines at the time were wood burners with a diamond stack or similar smokestack.
A claim was made that the original Jupiter was used in the movie. After the Central Pacific Railroad was reorganized as the Southern Pacific, the steam engine was numbered SP1195, was converted to a coal burner and then sold to the Gila Valley, Globe & Northern Railroad in Arizona. Unfortunately, it was scrapped in 1906 for $1000, so it could not have been in this movie.