Burlington Northern Railroad Bridge 5.1

The Burlington Northern Railroad Bridge 5.1 or BNSF Railway Bridge 5.1, also known as the St. Johns Railroad Bridge or the Willamette River Railroad Bridge, is a through truss railway bridge with a vertical lift that spans the Willamette River in Portland, Oregon, United States. Built by the Spokane, Portland and Seattle Railway and completed in 1908, it was originally a swing-span bridge, and its swing-span section was the longest in the world at the time. However, 81 years later the main span was converted from a swing-type to a vertical-lift type, in order to widen the navigation channel. The lift span is one of the highest and longest in the world. The bridge consists of five sections, with the two sections closest to the bank on each side fixed.

The BNSF Railway owns the bridge, and the 5.1 denotes the distance in miles from Portland's Union Station or from the nearby North Bank Depot, which was the Portland terminus of SP&S passenger service coming via this bridge until 1922.