The Poughkeepsie-Highland Railroad Bridge was initially built in 1888 and at 6,767 feet in length, was the longest bridge in the world at that time. Work activities began in 2007 to convert the bridge into the world’s longest dedicated pedestrian bridge. This pedestrian pathway is known as the “Walkway Over the Hudson State Historic Park” and is managed and maintained by the New York State Office of Parks, Recreation, and Historic Preservation with assistance from Walkway Over the Hudson, a 501(c)(3) not-for-profit organization, which was founded in 1992.
Spectra was retained by Harrison & Burrowes Bridge Contractors, Inc. to provide surveying services to meet an October 2009 deadline. Spectra provided detailed as-built survey of the steel railroad bridge spanning the Hudson River and collected continuous survey field data during the construction phase of the project. GPS was utilized to tie the project into the New York State Plane Coordinate System using NYS CORS network for “in-field” corrections.
The new walkway consists of prefabricated concrete panels set in place on the pre-existing ironwork. Spectra provided services to aid in the design of the panels and to identify areas of twisting, sagging, and/or bulging steel. Surveying also included collecting measurements between support structures across the span of the bridge, mapping, and tabulating the data.
Construction activities for the “Walkway over the Hudson” project were featured on the DIY Network television program “Project Xtreme” and surveying activities for the project were featured in the August 2009 Point of Beginning Magazine, a national publication targeting professionals in the surveying, mapping, engineering and related geomatics fields.