Considered an engineering marvel when built in 1889, the 1.2-mi Poughkeepsie Railroad Bridge had burned and fallen into disrepair after 85 years of carrying commuter and freight traffic 200-ft above the Hudson River. Years passed before the nonprofit organization Walkway Over the Hudson stepped forward with plans to provide public access to the bridge in Poughkeepsie, N.Y., succeeding in transforming the structure into a New York State historic park in time for the 400th anniversary of Henry Hudson sailing up the river that now bears his name.
“[The project] took something that was a very important structure 120 years ago and went into complete decay and resurrected it for public benefit,” says Malcolm G. McLaren, president and CEO of McLaren Engineering Group of West Nyack, N.Y.
“Walking out on the bridge for the opening ceremony was the only time in my career I’ve had my breath taken away on a project,” adds Michael Cooper, project manager for the structural portion of the project for Bergmann Associates of Albany, N.Y. “It was an amazing feeling that I had a part in it.”
The design team of Bergmann and McLaren inspected the bridge to assess structural integrity, performed an in-depth structural analysis and developed a repair plan. Work began in August 2007. To meet the opening deadline, the team undertook many of the tasks simultaneously.
“It was an adventure,” McLaren says. “We had engineers swinging from the bridge, climbing the bridge, trained as riggers and rapellers. We had divers inspecting the foundations under the water, and we brought new technologies to bear, using sonar imaging to take pictures of the underwater portions.”
Even so, some areas of the bridge proved inaccessible due to a build up of debris until general contractor Harrison & Burrowes Bridge Constructors of Glenmont, N.Y., began work. Once cleaned out, Cooper says, the team found a couple of areas where truss members came together that needed repairs. Engineers, the contractor and ironworkers discussed alternatives onsite.
“We were all huddled around part of the bridge, 150 ft in the air,” Cooper said.
Design elements work together to complement the environment and create a functional and safe facility. The team incorporated textures into the surface of the bridge deck to gently delineate and encourage separation of pedestrians and cyclists. Unadorned galvanized bridge railings with clean lines create a visual ribbon that draws one further along the bridge. LED tube-lighting, beneath the upper bridge rail, softly lights the walkway. Three widened overlooks offer opportunities to pause and take in the vistas. Interpretive panels serve to educate all passersby about the bridge, the river and the region’s history.
Nearly 800,000 people have visited the park in the year since its October 2009 opening.
Says McLaren: “While we approached this with great interest as engineers, we never [expected] how much popularity this would have.”
Owner: Walkway Over the Hudson, Poughkeepsie, N.Y.
General Contractor: Harrison & Burrowes Bridge Constructors, Glenmont, N.Y.
Construction Manager: Bergmann Associates, Albany, N.Y.
Design team: McLaren Engineering Group, West Nyack, N.Y.*, and Bergmann Associates, Albany
*Submitted Project to New York Construction