A pair of viaducts carrying trains for more than a century across forested valleys west of the Hudson River were showing their age. Metro-North Railroad selected STV to inspect the trestles, calculate load ratings, develop a list of the most urgent repairs, and prepare designs and cost estimates. Both viaducts carry commuter and freight trains.

One of the structures, the picturesque 3,200-foot-long Moodna Viaduct, towers 193 feet above the Moodna Creek Valley, and is the highest and longest railroad trestle east of the Mississippi River.

The firm provided in-depth structural inspections, calculated live load ratings, developed a priority ranking of the recommended repairs, and prepared preliminary and final designs. STV provided construction support services for the repair of the Moodna Viaduct and resident engineering and inspection (REI) services for structural repairs to the Woodbury Viaduct.