BEAR MOUNTAIN BRIDGE crosses the Hudson river about 44m. above New York city. It is a highway toll bridge, with a deck accommodating four lines of vehicles and two sidewalks. The floor system was designed for 15 ton and 20 ton motor trucks, with impact allowance. Opened to public use in November 1924, 18 months after work on it was started, it had what was at that time the longest suspension span in the world, 1,632ft. from centre to centre of the towers. It was completed early in 1925.
Each of the two cables contains 7,252 annealed steel galvanized wires, giving a diameter of 188in. ; from them stiffening trusses of "silicon" steel carrying the roadway over the main span are sus pended by steel ropes passing over castings clamped to the cables. The trusses extend over the main span only, the roadway being carried on independent steel spans supported on concrete piers between the towers and the end of the bridge. The two towers are 355ft. high, built of structural steel with cast bases, and rest on four concrete piers founded on the natural rock on both shores, slightly above the water-level. The roadway and sidewalks are formed of a continuous reinforced concrete slab from railing to railing, with a roadway paving of sheet asphalt. Twelve expansion joints are provided in the main span. The bridge was designed and supervised by Howard C. Baird, with Francis P. Witmer as associate. It is owned by the Bear Mountain Hudson River Bridge Company, but will be come the property of the State of New York in (H. C. B.)