Mill Road

The Whipple Cast and Wrought Iron Bowstring Truss Bridge over Normans Kill in Albany, New York, United States, is one of the bowstring truss bridges introduced by Squire Whipple in 1841 and used widely to span the Erie Canal. An economic and innovative design patented by him, its light and inexpensive construction uses cast iron in compression in the bridge's arch and wrought iron in tension to offset the horizontal forces created by the arch. Such a design is similar to a tied arch bridge, but incorporates diagonals in tension similar to the Whipple truss and Pratt truss designs.

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