Cleft Ridge Span

The bridges of Prospect Park run the gamut from rustic to elaborate, but one phrase not usually used to describe them is technologically groundbreaking. However, the Cleft Ridge Span is just that. The bridge’s elaborate tile work isn’t composed of terra cotta or carved stone but cast concrete; a new advent at the time of the span’s construction.

The idea to use cast concrete was an experiment of sorts. Originally, the plan was to use brick or granite, but park designers Olmsted and Vaux proposed a new mixture to save money. Cast concrete, also known as Béton Coignet after its creator Francois Coigne, was brought to the United States in 1869 by the New York & Long Island Coignet Stone Company. It was this firm that Olmsted and Vaux collaborated with to construct the Cleft Ridge Span. When the span was completed in 1872, the company also completed construction on its headquarters along the Gowanus Canal.