Mathematical Bridge, Cambridge

The Mathematical Bridge is the popular name of a wooden bridge across the River Cam, between two parts of Queens' College, Cambridge. Its official name is simply the Wooden Bridge.

The bridge was designed by William Etheridge, and built by James Essex in 1749. It has been rebuilt on two occasions, in 1866 and in 1905, but has kept the same overall design.

The original "mathematical bridge" was another bridge of the same design, also designed by James Essex, crossing the Cam between Trinity and Trinity Hall, where Garret Hostel bridge now stands.

The arrangement of timbers is a series of tangents that describe the arc of the bridge, with radial members to tie the tangents together and triangulate the structure, making it rigid and self supporting. This type of structure, technically tangent and radial trussing, is an efficient structural use of timber, and was also used for the timber supporting arches (centring) used for building stone bridges.

Photo 205, 1979