NHHD's Chief Bridge Engineer Harold W. Langley (left), Assistant Bridge Engineer Robert J. Prowse (center), and Commissioner John O. Morton (right) in 1950.
Commissioner John O. Morton (left) and Assistant Bridge Engineer Robert J. Prowse (right) in the Bridge Engineering Division of NHHD in 1961.
Built in 1955, these bridges were the brainchild of Chief Bridge Engineer Harold Langley and Assistant Bridge Engineer Robert Prowse of the New Hampshire Highway Department (NHHD). This agency is currently known as the New Hampshire Department of Transportation (NHDOT).
The design was apparently Langley's idea as he is credited as "designer" on the plans. Prowse is credited with drawing the plans but considering these were the Number 1 and Number 2 designers in the Highway Department, they were undoubtedly advancing the design together, with Prowse being delegated the important task of putting the idea on paper in a manner where it could be both fabricated and constructed in a practical cost-effective method.
The total number of bridges of this type designed and built by the New Hampshire Highway Department has not been readily determined since these specific features of this bridge type have not been identified in the state’s bridge database.
The design of these bridges may have been the first of its type designed by the Highway Department.
For more information about Prowse and Langley, the following documents are provided below.