Neshanic Station Lenticular Truss Bridge, State Route 567, spanning South Branch of Raritan River, Neshanic Station, Somerset County, NJ

Significance: Neshanic Station Lenticular Truss Bridge is significant because it was built by a prominent 19th century bridge building company; the lenticular truss, of which it is an example, is an unusual truss type compared with other more common trusses such as the single intersection Pratt; and it is the only bridge of its type left in the State of New Jersey. Berlin Iron Bridge Company was the exclusive builder of the elliptical or parabolic truss. Though the design was patented in 1878 by an American, William O. Douglas, the truss form was used as early as 1857 in Germany and 1854 in England. Douglas may have developed this design without knowledge of the German or English bridges. Nonetheless, it was his patent and the Berlin Iron Bridge Company that introduced this type of bridge to the United States. In 1889, the company claimed to have built over 90% of the iron highway bridges in New York and New England during the ten previous years. In the same illustrated catalog, it lists 664 bridges that were erected in twelve states. Neshanic Station Lenticular Truss consists of two 140'-7-1/2" spans. Plans for stiffening the bridge were proposed by the Board of Freeholders in 1932. This altered the appearance of the portals and added new steel sections to other structural members, but did not significantly change the bridge's appearance. The present proposed rehabilitation will not alter the appearance either.

Unprocessed Field note material exists for this structure: FN-11

Survey number: HAER NJ-31

Building/structure dates: 1896 Initial Construction

Building/structure dates: 1932 Subsequent Work

iron truss bridges civil engineering bridge construction patents vehicular bridges neshanic station neshanic lenticular truss bridge neshanic station lenticular truss bridge state route south branch raritan raritan river somerset somerset county new jersey berlin iron bridge company william o douglas historic american engineering record liz jandoli ultra high resolution high resolution new england library of congress

1969 - 1980

Library of Congress

http://www.loc.gov/

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