Neshanic Station Lenticular Truss Bridge, State Route 567, spanning South Branch of Raritan , Neshanic Station, Somerset County, NJ
Photo Caption Pages
spanning South Branch of Raritan, Neshanic Station, NJ
Find maps of Neshanic Station, NJ
Documentation compiled after 1968.
Survey number HAER NJ-31
Unprocessed field note material exists for this structure (FN-11).
Building/structure dates: 1896 initial construction
Building/structure dates: 1932 subsequent work
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.
Iron Truss Bridges
Douglas, William O.
Berlin Iron Bridge Company
Historic American Engineering Record (Library of Congress)
1. View looking south with Neshanic Station Bridge appearing underneath Lehigh Valley Railroad Bridge in foreground. Jet Lowe, photographer, 1983
2. View looking south from Lehigh Valley Railroad Bridge showing Neshanic Station Bridge in elevation. Jet Lowe, photographer, 1983
3. View looking south showing bridge in elevation. Jet Lowe, photographer, 1983
4. View looking north showing bridge in elevation. Jack Boucher, photographer, 1977
5. 3/4 view looking southwest. Jack Boucher, photographer, 1977
6. 3/4 view looking west. Jet Lowe, photographer, 1983
7. Straight-on view of east portal. Jack Boucher, photographer, 1977
8. Angled view of east portal. Jet Lowe, photographer, 1983
9. View looking east down cantilevered walkway. Jack Boucher, photographer, 1977
10. Detail view of decorative cast and wrought iron railing on pedestrian walkway. Jack Boucher, photographer, 1977
11. View from west end looking down length of bridge. Jet Lowe, photographer, 1983
12. View of bridge underside showing deck beams, stringers and center pier. Jet Lowe, photographer, 1983
13. Telephoto view looking east showing center pier and deck superstructure. Jet Lowe, photographer, 1983
14. Detail view of connection between vertical post and bottom chord member. Jack Boucher, photographer, 1977
15. Detail view of connection between vertical posts and deck beam. Jack Boucher, photographer, 1983
16. Detail view of deck beam end. Jet Lowe, photographer, 1983
17. Detail view looking south showing elevation of last two panels and abutment at west end. Jet Lowe, photographer, 1983
18. Cast-iron bridge plate citing builder, date, and names of bridge committee members. Jack Boucher, photographer, 1977
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