Old Wells Street Bridge, Wells St. Fort Wayne, in Allen County, Indiana. Intersected-Wells St. over St. Marys, River. Construction Date-1884. Structure Length-180'. Structure Type-Single Span, Metal 15 Panel Pin-Connected Whipple (Double Intersection Pratt) Through Truss, Fixed. Builder/Contractor: Wrought Iron Bridge Company of Canton, Ohio, Engineer/Design: William H. Goshorn and Alvin John Stewart. Rehabilitation Date: 1982. Inventory Number: N/A. GPS: 41.082810, -85.144080.
Statement of Significance
The Wells Street Bridge is significant as a unusual example of an historic metal bridge type, the Whipple truss. The Whipple truss was designed as as improvement over the older Pratt truss. Squire Whipple, who was internationally recognized for his bridge designs, created the Whipple truss in 1846 by merely extending diagonal web members across two panels instead of one panel. (this single variation more evenly distributed stress and greatly improved the strength of the truss, allowing iron bridges to carry heavier loads across longer spans.) From 1865 to 1885, the Whipple was the favorite of engineers for long spans. The Pratt truss in more commonly used on Indiana's iron bridges. Over 350 Pratt truss bridges remain in Indiana, while only 30 Whipple truss spans exist in the state.
Architectural Description
Fabricated by the Wrought Iron Bridge Company of Canton, Ohio, this double-intersection Pratt (Whipple) through truss may have been erected under the watch of N. Goshorn, Allen County Engineer. It still stands upon its original cut stone abutments and wingwalls. The single span of 180' is carried by endposts and top chords of fabricated heavy channels and cover plate and is subdivided into fifteen panels by intermediate verticals constructed from four sizes of laced heavy channels (deceasing in size toward center span) riveted to reinforcing pin plates above and below. Double cylindrical eye-bars with turnbuckles stretch diagonally outwards from the five central pins; die-forged double rectangular eye-bars form the other diagonals. Double U-bolted to pins, girder floor beams stretch beyond the lower chord on each side to provide external sidewalks and internally support an asphalt-over-timber deck which carries a 23' roadway with 15'7' of vertical clearance.
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