Chinworth Bridge

Information and Findings From DHPA Historic Bridge Survey

Bridge History and Significance

In 1884, "numerous citizens and taxpayers" requested the construction of a bridge across the Tippecanoe River on the township line just west of Warsaw and less than a mile east of the Orion bridge. Crossing the property of Robert Chinworth, the proposed bridge would connect the main market road south of the river with a north-south road built by 1879 from the river to the Atwood and Etna Green road north of the river. Acceding to the petition, the board of commissioners contracted with Henry Loy for the construction of a pile bridge for $400. Hugh Foulk carted materials to the bridge site for Loy. In April 1997, the commissioners contracted with Captain David Braden to provide two iron bridge superstructures, one being at Chinworth's which was to be a 140-ft. span priced at $18 per lineal foot or $2,500 in all. While the county named Braden named as "contractor," the Bellefontaine Bridge & Iron Company fabricated the trusses. Henry Loy, who built the pile bridge at Chinworth's being replaced, carted 392 perch of stone to the site for the iron bridge substructure, and Alonzo U. Doty, who built most of the stone abutments for the county's metal spans, laid the field-stone masonry. Bellefontaine Bridge & Iron provided a pinned Pratt through-truss span subdivided into eight panels of 17.5 ft. each. The perimeter of the trusses is marked by horizontal and parallel top and bottom chords placed about 24 ft. apart and by inclined posts on the ends. The top chords and the end-posts -- which generally address compression -- were fabricated from a pair of channels with a cover plate riveted above and lacing bars below. Because they generally address tension, the lower chords consist of a pair of die-forged eye-bars varying in size from the smallest in the end panels (2 1/2 x 3/4") to the largest towards mid-span (3 3/4 x 1") where the greatest amount of tension is anticipated. The truss webbing is also adjusted for the nature and amount of stress a particular member might face. Acting as a hanger for a floor-beam, the outer or hip vertical consists of a 1.5 in. round rod. The intermediate verticals are designed to address compression. Each is composed of a pair of laced channels, varying in size from 6 in. for the second vertical to 5 in. for the third or fourth. Pratt diagonals are designed for tension with greater stress expected toward the span's end. In the second panel from the end, Bellefontaine used a pair of 2.5 x .75 in. die-forged eye-bars which dropped by the fourth panel to 1.5 x 5/8 in. The company also used a single counter-brace in the third panel and a pair in the fourth of .75 in. round rods with turnbuckles. Bracing between the trusses from one to the other of the upper and of the lower chords adds rigidity to the structure. Bellefontaine structured its portals simply by using a reinforced A-frame of a pair of angles riveted to each other. Interior struts consisting of two pair of angles -- with one pair laced to the other and placed between and bolted to the sides of the top chords at panel points -- help to keep the trusses from shifting away from or towards one another. Angle-iron knee braces bolted to the strut above and the intermediate vertical below add more stability. For protection against stresses induced through swaying, a round iron rod with threaded ends runs diagonally from one truss to the other within parallel panels. The end of the sway bracing rod extends through a plate attached to the top chord. A nut at each end tightens the rod at the respective plates. U-bolted around the lower pins of the verticals, 16-ft. long and 15-in. deep rolled I floor-beams carry the span's deck. As a secondary function, floor-beams behave like struts below the lower chords. Again, round-rod sway bracing runs diagonally from one truss to the other within the boundaries of parallel panels below. Each of the rod's threaded ends extends through an opening in a floor-beam where plates and nuts allow the rod to be tightened. Sets of nine I-beam stringers run longitudinally above the floor-beams and help support the 14-ft. timber running surface with 19 feet of vertical clearance. A latticed guardrail attached on the inside of each truss from end-post to end-post both guides the traveler across the span and provides modest protection to the truss webbing from vehicular wheels. The span carries a nameplate above the portal strut and a finial atop each end-post/top chord connection. Of the crossings of the Tippecanoe River west of Warsaw, Chinworth's grew in importance from the 1880s into the 1890s when it clearly surpassed Orion's by securing a metal through-truss span rather than a timber pile structure. Its later incorporation into a roadside rest area on a cross-country federal-state highway places the Chinworth Bridge within the development of a regional transportation system. Its builders and contractors add to the Chinworth Bridge's significance. Two figures important to bridge and other construction in Kosciusko County, Alonzo Ulysses Doty and Henry Loy, procured and built its substructure. Captain David A. Braden, who contracted for the bridge's superstructure, was widely known as a Civil War hero and court house figure. He had long served as a salesman-consultant to the Kosciusko County Board of County Commissioners. The Bellefontaine Bridge and Iron Company which designed and fabricated the Chinworth Bridge superstructure was a prolific Ohio firm which won many contracts across Indiana in the 1890s and first decades of the twentieth century. Very few of its bridges remain in Indiana. The Chinworth Bridge retains its structural integrity and decoration. References James L. Cooper, "Orion and the Chinworth Bridge" (1996). ISHC, "Bridge Survey," BR #195: 51-52; BR #1272: 35, 59. Kosciusko County, "Commissioners Record," 11: 332, 386; 14: 219, 350, 388, 400, 431, 435, 443, 445-446, 468. The ISHC sold its "small rest park" to the Historical Society. Samuel G. Olsen, Jr. (ISHC) to Historical Society of Warsaw, 29 Mar. 1976; Chris A. Specker (ISHC) to Suzanne E. Ware (President, Kosciusko County Historical Society), 25 June 1976.

Bridge Considered Historic By Survey: Yes