Mercer County Engineer's Office

HISTORIC BRIDGE - BRIDGE 3116

Mercer County Bridge No. 3116 was a structure eligible for the National Register of Historic Places. An Historic Bridge Recordation document was prepared to permit replacement of this structure. The Chestnut Street Bridge was located between Harvard and McConnell Streets in the Borough of Grove City, Mercer County, Pennsylvania and spaned Wolf Creek. The reinforced concrete, six-span bridge was built in 1930 to improve vehicular and pedestrian access between sections of the borough bisected by the creek. The bridge had an overall length of 312 feet (95 meters), and consisted of three adjacent open spandrel concrete arch spans on the east and three adjoining concrete T-beam spans to the west. The 92 foot (28-meter) long channel span over Wolf Creek was the largest of the bridge's six spans and was flanked on either side by a 44-foot (13.4-meter) open spandrel span. The arch span ribs had an approximate width of 3.5 feet (1 meter) in width and were strengthened by perpendicular concrete struts at the crown and spring lines of the main arch. The arch spans adjoined to a series of three 44-foot (13.4-meter) long T-beam spans on the west. Immediate access to the bridge was provided by a 76.5-foot (23-meter) long approach fill within retaining walls near McConnell Street on the west and a 40-foot (12-meter) approach fill with retaining walls near Harvard Street on the east. Bridge width was 34 feet (10.4 meters) from outer parapet edges, and included a 20-foot (6.1-meter) wide asphalt-paved roadway flanked by two five-foot wide sidewalks. Along the northern and southern elevations, the parapets consisted of forty reinforced concrete panels, each measuring approximately 3 feet (0.95 meters) in height by 7 feet (2.12 meters) in width. Aluminum tube handrails at the eastern terminus of the bridge provided additional protection against the steep slopes below Harvard Street.

The six Chestnut Street Bridge spans were supported by ten square concrete piers (i.e., five along each elevation); these were set on squared concrete footings and had been scored on their outer face to imitate cut stone blocks. The steeply curved eastern reinforced concrete abutment at Harvard Street was stepped and received the base of the easternmost arch at the spring line. The western bridge abutment was square in form and served as a transition between the free-standing T-beam portion of the bridge and the adjacent earthen approach fill that leads to McConnell Street.

The Chestnut Street Bridge contained two metal bridge plaques; these were situated along the northern and southern inner parapet walls, near Harvard and McConnell Streets, respectively. Both plaques were identical and listed the structure's official bridge number (Mercer County Bridge No. 3116) and its 1930 completion date. The plaques also identify the County Commissioners at the time of construction (W A. Bone, Harry Hunter, and Harry Gibson and lists Frank P. Graham (Mercer County engineer) and Wendell P. Brown (consulting engineer) as the designers of the bridge. The Roberts Supply Company of Lima, Ohio was listed as the builder. These plaques were transferred to the Mercer County Historical Society for preservation.

Urban development in the project vicinity during the 1920s led directly to the construction of the Chestnut Street Bridge in 1930. According to the minutes of the Mercer County Commissioners, the commissioners entered into an agreement with Grove City Borough authorizing construction of the bridge on June 17, 1929. Construction bids from 11 competing Pennsylvania and Ohio firms were opened on September 10, 1929, and the contract awarded to the Roberts Supply Company of Lima, Ohio, for its low bid of $66,300 At the time of its 1930 completion, the Chestnut Street Bridge was the longest bridge in the county and was one of four Grove City bridges carrying automotive traffic across Wolf Creek during the early 1930s.

The Chestnut Street Bridge is a significant representative example of the many reinforced concrete automotive bridges built across Pennsylvania and surrounding states during the first half of the twentieth century to facilitate efficient transportation within the state's emerging highway system. Construction of the bridge in 1930 contributed to Grove City Borough's increasing integration within the local and regional economy. The construction of the bridge in 1930 occurred as part of an evolutionary trend in bridge design that sought to improve the strength, ease of construction, and cost-effectiveness of highway bridges, using lighter and stronger materials.