Sugar Creek Covered Bridge, Chatham Illinois
- Categories:
- Illinois
- Covered Bridges
- Modified Burr Arch
Sangamon County's oldest covered bridge (only two remain in Sangamon County) with a 60-foot clear span over Sugar Creek was constructed in 1827 by Thomas Black and served the first settlers of Sangamon County who located in this area in 1817.
The Sugar Creek Covered Bridge is one of Illinois' seven wooden trussed bridges which remain in service at their original location. There were over 200 bridges at one time in Illinois. Between the 1830's and the 1880's such wooden trussed structures were preferred for bridges in Illinois.
The Sugar Creek Covered Bridge is a wooden trussed bridge with 8 panels of a modified Burr variety and assisted by an arch. The basic Burr truss was modified when constructed by the use of "X" diagonals within each panel rather than the simple diagonal compression member patented by Burr in 1840. The truss span is 60 feet and has 24-foot approaches leading to both the east and west portals. The portal height (deck to strut) is 8 feet 3 inches and the portal width (distance between end posts) is the same. The lower chords rest at each end on large metal piers. The arch no longer rests on the abutments and instead was cut at each end of the lower chord when reconstructed in 1965.
Major repairs were undertaken in 1965. They included jacking the bridge in approximately ten locations to straighten and repair the lower chord; replacing two steel rods with turnbuckle assemblies on each side of the structure beneath the lower chords with spacer blocks to relieve tension on the lower chord; fabrication and installation of steel assemblies at each end of the lower chord to support the steel tensile rod; replacement of approximately 50% of the bracing and 50% of the deck and tread plates; patchwork of the wood shingle roof; erection of handrails on approaches and the treatment of the structure with a wood preservative. To maintain the original appearance of the bridge, all materials used in the restoration were the same type and grade as used in the original structure.
