Person County Bridge No. 35
John Rogers Road over the Flat River in Hurdle Mills
This abandoned pony truss has been imposed upon by the forest, yet still stands strong.
A century ago, when the automobile was a novelty and the average speed of the nation's roads was far less than 60 miles per hour, roads were subservient to the contours of the land and path of rivers. In many cases the road leading down to a crossing was curved so that the bridge could span the river or creek at a straight angle, in order to save on materials. Not every bridge needed to be built to carry tractor trailers loaded with M1 Abrams Tanks. Like this simpler period of time, this 1910 pony truss bridge has been obscured, barely visible under the cover of poison ivy, Virginia creeper, and hardwood saplings.
This historic bridge was spared the fate of so many others once under the control of the North Carolina Department of Transportation: when a new bridge and a straighter alignment of the road were constructed, the old roadway and bridge were left in place. Much of the south approach road to the old bridge is graded and safe to drive on; today it is used as an illegal dumping ground. However, a portion of the road between the bridge and the barricade has been almost completely reclaimed by the forest, concealing this gem of 20th century engineering from most who drive down to the dead end. Be warned: there is poison ivy everywhere you turn along the old roadbed and around the bridge.
The bridge itself is a Pratt pony truss, one of the more common truss bridge types. According to the Historical American Engineering Record, which documented the bridge in 1979, the bridge spans a distance of 83 feet, at the long end of the distance that a pony truss can span (1). One of the forces that the engineers of pony truss bridges had to take into account was how to prevent the trusses from "tipping," a force that is counteracted by overhead bracing on through truss bridges. On some pony truss bridges there are "buttresses" on the outer sides of the trusses to handle this. This bridge lacks this feature; however, it has some notably strong vertical members comprised of three solid U-channel beams riveted together, an exceptionally strong design for its day. Perhaps these solid beams were meant as simplified substitutes for this function. As the bridge lacks vertical members in the vicinity of the front posts, it can be categorized at a "half-hip" pony truss (2).
The connections on this bridge all use steel pins as opposed to gusset plates. At the connection points the chords and vertical members are reinforced with riveted steel plates. The diagonal members are steel eyebars with teardrop-shaped holes; these also comprise the bottom chord. The bridge was built by the Champion Bridge Company of Wilmington, Ohio; some of the bridge's feature's may be signatures of this company. Fortunately, despite nearly three decades of vandalism and neglect, the bridge retains its plaque, located mid-span on the east-side top chord. The steel was forged by Jones and Laughlin.
There is strong evidence that the bridge was relocated from another crossing. On the mid-span connections that hold the two sections of the top chord together most of the original rivets have been replaced with bolts. Since machined bolts were not widely used in bridge construction until mid-century, it would appear that this bridge was moved closer to its abandonment than to its original erection. The bridge's railings, which seem to be original, were also re-bolted at one point. Prior to being bolted directly onto the vertical members, they were probably riveted to the brackets that remained attached to the verticals.
Having survived the blowtorch for this long, it would appear that this bridge's fate lies primarily with nature. As noted before, it has held up surprisingly well. It has survived periods of high water, as evidenced by the large amount of debris resting on its lower chord. Trees grow on the deck, but the layer of asphalt over the pine planks has kept them from rotting for the most part. The bridge rests atop sturdy concrete piers and has retained a great deal of its paint. Most likely to fail are the timber stringer approaches, which are moss-covered and subject to organic decay.
I should also note that it is very difficult to take good pictures of this bridge. In the summer and spring the vegetation covers much of the bridge and makes overview shots nearly impossible. In the winter, meanwhile, the excessive sun casts shadows on the trusses and manages to destroy the detail of certain shots. Photographing the bridge from the side is possible in the winter, but there will always be some sapling in the way to disrupt the shot.
Facts
- Year Built: 1910
- Year Abandoned: Circa 1981.
- Builder: Champion Bridge Co.
- Route Carried: Formally SR-1120
- Crosses: South Flat River
- Location: Person County, NC
- Design: 5 panel Pratt pony truss with pinned connections and timber stringer approaches
- Length of main span: 83 ft.
- Coordinates: 36°15'44.45"N, 79° 0'44.34"W
Pictures
- Left: An overview shot of the main span. Center: Three of the bridge's five panels (note the debris on the lower chord). Right: a partial oblique view of the west truss.
- L&R: South and North portal shots, respectively.
- L: Vertical member and railing detail. C: A top chord connection. R: A front post/top chord connection.
- L: A joint connection on the top chord, near mid-span; the bolts on the left indicate that it was moved at one point in history. C: a turnbuckle. R: a bottom chord connection.
- Left: the bridge plaque. Center: a bridge bearing. Right: the southern pier.