| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor |
| Watts Mills Road Bridge | Watts Mills Road Over North Fork Little Beaver Creek | Rural: Beaver County, Pennsylvania | Metal Pinned Pratt Full-Slope Pony Truss, Stationary | 1878 By: Penn Bridge Company of Beaver Falls, Pennsylvania |
| Technical Facts |
| Rehabilitation Date | Structure Length | Main Span Length | Bridge Width | Roadway Width | Main Spans | Approach Spans |
| 1976 | 109 Feet (33.2 Meters) | 47.9 Feet (14.6 Meters) | 15 Feet (4.57 Meters) | 12.5 Feet (3.8 Meters) | 2 | None |
This bridge was built by the West Penn Bridge Company which later became the Penn Bridge Works (Penn Bridge Company). This is one of the earliest remaining examples of the company's work.
This bridge enjoys a large amount of historic significance for a wide variety of reasons. The most important area of significance is the span configuration of this bridge, which is a two-span continuous pony truss. It is an extremely early and rare example of a multi-span pony truss bridge using a continuous design. Continuous truss bridges were more common for large bridges, not for small pony truss bridges like this one. Indeed multi-span pony truss bridges of any design are uncommon. As such, this bridge is quite unusual and noteworthy for this use of a continuous design. In addition, the bridge is simply an early surviving truss bridge, with an 1878 construction date. This was a period where bowstring truss bridges were common; this bridge is instead an early example of a more traditional form that became common in the 1880s, the pin-connected Pratt. Another source of significance is the bridge's use of two pins at the end post / top chord connection: one for the diagonal member and one for the hip vertical member. This detail was something that the Penn Bridge Company used on many of its bridges, and is a detail that is mostly unique to the Penn Bridge Company.
For all these reasons, this bridge is one of the most important pony truss bridges in the region. Its preservation is essential, either in place, or relocated to another place. It is a key part of Pennsylvania's impressive collection of historic bridges, and is also a bridge built by a regionally prolific local bridge company.
Information and Findings From Pennsylvania's Historic Bridge InventoryDiscussion of Bridge The 2-span, 109'-long and 15' wide, wrought iron pin connected Pratt pony truss bridge was built in 1878 by the West Penn Bridge Co. It is supported on masonry abutments and a masonry pier. The bridge is historically and technologically significant as an early example of its technology. Its unusual detailing of the center vertical illustrates period thinking about multi-span metal truss bridge design. It is also an early example of the production of the Penn Bridge Works of Beaver Falls, which was one of many bridge companies producing truss bridges for a regional market in the late 19th and early 20th centuries. Founded in 1868 in New Brighton, Beaver County, Penn Bridge moved to Beaver Falls in 1879 and changed its name from West Penn Bridge Co. Discussion of Surrounding Area The bridge carries one lane of a two-lane road over a stream in a sparsely developed, wooded setting. Bridge Considered Historic By Survey: Yes |
