In the 1930s, the WPA was responsible for building numerous structures as works projects during the Great Depression. This gave employment to people out of work, who in turn built a wide array of structures including band shells, picnic areas…and stone arch bridges. While the WPA did not always build their bridges with stone, they still built an impressive quantity of stone arch bridges and a total of roughly 78,000 bridges of all types between 1935 and 1943.
Concrete vs. Stone Arch Bridges
While historically stone arch bridges were used as an enduring alternative to steel and wooden bridges, with the advent of concrete, stone arch bridges fell by the wayside. This is largely attributable to the fact that stone arch bridges require extensive, often skilled, manual labor, while concrete bridges can simply be poured into shape.
The end result is that concrete remains the king where labor is more expensive than material, while stone in some parts of the world even now finds its place in bridge building where material is expensive and labor cheap. That said, stone arch bridges are in fact still being built in parts of the world where long-term reliability is of more concern than immediate cost.
In the WPA era, where the concern was more about giving people work than about cost, stone arch bridges were built extensively.
The WPA stone arch bridges provided enduring, very well-built structures to areas that needed reliable transportation. Cost, obviously, was not a terribly big concern, so stone was the logical choice to maximize the amount of labor needed. The stones of the WPA bridges are local, with few (if any) exceptions. The basic idea of the WPA bridges seems to have been similar to Walter Sharp’s methods inasmuch as the stone and labor came from the immediate area. Unlike Walter Sharp’s bridges, however, the WPA bridges feature extensive, precise stone cutting, where the stones are basically cut into brick shapes.
WPA Bridge Features
Architecturally, there is quite a bit of variety in WPA bridges. Many are simply basic, well-built stone arch bridges, but of these stone bridges quite a few have decorative features, especially in the parapet walls atop the bridge. WPA bridges built in parks in particular feature various picturesque treatments.
Another beneficial feature of WPA stone bridges was the fact that, unlike many earlier stone arch bridges, the WPA frequently built their bridges wide enough to handle two lanes.
One common theme among WPA stone arch bridges seems to be relatively short spans. As an example, the WPA Possum Kingdom stone arch bridge in Texas spans the Brazos River in eighteen spans. Instead of building a series of several long-span, low-rise arches, the WPA went with numerous, small, well-rounded arches. Nevertheless, the Possum Kingdom Bridge undoubtedly fulfilled its original purpose, for it provided out-of-work miners an opportunity to use their skills in producing a useful highway structure.
Another interesting WPA bridge is the Fort Fletcher bridge in Ellis County, Kansas. This bridge uses four sizable Roman arches to span Big Creek. The span of each of these arches is 35 feet, which is actually fairly sizable. For comparison, Walter Sharp, some decades before, spanned the same creek a few miles downstream in Russell County with a double-arch bridge featuring two lower-rise, 36 foot span segmental arches. By the time the WPA was building bridges, more care was taken to ensure ample waterway than was the case in the early days of Kansas stone bridge building. Both the WPA Big Creek Bridge and Walter Sharp’s Big Creek Bridge are still in use today.
Another observable theme in Kansas is that WPA stone arch bridges were mostly built in the more sparsely populated portions of the state. In the eastern part of Kansas there are but a handful of WPA bridges, but out in the western part of the state, WPA stone bridges and culverts are actually rather common. The reason for this is likely that the relatively scantily populated western counties did not have the money to build many bridges, so the WPA pitched in. One thing the WPA was definitely doing was bridging fords and replacing dilapidated structures; obviously in areas with less funds available there would be more fords to cross and derelicts to replace.
The WPA stone arch bridges represent an era of works projects typical of the Great Depression that from all appearances have helped to provide reliable transportation even to this day.
Stone Arch Bridges 