The Esch’s Spur Bridge (called Kirk Bridge on the plaque, and also known as Pudden Bridge) is a well-known triple-arch bridge outside Dexter, Cowley, Kansas, that is listed on the National Register of Historical Places.
Built in 1913 by Walter Sharp, this bridge has spanned Grouse Creek for over a century. Arguably the most renowned of the Cowley bridges, it is certainly a must-see for any stone arch bridge enthusiast. It is a very long bridge, and, though perhaps a little difficult to capture in a photograph, the sheer massiveness of this stone structure is awe-inspiring.
The Esch’s Spur Bridge is one of a kind among Cowley County bridges. Whereas Walter Sharp typically favored starting the arches at or near the stream bed, the three arches of the Esch’s Spur Bridge are “sprung” off of high up on piers to increase the waterway. As such, the arches are relatively flat, giving the bridge a unique appearance. For Walter Sharp this was an experiment that nearly failed, as during construction an arch collapsed shortly after completion due to overturning of the pier caused by the horizontal thrust inherent in a flat arch.
When all of the arches are in place, the bridge is stable (the horizontal thrusts tend to cancel out on the piers, as two arches are “pushing” in opposite directions on top of the pier), however, this typically requires the arches to be built up simultaneously rather than individually, increasing complexity of design and cost. Of course, as mentioned before, Walter Sharp was experimenting with ways to increase waterway and, apparently, did not realize how much horizontal thrust he had to reckon with.
Unfortunately, the Esch’s Spur Bridge was damaged in the same flood that took down the Fox stone arch bridge upstream. The bridge has been closed ever since. An investigation shows that the cause of the bridge being closed was probably arch damage. On the upstream face, right where the middle arch meets up with the pier, several arch stones are missing, while many others are broken. Furthermore, above the broken part of the arch, the spandrel walls that retain the road fill are sagging downwards, probably from partial loss of support.
Given the state of the bridge, a well-placed impact by floating debris can easily knock out more arch stones, now that the arch face has been loosened up. It is obvious from the damage to the bridge that the Grouse Creek must have been on an incredible rampage when the damage occurred.
High velocity debris can pose a bit of a threat to stone arch bridges, which is why the arch faces usually receive extra attention in stone arch bridge construction. Walter Sharp stated that he cut the arch faces of his bridges to fit reasonably well, while the interior archwork was done with mortar to make the angles.
Stone Arch Bridges 