Suspension Bridges

E.E. Runyon and Cable Stayed Bridges

The Bluff Dale Bridge was one of three bridges commissioned from Runyon and Flinn by Erath County in 1890. Barton Creek was another of these bridges; the third does not seem to have survived. The Bluff Dale Bridge showcases Runyon’s peculiar design for the bent, which supports the deck of the bridge at either end. Runyon’s bent is secured by a seemingly unwieldy system of cables and castings.

Barton Creek and Bluff Dale are not technically suspension bridges. In a suspension bridge, two long cables spanning the whole bridge attach to smaller vertical cables which ‘suspend’ the deck. But in a cable stayed bridge like Runyon’s, the cables attach directly to the tower. Cable stayed bridges do not require cable anchorages on the bank to be as strong, because the brunt of the force is placed directly on the tower.

Cable stayed bridges like these were exceedingly rare before World War II, and Bluff Dale may be the earliest bridge of this type ever built. The bridge was relocated to its present site in 1934 and was only closed =to traffic in the early 1990s, 100 years after its initial construction. Wrought iron gas pipes, which Runyon called “needle beams,” make up the deck. Runyon used this repurposed material because it was lightweight, cheap, and readily available in his rural surroundings.

E.E. Runyon and Cable Stayed Bridges

The Barton Creek Bridge was abandoned in the 1940s and quickly forgotten, until its rediscovery in 2000 prompted a thorough survey of this unique structure by the Historic American Engineering Record. Although severely dilapidated, the bridge still displays elements of Runyon’s unique cable stayed design.

Barton Creek Bridge contains no fewer than 120 hand twisted wires, several with the castings for Runyon’s patented tensioning method still attached.

This modern day reconstruction of the original Barton Creek Bridge includes a model of Runyon’s unique hand-tensioning technique in the bottom left.

The towers attach to the roadway through a complex series of castings and cables. Unfortunately, these features have severely deteriorated.

This photo shows the Barton Creek Bridge shortly after its completion in 1890.

A Vernacular Experiment in Hood County

The Rock Church Bridge spans the Paluxy River in Hood County near an old Methodist church. Because of poor records, researchers do not know who built this bridge or when it was constructed. The deck is 13 feet wide and would have been able to accommodate buggies and wagons, even though its construction methods are unsophisticated compared to Runyon’s and Greer’s bridges. The Rock Church Bridge was taken out of public service in the 1970s; it has since become private property.

The amateur design of this bridge is apparent in the diagonals seen in the top photo. They have no means to transfer their horizontal force component into the bridge deck, causing the beams to buckle.

The north side of the bridge used to have a timber approach, until ranchers removed it to stop their cattle from crossing the bridge. All that is left is the concrete pier on which the approach once rested. Read more about the bridge and images in the Historic American Engineering Record files.

William Flinn

William Flinn, Runyon’s partner in the Bluff Dale and Barton Creek Bridges, went on to construct his own suspension bridges with contractor A.A. Moyer. Flinn worked long hours on projects across the state and family tradition holds that he died of a tooth infection while at a bridge site in Palo Pinto County. Not long afterwards, Moyer married Flinn’s widow, Alice. The only surviving works of the Flinn-Moyer Company are the Beveridge Bridge over the San Saba River, and a bridge over the Clear Fork of the Brazos River in Shackelford County, both completed in 1896. Although originally built to be almost identical, both bridges were later repaired by the Austin Brothers Bridge Company (Beveridge in 1938 and Clear Fork in 1926). They so thoroughly remade the Beveridge Bridge that the towers and the builder’s plate are practically the only original components left.

The Beveridge Bridge uses tripod towers to support the main compression load. The Clear Fork Bridge used the same design, but its tripods were encased in concrete during the Austin Brothers Bridge Company’s 1926 renovations. This gave the bridge a monumental profile, unlike any of the other vernacular suspension bridges.

The Flinn-Moyer Company would set up camp while they worked at a bridge site. Construction on these lightweight suspension bridges generally lasted two or three months.

This photo, taken at an unidentified Flinn-Moyer Bridge Company site, reveals the scale of wire used in suspension bridges. The man on the left is standing in an anchorage hole.

Read more about the Beveridge and Clear Fork bridges and these images in the Historic American Engineering Record files.