Abandoned swing truss bridge in Louisiana

Vida Shaw Bridge, Loreauville Louisiana

Date added: June 17, 2023 Categories: Louisiana Bridges

View of Bridge facing east-southeast (2009)

The 1940 Vida Shaw Bridge is the result of an effort by Iberia Parish to build two bridges over Bayou Teche; one at this location, and one at Morbihan. The swing bridge replaced a timber bridge in that location. The bridges were designed by Thomas J. Jones and constructed by Daniel Jeffrey and Sons, Inc. The Parish released an advertisement for bids on June 29, 1938, and the winning bid was submitted by Daniel Jeffrey and Sons, Inc. for the total cost of $31,560.00. The contract between Parish and the contractor was then signed and executed on July 21, 1938.

The State of Louisiana has been the home to a large number of moveable bridges, especially swing-span bridges, because of the many navigable waterways and the soft soils that characterize the state. The four common moveable bridge types in Louisiana in the first half of the twentieth century were: pontoon, bascule, vertical-lift and swing span. The most productive period in highway and bridge construction in Louisiana, prior to the introduction of the Interstate Highway system, was 1928 to 1939. Governor Huey P. Long was largely responsible for this, as he made the improvement of roads in Louisiana a priority during his administration. During this period, 1,083 bridges were built; thirty-four of which were high steel swing-span bridges. As of 1999, the Louisiana Department of Transportation and Development (DOTD) identified eleven high steel swing span bridges that survived; only six of that number are still extant today. One, the Ouachita River Bridge at Sterlington, has already been replaced and is slated for demolition.

The very earliest swing bridges were wooden and were center-bearing, meaning they rotated on a central pivot. However, the earliest swing bridges in the United States were rim-bearing, meaning the bridges rested on a series of evenly-spaced rollers that traveled on a track. One of the earliest was the Rush Street Bridge in Chicago, built in 1856. Likewise, the earliest swing bridges in Louisiana were also rim-bearing, such as the no longer extant 1897 Ouachita River/ Desiard Street Bridge (Endom Bridge). Rim-bearing swing span bridges most commonly date from the 1890s to the 1920s, although there are some that were built later. Railroads, in particular, continued to build the rim-bearing swing span type because it was generally preferred for bridges with long or heavy spans. Rim-bearing swing span bridges are less common than other types of spans and are commonly operated by electric motors. Hand-operated swing spans are typically seen on older or smaller spans. As of the first quarter of the century center-bearing spans had largely replaced rim-bearing as the favored type for swing bridges in the U.S. This is due to their superiority for several reasons, which include: the live load is distributed to the pier instead of the pivoting mechanism, reducing the number of parts that are subject to wear from vertical loads; the manufacture and construction requires less precision; and a smaller central pier is required, resulting in economy of materials.

The bridge was vital to the ability of the mill to receive sugar cane for processing, and therefore vital to the economy of the communities of Vida and Loreauville. The Vida Sugar Mill operated in the Loreauville vicinity from the mid-19^th century until it closed in 1972. The bridge provided a direct route for sugar cane transport (raw and finished products) over Bayou Teche to and from the Vida Mill. Before its closure, the mill played an important role in the industry and commerce of the Loreauville vicinity. It supplied permanent, year-long employment to some of the local population and seasonal work during the harvest for others. It also supplied a local processing center for the sugar cane farmers in the Loreauville area. While sugar cane farming and processing are not unique to the Loreauville vicinity or Iberia Parish, the sugar cane industry was and still is very important to the area. Although the mill is gone, sugar cane is still grown at nearby farms today and still is an important contributor to regional and state agriculture and commerce. In addition, the sugarcane industry is today marketed for tourists; Iberia Parish holds an annual Sugar Cane Festival. Just as the mill played an important role in the commerce and agriculture of Loreauville and Iberia Parish, the bridge provided an important transportation link to this important agricultural processing facility. The Vida Shaw Bridge remains and is considered by the members of the community to be a tangible link to their contribution to the early twentieth-century development of sugar cane farming and processing in Louisiana. According to one resident, "the fact that we are still growing sugar cane in Louisiana is due to the investing in sugar mills by individuals and families in small communities of Louisiana to harvest crops in their immediate area until larger and more efficient mills came into being. I am proud to say that Vida was one of these mills."

Bridge Description

The 1940 Vida Shaw Bridge is a one-lane, vehicular bridge, located on Vida Shaw Road (Parish Route 402) over Bayou Teche in Iberia Parish, Louisiana, approximately one mile south of Loreauville. The steel swing span is composed of two Warren with verticals through trusses, each 65 feet long. The bridge has a wooden deck and sits on wooden piles with a wooden approach from the west and wooden abutments on both the west and east ends. The swing span has been locked in the open position since July 2007 to be navigable for marine traffic, but not for automobile traffic.

The 1940 Vida Shaw Bridge is the result of an effort by Iberia Parish to build two bridges over Bayou Teche, one at this location, and one at Morbihan. The bridges were designed by Thomas J. Jones in 1938 and constructed in 1940 by Daniel Jeffrey and Sons, Inc. at a cost of $31,000. The subject bridge is located on Vida Shaw Road (Parish Route 402) over Bayou Teche in Iberia Parish, Louisiana, approximately one mile south of Loreauville. Other, larger bridges that cross the bayou are in the vicinity of the Vida Shaw Bridge. The bridge rests on wooden piles and wooden abutments, and is composed of five spans-three timber stringer approaches and two main Warren with verticals thru truss spans. In length, the timber stringer approach spans are as follows (west to east): span 1 is 17' long, span 2 is 18'8" long and span 3 is 16' long. The two main steel spans are held together in tension and rotate on a rim-bearing mechanism. They are each 65' long. The bridge has a wooden deck and wooden rails. Including approaches, the bridge is 202' long and 13'1" wide from curb to curb. The roadway vertical clearance on the swing span is 13'. According to the Louisiana Department of Transportation and Development, the approach roadway width is 28'. When closed, the bridge has a marine vertical clearance of 12'8", but has no marine vertical clearance issues when opened; it has a marine horizontal clearance (largest space between piers for passage of water traffic) of 45'.

Each end of the bridge has an abutment with wingwalls of identical construction. They are described in the original plan as bulkheads and consist of a wooden pile frame with treated boards stacked horizontally and bolted to the framework in order to shore up the soil and support the weight of the roadway at each end of the bridge, and also support the weight of the west end of timber stringer approach span 1 on the west end of the bridge. At the west abutment, the west end of timber stringer approach span 1 is attached with bolts. Although the original plans identify two 19' approach spans on the west end of the bridge, the existing condition is three timber approach spans on that end, supported by the abutment on the west and three bents, consisting of 6 piles each. Because the approach spans are supported by timber piles, which would require replacement over time, and because of lateral movement of the bayou, it is possible that the approaches were rebuilt with a different configuration sometime after the original construction date. It is also possible that the layout of the approach spans was changed during construction. A "helper" bent was added in 1990 in the middle of timber stringer span 2. The wooden piles are cross-braced with wood planks. A grouping of 36 wooden piles in the center support the swing mechanism and the entire weight of the main spans. Additional piles on either end of the main truss spans allow the rollers to rest on tapered blocks anchored to them, resulting in the stabilization of the ends of those spans when the bridge is in the closed position. The east end of the main truss rests on the east abutment when the bridge is in the closed position. A wooden fender system is also in place to protect the bridge piers from errant water traffic and guide boats through the deepest part of the channel. According to the original plans, all of the structural timber in the bridge is Southern Yellow Pine and treated with creosote and all of the wood pilings are capped with galvanized iron.

The swing span rests on a rim-bearing swing mechanism, which supports the trusses with a large circular drum that moves on rollers spaced evenly around the circumference of the drum. The dead load of the bridge is borne on the rim-bearing mechanism. The live load is borne by the rim-bearing mechanism, but also by the fixed spans (through the locking mechanism), when the bridge is locked in the closed position. The rollers move within a track and are held in position by steel radial roller shafts which radiate out from a capstan or center pivot bearing located at the center of rotation.

The wooden deck, which runs the length of the bridge, including timber stringer approach spans and Warren thru truss main spans, is composed of tongue-and-groove wooden planks with 6" x 6" timber curbs. A wooden railing runs the length of the three timber stringer approach spans, but a steel railing is attached to the vertical members of the main truss spans.

The Warren trusses that compose the main spans are each 65 feet long and contain 4 panels apiece. The two main spans are tensioned together by pin-connections at three central panels and they rotate on a rim-bearing mechanism. All the other connections on the steel superstructure are riveted. The center panel dimensions are 25' high by 16'3" wide.

The bridge was originally designed to be hand-operated; however, an electric motor was installed ca. 1955 to operate the swing mechanism. This kind of modification is very common for swing bridges. Other than this alteration, and the addition of pilings underneath the approaches, the bridge has undergone few alterations. To the superstructure, there are no signs of major alterations and all repairs have been made with in-kind materials.

Due to shifting of timber piers supporting the approach spans, the swing span often stuck on the piers supporting the western approach. In July 2007, the bridge was forced open for a boat. Since that event, the bridge has been locked in the open position to be navigable for marine traffic, but not for automobile traffic.