The Milton-Madison Bridge
connects Milton, Kentucky to Madison, Indiana and carries U.S. Route 421 over the Ohio River. The historic two-lane Cantilever is currently being replaced in a design-build.
Constructed in 1928-1929, the two lane cantilever truss bridge cost over $1 million to construct and was financed with a 45 cent toll for automobile drivers. The span consists of a 5% approach grade and 19 spans, with five separate bridge design types. The Milton-Madison Bridge connected Kentucky State Routes 36, 37 and 42 with Indiana Highways 7, 29, 56 and 62.
On November 1, 1947, the toll was removed for the bridge and ownership of the span was transferred to the Kentucky Highway Department. The tolls were removed several years earlier than anticipated.
In 1997, the bridge received a thorough rehabilitation. The project included the replacement of the bridge deck, structural steel repairs, patching to existing concrete elements and a new paint overlay. Prior to the rehabilitation, the bridge required a weight restriction, which was removed after the work was completed.
In a 2006 fracture critical inspection, the bridge was given a rating of 4, or poor condition, on both main truss members and floor beams. While all of the truss members were adequate for Kentucky truck permit loadings, the crossing featured inventory ratings less than Inventory Loading (HS20). Issues included pack rust in numerous areas and pitting and section loss to truss members, exterior stringers and floor beams and lateral bracing members. The paint was also rated as fair, and was tarting to fail in several areas due to prior corrosion and poor adhesion. The deck was rated in good condition, although deck leaking was causing some stringers to rust beneath.
An estimated lifespan for the bridge without another rehabilitation was set at ten years.
In June 2008, the Kentucky Transportation Cabinet (KYTC) and the Indiana Department of Transportation (INDOT) launched the Milton-Madison Bridge Project in an effort to replace the aging bridge. The projected cost of the new bridge was $131 million, and it was expected that both states, Kentucky and Indiana, would identify state and federal funding sources for the cost of the project. The cost of the new bridge was split evenly between the states.
In February 2010, the bridge project received final federal environmental approval. In addition, the project received a boost when the project was awarded $20 million in funding from the American Reinvestment and Recovery Act. A project contract was advertised that June, and on September 23, the construction contract was awarded to Walsh Construction with a low bid of $103.9 million. Walsh’s bid was the only one submitted that had a total closure time of the bridge of less than one year. Ground was broken on November 30 for the new bridge.
Construction began in January 2011 with the first phase of the project, which involved strengthening the existing piers.
Work on temporary approach ramps from Kentucky State Route 36 and Vaughn Drive began in the summer, which will allow for the existing approach ramps to be removed and replaced.
During that time, work began on the temporary downstream piers, and construction of the first truss for the new bridge for the downstream piers began in the fall. The 600-foot, 1,700-ton section of truss is being preassembled, and when the span is completed, the span will be floated upstream where several hydraulic jacks will lift the entire section into place onto temporary piers. A second truss, 727-foot long, will then be constructed and lifted into place onto the temporary piers.
At some point, two nearly completed bridges will be side by side. Traffic will be moved onto the new bridge via the temporary ramps, and the old Milton-Madison Bridge will be severed from the piers using controlled explosives. The bridge will be removed from the river with cranes within 24 hours. The total bridge closure time will only be ten days, less than an earlier projected closure date of one year due to the innovative construction techniques being deployed with this project. As such, ferries that were going to be deployed during the construction project may not be needed.
In late 2012, Walsh Construction Company will “slide” the new bridge from its temporary piers onto the original but strengthened piers. The new bridge, which will include a pedestrian sidewalk and bike lanes, is expected to open by September 15, 2012.Further Reading
a. Milton-Madison Ohio River Bridge Replacement (blog): http://bridgestunnels.com/2012/01/23/milton-madison-ohio-river-bridge-replacement/
b. Milton-Madison Bridge (US 421): http://bridgestunnels.com/bridges/ohio-river/milton-madison-bridge-us-421/