Work is on to replace Yazoo bridge|[01/29/07]
Published 12:00 am Monday, January 29, 2007
Haulers of logs and heavy equipment must be counting the days.
With work on the first of two Yazoo River bridges under way at Redwood, the day when too-tall loads must find alternates to U.S. 61 is coming to an end.
Sources said the work is progressing well in spite of some aspects being hampered by high levels in the Yazoo.
Keys Constructors Inc. of Madison won the the $32.7 million project from the Mississippi Department of Transportation and began moving equipment to the site in September.
By June 1, 2009, an elevated two-lane bridge is to be in place immediately west of the existing bridge, said Walter Lyons, engineer for MDOT’s District 3 headquartered in Yazoo City.
Unlike the older bridge, which dates to 1950, the new structure will be “open top” with no overhead trusses.
Trusses on the existing bridge have been battered by drivers who tested the 14-foot, 6-inch clearance through the years and failed. The clearance is not the only problem for the bridge, which, despite its limitations, is one of the nation’s most scenic.
“The problem is it’s too narrow. The clearing is so small,” Lyons said. “It doesn’t meet the current standards.”
Lyons said the old bridge is the last of its kind in Warren County and only one or two truss-type bridges remain in the district, which includes 12 counties.
“There’s nothing of this magnitude, though,” Lyons said.
Giant cranes now dominate the Redwood site as forms are being built and concrete poured for supports.
“According to the December report they were 19 percent complete and have used 11 percent of their time,” Lyons said.
Rick Webster, chief executive officer for Keys, said the company is pleased with the progress.
“It is going well,” he said, adding the water level in the Yazoo has been hampering work on some of the bridge piers closest to the water. “The river forced us out earlier than we expected,” he said.
Along with the superstructure, work is under way on the approaches, which are part of the same contract. Warren Excavating is doing that work.
A challenge, Lyons said, is designing supports that will be substantial enough.
“There is no bedrock in the Delta and you have to drill a lot of shafts” to get enough mass in the ground to support something, Lyons said.
Until the new bridge at Redwood is opened trucks with overheight loads will be warned off by sirens, lights and horns installed on approaches to the old bridge.
Initially, the MDOT planned a second, two-lane bridge to be built immediately following the first, perhaps in the footprint of the existing span. That has changed.
“A second bridge is not part of this project,” Lyons said.
Instead, additional lanes from where the four-lane section of U.S. 61 North ends at Redwood north will not be built until the traffic load justifies it.
Lyons predicted, based on the progress so far, Keys would finish the project ahead of time.
Webster was more cautious, saying that all depended on the weather and river levels.
“You can’t predict Mother Nature,” he said.
But, he said, finishing on time or early is what the company likes to do.