A year and a half after being closed to traffic, closing off one of the city’s main thoroughfares, the 80-year-old Washington Street bridge at Clark Street began coming down Saturday in preparation for its replacement by a roadway-topped rail tunnel expected to be completed by next summer.

“The sooner they get it out, the happier I am,” said Bubba Rainer, Vicksburg public works director.

Construction crews have been waiting on Kansas City Southern Railway to give clearance to take down part of the 200-foot bridge directly over the railroad tracks. Rainer said construction crews were expected to need two to three hours without rail traffic to take down the most vital section of the concrete span. Though city officials had expected that window frame to open up Monday, crews began chiseling away at the concrete bridge around 1:30 Saturday afternoon.

“The plan is to take that middle section out first, and then they can come back and pull the main beams without needing the trains to be stopped,” Rainer said.

The span is the lone bridge along the main north-south corridor connecting downtown and Interstate 20, and its closure since January 2009 has become a major headache for motorists and business owners along Washington Street. Kanzaa Construction of Tokepa, Kan., inked a not-to-exceed $8.6 million contract for the project earlier this summer, and crews have been doing preliminary ground work since late June.

“It might look like it’s been moving slow, but they’re still in the preliminary stages and that’s when a lot of time is spent planning and testing,” Rainer explained. “Right now, I’d say they’re about right on schedule.”

Phase one of the 12-month bridge replacement project includes the creation of a temporary city street running parallel to the DiamondJacks Casino entrance off Washington Street, just south of the bridge. The casino entrance will be widened to three lanes, two for city traffic and one for the casino. The street will connect with Lee Street and become the new detour route until the tunnel is complete.

On Saturday, groundwork also was in full swing on the new roadway, which is expected to be done in the next five months. Traffic is being detoured east around the bridge via Lee Street, Army-Navy Drive and North Frontage Road.

The city agreed to the contract price with Kanzaa last summer, but did not have funding in place to get the work started because the cost had nearly doubled since officials set aside $5 million of a $16.9 million bond for the work in 2006.

The mayor and aldermen got the funds in place in late March by rededicating $3.7 million in bond funds — also from the 2006 loan — to the tunnel project. The bond funds were originally earmarked for paving projects in the North Ward and the final phase of the developing sports complex on Fisher Ferry Road. They will be replenished if a $4 million federal earmark the city formally requested of local legislators in February comes through.

KCS is to pay $4 million of the project.