LOUISIANA, Mo. — Now that a new Champ Clark Bridge is carrying traffic across the Mississippi River at Louisiana, it's time for the old Champ Clark Bridge to come down.
Demolition of the old bridge, built in 1928, is already underway. However, the work will become more dramatic in the next few weeks when explosive charges are used to drop two big sections of the bridge into the river before those sections are hauled away.
Keith Killen, project manager for the Missouri Department of Transportation, said MoDOT officials have been fielding lots of questions from area residents about the demolition plans.
"We've been asked more about the demolition than the ribbon cutting," said Killen, who served as master of ceremonies at the Aug. 3 dedication of the new Champ Clark Bridge.
Killen will be on hand when MoDOT and Massman Construction co-host the monthly update meeting for the Champ Clark Bridge project at 10 a.m. Saturday in Louisiana's Riverview Park. The primary topic will be the demolition of the old bridge.
Massman Construction was the general contractor for the $60 million bridge construction project. The company is also overseeing the demolition of the old bridge.
Killen said the first step in the demolition process involved milling off the asphalt driving surface from the old bridge's concrete deck.
"That didn't take too long," he said.
The next step -- now underway -- involves removing the concrete deck itself. This process is more tedious. It requires using a jackhammer to slash through large slabs of steel-reinforced concrete, which are then lifted out and hauled to a landfill.
"When you pull a section out, all you see is water below," Killen said.
Crews are working from west to east on the deck removal.
Once the deck is gone, demolition will begin on the steel trusses. Killen said this will require making strategic cuts to weaken the steel at key points. Explosive charges will then be placed near the cuts.
"Then when they blow the bridge, it will break the truss into manageable pieces that will fall into the river," Killen said. "They will then be able to pick up those pieces with a crane and set them on a barge to get them out of the river."
Killen said two sections of trusses will be dropped in two separate blasts. One of the fallen trusses will temporarily block the Mississippi River's main navigation channel. Based on U.S. Coast Guard regulations, Killen said, "when we drop the bridge (into the navigation channel), we will have 24 hours to get that material out of the water and get that shipping channel back open."
After the second truss section is dropped -- in an area outside the navigation channel -- the demolition crew will have two or three days to remove the debris from the river, Killen said.
Killen said the blasting dates haven't been finalized, but he estimates this work will take place "sometime in mid-October." MoDOT will announce the dates well in advance because of the strong public interest.
Killen said the new bridge -- about 50 feet downstream from old one -- shouldn't be threatened by the demolition.
"The old bridge will drop straight down," he said. "It won't tip to one side or the other."
Killen said safety measures will be taken to make sure any debris from the explosions won't strike the new bridge. He said the charges will be covered by a heavy belt, and "blast curtains" will be draped from the new bridge to stop or slow down any flying debris.
Once the two truss sections are dropped and removed, work will begin on removing a final truss section on the Missouri side of the river where the old bridge crosses some railroad tracks.
"That one will have to be disassembled in place," Killen said. "We can't drop material onto the tracks."
Killen said a "shoring tower" will be erected at that location to support the truss as it is disassembled.
Once all the trusses are gone, the contractor will remove the old bridge's concrete piers. This will require using jackhammers on any piers protruding above the water line. Explosives will be used on sections of piers below the water line.
"We will have to remove the piers (below the water) to an elevation given to us by the Coast Guard so that shipping navigation up and down the river will not be impacted," Killen said.
All demolition work is expected to be completed by the end of this year.
As part of the demolition process, some metal elements from the old bridge will be salvaged so they can be incorporated into a student-designed interpretive panel to be built in Riverview Park. The panel will showcase the history of the old bridge.