Company will use both mechanical removal and dynamiting to remove rocks from a two-mile stretch of the Mississippi River.
Newt Marine, a dredging, marine construction and dry docking firm based in Dubuque, Iowa, has begun the process of clearing the rocks that have slowed barge traffic in the Thebes, Ill., area of the middle Mississippi River. The U.S. Army Corps of Engineers (USACE) says the area, which runs from River Mile 46-41 of the Mississippi, has seven areas that were identified as key target areas for rock removal.
Newt Marine was one of two firms that were recently awarded a contract by the USACE to undertake the removal of rock pinnacles in a two-mile stretch two miles upstream of the Thebes Bridge around mile 47. The other company receiving the high-priority contract is Durocher Marine.
According to Dan Arnold, Newt Marine’s construction manager, the company started work on the project on Dec. 10, and will be working roughly 16 hours a day, from 6 a.m. to 9 p.m. to clear the rocks that have been slowing the flow of barge traffic in the region. Barge traffic will be allowed to pass through the channel the other eight hours. The USACE says that due to the low water and time of the year, the impact to navigation will be minimal.
Newt Marine will use a mechanical removal process with excavators and buckets for a majority of the project. Rock outcropping that can’t be handled with the excavators will be removed by drilling and dynamite, Arnold says. For the mechanical removal, the company is using two CAT excavators on specialized barges. The company also has barges attached to the excavators where the rock that is removed will be placed. The company will deposit the rock in deeper areas of the Mississippi River.
For dynamiting, in a local report Arnold says, “At this point, we have about 20,000 pounds of dynamite ready to go on site, and we will probably drill somewhere in the neighborhood of 1,400 holes in the rock is what we have planned right now to break up the areas that need to be dynamited.”
Arnold says the company’s goal is to complete the clearing of the rock from the three-mile stretch by the end of January 2013.
The other firm that has received a contract by the USACE to remove the rock pinnacles is Durocher Marine, a division of Kokosing Construction Company Inc.
According to the USACE, removal work began on Dec. 15. The USACE says most of the rock removal will be through excavation, although blasting also will be used where mechanical removal is not possible.
The work is expected to remove around 890 cubic yards of limestone from the river to reduce the risk for vessels in the channel during low water. Mike Petersen, a spokesman for the USACE’s St. Louis office, says that the Corps has earmarked an additional 6,000 cubic yards of rock that should be removed on a longer-term project.
The rocks are part of a large formation that impedes the navigation channel during low water. More rock removal is planned for later dates, but the work being done at the present time will have the most immediate impact on the navigation, the USACE notes.
“It has been going great right now. We are sitting down with all the parties. It has gotten lots of attention,” Petersen adds.