Start 4: Olmsted Dam
Cost: $564 million

In the 1920s, some 50 locks and dams were built in the Ohio River for navigation between Pittsburgh and Cairo, Ill.

They have been replaced over the years, typically with one dam and lock replacing two or three old ones.

Only two of the original locks remain and by the end of this decade, these outmoded and crumbling structures will be replaced by the Olmsted Dam and Lock, crossing from Pulaski County, Ill., near Olmsted to Ballard County, Ky.

The Olmsted Dam will be a 2,400-ft.-long structure that will serve the busiest stretch of inland waterway in the United States. Some 90,000,000 tons of cargo transits this area annually, according to Larry Bibelhauser, project manager for the dam.

The U.S. Army Corps of Engineers awarded the contract in January to a joint venture of Boise, Idaho-based Washington Group International and St. Louis-based Alberici Constructors. The dam will be built over an eight-year period, and it is expected to be complete in November 2011.

The joint venture was selected on the basis of its proposal, past river experience and management team, Bibelhauser said.

Unique Dam Building

The Olmsted project will feature a new method of dam construction. Without halting the flow of the river, piles will be driven in the river bottom, and rebar cages will be placed on the bottom around the piling.

"We build big concrete shells on the shore, like a precast yard, then let them down a ramp like you'd launch a barge," Bibelhauser said. "We pick them up with catamaran barges and carry these big, empty, shoebox-like shells out into the river to the place where the piles are, then put this shell over the piles and fill the shelling with tremie concrete."

The concrete shells are enormous. Measuring about 100 by 125 ft., they cover roughly the area of a quarter acre. They stand as much as 30 ft. tall, and weigh as much as 3,700 tons.

The contractor will work year-round fabricating the shells. The actual river work takes place during a 5.5-month construction season, from mid-June to December, when the river is at its optimal level for construction.

When complete, the ownership of the dam will pass from project management division to the operations division of the U.S. Army Corps of Engineers.

The federal budget is one of the biggest issues, Bibelhauser said. "I will be challenged to find enough money to pay the guy each year," he added.

The other problem is "figuring out how to get the rebar cages on the bottom, around the piling, so that you can set that shell over the top of the rebar cage. Just dealing with Mother Nature in general during that 5.5-month construction season [is complex]."

Nevertheless, Bibelhauser is upbeat about the project. "I've got a new team excited to get started, and looking forward to the new challenge," he added.

Return to Top of 2004 list