Summertime in the Great Lakes region is busy not just for marine navigation; it’s also prime time for dredging and maintenance of navigational infrastructure.
The Manitowoc crane barge and its accompanying tugs, the Racine and Kenosha, are regularly deployed from the Kewaunee Area Office to do work in the Detroit District and adjacent Chicago District in southern Lake Michigan.
Recently its nine-member crew completed breakwater maintenance at Milwaukee Harbor in Milwaukee, Wis., and Calumet Harbor in Chicago, Ill.
At Milwaukee Harbor, workers placed armor stones along the north wall — a 700-foot section of the four-mile-long breakwater, said Joe Kane, captain of the Manitowoc.
A few weeks later, the crew rebuilt 1,150 feet of the Calumet Harbor breakwall in South Chicago. This included recharging 50-foot segments enclosed and partitioned by sheet piling, called “cells” - by placing core stone in each cell. After placing core stone (crushed limestone) into the cells, crews placed cut stones, each weighing up to nine tons, along the top of the cells. Then they added armor stone along the sides. The crew also shored up the sheet piling on the sides of the breakwall. Next summer, the crew will devote considerable time to grouting the Calumet Harbor breakwalls.
On July 31, the Manitowoc crew arrived at Indiana Harbor in East Chicago, Ind., to begin dismantling a decaying steel superstructure from atop the pier. The catwalk-like structure, 2,300 feet long, was corroded and coming loose from some of its attachments to the concrete pier.
Crews removed the structure in pieces which they loaded onto the Manitowoc. The Corps worked out an arrangement with a local scrap metal company to take possession of the metal, thus eliminating disposal concerns. “It’ll be a win-win for both of us,” Kane said.
On the dredging front, several key projects were recently completed, said Mollie Mahoney, project manager in the Operations Office. These include Green Bay, Wis., and the Michigan harbors of Holland, Muskegon, St. Joseph and New Buffalo. Grand Haven Harbor was slated to be done by Aug. 31.
Several dredging projects were ongoing as of mid-August, including the Detroit River, Saginaw River/Bay, the Saginaw River turning basin emergency dredging and Manistee Harbor. Approximately a dozen other dredging projects had been awarded by mid-August or were scheduled to be awarded in the coming weeks.
Last winter, Congress approved a relief package for areas affected by Hurricane Sandy. The legislation included $2.6 million for seven Detroit District dredging projects intended to eliminate shoaling in storm-affected navigational channels.
The state of Michigan also approved $5.9 million for dredging seven harbors.
“Due to the addition of Hurricane Sandy projects, emergency dredging in the Saginaw River and the seven state of Michigan dredging projects, the district’s fiscal year 2013 dredging program has turned out to be much more robust than anticipated,” Mahoney said.
She added the district has been pleased with the dredging proposals received this year. “They have been competitively priced and have allowed us to use our limited dredging dollars more effectively.”