Workers began blasting a section of the old upstream guard wall Wednesday at Locks and Dam No. 4 along the Monongahela River in Charleroi as part of the construction of a new river chamber.
Lockmaster Paul Meininger said the top half of the wall had already been demolished by a concrete-busting machine, leaving contractors for the U.S. Army Corps of Engineers to use computer-controlled explosives to blast the submerged portion.
Meininger said blasting on a 60-foot section of the wall went smoothly and the chamber was closed for only about three hours Wednesday. Crews are hoping to take on a longer piece of the wall next time, he said.
“What they’re going to do is blast it all before they remove any (debris) from the river,” Meininger said.
This particular phase of blasting and debris removal is slated to be complete by March 1.
Described as a concrete bumper designed to take a beating, the wall had served to keep boats from being drawn toward the dam as they enter the chamber, Meininger explained.
With regard to the forthcoming improvements, Meininger said the new chamber will be wider and twice as long as the current one.
The present site of Locks and Dam No. 4 was completed in 1932 and later underwent a major rehabilitation project that wrapped up in 1967.
More recent plans to update the crumbling navigational locks and dams in Charleroi, Elizabeth and Braddock were authorized by Congress in 1992, but went underfunded in nearly every subsequent federal infrastructure bill. Given the funding issues and increasing costs, the work in its totality isn’t expected to be finished until 2024.
In early 2010, Locks and Dam No. 4 celebrated $67 million in new construction work funded through the federal Recovery Act.