The first pieces of the new Main Street Bridge are expected to be put in place next week, although residents won’t get to see too much of it happening.

That’s because the work will be happening some 35-feet below the surface of the St. Joseph River in a water-protected cofferdam where steel pilings are being driven into the soil.

Christopher Jacobs, the lead engineer on the $10.6 million MDOT project to replace the Niles bridge, said the pilings would make up the foundation for the abutment on the east side of the river.

The pilings, he said, would be driven some 70 feet below the surface by a “huge diesel hammer” that is hoisted in the air by a crane. The hammer will start off just above the cofferdam and go lower into the dam as it drives the pilings farther into the ground.

“You will see it (the hammer) and you will hear it too,” he said.

That process is expected to begin next week after workers finish the cofferdam for the abutment on the east side of the bridge.

What is a cofferdam?

Jacobs explained that it is essentially a box made out of steel sheets that surround an area in which work is to be done. Water is pumped out of the cofferdam, allowing workers to work in a dry area.

After pilings are driven into the ground at the east abutment, the same process will be repeated for the west abutment and each of the bridge’s two piers, in no particular order.

Jacobs said they are currently on schedule to finish the project by November.

“We will try hard,” he said. “Even if we do get behind we have other means to accelerate (the process). The residents of Niles I’m sure are anticipating the opening of the new bridge.”

Work to replace the 90-year-old bridge began in October 2014.