An engineer with the Michigan Department of Transportation said Thursday that nearly two-dozen massive bridge beams will begin arriving at the Main Street Bridge project site in downtown Niles Sept. 1.

Chris Jacobs said the 21 beams are all approximately 123-feet long, and each weigh approximately 72 tons.

The beams won’t be placed immediately as originally planned, Jacobs said, because workers are waiting to receive a special crane needed to complete the job. Instead, the beams will be staged (stored) at the construction site until the crane is available, likely on Sept. 10. At that time, the beams will be set in place spanning the abutments and piers.

About half the beams will arrive Sept. 1 and the rest about a week later.

Jacobs said people might encounter brief traffic delays as the beams are being delivered.

“There could be some short delays because the pilot cars will have to block intersections off,” he said.

Beams being delivered to the east side of the bridge will travel from US-12 to M-51 (South 11th Street) and then through downtown Niles using East Main Street.

Beams being delivered to the west side will travel from US-12 to M-139 (West Chicago Road) to Lincoln Avenue and finally to West Main Street.

In the past week, Jacobs said workers finished building and pouring concrete for the abutment on the west side of the St. Joseph River. Workers also removed retaining walls along the bike path on the west side of the river in preparation for the construction of new retaining walls.

Jacobs said workers would begin backfilling the west side abutment and pulling the sheet pilings next week.

As for the timeline, Jacobs said they are still about three weeks behind schedule, but still on track to have the bridge open to traffic at the end of November or beginning of December.

Work on the $10.6 million MDOT project to replace the 90-year-old Main Street Bridge began in October.