DETROIT – General Motors’ Detroit-Hamtramck Assembly Plant is undergoing its first major expansion since it opened in 1985.

Built on a 365-acre site, GM’s “Poletown” plant is currently undergoing an expansion that includes five major additions totaling 500,000 square feet. General contractor Ideal Contracting is managing the project, and along with its subcontractors, about 125 to 150 Hardhats have been employed at the site this summer.

The new space is all about logistics: it will provide GM additional room to store parts on site and to more easily move materials.

Work on the $40 million expansion started last November , and is expected to wrap up in October. There are five separate additions going in at the plant: the West Logistical Operations Center (LOC), the West LOC 16Bay-Area 2B, the North LOC, a Five Bay Loading Dock, and the East LOC.

“The work is scattered throughout the site,” said Ideal Contracting Project Manager Glenn Peer, Jr. “Most of the work is building big warehouses for parts, so GM can eliminate off-site storage.”

Peer said the building additions, all separate from each other, are all fairly standard shell spaces. Eight-inch thick concrete floors are built above caissons, with 30-foot walls to match those of the existing plant. “The tradespeople have been great; fantastic,” Peer said. “They worked through one of the toughest winters we’ve ever had, and we’re still on schedule.”

Peer said one of the major challenges of the project is simply staying out of the way of the plant’s operations. He said the schedule is tight, and the different additions are being turned over to GM one by one. When the 3.6 million-square-foot Detroit-Hamtramck Assembly Plant was built, Peer said GM allowed for future expansion, but “it’s still pretty tight, and we’re landlocked in a number of areas.”

The Poletown plant employs about 1,600 workers, who build the Chevrolet Volt, Opel Ampera, Holden Volt and Chevrolet Malibu and Impala and Cadillac ELR. More than 3 million cars have been assembled at the plant since it opened.

“We basically started busting at the seams and moving material off-site,” Plant Manager Doneen McDowell told The Detroit News. “A lot of waste was driven at that process primarily because we didn’t have the floor space to support all the models we’re currently building in-house.”

The expansion at the Detroit-Hamtramck Assembly Plant was one of three major investments in Michigan facilities announced by GM last December , totaling $1.2 billion. The automaker also announced investments of $600 million at its Flint Assembly plant and $493 million at its Romulus Powertrain Operations facility.

“GM is committed to a strong American manufacturing base and creating jobs in dozens of communities throughout the country. Today’s announced plant upgrades continue the momentum of a resurgent auto industry,” GM North America President Mark Reuss said in a statement. “More importantly, these investments add up to higher quality and more fuel-efficient vehicles for our customers.”

ROLLING OUT a wet cure membrane for newly poured concrete inside the Poletown Plant’s new East Logistical Operations Center addition is Silas Cox of Cement Masons Local 514. He’s employed by Barton Malow.

RELOCATING A FIRE SPRINKLER supply line near the Five-Bay Loading Dock at the GM Detroit-Hamtramck Assembly Plant are Kevin Grosbenor and Craig Sims of Sprinkler Fitters Local 704. They’re employed by Simplex Grinnell. In the foreground is the crew helping them with the excavation process: Local 324 operating engineer Dion Oscendosky, and laborers Kingyero El-Shabazz (Local 1191) and Ignacio Angel (Local 1076).