(CHICAGO) The city will break ground Thursday afternoon on a $100 million factory that will churn out new rail cars for the CTA on the Southeast Side.

The new manufacturing plant at 13535 S. Torrence Ave. will create more than 300 skilled factory and new construction jobs, according to a statement from Mayor Rahm Emanuel’s office.

Once complete, the first order of 400 new, 7000-series rail cars will mark the first time in more than 50 years that CTA cars have been built in the city, officials said. The new cars will replace the oldest ones currently running, which date back to the 1980s.

In a contract awarded last year, the CTA ordered a total of 846 new rail cars from CRRC Sifang America, which will manage the plant.

When the new vehicles are in service, the CTA will have one of the youngest fleets of any U.S. transit agency, according to the mayor’s office, which hasn’t offered a timeline for when the plant will be complete.