The purchase of 20 steel ballast cars by the Massachusetts Department of Transportation will make track work easier and save money on leasing equipment, according to the department.

At a cost of $3.2 million, the cars that arrived last week are expected to last 50 years and will obviate the need for renting similar equipment, according to MassDOT, which said it cost $109,000 to lease ballast cars in fiscal 2017.

Ballast cars are hopper railroad cars filled with chunks of stone. The stone provides a foundation for railroads. The new cars have remote-operated gates that “makes the process of pouring ballast speedier, more efficient and safer than traditional ballast cars, which typically require personnel to crank the gates open and closed by hand,” MassDOT said.

“With this investment, MassDOT is continuing to take steps to improve its rail infrastructure and ensure that our customers can count on reliable service and our freight partners can use our system for their transportation needs,” MassDOT Rail & Transit Division Administrator Astrid Glynn said in a statement.

The cars were manufactured by FreightCar America in Danville, Illinois, according to a MassDOT spokesman, who said they “will be deployed on all state-owned rail lines as part of a system-wide rail tie replacement project.”