THOMASTON — Dragon Products expects to stop shipping cement along the Rockland South End rail line starting next year.

The cement plant purchased the 44 Atlantic St. property in 1994. The Thomaston cement plant since operated the marine terminal in Rockland.

The cement plant sends rail cars about five miles on the line from the Thomaston plant to its dock on Rockland’s South End waterfront, where a barge is then filled and product shipped to the Boston market.

Next year, the rail cars will no longer be licensed for service, said Dragon environmental, health and safety manager Anna Hooper.

“Therefore, we must take these cars out of service and replace with new cars that comply with the new specifications. At the same time, and due to this rail car change, modification to the marine loading operations must be done. Presently, cost estimates and timing are being considered,” Hooper said.

Dragon will continue to sell cement from the plant in trucks and ship cement in rail directly to its customers but not to the terminal, she said.

She said the change should not impact the employees because the company sends full-time plant employees to the terminal, as necessary to operate the Rockland terminal. Those employees work full time at the main plant when not at the terminal, Hooper added.