The Chessie System plans to start running excursion passenger train service next year over its 13-mile line between Baltimore and picturesque Ellicott City, but it won't use equipment resembling either of the trains that pioneered service over the same route in 1830.

But the journey to be made on weekends and holidays in self-propelled diesel cars, the same ones now used for weekday commuter trains on Chessie's Baltimore & Ohio line into Washington, will be a nostalgia trip just the same.

Excursion trains will start near B&O's museum and historic Mount Clare shops in west Baltimore and wind along the railroad's Old Main Line through the Patapsco River valley. After a 3 1/2-hour layover in Ellicott City, the Howard County seat, the trains will return to Baltimore.

Baltimore Mayor William Donald Schaefer disclosed the railroad's plan -- and claimed credit for suggesting it -- at a meeting of the Howard County Chamber of Commerce. It will be related to, but not financially connected with, the Mount Clare Junction commercial project, in which Chessie is a participant.

Lloyd Lewis, news and community relations director at Chessie's Cleveland headquarters, confirmed the plan. But he stressed that the excursion service must run at a profit based upon fare collections. "We can't subsidize it," Lewis said. The schedule and level of fares haven't been determined, he said.

Trains from Baltimore to Ellicott's Mills, as the town was then called, began running on May 24, 1830, with horse- drawn cars. The picture above depicts the tiny steam locomotive Tom Thumb racing a horse over the same route on Aug. 28 of that year. The locomotive led much of the way but broke down, and the horse won.

But the demonstration was persuasive enough that the B&O soon shifted to steam power.

Old Main hasn't had passenger trains for decades, and is now used as a bypass around Washington for heavy freight trains -- notably coal carriers -- from the Alleghenies.