Swanage Railway volunteers are a step closer towards running steam trains between Wareham and Corfe Castle.
In 1972 seven miles of track were lifted in just seven weeks.
Plans are under way to initially run non-passenger trains, providing track maintenance on the line, followed later by passenger locomotives.
The plan would need approval by Network Rail and the Railways' Inspectorate.
Plans for a permanent connection on the newly-relaid Purbeck Line have been mooted since the old branch line closed more than 30 years ago.
Nick Brown, Swanage Railway general manager, said: "It took British Rail just seven weeks to lift the seven miles of track between Swanage, Corfe Castle and Motala near Furzebrook during the summer of 1972.
"It took the volunteer-run Swanage Railway 30 years to relay it."