In 1950, five trains operated a week, and with non-limestone traffic dwindling it was inevitable that the Dunback section would be closed and services concentrated on Makareao. Closure of the four kilometres from Inch Valley to Dunback took place on 1 January 1968 and limestone became the line's sole traffic. Services operated thrice weekly to Dunedin's Burnside Cement Works, with the trains of four-wheeled wagons, typically hauled by DJ class locomotives, nicknamed "stone trains". From at least 1952 trains were limited to 30 km/h for the entire line, and in 1988 this dropped to 20 km/h. During these later years occasional passenger excursions were operated down the line by railway enthusiasts and organisations, notably the Otago Excursion Train Trust.