The Public Works Department began building the 5.5-km line in 1902, but it was plagued with difficulties. Construction of the Grey River bridge suffered from delays, a contractor for a trestle bridge further along the line went bankrupt, and torrential rain made working conditions hard and problematic. As construction slowly progressed, work on an incline from Blackball into the Paparoa Ranges was commenced by the Paparoa Coal Company. This line was ultimately taken over by the State Mines Department and involved a Fell centre rail for braking due to grades as steep as 1 in 25. This was not a full incline like its North Island counterpart, the Rimutaka Incline.