 Until 1967, the Wairarapa Line was the only way DA class locomotives could access Wellington due to tunnels south of Paekakariki being too small.In the 1980s, the DG class had been fully withdrawn and the DA class in the process of withdrawal or conversion to the DC class; accordingly motive power on the Wairarapa Line changed.Until 2015, the DC class was the mainstay of the Wairarapa line south of Masterton, with locomotives of the DBR, DF/DFT and DX classes occasionally used.