Rimutaka Tunnel the first fully dieselised line in New Zealand. Today, DBR, DC, DFT and DX class locomotives run the route. There have been proposals to electrify the tunnel and the Wairarapa line as far north as Masterton as an extension of the Wellington suburban electrification. The tunnel was designed to enable catenary to be installed but this has not happened, and the catenary finishes just north of Upper Hutt station. In 2007, Greater Wellington Regional Council rejected a call to electrify the tunnel, on the basis that patronage did not justify the expenditure, and that the tunnel would "have to be
Wairarapa Line North Island Main Trunk section between Wellington and Palmerston North. The line originally included the famous Rimutaka Incline, which used the Fell mountain railway system to cross the Rimutaka Range between Upper Hutt and Featherston. In the mid-1950s, the line between Petone and Featherston was substantially realigned, with the line diverted to the east of the Hutt River between Petone and Haywards to serve new housing developments in northern Lower Hutt, and the construction of the Rimutaka Tunnel to replace the Rimutaka Incline. Part of the former route west of the Hutt River has been retained as the Melling Branch.