Rimutaka Tunnel Rimutaka Tunnel The Rimutaka Tunnel (officially Tunnel 2, Wairarapa Line) is a railway tunnel through New Zealand's Remutaka Range, between Maymorn, near Upper Hutt, and Featherston, on the Wairarapa Line. The tunnel, which was opened to traffic on 3 November 1955, is long. It was the longest tunnel in New Zealand, superseding the Otira Tunnel in the South Island until the completion of the Kaimai Tunnel (8.88 km, 5.55 miles) near Tauranga in 1978. Rimutaka remains the longest tunnel in New Zealand with scheduled passenger trains. The tunnel was built as part of a deviation to replace the costly Rimutaka
Otira Tunnel tunnel in the world and the longest in the British Empire. The Midland Railway Company investigated options to a long tunnel; but a line over the pass with gradients of 1 in 50 on both sides was not practical. Other options for a line over the pass were a cable-hauled system or a line of 1 in 15 gradient using either the Fell system or a rack railway using the Abt system (or even a S-shaped tunnel under Mount Rolleston). However the government did not favour the Fell system as used on the Rimutaka Incline which was expensive to operate.