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
Rimutaka Tunnel cutting for the new formation completed and the remainder of the track laid. On Thursday, 3 November, the new line was opened and two special trains travelled from Wellington to Speedy’s Crossing to the inauguration ceremony. The deviation's ruling grade is 1 in 70, compensated for curvature. The tightest curve is 400 metres (20 chain) radius. The tunnel rises at 1 in 400 from the western portal to the highest point on the deviation, roughly halfway through the tunnel, and then descends to the eastern portal at 1 in 180. It has an internal height of 5.18 metres (17 ft)