Kaimai Tunnel Kaimai Tunnel The Kaimai Tunnel is a railway tunnel through the Kaimai Range in the North Island of New Zealand. Since it was opened in 1978, it has held the title of longest tunnel, at 8.879 kilometres, in New Zealand, assuming this distinction from the previous title holder, the Rimutaka Tunnel. It is part of the Kaimai Deviation, which was constructed to bypass the old route of the East Coast Main Trunk Railway through the Karangahake Gorge (part of which has been preserved as the Goldfields Railway). The Kaimai Deviation is a 24 km line between Waharoa and Apata, including
Wainuiomata railway proposals proposed railway declined, but at the same time the population of Wainuiomata increased and commuters to Wellington desired a railway line. However, the terrain is not favourable for a railway. A line into Wainuiomata would require either a steep route over the hills, resulting in a slow journey, or a lengthy and costly tunnel. This geography has been the main contributing factor to the rejection of all proposals so far. The first proposal for a railway to Wainuiomata came as part of a route for the Wairarapa Line across the Rimutaka Range. Four routes were surveyed, including one through Wainuiomata.