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
Kaitoke Upper Valley Gliding Club for the purposes of gliding the area's thermals. The Pakuratahi River flows through the eastern Kaitoke Basin from its source in the Remutaka Ranges. The old route of the Wairarapa Line railway, which closed with the opening of the Rimutaka Tunnel in November 1955, ran from Upper Hutt via Maymorn to Kaitoke and around Goat Rock up the Pakuratahi to the Summit, and from there, because of excessive steepness, the Fell mountain railway system was used to aid trains on the Rimutaka Incline between Summit and Cross Creek. This railway is now the Remutaka Rail Trail.