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
Dularcha Railway Tunnel the southern approach of the tunnel runs parallel to the current North Coast Line rail track. The tunnel runs on a north–south axis. Two semi-elliptical concrete portals are located at the north and south openings of the tunnel. The tunnel is concrete-lined throughout with cuttings at either end. A vehicular dirt track in the National Park in part following the original rail line now removed, passes through the Dularcha Railway Tunnel joining the two towns. The tunnel is approximately long and curves slightly towards the northern portal. The northern and southern portals are both similar in structure and design. They