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
Otford railway tunnel 8 original tunnels on the Illawarra line from Waterfall to Clifton. The Otford Railway Tunnel, the seventh after Waterfall, was the final major engineering project which permitted the linking up of the northern part of the Illawarra Line to the isolated southern part in 1888. The Otford Railway Tunnel opened on 3 October 1888. The single line connection was made at (old) Stanwell Park Station (now bypassed by the 1915 Stanwell Park Deviation). The tunnel was built of brick arched form and when built was the largest and steepest (5,985 feet long - 1824m - and 1 in 40 gradient)