Kaimai Railway Tunnel
The Kaimai Railway Tunnel, which is to be driven through the heavily forested Kaimai Range as part of a new 15 ½-mile railway deviation linking the eastern Waikato district with the Bay of Plenty, will have a completed length of 29,000 ft. It will be the longest tunnel in New Zealand, exceeding the length of the 28,864-ft Rimutaka Tunnel by 136 ft. Work on the earthworks as part of the construction of the tunnel approaches had already begun by October 1965. The tunnelling contract is to be let at the end of 1966, and it is hoped that the whole deviation will be ready for use about July 1970.
This major construction project, including the tunnel, station facilities, bridges, track, signalling, communications, and other equipment, is estimated to cost some £5,700,000. It is expected that more than 1,000,000 tons of railway freight will pass through the tunnel during the first year after it has been completed. Ministry of Works engineers are making extensive use of modern technology in their preparatory work, including helicopters to check surveys and to place trigometrical stations at various points in the ranges. To measure distances, they are using a tellurometer, which is an electronic measuring device worked by radar impulses.