Rimutaka Tunnel The first shot was fired in 1948 when the Public Works Department started the tunnel with bores of at the western end and at the eastern end. A contract for completing the tunnel was let to a consortium of Morrison Knudsen Inc. and Downer and Company on 7 May 1951. The work commenced at the west end in July 1951 and at the east end in August. The contract was expected to be completed in four years, but the headings met on 20 April 1954 with the concrete lining finished a month later. New Zealand Railways took possession of the
Rimutaka Tunnel five-span 91 metres (300 ft) bridge across the Mangaroa River and two underpasses near Maoribank. There is a tunnel of 539 metres (1767 ft) near Maoribank, but on the eastern side where two short tunnels (220 metres (11 chain) and 180 metres (9 chain)) had been proposed through a spur it was cheaper to lengthen the line by 140 metres (7 chain) and have open cuttings. The construction of the Rimutaka Tunnel consumed: The first locomotives to work through the tunnel were the 560 kW DG class - the tunnel was too long for steam locomotives, making the Wairarapa Line