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 at that time. It was not until the 1920s that significant campaigning for a replacement again prevailed on the government. In 1921-22 a feasibility study was conducted, including distances and estimated costs. Several routes were considered, including variations on previous ideas, but nothing more was done at the time; although a deviation of "about 5 miles 48 chain" (9 km) as the Wellington-Napier Line (Rimutaka Deviation) "running generally to the south-eastward of the existing line" was authorised by the Railways Authorisation Act, 1924. The new Labour government of 1936 announced its intention to proceed with the Mangaroa to Cross Creek