Mangaroa railway station war. After the war the depot was a disposal site for surplus stores until RNZAF use ceased in July 1949, at which time it is assumed that the site was transferred to the NZ Army for their use. Prior to the construction of the Rimutaka Tunnel, several proposals for a tunnel under the Rimutaka Ranges to bypass the Incline section involved tunnels with a western portal to the north-east of Mangaroa station. In 1898 a survey was completed for a tunnel between Mangaroa and Cross Creek. The idea received a great deal of attention, but ultimately went nowhere as such
Rimutaka Tunnel tunnel. Detailed surveys were completed in 1938/1939, but the project was again postponed due to World War II. After World War II it became a matter of urgency to consider a replacement. The H class locomotives were showing their age, the Incline was in bad shape, and maintenance costs were increasing. Between September 1945 and July 1947 four options were considered. It was accepted that no contour line could be the solution and that a tunnel under the Rimutaka Ranges was the only satisfactory answer. The adopted route was the shortest route, a tunnel between Mangaroa and Lucena’s Creek gully.