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 and a width of 4.68 metres (15 feet 4 inches); it is lined with concrete with a minimum thickness of 38 cm (15 inches) inside the face of the excavation. When the tunnel holed through on 20 April 1954 the surveying error was found to be only 44.5 mm (1.75 inches). The tunnel was planned to reduce the distance between Upper Hutt and Featherston from to . After its completion, a 2.74 metre (9 ft) diameter vertical ventilation shaft was driven up from a point almost halfway through the tunnel. It reaches the surface beside the Remutaka Rail Trail near