Construction started in 1932 but was halted a couple of years later when only partly completed due to a lack of funds brought about by economic depression.

The tunnel was never opened to road traffic, and other than a brief stint of military service during World War II, remained unused until sold in 1975.

Plant included an electric motor for running air compressors, ventilation, and the equipment used to apply the concrete lining to the completed tunnel walls.

Consequently, the Company temporarily suspended all work on the tunnel in April 1934 as it sought alternative finance to restart the project.

[1] During the 1935 general election campaign in November of that year, the Labour candidate for the Hutt electorate, Walter Nash, criticised his opponent for supporting the expenditure of unemployment subsidies on the improvement of access to Wainuiomata including work on both the widening of the hill road and the driving of the tunnel through the hill.

Work included installation of electric lighting, an upgrade of the drainage, erection of a security fence enclosing the entire tunnel section with a gate allowing truck access, levelling inside the tunnel to make it suitable for stacking the explosives, and the building of a loading dock to facilitate the transfer of goods to and from the trucks.

Early termination of the lease was requested when the Quartermaster-General advised the Company that the Army intended to vacate the site effective 15 September 1944.

A conference was held around 1956 at which the Public Works Department, the Hutt City Council, and the development company were represented to consider the future of the tunnel.

It was estimated that the tunnel could be completed to suit requirements for around £600,000 (in 1966), which would likely involve the removal of the existing lining so the size of the bore could be increased.

[1] During the 1963 general election campaign, the Labour candidate for Petone, Michael Moohan, stated that the issue of the Wainuiomata Tunnel was a “dead duck”.

Greater Wellington Regional Council is responsible for the tunnel, and also maintains the water supply pipe that runs through it.

As this wasn’t an option at the time, they were offered, and accepted, the alternative of the nearby smaller, and much older, Waiwhetu Tunnel that had previously been used for a water supply pipe.