Parnell Tunnel

The Parnell Tunnel is a railway tunnel under Parnell, Auckland, New Zealand. It is 344.5 metres (1,130 ft) long, and is on the Newmarket Line.

The tunnel allows the Western, Southern and Onehunga lines coming from the Newmarket Train Station to Britomart Transport Centre to pass under the Parnell Ridge before the line drops to harbour level. The Newmarket Line connects the North Island Main Trunk (NIMT), which runs into Britomart via the waterfront, and the North Auckland Line, which runs between Westfield and Otiria via Newmarket and Whangarei.

There are two Parnell Tunnels, an older now unused single-track tunnel and a newer double-track tunnel. The older tunnel was superseded by the newer double-track tunnel, so has been closed off and has not been in use for most of the last century.

The rail tunnel, originally intended in part to provide a connection to Drury for the New Zealand land wars, has been lauded as having enabled the first public railway line in Auckland, and opening the city up to the wider New Zealand.

The first tunnel shaft was constructed as part of the initial construction of the line. However, works took a very long time - 9 years - having started in 1864. This was partly due to funding issues, but also due to a massive land slip which occurred at the northern end, with investigation of the causes and removal of the slip holding up the works for a long time. After the tunnel was pierced through in June 1872, work speeded up and it was finished in February 1873.

The first tunnel and its approach were relatively steep, often requiring double engines to pull the trains and there are records of the "inconvenient habit" of some "well-loaded" passenger trains coming to a standstill on the gradient in the tunnel. The tunnel was also apparently known for forcing large amounts of steam locomotive fumes into the passenger coaches. During events like Cup Day at Ellerslie Racecourse, when extra trains needed to be provided for the large numbers of travellers (with the trains often composed of open cattle trucks) the sparks thrown by the locomotives tended to rebound into open carriages, often causing burn holes in passengers' clothing. The newspapers of the time often commented on this in sarcastic form.

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