Otira Tunnel
The Great Journeys of New Zealand | |
Character | Single bore rail tunnel |
---|---|
Technical | |
Line length | 8566 m |
Track gauge | 1067 mm (3' 6") |
The Otira Tunnel is a railway tunnel on the
Construction
Construction commenced in 1907 and a "breakthrough" celebration was held on 21 August 1918 by the Minister of Public Works Sir William Fraser. When the tunnel opened on 4 August 1923, it was the seventh longest tunnel in the world and the longest in the British Empire.[1]
The
A contract to build the tunnel in five years was let to the engineering firm of John McLean and Sons who started at the Otira end in 1908, using the "drill and blast" method. With progress difficult and slow McLeans asked to be relieved from the contract in 1912, and were financially ruined (the tunnel cost over twice the contract price of £599,794 ($1,200,000). The government could find no other tenderers, so the work was taken over by the
Electrification
The tunnel dimensions were 4.72 metres (15 ft 6 in) high and 4.27 metres (14 ft 0 in) wide at rail level, increasing to 4.57 metres (15 ft 0 in) at the widest point. Because of its length and gradient, gases such as
Because of the increasing age of the electrification and the availability of upgraded DX class diesel locomotives, the electrification was decommissioned in 1997 and the equipment removed. This marked the end of electrification in the South Island.[6]
To overcome the fume problem, a combination of a door and fans are used, similar to that used in the Cascade Tunnel in the United States of America, which was also once electrified. After a train enters the tunnel from the Otira end the door closes off the entrance, and a large fan extracts the fumes behind the train. Once the fumes have been extracted, the door is reopened. Because of the fumes, the TranzAlpine's observation cars are closed for the trip through the tunnel.[7]
References
- ^ Wright 2009, p. 23.
- ^ Wright 2009, p. 17,21.
- ^ Wright 2009, p. 22,24,25.
- ^ "The British and Intercolonial Exhibition, Hokitika, Westland, New Zealand, December 15th, 1923 to February 2nd, 1924 : to celebrate the opening of the East and West Coast railway, to commemorate the diamond jubilee of the Province of Westland, 1864-1924. - Version details - Trove". Retrieved 16 June 2020.
- ^ Churchman 1988, p. 52.
- ^ a b "Rails". Southern Press. May 1997. p. 216.
- ^ Gibson, Anne (20 January 2007). "Cross-country call of the whitebait". The New Zealand Herald. Retrieved 1 November 2011.
Further reading
- Churchman, Geoffrey B (1988). The Midland Line: New Zealand's Trans-Alpine Railway. Johnsonville, Wellington: IPL Books. ISBN 0-9597832-8-8.
- Wright, Stephen; Wright, Matthew (2009). Journey to the Pass: Memories of the Midland Line. Templeton, Christchurch: Hilton Press. p. 29. ISBN 978-0-473-14641-2.
External links
- Otira steam power station, 1928
- Photo of Power House, Otira
- View of the Power House and Otira
- View approaching Otira at 40 mph
- Inside Compressor House used during construction
- View of Colour Light signals Otira, 1926
- Winchester, Clarence, ed. (1938), "British Empire's longest tunnel", Wonders of World Engineering, pp. 683–687, illustrated description of the construction and opening of the Otira Tunnel
- "Prime Minister Massey feeding money to the tunnel (a hostile Auckland cartoon)". The New Zealand Herald. 1 August 1913.
- "Crumbs from Otira's Table (another hostile Auckland cartoon)". The New Zealand Herald. 6 June 1914.
- "Electrified lines outside the tunnel". Evening Post. 1 August 1923.
- "Report of the natural features of the Arthur's Pass tunnel". Transactions of the Royal Society of New Zealand. 1919.