Tawa Flat deviation
Encyclopedia
Wellington
Wellington is the capital city and third most populous urban area of New Zealand, although it is likely to have surpassed Christchurch due to the exodus following the Canterbury Earthquake. It is at the southwestern tip of the North Island, between Cook Strait and the Rimutaka Range...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. It includes two tunnels, Tawa No. 1 (1238 metres (4,061.7 ft)) and Tawa No. 2 (4323 metres (14,183.1 ft)), separated by the Ngauranga Gorge
Ngauranga Gorge
The Ngauranga Gorge is in the Wellington Region of New Zealand. State Highway 1 runs through the gorge, a vital link between Wellington City and the Kapiti Coast and the main route north out of Wellington. It is 2 kilometres long and has a grade of approximately 8%...
. No. 2 tunnel passes under Newlands
Newlands, New Zealand
Newlands is one of the northern suburbs of Wellington, New Zealand. It lies approximately 8km north of the city centre and to the east of its nearest neighbour Johnsonville. Newlands is located in a valley and covers two ridgelines, the side of one of which overlooks Wellington Harbour and up to...
and comes out at Glenside
Glenside
-Places:* Glenside, South Australia, a suburb of Adelaide* Glenside, Saskatchewan, Canada, a village* Glenside No. 377, Saskatchewan, a rural municipality* Glenside, Bristol, a campus of the University of the West of England** Glenside Museum...
, on the way to Tawa Flat
Tawa, New Zealand
Tawa is the northernmost suburb of Wellington located between Churton Park and Porirua in the North Island of New Zealand. It takes its name from the broadleaf tree, which was once prolific throughout the area, although its most famous tree is the Bucket Tree, a group of large macrocarpa with the...
(renamed Tawa in 1955). The tunnels were constructed by the Public Works Department
New Zealand Ministry of Works
The New Zealand Ministry of Works, formerly the Department of Public Works and sometimes referred to as the Public Works Department or PWD, was founded in 1876 and disestablished and privatised in 1988...
as no satisfactory tenders were received.
The deviation opened to goods trains on 22 July 1935 and to passengers on 19 June 1937 . It replaced a steep section of the former Wellington & Manawatu Railway, most of which is still in use as the Johnsonville Line.
The line from Wellington to Paekakariki was electrified at 1500 V DC from 24 July 1940, being delayed by late delivery of some items from England. Initially locomotive-hauled trains were used, and DM/D electric multiple unit
Electric multiple unit
An electric multiple unit or EMU is a multiple unit train consisting of self-propelled carriages, using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a number of the carriages...
s first ran on the line on 5 September 1949 , As was pointed out in the 1925 Merz & McLellan
Merz & McLellan
Merz and McLellan was a leading British electrical engineering consultancy based in Newcastle.-History:The firm was founded by Charles Merz and William McLellan in Newcastle upon Tyne in 1902 when McLellan joined Merz's existing firm established in 1899...
Report, electrification removed the need to relieve the steep gradients to Pukerua Bay summit by a deviation to the east, and was desirable in the long No. 2 tunnel. ED class
NZR ED class
The NZR ED class locomotive was a class of electric locomotive used in Wellington, New Zealand. They were built by English Electric and New Zealand Railways between 1938 and 1940, and hauled mainly passenger trains on the Wellington region's 1500 V DC electrification, and banked freight trains on...
electric locomotives were introduced in 1938 for use on this section.
The deviation is used by Tranz Metro
Tranz Metro
Tranz Metro, part of KiwiRail, is the operator of Metlink suburban trains owned by the Greater Wellington Regional Council in the Wellington Region of New Zealand....
electric units to Porirua
Porirua
Porirua is a city in the Wellington Region of New Zealand, immediately north of the city of Wellington, with their central business districts 20 km apart. A large proportion of the population commutes to Wellington, so it may be considered a satellite city. It almost completely surrounds...
and Paraparaumu
Paraparaumu
Paraparaumu is a town in the south-western North Island of New Zealand. It lies in the Kapiti Coast, 50 kilometres north of the nation's capital city, Wellington....
, Tranz Scenic
Tranz Scenic
Tranz Scenic is the long-distance passenger train brand of KiwiRail, formed from the New Zealand Railways Corporation InterCity Rail services. Tranz Scenic was renamed along with the other operating divisions of Tranz Rail in 1995...
's Overlander and Capital Connection, and KiwiRail
KiwiRail
KiwiRail Holdings Limited is the rail operations subsidiary of the New Zealand Railways Corporation, which trades as KiwiRail. Headquartered in Wellington, New Zealand, KiwiRail is the largest rail transport operator in New Zealand. Since July 2010 John Spencer has been the Chairman...
freight trains.