Infrastructure and mechanical Rail transport in New Zealand

1 infrastructure , mechanical

1.1 rail network
1.2 signalling
1.3 motive power
1.4 couplings
1.5 workshops

infrastructure , mechanical
rail network

the new zealand rail network has around 4,128 kilometres (2,565 miles) of line, of 506 kilometres (314 miles) electrified. @ network s peak in 1953, 5,689 kilometres (3,535 miles) of line open. there 1787 bridges , 150 tunnels (totalling 80 km in length) on rail network.

the entire network built 1,067 mm (3 ft 6 in) gauge, chosen due need cross mountainous terrain in country s interior , lower cost of construction. difficult terrain meant lines took years complete, , has necessitated number of complicated engineering feats, notably raurimu spiral , rimutaka incline (the latter no longer in use).

the network has been subject of major upgrading works on number of occasions. major of these westfield deviation of north island main trunk auckland westfield junction via panmure , glen innes, opened 1930, tawa flat deviation in wellington, opened 1937; rimutaka deviation wairarapa, opened 1955; , kaimai deviation in bay of plenty, opened 1978. of these involved major tunnelling works, of close 9 kilometres (5.6 miles) each in 2 latter cases. significant infrastructure improvements carried out on north island main trunk in mid-1980s, part of electrification scheme.

as part of 10-year turnaround plan announced in 2010, number of regional lines placed under threat of closure:

all lines in northland form part of north auckland line;
the stratford–okahukura line in taranaki; (mothballed since 2009)
the northern portion of wairarapa line;
the gisborne – napier section of palmerston north - gisborne line (mothballed due storm damage north of wairoa 2012, mothballed napier – gisborne october 2012)


signalling

six signalling systems used in new zealand: automatic signalling rules (asr), double line automatic (dla), single line automatic (sla), centralised traffic control (ctc), track warrant control (twc), , station limits. signals of colour light type , operate on speed signalling principals, i.e. signals tell driver speed should proceed, not route take. auckland suburban network equipped european train control system (etcs) level 1 signalling , train protection.

motive power

from inception until 1950s, steam locomotives main motive power on new zealand s railways. 2 short sections of line electrified @ 1500 v dc – arthur s pass otira (electrified 1923), christchurch lyttelton (1929), both have since been decommissioned. electrification of wellington suburban network @ 1500 v dc began in 1938 johnsonville line, followed north island main trunk (nimt) far paekakariki in 1940, , hutt valley lines in 1953–55. nimt electrification extended paraparaumu in 1983 , waikanae in 2011.

dieselisation began in late 1940s shunting locomotives. first mainline diesel locomotives, english electric df class, introduced in 1954, wasn t until introduction of da class following year steam began displaced in north island. last steam locomotive built nzr, j 1274, introduced service in december 1956, , 1967, steam had disappeared north island. steam remained in south island until november 1971, when last 7 j locomotives worked main south line withdrawn revenue service, steam in south island having been displaced dj class locomotive.

in 1988 25 kv ac electrification of north island main trunk (nimt) between palmerston north , hamilton commissioned, , new generation of mainline electric locomotives, ef class introduced.

as part of kiwirail s 10-year long-term plan, new capital spent on locomotives, wagons , auckland – wellington – christchurch freight corridor.

couplings

the norwegian coupling standard coupler used in new zealand non-passenger rolling stock , locomotives until recent years. alliance couplers have been progressively introduced, newer rolling stock , rebuilt locomotives. program of retro-fitting older rolling stock has been underway since 2013. auckland s class , wellington s fp/ft class matangi electric multiple units use scharfenberg coupling.

workshops

the new zealand railways department had major workshops @ addington (christchurch), easttown (wanganui), hillside (dunedin), petone (lower hutt, near wellington) hutt (lower hutt, near wellington) , newmarket otahuhu, (auckland). progressively closed (mostly in 1980s), leaving hutt workshops still operating. number of small maintenance depots operate, example @ addington, christchurch.