Passenger services For much of New Zealand's railway history, the passenger service from Christchurch to Dunedin was the flagship of the railway. What is regarded as the country's first "express" run on 6 September 1878 was a special train hauled by the new Rogers
K class locomotive "Washington". Leaving Christchurch at 6 am the train arrived at Dunedin at 6.40 pm; there was a breakfast with the Governor and other official guests at Oamaru, passengers were left behind at intermediate stops, and the train was assisted by the Double-Fairlie "Josephine" between Oamaru and Seacliff (where the engine was left for fitters as Ben Verdon the "K" driver made "Josephine" do too much of the work). When trains began to run between Christchurch and Invercargill in a day in November 1904, the main passenger services on the Dunedin-Invercargill section were essentially an extension of the Christchurch-Dunedin trains. When the line was completed in the late 19th century, trains took 11 hours to travel from Christchurch to Dunedin and were usually headed by
steam engines of the
original J class or the
Rogers K class, except on the hilly section south of Oamaru where the
T class was used. In 1906, the
A class was introduced and maintained an eight-hour schedule, though they soon handed over duties to the superheated
AB class of 1915. The introduction of the
J class and
JA class in 1939 and 1946 respectively was the final development in steam motive power, and they took just 7 hours 9 minutes to haul the "
South Island Limited" express from Christchurch to Dunedin. During their heyday, these steam-hauled expresses were famous for the speeds they attained across the Canterbury Plains along a section of track near Rakaia nicknamed the "racetrack". They were replaced on 1 December 1970 by the
Southerner, headed by
DJ class diesel-electric locomotives. Steam engines continued to operate Friday and Sunday night expresses, and they were the last steam passenger trains in New Zealand. This makes New Zealand unusual, as steam saw out its final days on quiet, unimportant branch lines in most countries, while the last regular services operated by New Zealand's steam engines were prominent express passenger trains. This was because the trains' carriages were steam heated, so separate steam heating vans with boilers were required. So on 26 October 1971, an express from Christchurch to Invercargill became the last regular service in New Zealand to be hauled by a steam locomotive.
Other services An extra evening South Island Main Trunk (SIMT) passenger service for businessmen, to compete with the Starliner private buses on the Christchurch to Dunedin route, started in March 1953 with first-class, steam-heated
NZR 56-foot carriages attached to overnight express freights 138 and 151 between Monday to Thursday, departing Christchurch at 8:25pm and stopping for passengers only at Timaru, Oamaru (1:26am) and Dunedin at 4:58 am, where the carriage remained stopped and heated at the platform until 7:00am. The northbound service left Dunedin at 9:40pm to arrive at Christchurch at 6:30pm.
88 seater railcars replaced this service in September 1956 with a 6 hour schedule, departing at 5:30pm and arriving 11:30pm in both directions, daily until 28 April 1976. The railcars were well patronised at weekends and between Dunedin and Oamaru. The 88-seater railcars also introduced a second daylight service from Dunedin to Invercargill leaving Invercargill on the return leg at 1:25pm. The railcar service offered a more convenient and comfortable, second-class timetable than the South Island Limited with its early departures and late arrivals in Southland. A night express service, including two
sleeping carriages, ran from 1928. The four sleepers for the service were rebuilt at
Addington Railway Workshops from ordinary cars, each with an 8-berth compartment for ladies, and a 12-berth for men. The sleeping cars had gone by 1935, and by 1943 the only night trains were on Sundays. From 1949 to 30 September 1979 trains 189 and 190 ran an overnight weekend express Christchurch-Dunedin departing at a late 10.30/10.50 pm on Friday-Sunday to arrive 6:30/6:58am on Saturday and Monday. Until 1971 the steam-hauled train consisted of a 56-foot second-class carriage, a sleeping carriage and two 50-foot first-class carriages. The diesel hauled 189/190 of 1971-79 consists of excluded sleeping carriages again and usually consisted of sets of only a partitioned 56 ft first-class and two 56 ft second class carriages, guards van and seven container and mail wagons. Only the connecting part of 190 leaving Invercargill at 6:35pm was ever well patronised by the sports team and weekend university students. In its last years, 1976-79 189/190 was second class only but did provide a connection for Dunedin students and Otago Peninsular residents on the new
Cook Strait ferry express, providing a low-cost, but poorly patronised interisland connection, with patronage given at 10-93 (average 50) in July 1979.
The Southerner The Southerner ran to an even faster schedule than the "South Island Limited". The journey between Christchurch and Dunedin was initially cut to just 6 hours 14 minutes, and by utilising two DJs north of Oamaru and three south, the schedule was further cut to 5 hours 55 minutes. Part of these gains resulted from the Southerner not carrying
mail, while the South Island Limited was slowed down by handling mail. When many branch lines were open, local passenger services and "mixed trains" of both passengers and freight were a regular sight on the Main South Line as they made their way to their branch destination, but such trains were progressively cancelled during the 20th century and ceased to exist entirely a number of decades ago. An evening
railcar service operated in the middle of the 20th century and took 6 hours 10 minutes between Christchurch and Dunedin: it was cancelled in April 1976. The Main South Line was used in Dunedin to provide
commuter services both north to
Port Chalmers and south to
Mosgiel. In the days of steam, AB,
B, and
BA classes operated suburban trains, though railcars were used on occasion until 1967. In 1968 commuter services were dieselised and operated by the DJ class, or sometimes the
DI class and
DSC class. The Port Chalmers services lasted 11 more years and were cancelled in late 1979, followed by the Mosgiel services in December 1982. Between 1908 and 1914, the line to Mosgiel was double-tracked because of the commuter traffic, but it has been converted back to single track since the end of commuter services. On 10 February 2002, the Southerner was withdrawn as it was claimed to no longer be economic to operate. As of January 2020, only two regular passenger services utilise small portions of the Main South Line: between Christchurch and Rolleston by the
TranzAlpine before it heads along the
Midland Line to
Greymouth; and the only passenger trains to use
Dunedin Railway Station are those operated by
Dunedin Railways, which is as of May 2020 is mothballed.
Freight services Until the 1960s, there was little focus on long-distance freight between the major centres. Instead, the Main South Line was used to feed its many branch lines, with the majority of goods trains being local services between regional areas and major centres or harbours in Christchurch (
Lyttelton), Timaru, Oamaru, Dunedin (Port Chalmers), and Invercargill (
Bluff). A good example of how regionalised this traffic was comes from the Dunedin-Invercargill portion of the line. North of
Clinton were five branches whose traffic essentially ran to and from Dunedin/Port Chalmers, while south of Clinton were four branches whose traffic essentially ran to or from Invercargill/Bluff. As this short-distance local traffic declined in the 1950s and 1960s and branch lines closed, long-distance freight increased, with through services between the major centres rising to prominence. The concentration of exports on fewer ports and the development of containerisation spurred on long-distance freight, and the first freight train from Christchurch to Invercargill was introduced in December 1970 on a 16-hour schedule. Today, to meet the demands of modern business and to compete with road transportation, operations continue to be enhanced, and much traffic comes in the form of bulk cargo from large customers. Although passenger services no longer exist, the future of long-distance bulk freight on the line appears secure and the Main South Line is an important link in New Zealand's transport infrastructure. ==List of secondary and branch lines==