South Island Limited
Expresses between Christchurch and Dunedin began operating as soon as the Main South Line was opened. These services, the precursor to the South Island Limited, were the flagship of New Zealand's railways in the nineteenth century, and accordingly had the most modern motive power and rolling stock available. They were initially hauled by members of the first J class and limited to a speed of 60 km/h, resulting in a journey time of eleven hours, but they were sped up with the introduction of the Rogers K class. The K locomotives could achieve speeds of up to 90 km/h and they helped to quicken the schedule, with the T class handling the train on the hilly section between Oamaru and Dunedin. Upon their introduction in 1885, the N class took on the express duties, followed by the U and UB classes, and then the Q and A class Pacifics cut the journey's time to eight hours in the early years of the twentieth century.
In 1904, it became possible to operate an express all the way from Christchurch to Invercargill in a single day. The Dunedin-Invercargill run was treated as an extension of the Christchurch-Dunedin express, and the train was sometimes called the Invercargill Express. In March 1914, it was possible to travel from Christchurch to Invercargill in thirteen hours. AB class locomotives capable of speeds of 107 km/h and higher took over from the A and Q locomotives from 1915, but in the 1930 and wartime maximum, SIMT speed was limited to 50 mph and track and running conditions did not allow the acceleration of the late 1940s when the express at its zenith reached sustained speeds on the Plains of 72-3 mph and became the South Island Limited.
In 1939, the second J class was introduced, followed by the JA class in 1946. These locomotives allowed the service's schedule to be quickened, and in 1949, the South Island Limited was introduced. It operated three days a week and had less stops than the expresses which continued to operate on all other days. In its very early days, it was occasionally operated by AB class engines, but the more powerful J and JA locomotives quickly became the sole motive power, and they were famous for hauling long strings of red carriages at high speed, achieving a travel time between Christchurch and Dunedin of 7 hours and 9 minutes, and completing the entire journey to Invercargil in 11 hours 20 minutes. in the immediate post war years until 1956, the general aim of two daylight expresses daily in both directions on the SIMT continued with the SI Limited being supplemented on Mon, Wed, Fri the peak demand by a second stopping express, trains 160/175 which also provided an early morning departure from departure from Dunedin, at 8.45 am in the 1935 and 1952 timetables  on the Dunedin express to Christchurch and southbound following the Limited out of Christchurch at midday in the 1920s and 30s and postwar at 9.00am south  to arrive at Dunedin a 5.25pm, 2hrs later than the SI Limited. The second stopping express was intended to be upgraded to a daily service by multiple unit operation of the second batch of twin set railcar approved in 1955 and cancelled in 1957 because mechanical troubles experienced in the first years of Fiat engined railcar operation, meant a dozen Fiats had to have new engines and crankcases fitted in 1957-8 and all the railcar engines needed to be rebuilt by Fiat/NZR personnel, raising costs and losses to the point where South Island express operations were consolidated, into a single daily express in 1956. However 160/175 contined to run as relief holiday express until 1966 and were reincarnated as a pure mail and express freight trains DJ hauled from 1970-1985 on essentially the same 1949 timetable leaving Christchurch (Middleton) and Dunedin at 9am for arrival at 5pm, but stopping only at Timaru and Oamaru for 30min, required for shunting which made offering passenger service on 160/175 no longer compatible with passenger or freight requirement A supplementary operations of the 'car' equipped overnight express goods, which stopped for passengers only at Timaru and Oamaru were cancelled in 1956. This service which had a more convenient timetable than operated by 189/190 (F,S) ran M,T,W,Th Christchurch to Dunedin (8.25pm-4.58am), Oamaru was reached at 1.26am and the carriage was held at a Dunedin station bay, till the more civilised hour of 7am and Dunedin-Christchurch (9.40pm-6.38am) which carried a first class carriage to compete with the private 'Starliner' evening buses as an interim measure until the new railcars were delivered, were cancelled along with supplementary Ch- Ashburton subbies in 1958, resulted in a South Island limited operating a compromise, unattractive timetable which left Invercargil too early, had too many stops and relied too much in slab seated 2nd class carriages of great discomfort. The original consist of the SI Limited was 3 first and 4 second class carriages for 330 seats overall  with capacity of over 500 in the school holidays but by the late 1960s the holiday peak had eroded and the usual consist most of the year was two first and two second smoker and non smoker carriages  for 176 seats and mainly the SI Limited was a train to connect with the inter island ferry at Lyttelton and carry mail with up to 5-6 ZP wagons  for maximum revenue.
The South Island Limited carried mail as well as passengers, and this meant the train would have up to six mail carriages attached to the consist. The quantities of mail that had to be exchanged on and off the train during the course of its journey often led to delays, and the attempts of J and JA engine crews to regain lost time became legendary. A stretch of fairly straight track across the Canterbury Plains near Rakaia acquired the nickname of "the racetrack" in New Zealand railway jargon due to the high speeds late-running South Island Limiteds would achieve. Crews claim to have broken the New Zealand railway speed record of 122.5 km/h (78 mph), set on 25 October 1940 by an RM class Vulcan railcar, but none of these claims were authenticated and remain unofficial.
By 1970, steam locomotives had been almost entirely withdrawn from New Zealand. The North Island had been completely dieselised by the end of 1967, and the 1968 introduction of the DJ class had led to the dieselisation of almost all of the South Island's services. However, the South Island Limited continued to operate with steam motive power, repeating the pattern in the North Island where the KA and JAs hauled the Express and relief expresses until 1965 9 to 10 years after steam had been replaced on NIMT freight and the Wairarapa line by 1955–56. An apparently peculiar circumstance given that steam locomotives would have been expected too have finished their day on quiet, unimportant rural branch lines rather than the country's premier express. However, not unusual, Southern Pacific used steam on the LA- Frisco Daylight till 1955, Norfolk and Western ran its 3 Norfolk- Cincinnati expresses under steam till late 1958 and all NYC Niagara and Hudsons 3Ja remained in service till 1956–57. The SI Limited averaged 40.7 mph from Christchurch to Oamaru while the Daylight, Lark and Pochantas and Cavalier just beat that at 43 mph, dogged by grades and the same political demands for extra stops. The last British steam express routes were London-Southampton-Bournemouth, 1967 (107 miles, 1 stop, 2.05 hrs); Edinburgh–Aberdeen, 1966 (151 miles, 4 stops, 3hrs) and London to Exeter 1964 (171 miles, 4hrs) & Liverpool to Glasgow in 1967 (2.5 hrs), were fast and demanding. The last generation of BR and NZR steam were more suitable for fast passenger, being reasonably thermally efficient at 50–90 mph but inefficient below 30 mph. The SI Limited schedule was slightly slower from 1956, as a number of stops had been re-introduced, with the consolidation of passenger services in 1956, raising the stops to 19 and overall the Invercargil- Christchurch journey took half an hour longer, 11hrs 50 minutes requiring a cold early start from Invercargil at 7:40 am. In the last years of the South Island Limited intermediate stops were increased to 21 but overall journey time reduced to 11 hrs 40 minutes The decision was finally taken to withdraw railcars and end the use of steam locomotives in 1967, with the order for the final 9 DJs to replace the J/JAs on SIMT expresses and express freights, on 26 Nov 1967, (without calling for tenders as planned,to consider more suitable alternatives to the DJ) to take advantage of World Bank financing which required locomotives financed by the loan to be delivered by the end of 1969. The problem was the DJ was not suitable as it had only 50–60% of the JA capacity to pull 400 tons at 50–60 mph. The South Island Limited was replaced by the diesel-hauled Southerner on 1 December 1970. This was not the end of the steam expresses, however; J and JA locomotives continued to work Friday and Sunday evening expresses on the same route for almost a year. The last steam-hauled express, and last use of a steam locomotive in revenue service in New Zealand, ran on 26 October 1971.
- J.D. Mahoney.'Kings of the Iron Road'. Dunmore. Palmerston North (1982),p127
- Mahoney. Kings of the Iron Road
- T.A. McGavin (ed) South Island Working Timetable Dec 1952. NZLRS (1979)Wellington
- E.McQueen, NZR Mgmt 1980
- J. Mahoney, Kings of the Iron Road (1982)p 128-9
- Ibid, p129
- NZ Treasury and World Bank Correspondence, (inc internal/external and informal notes, 1967) and 27-11-67. NZR Acting GM to International Bank of Reconstruction( World Bank), inc tabulated, details of drawing WB loan re DJ purchases. DJ Purchase files National Archives, Wgtn.