The Southerner was a passenger express train that ran in New Zealand's South Island between Christchurch and Invercargill via Dunedin along the Main South Line. It commenced service on Tuesday, 1 December 1970 and ceased on Sunday, 10 February 2002. It was one of the premier passenger trains in New Zealand and its existence made Invercargill the southernmost passenger station in the world.

Before the Southerner
By the late 1960s steam motive power had been phased out from the North Island, and a serious effort was being made to replace it with diesel-electric engines in the South too. The introduction of the DJ class in 1968 sealed steam's fate, and in 1970, plans were made to introduce a brand new diesel-hauled express to replace the premier express between Christchurch, Dunedin, and Invercargill, the South Island Limited. The new train was named the Southerner. It would be hauled by members of the DJ class, and unlike the steam-hauled expresses, it would not carry mail. It entered service 1 December 1970.
Despite the introduction of the Southerner, steam-hauled expresses continued to operate on Friday and Sunday evenings for almost 11 months. The last one ran on 26 October 1971; this was the last steam-hauled regularly-scheduled revenue service in New Zealand. The service was replaced with a diesel-hauled train, which continued until 1979. The evening railcars lasted a few years longer, but the age of the Vulcan railcars was becoming increasingly obvious and the service was canceled in April 1976 without replacement. After 1979, the Southerner was the only long-distance passenger service on the Main South Line.

Introduction
The original Southerner consisted of ten (later 12) 56-ft single-toilet (later designated South Island Main Trunk Railway) first class cars, two (later three) full buffet cars, three vans and, in the 1980s, three wooden 50-ft bogie box wagons for parcels. All passenger cars were rebuilt 56-ft stock dating from 1938-1945.
Two 56-ft cars, one a pressure-ventilated former half first class (14 seats) half second class (28 seats) car, and the other the only 56-ft car to serve in a Vice Regal capacity for a Governor-General as a kitchen carriage (hence the unique design), were rebuilt as full buffet cars, incorporating full length counters and 20 stools. In 1973, a former double-toilet (later designated a North Island Main Trunk Railway first class car) was rebuilt as a third buffet car. Two cars retained their "coupe" compartment for train staff, one car for each train, and another two retained their compartments for hostesses, again, one car to each train.

Rolling Stock
The buffet cars were fitted with new Japanese bogies of Kinki-Sharyo manufacture. Compared to the Timken spring bogies under the other carriages and vans, the Kinki bogies offered a superior quality ride - passengers complained about the riding quality of the other cars.
With the success of new Korean bogies underneath Northerner carriages, the Southerner cars were also fitted with this type of bogie. Work on car underframes was less substantial than that carried out on the Northerner.

InterCity Rail upgrade
At the same time the InterCity refurbishment programme started, a private tourist firm leased a Southerner carriage and marketed it as The Connoisseur car. It was thoroughly overhauled and refurbished, and offered users a more upmarket service.
In 1988, three more red Picton/Greymouth cars and an Endeavour car were refurbished as a "new" Southerner, entering service Monday, July 4, 1988, joining the two cars already fitted as such. The Endeavour car and one Picton/Greymouth car were fitted out as servery cars, each seating 31 in bays of four, alcove-style. The other two cars seated 50 alcove-style. The seats were reupholstered and new carpet laid down in all four cars. Two Mitsubishi-built modular vans were equipped with 11 kW generators on their handbrake ends and became power-baggage vans for the "new" trains. Its reintroduction also saw the ceasation of parcels traffic on the trains.
This seating arrangement, while accepted on the TranzAlpine, Coastal Pacific, and Bay Expresses, proved unsuccessful on the Southerners, so one car from each set had seating re-arranged to a "forward-facing" layout.

Connoisseur
At the end of 1993, a former Wairarapa Connection car turned NIMT servery car was brought in to replace the damaged servery car, and the first of the two Bay Express panorama cars was also allocated to this train as the initial attempt to re-equip this train with panorama cars.
In 1995, seven of the first batch of 11 non-air conditioned panorama cars were thoroughly overhauled, air conditioning and a new-style seat (as in the third three-car Northerner and Overlander set) were installed. Two of these were permanently allocated to the Southerner, the second two temporarily, with the fifth juggling duties between Invercargill, Greymouth and Picton. The two original servery/observation cars were similarly refurbished. The third TranzAlpine/Coastal Pacific and the first of the two Southerner 11kW power/baggage vans were fitted with newer, more powerful generators (though less powerful than their NIMT counterparts) and the Southerner van had its public viewing module re-enclosed for luggage carriage again. Later that year, when the Bay Express was re-equipped with two of those seven refurbished cars, the original two Bay Express cars were similarly refurbished and permanently allocated to the Southerner.
Patronage continued to fall away, even when from 1993 onwards panorama cars were introduced to this service. Two cars came from the original Bay Express, two were Southerner cars turned panorama cars for the TranzAlpine and Coastal Pacific and one car that was formerly The Connoisseur car (also an original Southerner car). Two Picton/Greymouth cars turned panorama cars also served these trains until joining the Bay Express to Napier. The original TranzAlpine servery/observation car and its Coastal Pacific equivalent were assigned to the Southerner.

Replacement rolling stock
On Wednesday 25 August 1993, the southound Southerner, consisting of a DF class locomotive, passenger car with luggage space at one end, servery car, day car and the second of three TranzAlpine and Coastal Pacific power-baggage vans was hit at Rolleston by a concrete mixing truck. The bowl of the truck bounced off all three passenger cars, and ripped two wide open. Two people were killed.
Two days later, a replacement train consisting of three recently refurbished cars and the Mitsubishi-built modular power and baggage van with 37.5 kW generator from the Auckland excursion fleet was brought in to supplement the remaining four Southerner cars. The first and second of these temporary replacement cars seated 50, alcove-style, like the Southerner cars, but with a more modern seat, seen on upgraded Masterton cars and the NIMT cars. The third car seated 54 in the same type of seat, but with all seats facing into two centre tables, one on each side of the aisle. The NIMT car turned buffet car in 1973 returned to the train as part of the replacement consist.

Accidents
The advantages of the new technology and the removal of delays caused by the carriage of mail, and the elimination of refreshment stops (with the inclusion of a buffet car) became apparent instantly, with the travel time between Christchurch and Dunedin cut by almost an hour from 7 hours 9 minutes to 6 hours 14 minutes. Typically, two DJ diesels hauled the train, and when a third was added to increase power on the rugged, difficult line between Oamaru and Dunedin, another 19 minutes was slashed from the schedule.

Timetable
The Southerner is also notable for being the first train to include a full dining service on New Zealand Railways since the abolition of dining cars as an economy measure in World War I. The Southerner had a full service buffet car with 20 seats, that served hot meals and cafeteria style food, until this was replaced with a buffet bar service in the early 1990s, for passengers to purchase food to be consumed at their seats.

Withdrawal
There are currently no plans to re-instate a service on the Southerner's route and the Main South Line is now almost wholly without any passenger trains. The northern portion between Christchurch and Rolleston is still used by the TranzAlpine, and Dunedin Railway Station and the Main South Line to Wingatui remain in use as by the Taieri Gorge Limited, a popular daily tourist train operated by the Taieri Gorge Railway along the former Otago Central Railway. Taieri Gorge Railway also run weekly trips on their Seasider service on the section of line between Dunedin and Palmerston.