NZR Ba class
Encyclopedia
The BA class was a class of steam locomotive
built by the New Zealand Railways Department
(NZR) for use on New Zealand
's national rail network
. The first BA entered service in November 1911, with the last of the 11 class members introduced on 14 May 1913.
of 1899-1903, but superheated
and with a smaller firebox. They were designed primarily for use on freight trains in the South Island
, and were capable of hauling a load of goods at speeds up to 30 mph.
In March 1928, BA 552 was modified to have a wider firebox, and later that year the same work was done on BA 498. It was almost two decades before the alterations were performed on any other members of the class: BA 553 was done in May 1948, BA 148 the next month, and fifth and last was BA 499 in November 1949. The other BA locomotives were left with unmodified fireboxes.
The upgraded engines were capable of producing more power: their boiler pressure was raised to 200 psi and they could generate 21,200 lbf. On straight, flat track, they could haul 700-750 tons, and on the arduous steep section of the Main South Line
north of Dunedin
they were capable of hauling 270 tons, 50 tons more than the five locomotives that were not upgraded.
In their later years, eight of the ten BA locomotives were modified to perform shunting duties. This included an all-weather cab fixture on the tender
to provide shelter for crews.
and Southland on the Main South Line and the many branch line
s that fanned from it in the first half of the 20th century. The enhanced locomotives with larger fireboxes were often seen on the Otago Central Railway.
In later years, more powerful steam locomotives and then diesel-electrics were introduced and the BA class was largely confined to heavy shunting duties and short-haul freight services in and around Dunedin. Some members of the class were transferred in the 1950s to the West Coast
, where they operated for a few years on both shunting and longer distance services.
hauled the last regularly scheduled steam-hauled revenue service on 26 October 1971. The first BA to exit service was BA 554 in May 1963, and through the mid-1960s, the class was progressively withdrawn. At the start of 1969, only one was left in service, BA 552.
BA 552 hauled railfan excursions in the mid-1960s, and in 1968 and into 1969 it was retained by NZR on standby, should extra motive power be required. In June 1969 the decision was made to withdraw the locomotive, and pressure came from railfans to retain it for preservation. It was used to haul an excursion in November of that year, and in September 1970 it was transferred to the North Island
, in the process becoming the only member of the BA class to leave the South Island. Although steam had technically ceased in the North Island, BA 552 and A
423 were used on a steam delivery trip between Palmerston North
and Frankton
, with BA 552 leading for much of the journey. It was then transferred to private ownership in Te Awamutu
, where it was held in on static display, and is today based at Mainline Steam
's Auckland depot. It has been refurbished and is in full running order, capable of hauling mainline excursion trains.
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
built by the New Zealand Railways Department
New Zealand Railways Department
The New Zealand Railways Department, NZR or NZGR and often known as the "Railways", was a government department charged with owning and maintaining New Zealand's railway infrastructure and operating the railway system. The Department was created in 1880 and was reformed in 1981 into the New...
(NZR) for use on 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...
's national rail network
Rail transport in New Zealand
Rail transport in New Zealand consists of a network of gauge railway lines in both the North and South Islands. Rail services are focused primarily on freight, particularly bulk freight, with limited passenger services on some lines...
. The first BA entered service in November 1911, with the last of the 11 class members introduced on 14 May 1913.
Construction and later enhancements
In design and appearance the BA class was very similar to the B classNZR B class (1899)
The B class of 1899 was a class of steam locomotives that operated on New Zealand's national rail network. An earlier B class of Double Fairlies had entered service in 1874, but as they had departed from the ownership of the New Zealand Railways by the end of 1896, the B classification was free...
of 1899-1903, but superheated
Superheater
A superheater is a device used to convert saturated steam or wet steam into dry steam used for power generation or processes. There are three types of superheaters namely: radiant, convection, and separately fired...
and with a smaller firebox. They were designed primarily for use on freight trains in the South Island
South Island
The South Island is the larger of the two major islands of New Zealand, the other being the more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman Sea, to the south and east by the Pacific Ocean...
, and were capable of hauling a load of goods at speeds up to 30 mph.
In March 1928, BA 552 was modified to have a wider firebox, and later that year the same work was done on BA 498. It was almost two decades before the alterations were performed on any other members of the class: BA 553 was done in May 1948, BA 148 the next month, and fifth and last was BA 499 in November 1949. The other BA locomotives were left with unmodified fireboxes.
The upgraded engines were capable of producing more power: their boiler pressure was raised to 200 psi and they could generate 21,200 lbf. On straight, flat track, they could haul 700-750 tons, and on the arduous steep section of the Main South Line
Main South Line
The Main South Line, sometimes referred to as part of the South Island Main Trunk Railway, is a railroad line that runs north and south from Lyttelton in New Zealand through Christchurch and along the east coast of the South Island to Invercargill via Dunedin...
north of Dunedin
Dunedin
Dunedin is the second-largest city in the South Island of New Zealand, and the principal city of the Otago Region. It is considered to be one of the four main urban centres of New Zealand for historic, cultural, and geographic reasons. Dunedin was the largest city by territorial land area until...
they were capable of hauling 270 tons, 50 tons more than the five locomotives that were not upgraded.
In their later years, eight of the ten BA locomotives were modified to perform shunting duties. This included an all-weather cab fixture on the tender
Tender locomotive
A tender or coal-car is a special rail vehicle hauled by a steam locomotive containing the locomotive's fuel and water. Steam locomotives consume large quantities of water compared to the quantity of fuel, so tenders are necessary to keep the locomotive running over long distances. A locomotive...
to provide shelter for crews.
Operation
The locomotives occasionally hauled suburban passenger trains in Dunedin, but were primarily freight locomotives. They operated in OtagoOtago
Otago is a region of New Zealand in the south of the South Island. The region covers an area of approximately making it the country's second largest region. The population of Otago is...
and Southland on the Main South Line and the many branch line
Branch line
A branch line is a secondary railway line which branches off a more important through route, usually a main line. A very short branch line may be called a spur line...
s that fanned from it in the first half of the 20th century. The enhanced locomotives with larger fireboxes were often seen on the Otago Central Railway.
In later years, more powerful steam locomotives and then diesel-electrics were introduced and the BA class was largely confined to heavy shunting duties and short-haul freight services in and around Dunedin. Some members of the class were transferred in the 1950s to the West Coast
West Coast, New Zealand
The West Coast is one of the administrative regions of New Zealand, located on the west coast of the South Island, and is one of the more remote and most sparsely populated areas of the country. It is made up of three districts: Buller, Grey and Westland...
, where they operated for a few years on both shunting and longer distance services.
Withdrawal and preservation
The BA class lasted into the 1960s, late in the days of steam; the era ended when a member of the JA classNZR Ja class
The NZR JA class were a type of 4-8-2 steam locomotive used on the New Zealand railway network. The class was built in two batches, with the second batch possessing some differences from the first...
hauled the last regularly scheduled steam-hauled revenue service on 26 October 1971. The first BA to exit service was BA 554 in May 1963, and through the mid-1960s, the class was progressively withdrawn. At the start of 1969, only one was left in service, BA 552.
BA 552 hauled railfan excursions in the mid-1960s, and in 1968 and into 1969 it was retained by NZR on standby, should extra motive power be required. In June 1969 the decision was made to withdraw the locomotive, and pressure came from railfans to retain it for preservation. It was used to haul an excursion in November of that year, and in September 1970 it was transferred to the North Island
North Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...
, in the process becoming the only member of the BA class to leave the South Island. Although steam had technically ceased in the North Island, BA 552 and A
NZR A class (1906)
The A class were steam locomotives built in 1906 with a 4-6-2 wheel arrangement for New Zealand's national railway network, and described by some as the most handsome engines to run on New Zealand rails. The class should not be confused with the older and more obscure A class of 1873. They were...
423 were used on a steam delivery trip between Palmerston North
Palmerston North
Palmerston North is the main city of the Manawatu-Wanganui region of the North Island of New Zealand. It is an inland city with a population of and is the country's seventh largest city and eighth largest urban area. Palmerston North is located in the eastern Manawatu Plains near the north bank...
and Frankton
Frankton, Waikato
Frankton is a central suburb of the city of Hamilton, New Zealand. It is the site of the city's passenger railway station, a major industrial-commercial stretch of State Highway 1, and a commercial shopping area.- Tornado :...
, with BA 552 leading for much of the journey. It was then transferred to private ownership in Te Awamutu
Te Awamutu
Te Awamutu is a town in the Waikato in the North Island of New Zealand. It is the council seat of the Waipa District and serves as a service town for the farming communities which surround it...
, where it was held in on static display, and is today based at Mainline Steam
Mainline Steam
Mainline Steam is a New Zealand organisation devoted to the restoration and operation of historic New Zealand Railways mainline steam locomotives. Regular day excursions and multi-day tours are operated over rail lines throughout New Zealand...
's Auckland depot. It has been refurbished and is in full running order, capable of hauling mainline excursion trains.