NZR Ab class
Encyclopedia
The NZR
AB class was a class of 4-6-2 Pacific
tender
steam locomotive
that operated on New Zealand
's national railway system
. Originally an improvement on the 1906 A class
, 141 were built between 1915 and 1927 by NZR's Addington Workshops
, A & G Price Limited of Thames, New Zealand
, and North British Locomotive Company
, making the AB class the largest class of steam locomotives ever to run in New Zealand. An additional ten were rebuilt from the tank version of the AB – the WAB class
– between 1947 and 1957, while another two North British-made locomotives were built, but were lost in the wreck of the in May 1922.
Reputedly the first engine able to generate one horsepower for every 100 pounds of weight, the AB class was efficient and versatile, and the engines were easy to maintain and operate. Members of the class worked almost every part of the New Zealand rail network, and were used for both freight and passenger trains. The AB class was easily able to pull an express passenger train at speeds of 100 km/h (62.1 mph), or haul 700-tonne goods trains on easy grades. They, along with the earlier 'F' class, were known as the 'Maids of all work'.
A distinctive feature of the AB class's design is their Vandebuilt tenders, which gave them their cylindrical back. Several features of the class, notably their boilers, were used on other NZR locomotives.
The AB class were superseded on principal express trains and heavy freight trains by the K class of 1932
and the J class of 1939
, and were relegated to secondary duties. However they were still to be seen running relief expresses during the busier parts of the year. The majority of the class was withdrawn from NZR services during the 1960s, as diesel traction replaced steam
, with a few members of the class lasting to the end of steam itself in 1971. Two were retained to operate the Kingston Flyer
, possibly New Zealand's most famous heritage railway. The Flyer has now passed into private ownership and it is still run by AB 778 and AB 795. Five more have been preserved by various other preservation societies.
The WAB class
of 1917 was essentially a tank locomotive
version of the AB class.
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...
AB class was a class of 4-6-2 Pacific
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...
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...
steam locomotive
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...
that operated 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 railway system
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...
. Originally an improvement on the 1906 A class
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...
, 141 were built between 1915 and 1927 by NZR's Addington Workshops
Addington Workshops
The Addington Railway Workshops was a major railway facility established in the Christchurch suburb of Addington in May 1880 by the New Zealand Railways Department. The workshops were previously in Carlyle Street and closed in 1990.-Description:...
, A & G Price Limited of Thames, New Zealand
Thames, New Zealand
Thames is a town at the southwestern end of the Coromandel Peninsula in New Zealand's North Island. It is located on the Firth of Thames close to the mouth of the Waihou River. The town is the seat of the Thames-Coromandel District Council....
, and North British Locomotive Company
North British Locomotive Company
The North British Locomotive Company was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp Stewart and Company , Neilson, Reid and Company and Dübs and Company , creating the largest locomotive manufacturing company in Europe.Its main factories were...
, making the AB class the largest class of steam locomotives ever to run in New Zealand. An additional ten were rebuilt from the tank version of the AB – the WAB class
NZR Wab class
The WAB class locomotives were steam locomotives designed, built and used by New Zealand Railways Department. Their wheel arrangement is described by the Whyte notation 4-6-4T. The locomotives were designed by NZR chief draughtsman S.H. Jenkinson as tank versions of the AB class 4-6-2 Pacific...
– between 1947 and 1957, while another two North British-made locomotives were built, but were lost in the wreck of the in May 1922.
Reputedly the first engine able to generate one horsepower for every 100 pounds of weight, the AB class was efficient and versatile, and the engines were easy to maintain and operate. Members of the class worked almost every part of the New Zealand rail network, and were used for both freight and passenger trains. The AB class was easily able to pull an express passenger train at speeds of 100 km/h (62.1 mph), or haul 700-tonne goods trains on easy grades. They, along with the earlier 'F' class, were known as the 'Maids of all work'.
A distinctive feature of the AB class's design is their Vandebuilt tenders, which gave them their cylindrical back. Several features of the class, notably their boilers, were used on other NZR locomotives.
The AB class were superseded on principal express trains and heavy freight trains by the K class of 1932
NZR K class (1932)
The NZR K class of 1932 was a class of mixed traffic 4-8-4 steam locomotives that operated on New Zealand's railway network. The locomotives were developed following the failure of the G class Garratts...
and the J class of 1939
NZR J class (1939)
The NZR J class steam locomotives were a class of locomotive used in New Zealand. Following the success of the K class on NZR main lines, there was an urgent need for a modern, powerful locomotive capable of running over secondary lines laid with lighter rails. Thus a new "Mountain" 4-8-2 type...
, and were relegated to secondary duties. However they were still to be seen running relief expresses during the busier parts of the year. The majority of the class was withdrawn from NZR services during the 1960s, as diesel traction replaced steam
Dieselisation
Dieselisation or dieselization is a term generally used for the increasingly common use of diesel fuel in vehicles, as opposed to gasoline or steam engines.-Water Transport:...
, with a few members of the class lasting to the end of steam itself in 1971. Two were retained to operate the Kingston Flyer
Kingston Flyer
The Kingston Flyer is a vintage steam train operating in the South Island of New Zealand at the southern end of Lake Wakatipu. It uses 14 kilometres of preserved trackage that once formed a part of the Kingston Branch.-History:...
, possibly New Zealand's most famous heritage railway. The Flyer has now passed into private ownership and it is still run by AB 778 and AB 795. Five more have been preserved by various other preservation societies.
The WAB class
NZR Wab class
The WAB class locomotives were steam locomotives designed, built and used by New Zealand Railways Department. Their wheel arrangement is described by the Whyte notation 4-6-4T. The locomotives were designed by NZR chief draughtsman S.H. Jenkinson as tank versions of the AB class 4-6-2 Pacific...
of 1917 was essentially a tank locomotive
Tank locomotive
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of pulling it behind it in a tender. It will most likely also have some kind of bunker to hold the fuel. There are several different types of tank locomotive dependent upon...
version of the AB class.
Class register
| Number | Builder | Introduced | Current status | Notes | |
|---|---|---|---|---|---|
| 608 | NZR Addington | Undergoing restoration | NZRLS on lease to Steam Incorporated Steam Incorporated Steam Incorporated, often abbreviated to Steam Inc., is a railway heritage and preservation society based at the Paekakariki Railway Station, Paekakariki at the southern end of the Kapiti Coast, approximately 50 minutes north of Wellington on the west coast of New Zealand's North Island. Unlike... , Paekakariki Paekakariki Paekakariki is a town in the Kapiti Coast District in the south-western North Island of New Zealand. It is 22 km north of Porirua and 45 km north-east of Wellington, the nation's capital city.... . |
||
| 663 | NZR Addington | Operational and mainline certified | Preserved, 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... , Plimmerton Plimmerton The township of Plimmerton is adjacent to one of the more congenial beaches in the northwest part of the Wellington urban area of Porirua in New Zealand... . |
||
| 699 | A & G Price | Operational | Preserved, Pleasant Point Museum and Railway Pleasant Point Museum and Railway thumb|right|Pleasant Point Museum and Railway YardThe Pleasant Point Museum and Railway is a narrow gauge heritage railway located in the small country town of Pleasant Point in southern Canterbury, New Zealand, inland from Timaru. Its main terminal is located at Pleasant Point station, which was... . |
||
| 745 | North British Loco. | Awaiting restoration | Preserved, Taranaki Steam Locomotive Trust (Taranaki Flyer Society). | ||
| 778 | NZR Addington | Operational (stored in shed) | Preserved, Kingston Flyer Kingston Flyer The Kingston Flyer is a vintage steam train operating in the South Island of New Zealand at the southern end of Lake Wakatipu. It uses 14 kilometres of preserved trackage that once formed a part of the Kingston Branch.-History:... . |
||
| 795 | NZR Hillside | Operational (Stored in shed) | Preserved, Kingston Flyer Kingston Flyer The Kingston Flyer is a vintage steam train operating in the South Island of New Zealand at the southern end of Lake Wakatipu. It uses 14 kilometres of preserved trackage that once formed a part of the Kingston Branch.-History:... . Originally built as a Wab class locomotive. |
||
| 832 | North British Loco. | Awaiting restoration | MOTAT on lease to Glenbrook Vintage Railway Glenbrook Vintage Railway The Glenbrook Vintage Railway is a steam railway in Glenbrook, New Zealand. One of New Zealand's premiere rail heritage sites, it is not a museum as such, but rather a fully self-supporting, operating steam railway, built almost entirely by volunteer labour... , Auckland. |