The NZR Q class was an important

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

class not only in the history of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

network but also in worldwide railways in general. Designed by

New Zealand Government Railways The New Zealand Railways Department, NZR or NZGR (New Zealand Government Railways) and often known as the "Railways", was a government department charged with owning and maintaining New Zealand's railway infrastructure and operating the railway ...

' (NZR) Chief Mechanical Engineer

A. L. Beattie Alfred Luther Beattie (1852 – 2 May 1920), typically referred to as A. L. Beattie, was a pioneering locomotive engineer. Born in Yorkshire, England,The Rock, September 2010 http://www.stpeterscaversham.org.nz/The%20Rock/1009.pdf he gained fame ...

and ordered from the

Baldwin Locomotive Works The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades t ...

in 1901, they were the first locomotives in the world to be built with the wheel arrangement of

4-6-2 Under 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. The locomotiv ...

. This wheel arrangement came to be known as the ''Pacific'' type after the voyage the completed locomotives had to make across the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

to New Zealand. A few instances of the 4-6-2 wheel arrangement are known to have existed prior to 1901, but these were all reconstructions of locomotives that were originally built with a different wheel arrangement, thereby making the thirteen members of the Q class the first "true" Pacifics in the world. The Pacific style went on to become arguably the most famous wheel arrangement in the world.

Design

The Q class's design stems from the requirement for a locomotive similar to the U^B class with the inclusion of a wide

firebox Firebox may refer to: *Firebox (steam engine), the area where the fuel is burned in a steam engine *Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records, a Finnish 8101705801record label * Firebox.com, an electro ...

to burn poor quality

lignite Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

from the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

and the Waikato. Originally plans to equip the new locomotives with a

Wootten Firebox The Wootten firebox is a type of firebox used on steam locomotives. The firebox was very wide to allow combustion of anthracite waste, known as " culm". Its size necessitated unusual placement of the crew, examples being camelback locomotives. The ...

would have seen the "Camelback" configuration adopted.

Operation

In operation, the locomotives proved to be satisfactory rather than brilliant and they suffered from occasional gear problems. They were soon displaced from the most important and difficult work by members of the A and A^B classes; in fact, later in life, they were re-boilered with A^B boilers. An improved slightly larger 'Q' type was ordered from Baldwins in 1914, but classified A^A due to their dimensions similar to the A class. In a 1902 trial of various locomotives between Invercargill and Gore, the Q class with large fire-grate area "gave the most efficient results" of the larger locomotives.

Withdrawal

They saw out their final years working in

Otago Otago (, ; mi, Ōtākou ) is a region of New Zealand located in the southern half of the South Island administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local government reg ...

and the

West Coast West Coast or west coast may refer to: Geography Australia * Western Australia *Regions of South Australia#Weather forecasting, West Coast of South Australia * West Coast, Tasmania **West Coast Range, mountain range in the region Canada * Britis ...

and the last Q class locomotive was retired in 1957. No examples of the class were preserved.

References

Citations

Bibliography

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External links

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NZR Steam locomotives - Q class

{{NZR Locomotives Q class 4-6-2 locomotives Baldwin locomotives 3 ft 6 in gauge locomotives of New Zealand Railway locomotives introduced in 1901 Scrapped locomotives