The NZR K
B class of 1939 was a class of six mixed traffic
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 ...
s built for
New Zealand Railways Department
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), that operated on
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 ...
's
railway network. After the success of the
K class, the K
B class were built to meet the increasing traffic demands on the
Midland Line in 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 ...
. The locomotives had a
wheel arrangement
In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...
of
4-8-4
Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type w ...
and first appeared with distinctive streamlining, mainly to hide their ACFI feedwater systems.
History
Following the success of the K class in the
North Island
The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...
, there was a need for similar locomotives to operate the
Midland Line, primarily between
Springfield
Springfield may refer to:
* Springfield (toponym), the place name in general
Places and locations Australia
* Springfield, New South Wales (Central Coast)
* Springfield, New South Wales (Snowy Monaro Regional Council)
* Springfield, Queenslan ...
and
Arthur's Pass
Arthur's Pass, previously called Camping Flat then Bealey Flats, and for some time officially Arthurs Pass, is a township in the Southern Alps of the South Island of New Zealand, located in the Selwyn district. It is a popular base for explorin ...
. These new locomotives incorporated a number of improvements upon the K class, including a re-designed
plate frame
Plate may refer to:
Cooking
* Plate (dishware), a broad, mainly flat vessel commonly used to serve food
* Plates, tableware, dishes or dishware used for setting a table, serving food and dining
* Plate, the content of such a plate (for example: ...
to eliminate cracking issues the K class experienced;
roller bearings
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing (mechanical), bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, Groove (engineering), g ...
on all wheels; hydrostatic lubrication throughout; and the inclusion of the ACFI feed-water system that had been pioneered on K 919. The ACFI equipment's aesthetic appearance had been criticised, hence the K
B and contemporary
KA classes were both fitted with shrouding to obscure it.
The K
B class were technically very similar to the K
A class, but were distinguished by the inclusion of a
booster engine
A booster engine for steam locomotives is a small two-cylinder steam engine back-gear-connected to the trailing truck axle on the locomotive or the lead truck on the tender. A rocking idler gear permits it to be put into operation by the drive ...
on the rear axle of the trailing
bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...
and Nicholson
thermic syphon
Thermic siphons (alt. thermic syphons) are Heat-exchanger, heat-exchanging elements in the Firebox (steam engine), firebox or Combustion chamber#Steam engine, combustion chamber of some steam boiler and steam locomotive designs. As they are dire ...
s in the
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
Firebox Records was a Finnish record label based in S ...
. The use of the booster, first proposed for the K class in 1932, was mainly due to steeper gradients and heavy freight trains on the Midland Line, especially
Cass
Cass may refer to:
People and fictional characters
* Cass (surname), a list of people
* Cass (given name), a list of people and fictional characters
* Big Cass, ring name of wrestler William Morrissey
* Cass, in British band Skunk Anansie
* Cass, ...
bank. Additional piping and sanding equipment for the booster gave the K
B a slightly different appearance to the K
A. The booster was intended solely for use at low speed, and some class members ultimately had the booster removed due to problems such as jamming in gear, reducing the locomotive's top speed.
Construction of the locomotives commenced in 1939. Construction and assembly took place at NZR's
Hillside Workshops
Hillside Engineering Group is a trading division of the rail operator KiwiRail in Dunedin, New Zealand. Most of its work is related to KiwiRail, but it also does work for the marine industry in Dunedin. On 19 April 2012 KiwiRail announced it was ...
. The first of the six-member class was produced before the first of the K
A class under construction at
Hutt Workshops
The Hutt Railway Workshops is a major railway engineering facility in the Lower Hutt suburb of Gracefield in the Wellington region of New Zealand's North Island. It is state-owned enterprise KiwiRail's only workshops, and was opened in 1930. ...
, in June 1939. All of the class were in service by 1940.
In service
As intended, the K
B class were based solely in the South Island and performed most of their work hauling freight trains on the
Midland Line. During the
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
, they were also used on the
Main South Line
The Main South Line, sometimes referred to as part of the South Island Main Trunk Railway, is a railway line that runs north and south from Lyttelton in New Zealand through Christchurch and along the east coast of the South Island to Inverca ...
.
While the aesthetic shrouding cleaned up the appearance of the locomotives, it was open at the top and gathered soot and dust which affected the working environment in the cab. After the war, the aesthetic shrouding was removed from the locomotives and the ACFI feed-water system was replaced with exhaust steam
injector
An injector is a system of ducting and nozzles used to direct the flow of a high-pressure fluid in such a way that a lower pressure fluid is entrained in the jet and carried through a duct to a region of higher pressure. It is a fluid-dynamic ...
.
Although the K and K
A classes were converted to burn oil at the time, the K
Bs unlike their North Island counterparts the K
A class remained as coal burners due to the availability of high grade
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 ...
coal.
Withdrawal and disposal
From the mid-1950s,
dieselisation
Dieselisation (US: dieselization) is the process of equipping vehicles with a diesel engine or diesel engines. It can involve replacing an internal combustion engine powered by petrol (gasoline) fuel with an engine powered by diesel fuel, as o ...
impacted the utilisation of the K
B class. With the introduction of diesel railcars in the 1950s, the class stopped hauling passenger trains. This became especially pronounced in the 1960s, and the introduction of the
DJ class in 1968 brought about their ultimate demise. As they were displaced from duties in the late 1960s, some members were used on the Main South Line, including hauling the
South Island Limited
The ''South Island Limited'' was a passenger express train operated by the New Zealand Railways Department (NZR) between 1949 and 1970. It operated over the almost route between Christchurch and Invercargill. It was replaced by the '' Southerne ...
.
The first withdrawals were K
Bs 966 and 969 in October 1967; both were cut up for scrap. K
B 969 was withdrawn after hauling the only ever
double-headed K
B train, having suffered a cracked motion bracket. Before it was sent to the breakers' yard, it was inscribed with a message reading ''"Goodbye Kb 969, you'll come back as
roofing iron"''.
K
B 967 was withdrawn in October 1968. This left only three K
B's in service (965, 968 and 970), and of those, only 968 and 970 were still used regularly while 965 was kept as a standby spare locomotive from July 1968 onwards; with the remaining two being withdrawn in March 1969. 970 was scrapped in late March 1968, while 968 made its last journey on 22 June 1969, hauling a railway enthusiast's excursion from Christchurch to Arthur's Pass and return, and 965 was scrapped in late September 1969.
Preservation
NZR donated members of the K and K
A classes for preservation, but due to the considerable technical similarities, it chose not to donate a K
B. Instead, enthusiasts purchased one at the scrap market rate of
NZ$
The New Zealand dollar ( mi, tāra o Aotearoa; sign: $, NZ$; code: NZD) is the official currency and legal tender of New Zealand, the Cook Islands, Niue, the Ross Dependency, Tokelau, and a British territory, the Pitcairn Islands. Within New ...
1500 (equal to $22,200 in December 2008 dollars).
K
B 968 was supposed to be cut up the week following its last excursion, but a collection on the return journey was sufficient to temporarily save the locomotive. Retired school teacher Cyril Evans raised the rest of the $1500 by showing railway films to Christchurch school children and collecting their donations. The locomotive was then vested into the Ferrymead Trust on behalf of the children of Canterbury and was displayed for a number of decades at the
Ferrymead Railway
The Ferrymead Railway is a New Zealand heritage railway built upon the track formation of New Zealand's first public railway, from Ferrymead to Christchurch, which opened on 1 December 1863. On the opening of the line to Lyttelton on 9 December 1 ...
. It is currently under restoration to mainline operating condition at
Mainline Steam
The Mainline Steam Heritage Trust is a New Zealand charitable trust devoted to the restoration and operation of historic New Zealand Railways and overseas mainline steam locomotives. Regular day excursions and multi-day tours are operated over ...
's Christchurch depot.
References
Citations
Bibliography
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External links
New Zealand Steam Locomotives - KB class*
{{NZR Locomotives
Kb class
4-8-4 locomotives
Railway locomotives introduced in 1939
3 ft 6 in gauge locomotives of New Zealand