# NZR KB class

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NZR KB class KB class 4-8-4 steam locomotive, NZR number 969, c. 1940 at Hillside Workshops in Dunedin.[1] Godber Collection, Alexander Turnbull Library. Type and origin Power type Steam Builder NZR Hillside Workshops, Dunedin Build date 1939 Specifications Configuration: ​ • Whyte 4-8-4 Gauge 3 ft 6 in (1,067 mm) Wheel diameter 54 in (1.372 m) Wheelbase 34 ft 10 in (10.62 m) Length 69 ft 8 in (21.23 m) Width 8 ft 6 in (2.59 m) Height 11 ft 6 in (3.51 m) Adhesive weight 56.0 long tons (56.9 t; 62.7 short tons) Loco weight 94.8 long tons (96.3 t; 106.2 short tons) Tender weight 52.9 long tons (53.7 t; 59.2 short tons) Total weight 147.7 long tons (150.1 t; 165.4 short tons) Fuel type Coal Fuel capacity 7.5 long tons (7.6 t; 8.4 short tons) Water cap. 5,000 imp gal (23,000 L; 6,000 US gal) Firebox: ​ • Grate area 47.7 sq ft (4.4 m2) Boiler pressure 200 psi (1,379 kPa) Feedwater heater ACFI Heating surface 1,984 sq ft (184.3 m2) Superheater: ​ • Heating area 485 sq ft (45.1 m2) Cylinders 2 driving 2 booster Cylinder size 20 in × 26 in (508 mm × 660 mm) Performance figures Power output 1,400 hp (1,000 kW) Tractive effort 30,815 lbf (137.07 kN) 36,815 lbf (163.76 kN) with booster Career Number in class 6 Numbers 965 - 970[2] Locale South Island of New Zealand, mainly the Midland line First run 1939 - 1940 Last run December 1968 Retired 1967 - 1969 Current owner Ferrymead Trust, leased to Mainline Steam Disposition Withdrawn; 1 preserved

The **NZR KB class** of 1939 was a class of six mixed traffic [steam locomotives](/source/Steam_locomotive) built for [New Zealand Railways Department](/source/New_Zealand_Railways_Department) (NZR), that operated on [New Zealand](/source/New_Zealand)'s [railway network](/source/Rail_transport_in_New_Zealand). After the success of the [K class](/source/NZR_K_class_(1932)), the KB class were built to meet the increasing traffic demands on the [Midland Line](/source/Midland_Line%2C_New_Zealand) in the [South Island](/source/South_Island). The locomotives had a [wheel arrangement](/source/Wheel_arrangement) of [4-8-4](/source/4-8-4) and first appeared with distinctive streamlining, mainly to hide their ACFI feedwater systems.[3]

## History

Following the success of the K class in the [North Island](/source/North_Island), there was a need for similar locomotives to operate the [Midland Line](/source/Midland_Line%2C_New_Zealand), primarily between [Springfield](/source/Springfield%2C_New_Zealand) and [Arthur's Pass](/source/Arthur's_Pass). These new locomotives incorporated a number of improvements upon the K class, including a re-designed [plate frame](/source/Locomotive_frame) to eliminate cracking issues the K class experienced; [roller bearings](/source/Rolling-element_bearing) 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 KB and contemporary [KA](/source/NZR_KA_class) classes were both fitted with shrouding to obscure it.

The KB class were technically very similar to the KA class, but were distinguished by the inclusion of a [booster engine](/source/Booster_engine) on the rear axle of the trailing [bogie](/source/Bogie) and Nicholson [thermic syphons](/source/Thermic_syphon) in the [firebox](/source/Firebox_(steam_engine)).[3] 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](/source/Cass%2C_New_Zealand) bank. Additional piping and sanding equipment for the booster gave the KB a slightly different appearance to the KA. 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](/source/Hillside_Workshops). The first of the six-member class was produced before the first of the KA class under construction at [Hutt Workshops](/source/Hutt_Workshops), in June 1939.[2] All of the class were in service by 1940.[2]

## In service

As intended, the KB class were based solely in the South Island and performed most of their work hauling freight trains on the [Midland Line](/source/Midland_Line%2C_New_Zealand). During the [Second World War](/source/Second_World_War), they were also used on the [Main South Line](/source/Main_South_Line).

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](/source/Injector).

Although the K and KA classes were converted to burn oil at the same time, the KB class remained as coal burners due to the availability of high grade [West Coast](/source/West_Coast%2C_New_Zealand) coal.

## Withdrawal and disposal

From the mid-1950s, [dieselisation](/source/Dieselisation) impacted the use of the KB class. With the introduction of diesel railcars in the 1950s, the class stopped hauling passenger trains.[3] This became especially pronounced in the 1960s, and the introduction of the [DJ class](/source/New_Zealand_DJ_class_locomotive) 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](/source/South_Island_Limited).

The first withdrawals were KB's 966 and 969 in October 1967;[2] both were cut up for scrap. KB 969 was withdrawn after hauling the only ever [double-headed](/source/Double-heading) KB train, having suffered a cracked motion bracket. Before it was sent to the breakers' yard, it was inscribed with a message reading *"Good-bye, Kb969, and you'll come back as [roofing iron](/source/Corrugated_galvanised_iron)"*.[4]

KB 967 was withdrawn from service in October 1968.[2] This left only three KB's in service (965, 968 and 970), and of those, only Kb's 968 and 970 were still used regularly while Kb965 was kept as a standby spare locomotive from July 1968 onwards; with the remaining two being withdrawn from service in March 1969.[2] Kb970 was scrapped in late March 1968, while Kb968 made its last long journey on 22 June 1969, hauling a railway enthusiast's excursion from Christchurch to Arthur's Pass and return, and Kb965 was scrapped in late September 1969.

## Preservation

NZR donated members of the K and KA classes for preservation, but due to the considerable technical similarities, it chose not to donate a KB. Instead, enthusiasts purchased one at the scrap market rate of [NZ$](/source/NZ%24)1500 (equal to $22,200 in December 2008 dollars).[5] KB 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.[4] Retired school teacher Cyril Evans raised the rest of the $1,500 by showing railway films to Christchurch school children and collecting their donations. The locomotive was then vested into the Ferrymead Heritage Trust on behalf of the children of Canterbury and was displayed for a number of decades at the [Ferrymead Railway](/source/Ferrymead_Railway).[6] It was currently under restoration to mainline operating condition at [Mainline Steam](/source/Mainline_Steam)'s Wellington depot.

## References

### Citations

1. **[^](#cite_ref-FOOTNOTELloyd197478_1-0)** [Lloyd 1974](#CITEREFLloyd1974), p. 78.

1. ^ [***a***](#cite_ref-FOOTNOTELloyd197479_2-0) [***b***](#cite_ref-FOOTNOTELloyd197479_2-1) [***c***](#cite_ref-FOOTNOTELloyd197479_2-2) [***d***](#cite_ref-FOOTNOTELloyd197479_2-3) [***e***](#cite_ref-FOOTNOTELloyd197479_2-4) [***f***](#cite_ref-FOOTNOTELloyd197479_2-5) [Lloyd 1974](#CITEREFLloyd1974), p. 79.

1. ^ [***a***](#cite_ref-FOOTNOTEPalmerStewart1965118_3-0) [***b***](#cite_ref-FOOTNOTEPalmerStewart1965118_3-1) [***c***](#cite_ref-FOOTNOTEPalmerStewart1965118_3-2) [Palmer & Stewart 1965](#CITEREFPalmerStewart1965), p. 118.

1. ^ [***a***](#cite_ref-FOOTNOTESinclair1987140-145_4-0) [***b***](#cite_ref-FOOTNOTESinclair1987140-145_4-1) [Sinclair 1987](#CITEREFSinclair1987), p. 140-145.

1. **[^](#cite_ref-5)** ["New Zealand CPI Inflation Calculator - Reserve Bank of New Zealand"](https://web.archive.org/web/20100701190957/http://www.rbnz.govt.nz/statistics/0135595.html). Archived from [the original](http://www.rbnz.govt.nz/statistics/0135595.html) on 1 July 2010. Retrieved 27 March 2009.

1. **[^](#cite_ref-FOOTNOTECavalcade125198812_6-0)** [Cavalcade125 1988](#CITEREFCavalcade1251988), p. 12.

### Bibliography

- Barry, Colin; Brouwer, John; Dash, Colin; Dickenson, Peter; Shalders, Bruce (1988). [*Cavalcade 125*](https://trove.nla.gov.au/work/19528333). Ferrymead 125 Committee. Retrieved 22 March 2019.

- Lloyd, W. G. (1974). *Register of New Zealand Railways Steam Locomotives 1863-1971* (2nd ed.). Otago Railway and Locomotive Society & Triple M Publications. [ISBN](/source/ISBN_(identifier)) [0-9582072-1-6](https://en.wikipedia.org/wiki/Special:BookSources/0-9582072-1-6).

- Palmer, A. N.; Stewart, W. W. (1965). *Cavalcade of New Zealand Locomotives*. Wellington: [A H. & A W. Reed](/source/Reed_Publishing). [ISBN](/source/ISBN_(identifier)) [978-0-207-94500-7](https://en.wikipedia.org/wiki/Special:BookSources/978-0-207-94500-7).

- Sinclair, Roy (1987). *Rail - The Great New Zealand Adventure*. Wellington, New Zealand: Grantham House Publishing. [ISBN](/source/ISBN_(identifier)) [978-1-86934-013-1](https://en.wikipedia.org/wiki/Special:BookSources/978-1-86934-013-1).

- Jonathan Shingelton (2021). [*Alpine Thunder when the KB class ruled the Midland line*](https://railsoc.org.nz/alpine-thunder-when-the-kb-class-ruled-the-midland-line/). Wellington: [New Zealand Railway and Locomotive Society](/source/New_Zealand_Railway_and_Locomotive_Society). [ISBN](/source/ISBN_(identifier)) [9780995138506](https://en.wikipedia.org/wiki/Special:BookSources/9780995138506).

## External links

- [New Zealand Steam Locomotives - KB class](http://www.trainweb.org/nzsteam/kb_class.html)

- ["A Kb loco-hauled freight train approaching the Alps (undated photo)"](https://railsoc.org.nz/sm11/). NZRLS. 2022.

v t e Rail vehicles of New Zealand Diesel locomotives Mainline DA (inc. DAA, DAR) DB (inc. DBR) DC (inc. DCP) DF (English Electric) DF (General Motors) inc. DFT, DFB, DFM DG (inc. DH of 1956) DI DJ DL DM DQ and QR DX (inc. DXB, DXC, DXR) Shunt DE DH of 1978 DS DSA DSB DSC DSG DSH (on order) DSJ TR Electric locomotives 1500 V DC EA (later EO of 1968) EC ED EO of 1923 EW 25 kV AC EF Battery E EB Diesel multiple units ADK/ADB class diesel multiple unit ADL/ADC class diesel multiple unit Electric multiple units 1500 V DC (Wellington) "English Electric" DM (inc. D trailers) "Ganz Mavag" EM (inc. ET trailers) "Matangi" FP (inc. FT trailers) "Tūhono" BEMU (on order) 25 kV AC (Auckland) AM (inc. AMP, AMT, AMA) Railcars RM class 88 seater (also known as Fiats or twinsets) Clayton steam railcar Edison battery-electric railcar Red Terror railcar Midland railcar Leyland experimental petrol railcar McEwan Pratt petrol railcar Model T Ford railcar Sentinel-Cammell steam railcar Silver Fern railcar Standard railcar Thomas Transmission railcar Vulcan railcar Wairarapa railcar Westinghouse railcar Others A 88 Buckhurst petrol carriage Steam locomotives A of 1873 A of 1906 (inc. AD) AA AB B of 1874 B of 1899 BA BB BC C of 1873 C of 1930 D of 1874 D of 1929 E of 1872 & 1875 E of 1906 F FA (inc. FB) G of 1874 G Garratt of 1928 (inc. Pacific rebuild) H J of 1874 J of 1939 JA JB K of 1877 K of 1932 KA KB L LA M N NA NC O OA OB OC P of 1876 P of 1885 Q of 1878 Q of 1901 R S T U UA UB UC UD V W WA WAB WB WD WE WF WG WH WJ WS WW X Y Locomotive hauled carriages 50-foot carriage 56-foot carriage AC class (Grassgrubs) ex-British Rail Mark 2 carriage AK carriage FM class guards van SX carriages Track evaluation, cranes, and maintenance ETM class track evaluation car EL class rail cranes ETM class rail maintenance equipment Locomotives of New Zealand Rail transport in New Zealand Railway preservation in New Zealand.

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Adapted from the Wikipedia article [NZR KB class](https://en.wikipedia.org/wiki/NZR_KB_class) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/NZR_KB_class?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.