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 WW 644 as preserved on the Glenbrook Vintage Railway in 2011. | |||||||||||||||||||||||||||||||||||||||||||||
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The NZR WW class was a class of 4-6-4T tank locomotives that operated on the New Zealand national railway network. They were built for New Zealand Railways Department (NZR), and were the final development of the six-coupled tank engine in New Zealand, the penultimate class of tank locomotives to be built for NZR, and the first class of tank locomotives to be built with superheaters. [1]
The WW class were based on the earlier WG class 4-6-4T tank locomotives, but with a reduced boiler pressure of 180psi and larger cylinders. [2] The initial batch comprising locomotives WW 556-575 were built at Hillside Workshops in 1913, and initially carried the WG classification before being reclassified as the WW class, the 'W' indicating that these locomotives were intended for suburban work in Wellington.
Following the success of the first twenty locomotives, Hillside delivered a further thirty locomotives which were classified WW from new. A further fourteen locomotives were rebuilt from the WG class at Hutt Workshops in two batches between 1940–42 and 1950-52. [3]
Although most of the class were built with piston valves, WW 565 was delivered with slide valves, which were not suited to superheated steam, leading to their replacement with standard piston valves.
The WW class demonstrated to be extremely versatile in service, being capable of handling almost any task. Initially both Auckland and Wellington received allocations of these locomotives which were used in suburban passenger service and occasionally on goods work; later allocations saw engines of this class allocated to the West Coast at Westport and Greymouth. Here, the locomotives worked mostly on coal trains and occasionally hauled branch line passenger services.
During the early 1950s, the decision was made to fit new higher-pitched boilers with deeper fireboxes to four WG class locomotives, Nos. 479, 480, 486 and 488, as a trial when they were rebuilt to WW class specifications. This required a new type of smokebox saddle, cab and enlarged coal bunker. This alteration was deemed to be successful, adding an extra 100 sq. ft. of heating surface; [4] rather than rebuild the remaining six WGs due to the poor condition of their frames, NZR decided to rebuild twelve existing WW class locomotives, Nos. 571, 573-575, 644, 669, 672, 678-680, 683-684.
During the early 1960s, several of the WW class locomotives transferred from the North Island to Greymouth were altered to operate on the Rewanui Incline by the provision of 'trap-door' cowcatchers to clear the centre rail and additional air reservoirs on the tops of the side tanks. Following the removal of the centre rail in 1966, the locomotives' extra reservoirs were removed and the original brake pump was replaced by two larger pumps, one on each side of the smokebox. [5]
The first member of the WW class to be withdrawn was WW 491, which was withdrawn in August 1955 for use as a sectionalised aid for apprentice training at Otahuhu Workshops. A further forty-three locomotives were withdrawn by the first half of the 1960s, by which time the remaining twenty-one locomotives were in service in Auckland and on the West Coast. Further withdrawals were at a slower pace, with a final seven locomotives still in service on the West Coast at the start of 1969. [6]
Four WW class locomotives have been preserved, all in the North Island. Three were rebuilt with higher-pitched boilers while the fourth retains its original low-pitched boiler:
In addition, Steam Incorporated also owned an original low-pitched WW boiler which had originally been fitted to WW 646. This boiler was purchased for industrial use at the Ford Motor Company plant in the Hutt Valley in the 1970s and was stored at Paekakariki until early 2015 when it was sold to MOTAT to aid the future restoration of WW 491.
The New Zealand F class was the first important class of steam locomotive built to operate on New Zealand's railway network after the national gauge of 3 ft 6 in was adopted. The first locomotives built for the new gauge railways were two E class double Fairlies for the Dunedin and Port Chalmers Railway Company. The F class was the first class ordered by the central government, and between 1872 and 1888, a total of eighty-eight members of the class were constructed.
The NZR A class were a class of steam locomotives built in 1906 with a 4-6-2 wheel arrangement for the New Zealand Railways Department (NZR). The class should not be confused with the older and more obscure A class of 1873. They were designed by the NZR's Chief Mechanical Engineer, A. L. Beattie and his Chief Draughtsman, G. A. Pearson to replace less powerful locomotives struggling with increasing loads on the South Island Main Trunk Railway, and in anticipation of the traffic volumes that would be created upon the completion of the North Island Main Trunk railway.
The NZR AB class was a class of 4-6-2 Pacific tender steam locomotive that operated on New Zealand's national railway system for New Zealand Railways (NZR). Originally an improvement on the 1906 A class, 141 were built between 1915 and 1927 by NZR's Addington Workshops, A & G Price 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 eleven were rebuilt from the tank version of the AB – the WAB class – between 1947 and 1957. Two North British-made locomotives were lost in the wreck of the SS Wiltshire in May 1922.
The NZR WB class was a class of tank locomotives that operated in New Zealand. Built in 1898 by the Baldwin Locomotive Works, the twelve members of the class entered service during the first five months of 1899. Eight were withdrawn by the end of 1935, while four others survived with new boilers until the mid-1950s.
The NZR WD class was a class of tank locomotive built by Baldwin Locomotive Works to operate on New Zealand's national rail network.
The NZR 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 (NZR) by the end of 1896, the B classification was free to be re-used. Despite early difficulties, they were amongst NZR's most influential designs.
The NZR C class consisted of twenty-four steam locomotives built to perform shunting duties on New Zealand's national rail network. It is sometimes known as the big C class to differentiate it from the C class of 1873.
The NZR WAB class locomotives were steam locomotives designed, built and used by New Zealand Railways Department (NZR). 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 locomotive. Initially, the locomotives were separated into two classes, designated WAB for mainline work and WS for suburban work.
The Glenbrook Vintage Railway (GVR) is a heritage steam railway in Glenbrook, New Zealand.
The NZR JA class was a class of fifty-one 4-8-2 steam locomotives operated by the New Zealand Railways Department (NZR). The locomotives were built in two batches; the first batch was constructed in-home at the Hillside Workshops at Dunedin between 1946 and 1956, while the second batch was produced by the North British Locomotive Company (NBL) of Glasgow, Scotland in 1951. To differentiate between the two batches, the locomotives were identified by their builder.
The NZR G class was a type of Garratt locomotives used in New Zealand, later rebuilt as Pacific type locomotives. They were the only Garratt type steam locomotives ever used by the New Zealand Railways (NZR). They were ordered to deal with traffic growth over the heavy gradients of the North Island Main Trunk (NIMT) and to do away with the use of banking engines on steep grades. They were one of the few Garratt designs to employ six cylinders. A mechanical stoker was used to feed coal into the locomotive. The locomotives lasted longer in rebuilt form as standard Pacific locomotives than they did as Garratts, but their numerous mechanical issues lead to their final withdrawal following a union ban on their use in 1956.
The NZR J class was a class of forty 4-8-2 steam locomotives operated by the New Zealand Railways Department (NZR). Although designed to work on the lighter secondary lines, the class was frequently used on mainline express passenger trains as well as freight. When first introduced, the class boasted distinctive streamlining, which was later removed from 1947 onwards for maintenance reasons. Three of this class remained in service until the end of steam operation on 26 October 1971, when they were withdrawn and entered into preservation. This class should not be confused with the earlier J class from 1874.
The NZR LA class was a class of 4-4-0T steam locomotives used by the New Zealand Railways Department and the New Zealand Midland Railway Company. They were built by Nasmyth, Wilson and Company in 1887 for New Zealand Midland Railway Company, and were taken over by NZR in 1900, when the government acquired the incomplete Midland line. The designation also applies to the NZR 4-4-0Trebuilds of the Avonside L class of 1875 which were later reclassified LB after being rebuilt as 4-4-2Ts.
The NZR WF class were steam locomotives designed, built and used by New Zealand Railways (NZR). Their wheel arrangement is described by the Whyte notation 2-6-4T and the first members of the class entered service in 1904. The locomotives were tank engines designed by the Railways Department's Chief Mechanical Engineer A. L. Beattie, and were mainly built for suburban duties such as those between Christchurch and Lyttelton. They also saw main-line service in the Taranaki region, but most of the class members were assigned to branch line and local services throughout the country. Two were experimentally converted to oil burners in 1909-1910. The tests were satisfactory, but as coal was much cheaper than oil at the time, no further conversions took place.
The NZR W class consisted of two steam locomotives built at the Addington Railway Workshops in Christchurch, New Zealand by the New Zealand Railways Department (NZR). They were the first locomotives to be built by NZR.
The NZR FA class was a class of tank steam locomotives that was built as a larger version of the NZR F class 0-6-0T. The requirements were for larger water and coal capacity on a locomotive that could handle grades better than the F class. Due to costs involved in producing new machines, NZR chose to rebuild existing machines with larger coal and water capacity, larger boiler and firebox, higher boiler pressure and larger diameter pistons. Seven F class engines were rebuilt between 1892 and 1897. Another seven were built new, one at Newmarket Workshops in 1896 and six at Addington Workshops in 1902–03.
The NZR WA class locomotives were a class of tank locomotive built by New Zealand Railways (NZR). Eleven were built at NZR's own Addington Workshops in Christchurch and Hillside Workshops in Dunedin. Four more were converted from old J class 2-6-0 locomotives.
The NZR G Class was a class of four saddle tank locomotives from English builders Black Hawthorn in the early 1870s. Like the similarly sized D class, they were an attempt to produce a passenger version of the already highly successful F class.
The NZR L class were a series of ten small tank engines built in England for the New Zealand Railways Department (NZR) during the early years of the development of New Zealand's railway network.
The NZR WG class was a development of the preceding WF class of all purpose tank locomotive. Later in their careers most (14) were rebuilt as WW class. The locomotives were designed by A. L. Beattie, who described them as a "large tank locomotive."
