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Class of Australian 2-8-0 steam locomotives From Wikipedia, the free encyclopedia
The Victorian Railways J class was a branch line steam locomotive operated by the Victorian Railways (VR) between 1954 and 1972. A development of the successful Victorian Railways K class 2-8-0, it was the last new class of steam locomotive introduced on the VR. Introduced almost concurrently with the diesel-electric locomotives that ultimately superseded them, the locomotives were only in service for a relatively short time.[1]
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During the early 1950s, the Victorian Railways (VR) embarked on a massive upgrading of its ageing locomotive fleet as part of Operation Phoenix, an £80 million program to rebuild a network badly run down by years of underinvestment during the Great Depression, and the heavy workload imposed by World War II.[2]
Victoria's branch line railway network, laid with 60 lb/yd (29.8 kg/m) rail and featuring gradients of up to 1 in 30 (3.33%), was still largely served by the D1, D2 and D3 variants of the once 261-strong 1902-era Dd class 4-6-0 which, by the early 1950s, were at the end of their life.[3] The new J class locomotives were supplemented by 53 K class locomotives, some of which had been built as recently as 1946. Although highly successful, K class locomotives were unsuitable for conversion from 5 ft 3 in (1,600 mm) to 4 ft 8+1⁄2 in (1,435 mm) standard gauge in the event of the Victorian network being standardised, and VR policy was for all new locomotives to be engineered for easy conversion.[4][5] Consequently, the building of further K class was not a feasible option.
With mainline electric and diesel-electric locomotives already on order, the VR design team opted for an updated, gauge-convertible K class, which would turn out to be their final steam locomotive design.[6][7][8]
The key problem with the K class design was the placement of the firebox between the locomotive frame and rear driving wheels, making conversion to a narrower gauge impossible without a radical redesign of the firebox. A previous attempt to develop a gauge-convertible K class, the N class, utilised a 2-8-2 wheel arrangement and positioned the firebox above the frames and behind the driving wheels. However, the extra length of those locomotives (being a total 67 ft or 20.42 m long) made them unsuitable for a number of branch lines where only a 50-or-53-foot (15.24 or 16.15 m) turntable was available. The J class adopted an alternative approach to the problem by employing a high-set boiler (with the boiler centre 9 ft 2+1⁄2 in (2.807 m) above rail level,[9] compared with 8 ft 4 in (2.54 m) for the K class[10]) setting the firebox above the frames and driving wheels, and retaining the K class' short wheelbase.
The J class also featured a number of other design advances over the K class. It had a larger grate, enabling grate sections to be compatible with those of the N class and permitting an increase in firebox volume sufficient to allow two arch tubes to be installed.[11] Another innovation was the use of a regulator valve incorporating a centrifugal steam separator (to draw away any water and thus provide the driest steam), rather than the simpler (though extremely reliable) D regulator valve used in the K class.[11] The J class also featured substantially redesigned cylinder porting to improve steam flow and efficiency.[12] The innovative SCOA-P type driving wheel centre developed for the Victorian Railways R class was adapted for the 55 in (1,397 mm) diameter J class drivers.
The high-set boiler, together with the German-style smoke deflectors, gave the J class a distinctly European appearance.[5]
A total of fifty J class locomotives were initially ordered from the Vulcan Foundry in Lancashire, England. However, the VR reassessed its motive power requirements and opted to sell 10 of its brand-new, second-generation N class locomotives to the South Australian Railways, and increased the J class order to 60.[13][14] At the time of order, the per-unit cost of the locomotives was £36,000 ($72,000) each.[15]
With fluctuating oil prices and an unreliable supply of coal in the early 1950s, the VR appeared to take something of a bet either way, ordering thirty of the class as coal burners and thirty as oil burners.[5]
By the time the contract for the J class had been awarded, the VR had already begun to receive deliveries of the B class mainline diesel-electric locomotives, and it unsuccessfully attempted to cancel the J class contract in favour of an order for branch line diesel locomotives.[11]
The J class was introduced for both passenger and goods traffic on Victoria's branch line network, with a maximum permissible speed of 45 mph (72 km/h), later raised to 50 mph (80 km/h). Dynamometer car tests showed the locomotive developed 930 hp (694 kW) at the drawbar at around 20–25 mph (32–40 km/h), which suited the relatively low speed limits of much of the Victorian branch line network.[11]
Coal-fired J class locomotives were the regular engine on the 09:00 Melbourne to Yarram passenger service, with other duties being from Lilydale to Warburton and local services from Spencer Street to Werribee. The oil-fired J was also pressed into service hauling the final leg of The Gippslander express from Sale to Bairnsdale. In their later years, J class locomotives also ran the Horsham to Dimboola leg of the morning service from Melbourne, one of the last regular steam-hauled passenger train services in Victoria.[11]
Although J class locomotives produced the same nominal tractive effort as the K or N class, they had a slightly higher adhesive weight (and so a better factor of adhesion) and were permitted to haul heavier loads on gradients.[16] They could be found in goods service on branch lines across the state, but were also found on mainlines, running roadside goods services.[11]
Within a year of the introduction of the J class, the T class diesel electric locomotive was also introduced. Although the VR did not publicly indicate the T was intended to replace the J class,[17] the T class proved to be such a successful design that further orders of that locomotive class were made during the late 1950s and 1960s, and T class units gradually displaced the J class from many of the latter's normal duties.
Together with the K and N classes, the J class had its boiler pressure raised in the early 1960s from 175 to 180 psi (1,207 to 1,241 kPa),[11] which raised their nominal tractive effort to 29,500 lbf (131 kN).
Following recommendations from the 1957 Australian and New Zealand Railway Conference, locomotive J546 was selected for the installation of a Laidlaw-Drew oil firing system in place of the convention weir-type burner. However, the locomotive was found to steam poorly under load using the Laidlaw-Drew system and was converted back to weir burner operation. No further locomotives were converted.[11]
By the late 1960s, the J class was largely relegated to shunting at various country yards, with many losing their cowcatchers and gaining shunter's steps on sides of the tender. The introduction of the Y class diesel electrics saw the J class even superseded in that role and, in November 1967, J523 became the first J class to be scrapped.[18] Scrappings continued until June 1978, with J538 the last to go.[18] J550 holds the distinction of being the very last steam locomotive in normal revenue service on the Victorian Railways, being rostered on the 6 a.m. Bendigo pilot on 25 May 1972.[14]
The J class lasted as a complete class later than any other VR steam locomotive class. By the time that J class scrapping commenced, interest in railway preservation was sufficient for eleven examples to be preserved.[20]
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