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Victorian Railways A2 class

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This article is about the 1907 A2 class steam locomotive. For the 1884 'Old' A class steam locomotives, see Victorian Railways 'Old' A class (1884). For the 1889 'New' A class steam locomotives, see Victorian Railways 'New' A class (1889). For the 1900 AA class steam locomotives, see Victorian Railways AA class. For the 1984 A class diesel locomotives, see V/Line A class.

Victorian Railways A2 Class (Walschaerts)
A2 986 leading Cruise Express' 'Southern Steam Spectacular' rounding the curve in Golden Square.
Type and origin
Power typesteam
BuilderNewport Workshops
Ballarat North Workshops
Bendigo Workshops
Total produced185
Specifications
Configuration:
​
 • Whyte4-6-0
Gauge5 ft 3 in (1,600 mm)
Driver dia.73 in (1.854 m)
Length63 ft 3+3⁄4 in (19.30 m)
Axle load17 long tons 10 cwt (39,200 lb or 17.8 t)
Adhesive weight52 long tons 2 cwt (116,700 lb or 52.9 t)
Total weight121 long tons 7 cwt (271,800 lb or 123.3 t)
Tender cap.(after conversion to oil firing)
1,500 imp gal (6,800 L; 1,800 US gal) oil, 4,700 imp gal (21,000 L; 5,600 US gal) water
Firebox:​
 • Grate area29 sq ft (2.7 m2)
Boiler pressure185 psi (1,276 kPa)
Heating surface2,040 sq ft (190 m2)
CylindersTwo
Cylinder size22 in × 26 in (559 mm × 660 mm)
Valve gearStephenson (125)
Walschaerts (60)
Performance figures
Tractive effort27,480 lbf (122.24 kN) at 85% boiler pressure
Career
First run1907
Last run1963

The A2 class was an express passenger locomotive that ran on Victorian Railways from 1907 to 1963. A highly successful design entirely the work of Victorian Railways' own design office, its long service life was repeatedly extended as the Great Depression and later World War II delayed the introduction of more modern and powerful replacement locomotives.

History

[edit]

The introduction of the A2 class marked a turning point in Victorian Railways locomotive design, as it was entirely designed by VR engineers of the newly established Locomotive Design Section and the entire class built in-house at Victorian Railways workshops.[1]

The design, which started as a stretched evolution of the 1903 AA Class 4-4-0 with bogie tender, has been credited to Chief Draughtsman Ernest Victor Siepen, with overall supervision of Chief Mechanical Engineer T. H. Woodroffe.[2]; previously this had been attributed to Alfred Ernest Smith, a later Chief Mechanical Engineer.[3]

After a year of testing on the Sydney Express, which was otherwise double-headed in both directions between Melbourne and Seymour, the design of A2 572 was tweaked with relation to the cylinder attachments to the frame, boiler support at the firebox end and other minor details. However, the engine retained its distinctive flat-topped dome.[3] Five more of the class, 574, 576, 578, 580 and 722, were ordered in 190, and production continued from them on.

Production

[edit]

Based on the success[4] of the prototype A2572, a total of 125 Stephenson valve gear A2 locomotives were built between 1907 and 1915. The design was then altered to incorporate larger diameter cylinders, a higher pressure boiler and Walschaerts valve gear, and a further 60 locomotives of that design were produced between 1915 and 1922.[1]

Regular service

[edit]

For over forty years, the A2was the main express passenger locomotive on the VR, hauling intrastate and interstate services. With a maximum permitted speed of 70 miles per hour (115 km/h),[5] the A2was instrumental in the acceleration of timetables on many lines in the years following its introduction. A2 locomotives famously hauled the Geelong Flier,[6] the first named train in Victoria,[7] which ran express once a day in each direction between Melbourne and Geelong in 63 minutes, running from Flinders Street station,[8] later cut to 55 minutes, running from Spencer Street station.[9] However, other Geelong trains, stopping at wayside stations, still took about 90 minutes or more to make the journey.[8]

Due to their comparatively heavy axle load, A2 locomotives were initially limited to the principal mainlines, but gradual upgrades to secondary lines saw the route-availability of the class expand, together with the range of services they hauled.[10] Their size also meant that the outside cylinders of the new locomotives did not quite clear the stone or timber coping of some existing station platforms, requiring those platform edges to be cut back slightly to allow the locomotives to pass safely.[11]

With their comparatively high tractive effort (the Walschaerts A2 had a higher nominal tractive effort than any other VR locomotive, regardless of type, until the introduction of the C class 2-8-0 of 1918), they also saw widespread use as a fast goods locomotive, particularly later in their life.[1] As early as the 1920s, it was reported as normal practice that A2 class locomotives requiring adjustment to axle boxes and other moving parts be swapped from passenger to lower-speed freight service to extract more work from them between overhauls.[12]

A2s were also used to haul a number of special services, such as the Royal Trains for Australian tours of Prince of Wales and the Duke of York, in 1920[13] and 1927 respectively. Towards the end of their lives, A2995 and 996 also had the distinction of hauling the last broad gauge Spirit of Progress service into Melbourne on 16 April 1962.[14]

In 1933, two A2 class locomotives set a haulage record for Victorian Railways when they headed a 75-truck 1,598-long-ton (1,624 t) wheat train from Benalla to Seymour.[15]

In 1928, the A2 was replaced on the principal North East line Sydney Limited and Albury Express services by the considerably more powerful three-cylinder S class Pacifics. However, new locomotive development ground to a halt during the 1930s,[16] with the Great Depression severely affecting both VR traffic volumes and operating revenues, so the A2 continued to be the main express passenger power on all other VR mainlines.

Design Improvements

[edit]

Changes to the locomotive and tender designs slightly increased the roadworthy weight of engine and tender combined from 109 long tons 16 cwt (246,000 lb or 111.6 t) to 114 long tons 14 cwt (256,900 lb or 116.5 t), and the maximum axle load increased by about a quarter-ton. The Walschearts design was heavier again, with a roadworthy weight of 118 long tons 2 cwt (264,500 lb or 120 t), and maximum axle load of 17 long tons 10 cwt (39,200 lb or 17.8 t).[2]

Superheaters

[edit]

The majority of A2 locomotives were originally built with saturated steam boilers. The class were gradually fitted with superheaters (starting from A2842, built 1913, fitted 1915), and to differentiate between the two variants the saturated steam locomotives were renumbered as A1 class, each being reclassified as A2 class again when fitted with a superheater.[3]

All Walschaerts locomotives were intended to enter service with superheated boilers, but wartime shortages meant that thirteen of the first fifteen (including the first Walschaerts-equipped engine, A2 983) ran with saturated boilers for a few years.[3] As these engines were refitted, the cylinders were enlarged to 22 in (1 m) diameter, though they retained the stroke length of 26 in (1 m). Other changes included reducing the boiler pressure from 200 psi (1,379 kPa) to 185 psi (1,276 kPa) at 80% of maximum safe rated pressure, offset by the fitting of superheaters.[2][3]

The superheating equipment was of either the Robinson (369 sq ft (34 m2)) or Schmitt (499 sq ft (46 m2)) designs. Later, a new all-steel boiler and firebox was designed (in lieu of the prior copper inner firebox lining), and this style used ML5 equipment in lieu (331 sq ft (31 m2)); the steel boiler was interchangeable between the Stephenson and Walschaert locomotives, contingent on the safety valves being correctly set.[3] Superheated engines were also fitted with mechanical lubricators.[2]

Many engines were renumbered two or three times as the railways' management attempted to keep the two subclasses in different number blocks, and as the boundaries between the blocks shifted through the superheating program. The last of the A1 class, No. 808, was converted in October 1949.

Modified front end

[edit]

In 1933, C class heavy goods locomotive C 5 was equipped with a new front end, based on the Association of American Railroads (AAR) design of self-cleaning smokebox, to improve steaming qualities.

Other tests in May 1933 were conducted with A2 974 Melbourne, Bendigo and Seymour with 1+1⁄2 in (0 m) diameter superheater tubes, with a net improvement of 40% increased drawbar horsepower at 24 mph (39 km/h).[17]

The results were very promising, and in April 1934 A2998 was selected for a series of further tests aimed at further front end improvement, conducted under the direction of VR Rolling Stock branch engineer, Edgar Brownbill.[18]In September 1934, A2989 was the first to be fitted with the standard form of Modified Front End, and it completed a run from Bendigo to Spencer Street in 2 hours 10 minutes; A2 993 was the next converted, and the first with smoke deflectors fitted.[3]

Diagram of A2 locomotive boiler, firebox and smokebox following Modified Front End improvements

Experiments were conducted, based on the work of Dr Wagner of the Deutsche Reichsbahn and E. C. Young of the University of Illinois, with final modifications to the A2 locomotive including:[18]

  • Revision of exhaust nozzle and chimney position and diameter, using Wagner's recommended ratios, with a larger 23 in (580 mm) diameter funnel, and a 6 in (150 mm) diameter low exhaust nozzle replacing the original 18+1⁄2 in (470 mm) diameter narrow-flanged chimney and 5+1⁄2 in (140 mm) diameter high exhaust nozzle
  • Revision to the firebox grate, using a "rosebud" type grate with reduced air openings to improve fire stability under heavy load and give better firing qualities
  • Replacement of full-length 1+3⁄8 in (35 mm) return bend superheater elements with 8 ft 6 in (2.59 m)-long 1+1⁄2 in (38 mm) elements

The sum result of the changes was a significant improvement in power and available tractive effort. Maximum drawbar horsepower increased about 40%, from 860 hp (640 kW) at 26 mph (42 km/h) to 1,230 hp (920 kW) at 32 mph (51 km/h).[18] The improvement was such that the VR was able to further accelerate services hauled by the A2, with the running time of the Melbourne to Bendigo express on the steeply graded 100+3⁄4 mi (162.1 km) line being cut from 162 to 145 minutes, and literally hours being cut from the schedule of the Melbourne to Adelaide Overland express.[19]

The Modified Front End, which cost just £140 ($280) per locomotive at that time, was an extremely cost-effective improvement, and allowed the VR to defer new locomotive construction. The modification was so successful that not only was the entire A2 fleet converted during 1936–39, but also the C, K, N, S and X class locomotive fleets, and its principles were also incorporated into the design of all subsequent steam locomotives built or modified for the Victorian Railways.[18][20]

Other changes

[edit]

The original five locomotives had their Westinghouse air brake compressors mounted on the right-hand side of the firebox; all later engines had this changed to the smokebox, and within a few years the first five were amended to suit.[2][3]

Experiments were conducted in 1923–4 with A2 800 using Pulverised Brown Coal (PBC) burning equipment, but the experiment was discontinued and the locomotive returned to black coal operation.[21]

The A2 class, along with other post-1900 VR steam locomotive designs, was equipped with electric lighting from 1926 onwards. Automatic Staff Exchange equipment to allow non-stop high-speed running between track sections was also fitted from 1926 onwards.[22]

The forty engines built between 1907-1911 were fitted with Type AD tenders of capacity 5 long tons 0 cwt (11,200 lb or 5.1 t) coal and 4,460 imp gal (20,300 L; 5,360 US gal) water. The remaining 85 Stephenson locomotives entered service with larger, longer, self-trimming tenders, of 6 long tons 10 cwt (14,600 lb or 6.6 t) coal and 4,600 imp gal (21,000 L; 5,500 US gal) water, increasing the weight and axle load. Through the 1930s the older tenders were replaced or modified with self-trimming versions. From the 1930s many tenders had raised sides provided; initially to the shorter-wheelbase types, and later to all tenders. The longer tenders were generally of the Type ACN, though several sub-variants existed within that category.[2]

In 1922-1923 the Victorian Railways experimented with precipitated brown coal, using locomotives A2800, C16 and DD1022. After completion of the trials, all three engines reverted to black coal firing.[2]A photo of the engine with the modified tender appears in Newsrail, November 1983, p.295.[3]

May 1926 saw a Pyle National electric headlight, marker, cab and tender lights fitted to locomotive A2978, and this was rolled out to all A2 and many other classes of engine in subsequent years, generally operated by a Pyle or Stone generator mounted ahead of the safety valves.[2]

In 1935 an experimental A.C.F.I. (Accessoires pour les Chemins de Fer et l'Industrie) feedwater heater was fitted to A2973. However, there was not sufficient improvement in efficiency for the equipment to be fitted to other locomotives and it was removed twelve years later.[10] The equipment was, however, retained for significantly longer than equivalent experiments by the New South Wales, Commonwealth and Western Australian Railways.[2]

With the reduced exhaust blast resulting from the revised smokebox, smoke deflectors were fitted to prevent drifting smoke from obscuring visibility.[23]

By the 1930s the original plate frames of the A2 class had proven prone to cracking, particularly around the axle box cut-outs and the draw-gear (coupler) pockets. This resulted in at least five, possibly ten, engines being reframed with American-style bar frames in the period 1939-1945.[2][3] (Australian Railway History 2019 lists five engines, Newsrail November 1983 says ten engines but does not specify which.)

In the years following World War II, problems with the quality and availability of coal supplies caused VR to order the conversion of all 60 Walschaerts A2s to oil firing; in practice, only 56 were altered as four were scrapped before the conversion could be completed.[1] A2 942 was the first to be modified, being provided with a 1,400 imp gal (6,400 L; 1,700 US gal) gallon square oil tank fitted to the coal space of the tender. This style was selected to permit reconversion to coal burning if required.[3] When it became apparent that oil burning was a permanent conversion, a new cylindrical tank design with 1,500 imp gal (6,800 L; 1,800 US gal) capacity was provided, that style also later rolled out to C and N Class locomotives. Additional benefits included less time needed for enroute engine maintenance, e.g. breaking up clinker in the firebox and dumping of ash.[3] These tanks later had steam heating coils fitted, to allow the use of cheaper Bunker C oil.[2]

Late in their life, some of the A2s also received Boxpok driving wheels[10] as their conventional spoked wheels began to suffer fatigue cracks with age and mileage.[24] In July 1951, engine A2888 was fitted with a different style of driving wheel, described as "fabricated welded", but restricted to freight work from that point on.[2] A photo of these latter driving wheels appears in Newsrail, November 1983, p.295.[3]

Five Stephenson engines were fitted with shunters steps in the mid 1950s.[2]

Other alterations not noted above included fitting of Flaman speed recorders, solid bush big ends and hard grease lubrication, exhaust steam injectors (for a while), flanged smokebox doors, automatic couplers, conversion to all-steel boilers (most locomotives), trick-ported valves on A2963, Cardew track depression indicator gear on A2980 and later A2951, and tender scale buoy and continuous blowdown for A2875.[2] Some of the last changes involved fitting of integral water treatment units to the tenders, with a blow-down valve operated manually from the cab. This arrangement pulled sludge down to the boiler firebox water legs, allowing it to be discharged at regular intervals instead of needing to cool down and manually wash out the boiler.[3]

Later years

[edit]

In 1939, by which time most of the class was already over twenty-five years old, World War II broke out. The massive increase in traffic on the VR the war effort brought saw these ageing locomotives subjected to a punishing regime of heavy utilisation and minimal maintenance.[16]

Stephenson A2884 (right) dwarfed by H 220 (left), the locomotive intended to replace the A2 on Overland services

With VR's locomotive workshops switched to production of armaments and all available manpower given to the war effort, plans to eliminate the double-headed A2 operations on Melbourne–Adelaide passenger services with the introduction of more powerful H class 4-8-4 locomotives and additional S class locomotives did not come to fruition. The extra S class locomotives were never built and the line to Adelaide did not receive the necessary upgrades to take the weight of the H class.[25]

The A2's principal express passenger role continued into the postwar years as the VR, struggling with a backlog of repairs and limited capital expenditure, deferred new passenger locomotive construction. It was not until March 1946 when the first of the class, A2878, was withdrawn from service.[10]

In 1951, when the first of 70 new R class 4-6-4 express passenger locomotives were introduced, the A2 was finally superseded. In 1953, no fewer than 53 A2s went to scrap, followed by 36 more in 1954.[10] However, many of the class (particularly the later Walschaerts variants) continued on in secondary roles such as branch-line passenger and goods services and a number lasted into the 1960s. Their last regular mainline duty was hauling services between Flinders Street and Leongatha, on the South Gippsland line. The last in service, A2986, was withdrawn on 2 December 1963, exactly 56 years after the original A2572 entered service.[10][26]

Accidents

[edit]

Some A2 locomotives were unfortunate enough to be involved in major accidents:

  • At 2:58 am on 7 September 1951, the westbound and eastbound Overland expresses, both hauled by double-heading A2s, collided head-on at Serviceton.[27][28] All four locomotives were written off; three were so badly damaged they were scrapped on site.
  • Australia's worst level crossing accident occurred on 8 May 1943, when A2863 collided with a bus carrying troops at Wodonga.[7] 25 people were killed.[29]

List of engines and renumberings

[edit]

The A2 fleet was constructed in ten batches. All the Stephenson engines, batches 1 to 8, were constructed at the Victorian Railways' Newport Workshops. The same is true of Batch 9 and the first 20 engines of Batch 10. However, engines 1073–1077 (later 973–977) were built at Ballarat Workshops, and 1078–1082 (later 978–982) were built at Bendigo Workshops. There is no indication as to where engines 1083–1092 would have been constructed.

Except where otherwise marked, these tables are based on:

  • Australian Railway History, August 2019[2]
  • Australian Railway History, August 2019 (Web extra)[30]
  • Medlin, P. N. (2004) Victorian Railways Locomotives by Number (self-published, based on Victorian Railways' locomotive repair cards)
  • Victorian Railways locomotive record cards[31]

Stephensons engines

[edit]

Walschaerts engines

[edit]

Preservation

[edit]
Preserved A2 995, circa 1990
A2 996,
A2 986 at Newport station during a test run in 2015
A2 986 approaches Warragul on its official re-launch trip, 13 May 2017
A2 986 at Ballarat Station, 10 June, 2023

Only one of the original batch of 125 Stephenson A2 locomotives survives; 1913-built A2884 is today preserved at the Newport Railway Museum, along with (Walschaerts) A2995.[10] The museum notes that A2884 ran a total 1,002,624 miles (1,613,567 km) and A2995 a total 1,270,404 miles (2,044,517 km) during their service lives.[38]

A2964 is preserved at Edwardes Lake Park, Reservoir and A2996 in Echuca.[10]

After a 32-year-long effort, Steamrail Victoria restored A2986 to full working order as a coal burner. It first moved under steam on 30 May 2015 and entered service with Steamrail on 13 May 2017.

References

[edit]
  1. ^ a b c d Pearce et al., p. 12
  2. ^ a b c d e f g h i j k l m n o p q r s t u Biddle M (August 2019). "Victorian Railways A2 Class 4-6-0 locomotives". Australian Railway History. 70 (982): 12–23. ISSN 1449-6291.
  3. ^ a b c d e f g h i j k l m n o "The A2 Story". Newsrail. Vol. 11, no. 11. Vic: ARHS Victoria Division. November 1983. pp. 292–299. ISSN 0310-7477. OCLC 19676396.
  4. ^ "steamlocomotive.com Locobase #2385". Archived from the original on 27 September 2007. Retrieved 2 October 2006.
  5. ^ Pearce et al., p. 21
  6. ^ "A2 Class Steam Locomotive No.906 Geelong Flier First Trip". Public Record Office Victoria. Retrieved 3 September 2024.
  7. ^ a b "VR History". victorianrailways.net. Archived from the original on 30 May 2008. Retrieved 4 May 2008.
  8. ^ a b Bau, Mark. "Melbourne-Geelong-Port Fairy". Victorian Railways.net. Retrieved 3 September 2024.
  9. ^ "The Pride of the Diesel Fleet". The Victorian Railways Newsletter. July 1950. Retrieved 25 April 2008.
  10. ^ a b c d e f g h Oberg, Leon (1984). Locomotives Of Australia 1850's - 1980's. NSW: Reed Books. p. 96. ISBN 0-7301-0005-7.
  11. ^ "The Railways - Improvements at Wodonga Station". Wodonga and Towong Sentinel. Victoria. 25 February 1910. Retrieved 3 September 2024 – via Trove.
  12. ^ "Newport Workshops". The Argus. Melbourne. 4 January 1922. p. 14. Retrieved 3 January 2013 – via National Library of Australia.
  13. ^ Public Record Office Victoria Series VPRS 12800/P1 Item H 1027 Archived 1 September 2007 at the Wayback Machine retrieved 2 October 2006
  14. ^ "Victorian Railways, Museum Victoria, Australia: Spirit of Progress A2-class steam locomotive No. 995, 16 April 1962". prov.vic.gov.au. Retrieved 25 April 2008.
  15. ^ "Huge Wheat Haul by Train". The Horsham Times. Vic. 6 June 1933. p. 4. Retrieved 3 January 2013 – via National Library of Australia.
  16. ^ a b "AHRS Railway Museum: History 1900–1950". Australian Railway Historical Society. Archived from the original on 19 July 2008. Retrieved 2 October 2006.
  17. ^ "Some A2 Runs, 50 Years Ago". Newsrail. Vol. 11, no. 11. Vic: ARHS Victoria Division. November 1983. pp. 300–301. ISSN 0310-7477. OCLC 19676396.
  18. ^ a b c d Abbott, R.L. (November 1971). "Steam Locomotive Performance – the Modified Front End". ARHS Bulletin (409). Australian Railway Historical Society.
  19. ^ Lee, Robert (2007). The Railways of Victoria 1854–2004. Melbourne University Publishing Ltd. p. 157. ISBN 978-0-522-85134-2.
  20. ^ "100 defining aspects of Australian railways" (PDF). Australian Railway Historical Society. Archived from the original (PDF) on 16 July 2011. Retrieved 10 May 2008. (H220) had... benefit of Brownbill's modified front-end experience
  21. ^ Pulverised Brown Coal Fuel for Steam Locomotives Buckland, John L. Australian Railway Historical Society Bulletin, July 1972 pp145-161
  22. ^ "A2 locos". victorianrailways.net. Retrieved 14 June 2009.
  23. ^ Stevens, Colin (December 2000). "Stack Talk". Stack Talk. 11 (3). Steamrail Victoria: 10.
  24. ^ Carlisle, R M & Abbott, R L (1985). Hudson Power. ARHS. pp. 30–31. ISBN 0-85849-028-5.
  25. ^ Pearce et al., p. 19
  26. ^ "steamtrainartist.com Victorian Railways 'A2' CLASS 4-6-0". Archived from the original on 10 August 2004. Retrieved 2 October 2006.
  27. ^ "Auditor General's Department EMA Disasters Database". Archived from the original on 26 September 2007. Retrieved 2 October 2006.
  28. ^ "Railpage Discussion". www.railpage.com.au.
  29. ^ "Australian Defence Department: On This Day – 8 May". Archived from the original on 3 September 2007. Retrieved 2 October 2006.
  30. ^ a b c d e f g "Victorian Railways A2 Class 4-6-0 locomotives WEB EXTRA" (PDF). Australian Railway History. pp. 1–6.
  31. ^ a b "A2 Locos" (PDF). victorianrailways.net.
  32. ^ a b Steam Power
  33. ^ "How rail crash happened". The Argus. 2 July 1947. Retrieved 26 January 2022.
  34. ^ "VR A2 class - variations".
  35. ^ "VR A2 class - variations".
  36. ^ a b c d e ARHS Bulletin Supplement 1/58
  37. ^ a b c d e f g h i j "A2 Class history".
  38. ^ Railway Museum (guide to exhibits). ARHS. 2008. p. 30.
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