South Australian Railways 620 class
Encyclopedia
The South Australian Railways 620 class is a class of 10 4-6-2
Pacific steam locomotives built in the late 1930s, designed to operate on lightly laid 60-pound lines.
(SAR) broad gauge route between Adelaide
and Port Pirie
created a need for a fast, light passenger locomotive to haul this service, as well as other traffic on the lightly laid 60-lb (29.8 kg/m) rail branch lines of the SAR. The specification included the ability to haul a 200 long tons (203.2 t) train up a 1-in-45 (2.2%) grade at 25 mi/h.
Mr P.J. Shea, Chief Mechanical Engineer of the SAR designed a 140 ton Pacific type. A notable feature of the design, unique to South Australian Railways, was the use of Baker valve gear
in lieu of the more common Walschaerts valve gear. The first locomotive (620) was completed at the SAR workshops at the Islington Workshops in 1936, with the tenth and final locomotive of the class (629) completed in 1938.
Class leader No. 620 was also notable for being Australia's first streamlined
locomotive, the smokebox being covered with a chromed steel grille similar to those fitted to motor cars of the period, and painted Hawthorn green with yellow stripes. The remainder of the class were unstreamlined.
In service, the 620 class replaced the Q and S 4-4-0
types on branchline services, where they proved quite successful. With the introduction of the more powerful and modern 520 class
from 1943, these locomotives were relegated to the Willunga
, Bridgewater
and Tailem Bend
passenger services, as well as continued service on Mallee line services (the locomotives light axle loading providing good route ability plus the "get up and go" characteristics common to large wheeled Pacific type locomotives.
The 620 class was phased out in favour of Bluebird Railcar
s, although a spate of railcar failures in 1954–55 saw the 620 class return to service on the Port Pirie line.
In 1994, 621 ran a special tour to Bacchus Marsh in Victoria, when the Melbourne-Adelaide line was still broad gauge. This was the first ever time a South Australian Railways Steam Locomotive had worked east into Victoria. With the standard gauge conversion imminent the tour would be last steam special hauled by a South Australian Steam Locomotive running on the Broad Gauge.
All but two of the locomotives were scrapped by 1969. One is preserved in working condition by SteamRanger
(621) with the second (624) held in the Port Dock Museum.
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...
Pacific steam locomotives built in the late 1930s, designed to operate on lightly laid 60-pound lines.
Development of the 620 class
The completion of the South Australian RailwaysSouth Australian Railways
South Australian Railways built and operated railways in South Australia from 1854 to the incorporation of its non-urban railways into the Australian National Railways Commission in 1975, together with the former Commonwealth Railways and the former Tasmanian Government Railways...
(SAR) broad gauge route between Adelaide
Adelaide
Adelaide is the capital city of South Australia and the fifth-largest city in Australia. Adelaide has an estimated population of more than 1.2 million...
and Port Pirie
Port Pirie, South Australia
-Transport:Port Pirie is located off National Highway One. It is serviced by an airport five minutes out of the city.- Railways :The first railways in Port Pirie were of the narrow [3' 6"] gauge....
created a need for a fast, light passenger locomotive to haul this service, as well as other traffic on the lightly laid 60-lb (29.8 kg/m) rail branch lines of the SAR. The specification included the ability to haul a 200 long tons (203.2 t) train up a 1-in-45 (2.2%) grade at 25 mi/h.
Mr P.J. Shea, Chief Mechanical Engineer of the SAR designed a 140 ton Pacific type. A notable feature of the design, unique to South Australian Railways, was the use of Baker valve gear
Baker valve gear
Baker valve gear was the main competitor to Walschaerts valve gear for steam locomotives in the United States. Strictly speaking it was not a valve gear but a variable expansion mechanism adapted to the Walschaerts layout replacing the expansion link and sliding die block...
in lieu of the more common Walschaerts valve gear. The first locomotive (620) was completed at the SAR workshops at the Islington Workshops in 1936, with the tenth and final locomotive of the class (629) completed in 1938.
Class leader No. 620 was also notable for being Australia's first streamlined
Streamliner
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...
locomotive, the smokebox being covered with a chromed steel grille similar to those fitted to motor cars of the period, and painted Hawthorn green with yellow stripes. The remainder of the class were unstreamlined.
In service, the 620 class replaced the Q and S 4-4-0
4-4-0
Under the Whyte notation for the classification of steam locomotives, 4-4-0 represents the wheel arrangement of four leading wheels on two axles , four powered and coupled driving wheels on two axles, and no trailing wheels...
types on branchline services, where they proved quite successful. With the introduction of the more powerful and modern 520 class
South Australian Railways 520 class
The South Australian Railways 520 class is a class of 4-8-4 steam locomotives that were built at Islington Workshops, the first entering service in 1943 through to the last of this class in 1947...
from 1943, these locomotives were relegated to the Willunga
Willunga, South Australia
Willunga is a town south of Adelaide, South Australia in the City of Onkaparinga local government area. It is 5 km away from the wine growing region of McLaren Vale and is approx. 47 km from the Adelaide CBD...
, Bridgewater
Bridgewater, South Australia
Bridgewater is a town in the Adelaide Hills, southeast of Adelaide in South Australia.It is the former end of the Adelaide-Bridgewater railway line; this route was closed in 1987...
and Tailem Bend
Tailem Bend, South Australia
Tailem Bend is a town on the Murray River in South Australia. The town was proclaimed in 1887, the year after the main railway came through. At the 2006 census, Tailem Bend had a population of 1,457....
passenger services, as well as continued service on Mallee line services (the locomotives light axle loading providing good route ability plus the "get up and go" characteristics common to large wheeled Pacific type locomotives.
The 620 class was phased out in favour of Bluebird Railcar
South Australian Railways Bluebird railcar
The Bluebird Railcars are a self propelled railcar originally used for country passenger operations in South Australia by the South Australian Railways...
s, although a spate of railcar failures in 1954–55 saw the 620 class return to service on the Port Pirie line.
In 1994, 621 ran a special tour to Bacchus Marsh in Victoria, when the Melbourne-Adelaide line was still broad gauge. This was the first ever time a South Australian Railways Steam Locomotive had worked east into Victoria. With the standard gauge conversion imminent the tour would be last steam special hauled by a South Australian Steam Locomotive running on the Broad Gauge.
All but two of the locomotives were scrapped by 1969. One is preserved in working condition by SteamRanger
SteamRanger
SteamRanger is an historic train society in South Australia running trains on the Victor Harbor railway line. They are the only group regularly running broad gauge steam locomotives in South Australia...
(621) with the second (624) held in the Port Dock Museum.
Stocklist
- SAR 620 2C1-h2 Islington Works - / 1936
- SAR 621 2C1-h2 Islington Works - / 1936
- SAR 622 2C1-h2 Islington Works - / 1936
- SAR 623 2C1-h2 Islington Works - / 1936
- SAR 624 2C1-h2 Islington Works - / 1937
- SAR 625 2C1-h2 Islington Works - / 1937
- SAR 626 2C1-h2 Islington Works - / 1937
- SAR 627 2C1-h2 Islington Works - / 1937
- SAR 628 2C1-h2 Islington Works - / 1938
- SAR 629 2C1-h2 Islington Works - / 1938
External links
- State Library of South Australia photograph of streamlined locomotive 620 Sir Winston Duggan travelling through the Mount Lofty RangesMount Lofty RangesThe Mount Lofty Ranges are the range of mountains just to the east of Adelaide in South Australia.-Location and description:The Mount Lofty Ranges stretch from the southernmost point of the Fleurieu Peninsula at Cape Jervis northwards for over before petering out north of Peterborough...
, South Australia - 620class:SA:Trains:AJH Photographs and further details of the 620 class courtesy John Hurst
- SteamRanger website steam locomotive information page