The 700 class is a class of six diesel-electric locomotives based on the Alco DL500G model, built by AE Goodwin, Auburn, New South Wales for the South Australian Railways. They are virtually identical to the New South Wales 442 class locomotive.

South Australian Railways 700 class
704 passing through Tanunda with the Penrice limestone train in 2007
Type and origin Power type Diesel-electric Builder AE Goodwin, Auburn Serial number Alco G-6042-01 to G-6042-03 Alco G-6059-01 to G-6059-03 Model Alco DL 500G Build date 1971–1972 Total produced 6
Specifications Configuration: ​  • UIC Co-Co Gauge 1435 mm (4 ft 8+1⁄2 in) 1600 mm (5 ft 3 in) Wheel diameter 1020 mm (3 ft 4 in) Length Over coupler pulling faces: 18.67 m (61 ft 3 in) Axle load 18.6 t (18.31 long tons; 20.50 short tons) Loco weight 111.6 t (109.84 long tons; 123.02 short tons) Fuel type Diesel Fuel capacity 5455 L (1200 imp gal; 1441 US gal) Prime mover Alco 251C Engine type Four-stroke V12 diesel Aspiration Turbocharged Cylinders 12 Cylinder size 229 mm × 267 mm (9 in × 11 in)
Performance figures Maximum speed 112 km/h (70 mph) Power output Gross: 1490 kW (2000 hp), Tractive effort Continuous: 311.00 kN (69,916 lbf) at 11 km/h (6.8 mph), Starting: 389.00 kN (87,451 lbf)
Career Operators South Australian Railways, Australian National, One Rail Australia and predecessors Number in class 6 Numbers 700–705 (renumbered 701–706) First run 22 June 1971 Last run 2015 Preserved 703, 704 (both to operate), 705 (static display)

History

The locomotives, built in 1971 and 1972, operated on all main lines in South Australia and interstate to Broken Hill and Melbourne.[1][2]

The first three were delivered on 1600 mm (5 ft 3 in) broad gauge bogies and the latter three on 1435 mm (4 ft 8+1⁄2 in) standard gauge bogies. All were initially delivered in the South Australian Railways' red and silver colour scheme. The three standard-gauge locomotives were soon repainted in the South Australian Railways' "mustard pot" colour scheme (orange with brown lining and silver bogies).^{[citation needed]}

In 1975, 703 was damaged when a bridge at Crystal Brook collapsed and was repaired at Islington Workshops.[1]

In 1978, all six locomotives were included in the transfer of the South Australian Railways non-metropolitan assets to the Australian National Railways Commission. 703 was transferred back to broad gauge in 1979, to help cover the withdrawal of the first of the 900 class. After the Adelaide to Port Pirie railway line was converted to standard gauge in 1982, all four broad gauge locomotives were converted to standard gauge, marking the first time the entire class was on the same gauge.[1]

In 1986, a new Australian National Railways computer system required the class leaders of the former SAR fleet to be renumbered as the last member of the class; thus 700 became 706.[3] During 1987, all six locomotives were transferred to broad gauge to cover a locomotive shortfall as the older 930 class was withdrawn.

In 1994, 702 caught fire near Blackwood; it was scrapped in 1997.[4]

After the conversion to standard gauge of the Adelaide-Melbourne railway line in 1995, all of the remaining 700 class were converted to standard gauge.[5]

In 1997, the remaining five units were included in the sale of Australian National assets to Australian Southern Railroad. 706 was transferred back to broad gauge in 2000 to work on the daily Penrice stone train. Several years later it suffered a mechanical failure and was not repaired; in 2022 its engine unit was sold to the Australian Locomotive and Railway Carriage Company and its (broad-gauge) bogies were donated to the National Railway Museum, to be placed under 703's body, which One Rail Australia had donated. 704 was transferred to broad gauge to replace it, running until 2014, when it was stored after the Penrice stone train service ceased.[1]

The remaining three locomotives (701, 703 and 705) were mostly used on intrastate grain trains (together with GM and 22 class locomotives), especially on the lightly laid branch lines from Tailem Bend to Loxton and Pinnaroo, where more powerful but heavier locomotives were unable to go. They were also used as banker locomotives to assist trains up the steep grades of the Adelaide to Tailem Bend railway line. 701 was named Tailem Bend in 2014. In 2015, after the Loxton and Pinnaroo branch lines closed, 701 and 703 were stored in serviceable condition. 705 had suffered a major mechanical failure earlier in the year, and was deemed to be not economically repairable.^{[citation needed]}

Disposition

As of September 2022^[update], the disposition of the remaining five 700 class locomotives was as follows:[6]

References