The South Australian Railways R class engine, later upgraded to Rx Class engine is a class of 4-6-0 steam engines operated by the South Australian Railways.

South Australian Railways R & Rx class
Rx149 with a load of wine casks at McLaren Vale
Type and origin Power type Steam Builder Dübs & Co (6) James Martin & Co (24) Islington Railway Workshops (14) North British Locomotive Company (15) Walkers Limited (25) Build date 1885-1916 Total produced 84 Rebuilder Islington Railway Workshops Rebuild date 1899-1913 as Rx Number rebuilt 30 to Rx
Specifications Configuration: ​  • Whyte 4-6-0 (2′C 3) (2′C 2′2′) Gauge 1,600 mm (5 ft 3 in) Leading dia. 2 ft 11 in (889 mm) Driver dia. 4 ft 6 in (1,372 mm) Length 49 ft 11 in (15.215 m) Height 13 ft 4 in (4,064 mm) Axle load 9 long tons 17 cwt (22,100 lb or 10 t) (R) 11 long tons 8 cwt (25,500 lb or 11.6 t) (Rx) Adhesive weight 28.50 long tons 0 cwt (63,800 lb or 29 t) Loco weight 40 long tons (45 short tons; 41 t) (R) Tender weight 22 long tons (25 short tons; 22 t) (R) Total weight 65 long tons (73 short tons; 66 t) (R), 88 long tons (99 short tons; 89 t) Fuel type Coal Fuel capacity 4 long tons 18 cwt (11,000 lb or 5 t) (R), 7 long tons 16 cwt (17,500 lb or 7.9 t) (Rx), 6 long tons 17 cwt (15,300 lb or 7 t) (Rx 6 wheel tender) Water cap. 2,040 imp gal (2,450 US gal; 9,300 L) (R) 3,750 imp gal (4,500 US gal; 17,000 L) (Rx), 3,200 imp gal (3,800 US gal; 15,000 L) (Rx 6 wheel tender) Firebox:  • Firegrate area 17.6 sq ft (1.64 m2) (R) 20.37 sq ft (1.892 m2) (Rx) Boiler pressure 145 psi (1,000 kPa) (R) 175 psi (1,207 kPa) (Rx) Heating surface:  • Tubes 1,196 sq ft (111.1 m2) (R) 1,208 sq ft (112.2 m2) (Rx)  • Firebox 98.3 sq ft (9.13 m2). (R) 105 sq ft (9.8 m2) (Rx) Superheater: ​  • Heating area 178 sq ft (16.5 m2) (Rx) (not fitted to some locos) Cylinders 2 Cylinder size 18 in × 24 in (457 mm × 610 mm) Valve gear Allan Straight Link Valve type Piston
Performance figures Tractive effort 17,700 lbf (78.73 kN) (R) 21,420 lbf (95.28 kN) (Rx) Factor of adh. 3.49
Career Operators South Australian Railways Class R/Rx Number in class 84 Numbers 5, 9, 10, 15, 20*, 25*, 48, 55, 56, 91*-96*, 102*-107*, 138*-153*, 155, 158, 160, 190-203, 206-235 (* originally built as R class) First run 10.2.1886 Last run 5.9.1969 Withdrawn 1927-1969 Preserved Rx 5, Rx 55, Rx 93, Rx, 160, Rx 191, Rx 201, Rx 207, Rx 217, Rx 224 & Rx 231 Scrapped 1928-1974 Disposition Ten preserved, remainder scrapped

History

In 1886, Dübs and Company of Glasgow delivered the first six R class of engine. A further 24 engines had been built by James Martin & Co by November 1895. From 1899, all engines were rebuilt with higher powered Belpaire boilers and reclassified as the Rx class engine. A further 54 locomotives were built as Rx class by the Islington Railway Workshops, North British Locomotive Company and Walkers Limited with all engines in service by May 1916.[1]

The R class engines were the predominant locomotive used on broad gauge main line services in South Australia from their introduction. After the introduction of the large Webb engines they were relegated to secondary lines and services such as shunting and hauling goods trains and passenger trains. A large group of Rx class locomotives, mainly early builds, were withdrawn from service in 1934, however the remainder continued to serve into the mid 1960s.[1]

Survivors

Several Rx class locomotives and one R class engine survive to this day in various states of preservation.

• Rx5: plinthed at Kapunda[2]
• Rx55: preserved at Loxton[3]
• Rx93: preserved at National Railway Museum, Port Adelaide[4][5]
• Rx160: preserved at Murray Bridge[6]
• Rx191: plinthed at Victor Harbor[7]
• Rx201: plinthed at Tailem Bend[8]
• Rx207: preserved at SteamRanger, operational[9][10]
• Rx217: plinthed at Nuriootpa, South Australia[11]
• Rx224: preserved at SteamRanger, operational[12][13]
• Rx231: plinthed at Kadina[14]

References

External links

Media related to South Australian Railways R class at Wikimedia Commons