South Australian Railways R class
The South Australian Railways R class, later upgraded to Rx Class was a class of 4-6-0 steam locomotives operated by the South Australian Railways. History. In 1886, Dübs and Company of Glasgow delivered the first six R class. A further 24 had been built by James Martin & Co by November 1895. From 1899, all were rebuilt with higher powered Belpaire boilers and reclassified as the Rx class. A further 54 locomotives were built as Rx class by the Islington Railway Workshops, North British Locomotive Company and Walkers Limited with all in service by  May 1916. R class 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. A large group of Rx class locomotives, mainly early builds, were withdrawn from service in 1934, however the remainder continued to serve into the mid 1960s. Survivors. Several Rx class locomotives and one R class survive to this day in various states of preservation.