The class R was only created after the Second World War as an express locomotive to replace the class A2 ten-wheelers. By installing a stoker, they wanted to ensure that it would perform well with coal of varying grades. The 70 locos arrived at the same time as some diesel and electric locos, giving them a very short career in service pulling express trains. They were then put into a wide variety of services, in which they performed well despite often poor maintenance. Today there are still six locomotives, four of which are still operational and partly had multiple operators. The R 766 was even converted to standard gauge. 