This class consisted of only two wagons. XR 21101 was built in 1968 followed by XR21102 in 1970. They added to the rather motley collection of vehicles used by the WAGR for cement traffic. Visually they were frameless bogie tankers rather than hopper wagons and are described as "Cement Tankers" on the outline diagram. The WAGR outline diagram is shown below. In 1972 they were renumbered XR21181-2. They were both written off together in 1996. They operated from either Rivervale (Swan Portland) or Soundcem (Cockburn Cement) to either Utakarra (Geraldton) or the cement siding in Albany. Transits were via No 3/4 Geraldton Freighter and No 7/8 Albany Freighter. They may have operated to Kalgoorlie in their early days.