The W.A.G.R.'s first modern bogie hoppers and the first wagon made out of welded aluminium appeared in 1963 as class XB. Twenty-four were built (21000-21024) followed by a further four in 1967 (21025-21028). The whole class was converted to XBC standard in 1969. I think this involved conversion to air brakes and knuckle couplers.

An XBC in later life.

The WAGR outline diagram for the XBC is shown below.

In 1996 twenty-two wagons were sold to New Zealand (21001-21008, 21010, 21012, 21014, 21016-21022, 21024-21027) leaving 6 wagons (21009, 21011, 21013, 21015, 21023, 21028) in WA. These six wagons were still on the stocklist in 2010.