WO type iron ore waggon WO 31296 is one of a batch of fifteen built by WAGR Midland Workshops between July and October 1968 with fleet number 175 for Koolyanobbing iron ore operations, with a 75 ton and 1018 ft³ capacity, loaded with fines seen here at Bonnie Vale, 28th May 2006. This unit was converted to WOC for coal in 1986 till 1994 when it was re-classed back to WO.