WO type iron ore waggon WO 31411 is one of a batch of eleven replacement waggons built by WAGR Midland Workshops between 1970 and 1971 with fleet number 187 for Koolyanobbing iron ore operations, with a 75 ton and 1018 ft³ capacity, on empty train 1416 at Hampton, 22nd August 2010. This unit was converted to WOC for coal in 1986 till 1994 when it was re-classed back to WO.