WOB type iron ore waggon WOB 31390 is one of a batch of twenty five built by Comeng WA between 1974 and 1975 and converted from Mt Newman high sided waggons by WAGR Midland Workshops with a capacity of 67 tons with fleet number 315 for Koolyanobbing iron ore operations and is one of the 15 converted to WSM type ballast hoppers by re-fitting the removed top section of the body and fitting bottom discharge doors. Converted back to WOB in 1997. Binduli Triangle, 22nd August 2010.