China clay, more formally known as Kaolinite, is one of the main products of the south west of England. Until the 1980s this cargo was transported by rail using small wooden wagons covered with tarpaulin. Based upon the HAA wagon design, CDA wagons featuring a flexible hopper covering to protect the clay from the rain were introduced in 1987 carrying the livery of English China Clays, although more recently they have been repainted in EWS colours.