33-091A 5 Plank China Clay 3-Wagon Pack BR Bauxite (Early) with Tarp. CoversChina Clay Wagons were synonymous with Cornwall where the largest deposit of Kaolin, known more commonly as china clay, had first been discovered in 1746 by William Cookworthy . The resulting industry made Cornwall the pre eminent global source of china clay and as railways were established, they were used to transport the material both locally and further afield, to destinations where the material was required, like the Staffordshire potteries. The