The GWR provided special wagons, handling equipment and storage facilities for its largest traffic flows. For example, the coal mines in Wales sent much of their coal to the docks along the coast, many of which were owned and equipped by the railway, as were some in Cornwall that exported most of the china clay production of that county. The wagons provided for both these traffic flows (both those owned by the GWR and the mining companies) were fitted with end doors that allowed their loads to be tipped straight into the ships' holds using wagon-tipping equipment on the dockside.