Charlestown Harbour was designed by John Smeaton and built for Charles Rashleigh. Work on the outer harbour started in 1791 and by 1792 the excavation of the inner dock began. Rock was quarried back from the line of the beach and by 1795/96 it is thought that it was ready to receive ships. By 1801 the dock had been extended beyond its original size and lock gates had been fitted.
By 1825 the inner basin had a long water filled channel extending inland on the western side, possibly along the line of an old adit. Exports of china clay, copper ore and pilchard fishing were thriving so further plans to extend the inner basin were made from 1864 with the present form of the harbour dating from 1871. By this time the inner dock was segregated into two sides; dirty and clean or black and white. Coal for the mining industry was imported from South Wales and unloaded on the western side whilst processed blocks of china clay were loaded on the eastern side for export.
There are two principal quaysides walled with granite and with granite paving; concrete surfaces have also been added to the western side. A short pier-like structure divides the harbour into two bays at its inner end.
You will see opposite you along the eastern side of the inner dock the distinguishing features of the china clay cellars and chutes.
There are four china clay bays or cellars rising from the inner basin to road level. These substantial, granite structures were needed to hold the weight of the china clay. At the top of each (at road level) were trapdoors where the clay was unloaded from horse drawn wagons. At the bottom of each cellar is a plank covered space where a tram truck could be brought in and loaded by successively removing the planks and allowing the clay to drop into the trucks for loading onto the ships. A more recent cellar is built of reinforced concrete with the doors at the bottom covered with iron sheet and secured in place with brackets and iron straps. By the mid 20th century china clay shutes were being used to load the clay onto ships. These chutes were attached to a substantial buttress built of concrete block. Only one still survives comprising of a steel, rectangular sectioned inclined tube, the lower part of which could be positioned over a ships hold by raising or lowering the winch.