 Any damage to the canal bank could thus render the entire canal unnavigable.In 1909, following a collapse in the bank of the river, the canal company's chief engineer Mr A. J. Cullis called for old vessels to be run aground along the bank of the Severn, near Purton, to create a makeshift tidal erosion barrier to reinforce the narrow strip of land between the river and canal.Barges, trows and schooners were "hulked" at high tide, by towing them from the dock at Sharpness and releasing them to be carried up the bank on the tide.