In 1422, the masons responsible for Catterick Bridge were required to make riddeye groundes in the watir ware the brigge schalle be, that is prepare the sites for the abutments and pillars. In ideal circumstances that would have meant finding an area of solid rock and clearing it of loose material, if necessary excavating the river bed. Failing that, an area suitable for piling would have to be prepared. That was doubtless the meaning of the phrase clensyng of the ground werk used of Lady’s Bridge in Sheffield in 1485-6. In 1579, the growndworke of ... the landstayes of Elland Bridge referred specifically to the foundations and in 1601, help was given to the mason at Apperley Bridge to sett the ground worke once the water had been drawn off. It seems that the ground work may eventually have come to include some of the preliminary work on the structure itself.