The cutting pattern is being informed by the force lines (black) and topo-lines (orange) of the target thrust surface (a). This results in a solution that reflects -and emphasizes- the structural logic of the vault, but also helps recognizing the different transitions in vault typologies of this design, going from a groin vault part, to a more domical cap or the flaring edges of an Isler-type ‘free-form’ vault.
On the three-dimensional thrust surface, we are laying out possible approximate stone layouts (b). The average stone size is about 3 by 6 feet, with an average thickness of 1ft resulting in pretty heavy pieces of stone (about one ton each!). Cuts will be made perpendicular to this surface to avoid sliding and guarantee proper arch action.