1 00:00:01 --> 00:00:04 The formwork is a temporary structure made of wood 4 00:00:05 --> 00:00:10 that supports the arch stones, or voussoirs of an arch or vault, while it is being built. 2 00:00:11 --> 00:00:14 It is installed on the pillars that will support the arch. 3 00:00:15 --> 00:00:19 The cut arch stones are then positioned on the formwork. 4 00:00:20 --> 00:00:25 Once all of the stones have been placed, the formwork is removed. The arch is now in place.