- It is used for very large casting work and done on the foundry ﬂoor.
- A pit dug in a ﬂoor act as a lower ﬂask [drag] and top ﬂask [cope] is placed over the pit.
- The walls of the pit are brick-lined and Plastered with loam sand and allowed to dry.
- Sometimes pit bottom is rammed with 50-80 mm layer of coke to improve permeability of mould.
- Vent pipes are run from this layer to the surface.
- Coke is covered with backing sand.