Follows the direction of the Underground foreman for the layout, assembly, and installation of underground fire mains, ductile iron and C900 piping, fittings, valves, hydrants, post indicator valves (PIVs), fire department connections (FDCs), thrust restraints, and related underground fire protection components. Under the direction of an Underground Foreman, the apprentice learns excavation safety, underground pipe installation, thrust blocking, restraint systems, hydrants, post indicator valves (PIVs), fire department connections (FDCs), flushing, hydrostatic testing, and site restoration.