 This required increasingly larger ships, so NSS bought "Apanui" (1948–61), "Tainui" (1949–63), "Hotunui" (1950–67), "Ratanui" (1952-56), and then started building "Maranui" (1953–68), "Maunganui" (1955–71), "Poranui" (1956–69) and "Tawanui" (1959–73), "Moanui" (1961–66), "Awanui" (1962-73).A major contract in this period was shipping materials for the Manapouri Tunnel.A second "Moanui" (1967–75) and "Seaway Princess" (1967–69) were added to the fleet, the latter for a weekly Onehunga - Lyttelton ro-ro service.