Extension of the double track and automatic signalling continued with the Porirua to Mana section opened on 7 November 1960. The work involved harbour reclamation to construct straight tack from Porirua to Papakowhai, just south of Paremata, eliminating the tight curves as the former railway followed the coastline, and creating three lagoons on the eastern side of the harbour. The central lagoon, now known as Aotea Lagoon, remains but is reduced in size. From Paremata to Mana the track was realigned to the West of the original track and a new double-track bridge was built across the entrance to the Pauatahanui Inlet. The original single-track railway bridge, built in 1885, was removed allowing room for the construction of a second road bridge in 2004. The railway stations at Porirua, Paremata, and Dolly Varden were replaced with new stations with Dolly Varden station renamed Mana.