The Onehunga Branch railway line is in Auckland, New Zealand. It was constructed by the Auckland Provincial Government and opened from Penrose to Onehunga on 24 December 1873, and extended to Onehunga Wharf on 28 November 1878. It is 3.6 kilometres (2.2 mi) in length.After being closed to passenger traffic on 19 January 1973 and mothballed in 2007, the line was reopened on 18 September 2010 with regular passenger services beginning on 19 September 2010.