Māngere Bridge (bridges)
The older portion of the bridge, completed in 1983, carries a four-lane motorway with a cycle and pedestrian path suspended under the western side.
The location of the initial bridge was originally a naturally formed basalt rock causeway used by Tāmaki Māori, traversable by foot at low tide (except for a shallow tidal stream of a few metres in width).
[4] In 1866, a company was formed to investigate and construct a bridge between Māngere and Onehunga, funded by a grand provided by the provincial government.
The ferro-concrete beams and piles of bridge were created using prefabricated concrete, a very unusual method of construction in New Zealand at the time.
[6] In World War II, an anti-tank road block was erected on the bridge near the middle of the spans, with a small sentry shelter close by.
[16] A 300 ft container transport, the Spirit of Resolution, crashed into the bridge on 8 October 2005 as it attempted to leave a nearby Port of Onehunga berth during winds estimated later as being between 30 and 40 knots (with stronger gusts) and against a strong incoming tide.
The collision occurred despite the ship's bow thrusters working at full power and a small harbour tug assisting.
[17] Due to problems with the quality of the concrete and steel,[9] it was initially envisioned that the bridge would be dismantled and replaced by a newly designed footbridge.
[21] In 1963, a report by US consultancy firm De Leuw Cather and Co recommended that a motorway and rapid public transport system be developed for Auckland.
[22] The first section of the Southwestern Motorway, the Onehunga Bypass, was completed in 1977, spanning Queenstown Road in Hillsborough and terminating at the Old Māngere Bridge.
The partially constructed bridge was picketed for a period of two and a half years, becoming the longest continuous labour strike in the history of New Zealand.
A standard diamond interchange was initially chosen by Transit, but after consultation with Auckland City Council this was then reworked into a quarter-diamond design, with the northbound onramp hooking underneath a proposed Neilson Road bridge.
Auckland Airport had accused Transit of threatening to defer the project if it could not gain backing from the public and local Councils.
[28] In September 2007, Auckland Regional Transport Authority proposed to pledge NZ$2.5 million for future-proofing works to ensure that a rail link would be included.
The council's preferred version was to build the interchange at ground level with part of the motorway in a cut and cover tunnel.
[27] The recommendation, which Transit could have ignored only at the risk of drawn-out legal fights at the Environment Court level (which would probably have delayed the project until after the 2011 Rugby World Cup), was based on the concerns of residents, who feared that the new interchange would increase and cement separation of their suburb from the Manukau Harbour.
[27] Partly due to this, Transit New Zealand decided in August 2007 to continue with building the new bridge without including a new interchange for the time being.
[34] A number of works related to environmental mitigation, post-project landscaping or improvement of non-motorway transport links were associated with the project (and either paid for or undertaken by NZTA).
After finishing work, NZTA reinstated their large construction staging site along the southern harbour front as an open space, "passive recreation" park with Pohutukawa.
