The Auckland Harbour Bridge is an eight-lane motorway bridge over Waitematā Harbour in Auckland, New Zealand. It joins St Marys Bay on the Auckland city side with Northcote on the North Shore side. It is part of State Highway 1 and the Auckland Northern Motorway. The bridge is operated by the NZ Transport Agency Waka Kotahi (NZTA). It is the second-longest road bridge in New Zealand, and the longest in the North Island.What is the longest bridge in New Zealand? (from the Transit New Zealand FAQ webpage. Retrieved 9 June 2008.)
The original inner four lanes, opened in 1959, are of box truss construction. Two lanes were added to each side in 1968–1969 and are of orthotropic box structure construction extend as cantilevers from the original piers. The bridge is 1,020 m (3,348 ft) long, with a main span of 243.8 metres (800 feet) rising 43.27 metres (142 feet) above high water,1951–1961 The Auckland Harbour Bridge Authority (Auckland Harbour Board publication, 1960s) allowing ships access to the deepwater wharf at the Chelsea Sugar Refinery, one of the few such wharves west of the bridge.
While often considered an Auckland icon, many see the construction of the bridge without walking, cycling, or rail facilities as an oversight. In 2016, an add-on structure providing a walk-and-cycleway called SkyPath received Council funding approval and planning consent, but was not built. In 2021, a stand-alone walking and cycling bridge called the Northern Pathway was announced by the New Zealand Government, but also was not built.
About 170,000 vehicles cross the bridge each day (as of 2019), including over 1,000 buses, which carry 38% of all people crossing during the morning peak.
History
Early proposals Proposals for a harbour crossing date back to at least 1860, when North Shore farmers sought for more convenient way to transport livestock and produce to city markets. They commissioned Ponsonby farmer Fred Bell, who proposed a pontoon bridge at an estimated cost of £16,000. In the following decades, at least one major new crossing scheme was suggested in each decade. Interest waned during the First World War, but was renewed in the post-war period. For example, the 1927 and 1929 harbour crossing proposals. Two Royal Commissions in 1930 and 1946 were held on the viability of a bridge crossing the Waitemata.
Design approval Prior to the opening of the bridge in 1959, the quickest way from Auckland to the North Shore was by passenger or vehicular ferry. The fastest way via car was through the Coatesville-Riverhead Highway, now part of State Highway 18.
In the 1950s, when the bridge was being built, North Shore was a mostly rural area of barely 50,000 people, with few jobs and a growth rate half that of Auckland south of the Waitematā Harbour. Opening up the area via a new route unlocked the potential for further expansion of Auckland.
Construction
Original bridge construction (1954–1959) The 1946 Royal Commission report recommended a four lane harbour bridge, with carriageway between kerbs and two pedestrian footpaths that are wide each. The Royal Commission also considered two alternative options, a wider bridge with four lanes, and a wide two lane tunnel. The First National Government of New Zealand opting for an 'austerity' design of four lanes without footpaths, and including an approach road network only after local outcry over traffic effects. The decision to reduce the bridge in this way has been called "a ringing testament to [...] the peril of short-term thinking and penny-pinching". On 1 December 1950, an act of parliament formed the Auckland Harbour Bridge Authority, chaired by Sir John Allum, then Mayor of Auckland City, who appointed British firm Freeman Fox & Partners to design the bridge.
The bridge took four years to build, with Dorman Long (who had constructed the Sydney Harbour Bridge) and the Cleveland Bridge & Engineering Company contracted to construct the bridge in October 1954. The first stage of construction involved land reclamation at the Westhaven Marina, which was completed by September 1955. The steel girder structure pieces were fabricated in England and shipped to New Zealand. The steel bridge structure began construction in December 1956. Hundreds of labourers were employed on the construction including 180 men sent out from the UK. Progress was slowed with the workers going on strike in 1956 and 1957. The large steel girder sections were partially pre-assembled, then floated into place on construction barges. One of the main spans was almost lost during stormy weather when the barge began to drift, but the tugboat William C Daldy won a 36-hour tug-of-war against the high winds.References provided within the William C Daldy article.
The bridge was constructed from opposing sides of the harbour. The southern section was cantilevered, until both sides were joined in March 1959. Completed in April 1959, three weeks ahead of schedule,People who built the Bridge (from the Archives New Zealand, New Zealand Government website. Retrieved 5 June 2008.) the bridge was officially opened on 30 May 1959 by the Governor-General Lord Cobham. (historical video via YouTube. Retrieved 27 July 2008.)Record of 20 Years Activities 1951–1971 – Auckland Harbour Bridge Authority An open day had been held, when 106,000 people had walked across.Opening day and ceremonies New Zealand Government. Retrieved 5 June 2008. The opening period was extremely busy, despite the poor weather in Auckland experienced in June 1959. Either three or four men had been killed by accidents during construction, and the names of three of them are recorded on a memorial plaque underneath the bridge at the Northcote end."Happy 50th birthday harbour bridge", North Shore Times via Stuff.co.nz, 21 May 2009Bridge worker fatalities Archives New Zealand, New Zealand Government. Retrieved 5 June 2008.
The hollow girder design by Freeman, Fox and Partners design was unprecedented in New Zealand, and fell outside the 1950s building codes in New Zealand. Initial plans for the bridge were for an extremely slender structure, only 2.9 metres thick, due to the competing specifications from two stakeholders: the National Roads Board specified the gradient and locations where the bridge could launch from the shore on either side of the harbour, while the Auckland Harbour Board required an opening of 43.5 metres above the high tide point. Public Works commissioner Bob Norman, concerned about the narrow bridge design, attempted to negotiate with both the Roads Board and Harbour Board for additional width allowance for the bridge. The Harbour Board required the 43.5 metre clearance so that the entire fleet of ships operating within New Zealand could navigate the harbour, the largest of which was the P&O cruise liner SS Canberra. Norman argued that the Canberra was extremely unlikely to use the only major dock west of the bridge at the Chelsea Sugar Refinery, so the Harbour Board agreed to a smaller opening. This allowed Freeman Fox and Partners to redesign the bridge, increasing the width of the deep centre span from 2.9 metres to 4.12 metres. By the 1970s, many box girder bridges began to develop structural problems, such as the Freeman Fox and Partners-designed West Gate Bridge in Melbourne which collapsed during construction in 1970. The Auckland Harbour Bridge was inspected by the design firm, which found that the stiffening member had buckled by , so it was decided to strengthen the bridge's girder system.
Clip-ons (1967–1969)
The bridge was originally built with four lanes for traffic. Owing to the rapid expansion of suburbs on the North Shore and increasing traffic levels, it was soon necessary to increase capacity; by 1965, the annual use was about 10 million vehicles, three times the original forecast. In 1967, a contract was given to Japanese firm Ishikawajima-Harima Heavy Industries Co., Ltd. (now IHI Corporation) to construct two steel box girder bridges affixed to the Harbour Bridge, to greatly increase the number of lanes on the bridge. The girder sections were prefabricated in Japan and transported to New Zealand on a converted oil tanker. The eastern section was completed in January 1969, while the western side was completed shortly before the additional lanes were formally opened on 23 September 1969. Each side added two additional lanes to the bridge, doubling the number of lanes to eight.
As the sections were manufactured by a Japanese company, this led to the nickname 'Nippon clip-ons'. The selection of the company was considered a bold move at the time, barely 20 years after WWII and with some considerable anti-Japanese sentiment still existing.. The costs of the additions were much higher than if the extra lanes had been provided initially.
Operations and uses
Tidal flow A "tidal flow" (dynamic lanes) system is in place, with the direction of the two centre lanes changed to provide an additional lane for peak-period traffic. During the morning peak, five of the eight lanes are for southbound traffic; in the afternoon, five lanes are northbound. At other times, the lanes are split evenly, but peak traffic has become proportionately less – in 1991 there was often a higher than 3:1 difference in directional traffic; in 2006, this had dropped to around 1.6:1. The bridge has an estimated capacity of 180,000 vehicles per day, and in 2006 had an average volume of 168,754 vehicles per day (up from 122,000 in 1991).
In March 1982, the Ministry of Transport and Auckland Harbour Bridge Authority conducted a week-long traffic blitz in an attempt to improve the standard of driving. Of the 600,000 vehicles which used the bridge over this period, 6,000 were stopped, with half of those receiving a ticket and the rest cautioned. A second blitz was held for 36 hours a few weeks later.
For many years, lane directions were indicated by overhead signals. In the late 1980s, a number of fatal head-on accidents occurred when vehicles crossed lane markings into the path of oncoming traffic. In 1988, feasibility investigations began into the use of a movable lane barrier on the Auckland Harbour Bridge. In July 1989, the government approved the project.
Moveable barriers In November 1990, a moveable lane barrier (MLB) system, 2.2 km long, became operational. At the time, it was the first concrete safety barrier system of its kind installed on a bridge with a significant grade (5%) and horizontal curvature. Two barrier transfer machines were built in Auckland, with key components sourced from the USA. Capable of travelling at 30 km/h on the road unladen, and 3 km/h when shifting barriers.
In February 2008, new 2.2 km MLB system was installed, which included new barrier transfer machines. A US-based company, Barrier Systems Inc., in California, oversaw the project. The new machines can move the barrier in half the time the old ones did, taking 20 minutes instead of 40.
As part of the Victoria Park Tunnel project, the moveable barrier has been extended southwards to the Fanshawe Street onramp."Gateway to Auckland", The Aucklander, 12 November 2009, Page 5
Tolling (1959–1984)