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Auckland Harbour Bridge
Providing a valuable and iconic link between Auckland City and the North Shore
Looking after Auckland Harbour Bridge
View a letter to the people of Auckland from the Chief Executive
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Upgrade of the Auckland Harbour Bridge Clip-ons
Transit New Zealand will spend $45 million upgrading the clip-ons of the Auckland Harbour Bridge as part of its maintenance programme, following a detailed engineering review to ensure they remain 'fit for purpose' for at least the next 20-30 years.
Work will start next year and take two-and-a-half years to complete.
"It is critical to stress that the bridge is safe and the upgrade is planned preventative maintenance work similar to that carried out a number of times since the clip-ons were opened in 1969," Transit New Zealand Chief Executive Rick van Barneveld said
"The clip-ons are stronger today than when they opened. What we are doing is retrofitting them so that they are fit for their purpose of meeting the growing traffic demand on this vital piece of infrastructure. They will be better than new when we've finished."
Transit plans to do most of its upgrading work at night when traffic can be diverted to the original bridge that does not need any upgrading. This will avoid disrupting traffic during the daytime when the number of vehicles using the bridge is highest.
Clip-on LanesRestricting the use of the outer clip-on lanes in May 2007 year to vehicles under 13 tonnes eased load pressures on the extensions by 20 percent. This is now covered by a bylaw that came into effect in July.
This was not the first time there has been a vehicle restriction. Heavy trucks were banned from the outside lanes for four years in the 1980s.
When the project is finished, the extensions will meet current standards with adequate capacity to carry current peak traffic loads, as well as meet extra demand that will be generated on both sides of Auckland Harbour by the 2011 Rugby World Cup.
"The 165,000 vehicle per day lifeline that is the Auckland Harbour Bridge is going to be around forever, and will continue to provide service to Auckland and the rest of the country," said Mr van Barneveld.
"The bridge is nearly 50 years old and, without doubt, is our most important bridge. Our management regime for looking after it, and making sure it is 'fit-for-purpose', reflects that. We have had in place for the last eight years a contract that covers inspections, painting and other more major maintenance. The annual value of this is some $3 million.
"In addition, because of the importance and nature of the bridge, we have an ongoing structural assessment programme. The bridge is monitored continuously - through annual, six and three-month inspections and daily monitoring."
Back To TopThe Auckland Harbour Bridge - Frequently Asked Questions
Does the bridge need strengthening and if so what is Transit doing to strengthen the bridge?
As part of Transit's ongoing maintenance and monitoring, a recent structural assessment, conducted by international bridge specialists, Beca, and peer reviewed by British bridge specialists, Hyder, showed that the box girders (clip-ons) should be further strengthened. Extra steel will be added to the upper layer of the clip-ons and cross members will be installed inside the box girders.
How long will the upgrade take?
Work will start next year and take two-and-a-half years to complete.
Is Transit speeding up the repairs?
Doing the work over this time period allows us to make the best use of specialised resources, to minimise the inconvenience to the public and to have the work completed as soon as possible. Incidentally, this also means that the upgrade will be completed in time for the Rugby World Cup in 2011.
Auckland Harbour BridgeWhen will the upgrade start?
Design work is being finalised and physical work is due to start in June/July 2008. In the meantime the annual resurfacing of the bridge will continue as normal over the December holiday period this year.
Is the bridge safe to drive on before the upgrade is completed?
The bridge is safe to drive on at all times. Besides banning heavy trucks weighing more than 13 tonnes from the outer clip-on lanes, Transit has a comprehensive traffic management system on the bridge by means of CCTV cameras, VMS (variable message signs) and lane control signals, as well as weigh and motion apparatus on both the southern and northern approaches to the bridge. These are monitored 24/7 by the ATTOMS Traffic Control Centre at Northcote. As a result, Transit is able to manage traffic across the bridge at all times.
How much will the upgrade cost?
The work will cost around $45 million.
Will the upgrade work cause delays?
The aim is to do most of the work at night to minimise disruption.
How long will the bridge last once the upgrade is complete?
This upgrade will accommodate expected traffic growth for at least the next 20 to 30 years. Transit is working with local authorities to protect an additional route across the harbour.
Why were trucks banned from the outer clip-ons earlier this year?
Transit has always managed heavy traffic on the bridge - in the mid eighties all heavy vehicles were banned completely from the clip-ons for a period of four years while strengthening work was carried out. Keeping trucks off the outer clip-on lanes reduces stress and helps Transit manage the amount and timing of maintenance to the bridge. Since the ban, weight on the outer clip-ons lanes has eased by some 20%.
Why are buses not banned from the outer clip-ons?
The average weight of a bus is approximately 20 tonnes, less than half the legal maximum of 44 tonnes for heavy vehicles. Also, when bus traffic is at its heaviest, cars dilute the load of the buses.
Do heavy winds pose a serious problem to the bridge?
Transit continuously monitors wind speed on the bridge and there are procedures in place to limit the use of the bridge by heavy/high sided vehicles through active traffic management. In terms of what speed we would impose restrictions that depends on not only the speed but the direction of the wind. Wind speeds in excess of 120kph result in heavy vehicle restrictions and the purpose of additional wind tunnel modelling is to refine our setting of the wind level indicator.
Is the AHB in danger of collapsing?
No it is not. You can be confident the bridge is safe to use. If we thought motorists' safety was at risk Transit would close the bridge immediately.
Doesn't the term 'catastrophic failure' imply that the bridge is inherently unsafe?
Beca reported on a theoretical worst case scenario. They analysed an "extreme" event on Auckland's motorways between 4am and 6am when large truck traffic across the Harbour Bridge is at it heaviest. This showed a theoretical risk of a 'catastrophic failure' of the clip-ons if a very large number of heavy trucks (trucks of the maximum legal weight of 44 tonnes), stopped across the central spans because of a traffic jam at that time of the morning. The word 'catastrophic' is used in an engineering sense to describe a situation where many parts of a complex structure are damaged at one time. The bridge has never experienced anything even approaching the load described in such an extreme scenario. Such a scenario is extremely improbable if not impossible.
Is Transit going to add a cycle/pedestrian facility on the bridge?
Transit investigated the possibility of providing a cycle/pedestrian facility on the Auckland Harbour Bridge as a result of a Transport Select Committee request. The cost of additional strengthening to accommodate the pedestrian/cycle facility is circa $30-$40 million. We still have some building code issues to review before reporting back to the Select Committee. Transit expects that we would at least include in our upgrade the work needed to allow a pedestrian/cycle facility to be built in the future if that is a priority for Auckland.
Back To Top"A New Zealand Icon"
A New Zealand icon is to get a strengthening upgrade to meet the demands of the growing Auckland Region
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New Zealand IconThe Auckland Harbour Bridge is one of New Zealand's truly iconic structures. For nearly 50 years it has straddled the Waitemata Harbour providing a vital link from the Auckland isthmus to the North Shore and beyond.
The 1.2 kilometre structure is actually made up of three bridges. The section in the middle with the steep arches and flags on top, is the original four-lane 'truss'bridge that was built over four years by a team of 1000 men at a cost of £7,516,000. It was opened with tremendous excitement on 30 May 1959. The bridge was financed through tolls with cars and taxis paying 2s/6d (25c), motorcycles 1s/3d (15c), buses 5s (50c) and 4s (40c) for commercial vehicles. Within one year 4.9 million vehicles had crossed the bridge and by 1965 traffic rose to 9.3 million.
Within a relatively short time it was apparent that the bridge would not be able to cope with the rapidly growing North Shore population. The decision was made to extend the bridge from four lanes to eight lanes to increase its capacity and ease congestion. This was done by adding two box girder bridges to each side of the bridge at a cost of $7.4 million.
Designed and manufactured in Japan they instantly became known as the 'Nippon clip-ons' and were opened to traffic on 23 September 1969. With population and development north of the bridge continuing to grow, traffic across the bridge kept increasing and tolls were abolished in March 1984 by which time they had paid for the bridge.
By 1988 the number of vehicles crossing the Auckland Harbour Bridge each day had reached 120,000 and the number of head-on collisions was rising too. The Moveable Lane Barrier - the first ever permanent lane barrier system on a major bridge anywhere in the world - was introduced to manage traffic flows in a 'tidal' morning and evening peak system.
The most important bridge in New Zealand, the Auckland Harbour Bridge is one of the best maintained anywhere in the world. From day one comprehensive maintenance has been carried out and over the years there have been a number of major upgrades including seismic, wind loading and fatigue crack upgrades. Between 1985 and 1989, all heavy trucks were banned from using the clip-ons altogether while the fatigue crack upgrade took place.
In the last eight years alone, Transit has conducted annual, six and three month inspections and daily monitoring, painting and other more major maintenance at a cost of $3 million a year.
With around 60 new cars entering Auckland roads every day, traffic numbers across the bridge continue to grow and grow. The daily average is presently up around 165,000 vehicles, with some days more than 200,000 vehicle crossings recorded.
Now, nearly 50 years since the Auckland Harbour Bridge was first opened Transit is preparing to upgrade the strength of the bridge once more to cope with the increasing number of vehicles, especially heavy trucks, using it. The upgrade is based on reports from internationally respected civil engineering consultants, Beca, were commissioned by Transit in 2004 to undertake a structural review as part of the ongoing assessment of the Harbour Bridge.
Beca reported in June 2006 on a theoretical worst case scenario. They analysed an 'extreme' event on Auckland's motorways between 4am and 6am when large truck traffic across the Harbour Bridge is at it heaviest. This showed a theoretical risk of a 'catastrophic failure' of the clip-ons if a very large number of heavy trucks stopped across the central spans because of a traffic jam at that time of the morning.
City of SailsThe word 'catastrophic' is used in an engineering sense to describe a situation where many parts of a complex structure are damaged at one time. However, the bridge has never experienced anything even approaching the load described in such an extreme scenario.
The upgrade is scheduled to start in mid 2008 and will involve strengthening the box girder clip-ons to enable them, and the Harbour Bridge, to continue carrying traffic across the Waitemata Harbour between Auckland City and the North Shore for at least the next 20 to 30 years.
Involving the welding of 312 tonnes of additional steel girders and 100,000 bolts to the clip-ons, the upgrade will take two and a half years to complete - in time for the Rugby World Cup in 2011 when tens of thousands of fans will use the bridge to go to games at Eden Park and North Harbour Stadium.
In the meantime, the bridge is safe to drive on at all times, including peak hours when traffic flows are highest. Besides banning heavy trucks weighing more than 13 tonnes from the outer clip-on lanes, Transit is continuing to improve its traffic management on the bridge by means of CCTV cameras, VMS (variable message signs) and lane control signals, as well as weigh and motion apparatus on both the southern and northern approaches to the bridge. These are monitored 24/7 by the ATTOMS Traffic Control Centre at Northcote.
So the New Zealand Icon, in the hands of ever vigilant experts, will continue to serve the people of the Auckland Region for as long as she is required to do so.
Back To TopFlag Flying Policy
In 2007 Transit reviewed its policy for flying flags on the Auckland Harbour Bridge.
The Transit Board simplified the policy to allow Transit to focus on its core business of planning, building and operating the state highway network.
Transit chief executive Rick van Barneveld said as from 1 June 2007, the new policy would be:
The New Zealand flag will be the sole flag flown on the Auckland Harbour Bridge. It will be flown on both flagpoles and will fly at half-mast on occasions of national mourning as directed by the Minister for Arts, Culture and Heritage.
"The Transit Board appreciates the interest many people have in what flag is flying on the bridge on any given day. However, our focus needs to be about the safe and efficient operation of the state highway network," Mr van Barneveld said.
View media release
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History about the Auckland Harbour Bridge
Selected Extracts on the history of Auckland Harbour Bridge
| Title | Download |
|---|---|
| 1951-1961 The Auckland Harbour Bridge Authority (Extract) * | PDF (6.57MB) |
| 1951-1971 A Pictorial Record of 20 Years Activities* | PDF (5.16MB) |
| 1984 Auckland Harbour Bridge and Approaches (Extract) # | PDF (1.02MB) |
| Auckland Harbour Bridge: Growth - Past and Future (Extract) * | PDF (423KB) |
* Published by the Auckland Harbour Bridge Authority (now a defunct organisation)
# Published by the Ministry of Works (Transit's predecessor)
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