Auckland Harbour Bridge

Bridges are often admired for their form, view and scale. However, their success is measured via the efficiency of daily operation; how quickly and seamlessly we can crossover.

Location

Auckland, New Zealand

Project Status

Ongoing

Constructed of structural steel and reinforced concrete the Auckland Harbour Bridge is recognised as a national landmark, a tourist attraction and a vital artery, connecting people, place and services via its manmade corridors.

The 1.2-kilometre bridge that spans the Waitemata Harbour connects water, telecommunication, power and gas services to the North Shore and beyond. It is a focus point for many Aucklanders with an average of 180,000 vehicles crossovers daily; over sixty-four million a year. During morning peak times, around 200 busses cross the bridge southbound, carrying around 9,000 passengers.

What people often aren’t aware of is the amount of maintenance that is needed to sustain its daily upkeep. Currently, over 20 AHBA asset management staff work on and around the bridge daily.

WSP partnered with Fulton Hogan and TBS Farnsworth in 1998 to create the Total Bridge Services Joint Venture, and in 2012 we became part of the Auckland Harbour Bridge Alliance.

Since, WSP and its forbears have continued a tradition of managing large, significant assets, whilst developing innovative tools and solutions to ensure for future-ready infrastructure.

Our work has led to a number of world-first achievements that bridge the gap between future ready, cost-efficient and environmental civic design.

EXTERNAL COATED STEEL SURFACE Area (m2)

125,000

METRES ABOVE THE WATER AT THE HIGHEST POINT

64

METRES IN LENGTH

1.2km

VEHICLES CROSS DAILY

180,000

YEARS IN OPERATION

60

World First Road Surfacing: In the early 1990’s, it was found that there was a lack of proprietary off-the-shelf road surfacing system that can be used on the bridge. Our team of material specialists, environmental engineers and asset managers identified a possible candidate, which working with the surfacing supplier, we tested, modified and developed a road surfacing tailor made for the conditions and to the required criteria. This modified surfacing option was applied onto the Auckland Harbour Bridge in 1995; which was the first bridge in the world to apply and utilise this material.

World First Quick Set Repair Material: In 2015 Principal Bridge Engineer and Asset Management Engineer, David Ashby along along with the surfacing supplier modified and developed a quick-set repair material for surface defects. The material was trailed and adapted by the bridge. As a result, the new process has saved time, money and minimise traffic disruption to road users . Its high strength suits the AHBA’s need to provide long-lasting repair at a single application and has reduced the maintenance costs for pot-hole care.

Coatings Management Plan: WSP NZ along with our AHBA partners have developed a Coatings Management Plan for the maintenance of the steel protective coatings. This was undertaken by dividing the bridge into distinct zones, each with its own atmospheric corrosivity, access and containment requirements. Hence by better understanding the requirements of each of those zones, an optimum maintenance strategy was developed; which when combined together, with the aim of minimising the environmental impact of the coating maintenance activities, the most cost effective lowest whole of life solution identified.

Asset Manager: Auckland Harbour Bridge Alliance
The Alliance currently consists of:

New Zealand Transport Agency
Beca
Total Bridge Service, which comprises of:
- WSP NZ
- SRG Global (previously TBS Farnsworth)
- Fulton Hogan

Auckland Harbour Bridge gets lit

An innovative new system, designed by WSP NZ, is lighting the way for users of the Auckland Harbour Bridge.

It has seen more than 140 High Pressure Sodium (HPS) lamps replaced with low energy Light-Emitting Diodes (LEDs).

The solution has had an immediate impact, delivering over 50% power savings, lowering future maintenance costs and significantly reducing light pollution from the bridge.

Crucially, the new lights improve night time visibility for drivers and are more effective in the rain, making for a safer driving experience.

For those involved, the eight-year project has been a massive undertaking.

Andy Collins, WSP Technical Principal – Lighting Design, says there was a very real need for the upgrade and involved multiple engineering disciplines.

“LEDs are more robust than the old luminaires, which themselves have been replaced a number of times over the decades. This solution encompasses the latest changes in lighting technology saving over 50% in energy consumption and maintaining the NZ Transport Agency’s requirements,” he says.

Collins adds that the reduced visual impact from the LEDs also benefits the regular Vector Lights displays – which are also driven by thousands of LEDs attached to the bridge structure.

The project grew in complexity when taking into account the fatigue issues associated with the ageing lighting poles.

Raed El Sarraf, Technical Principal – Materials and Corrosion, says the upgrade required the design of new poles, as the original poles were reaching the end of fatigue life due to vibration from the bridge traffic and wind loading.

“Fatigue has been a concern for the past decade resulting in the annual inspections and monitoring to detect cracks at high stress locations on the poles. All of which adds to the operating cost of the poles,” he says.

El Sarraf says the new hot dip galvanized poles have been designed to withstand the applied loadings and vibrations, while combining the aesthetics of the original 1959 and 1969 poles. This ensures a visual continuation between the past and the future, while providing a low maintenance durable solution for the next 50 years.

All up, 118 poles were installed by Total Bridge Services and delivered by the Auckland Harbour Bridge Alliance.