Bridges

The Eastern Busway was commissioned by Auckland Transport to provide bus lanes, road upgrades and a walking & cycling route from Panmure to Pakuranga in East Auckland, an area that has been demanding more reliable public transport for decades. On opening Transport Minister Michael Wood said ìThe dedicated bus lanes will be a game-changer, allowing commuters to link in with Auckland's rail networkî. The Panmure Busway Bridge is a critical crossing over the Tamaki River.

Designed to fit within the constraints of the riverside site in a built-up suburban area, a key factor was minimising impacts on an important historic site. Mokoia Pā on the west bank was an important Māori settlement and site of a historic battle. The bridge carries the busway over the land with minimum impact and was designed in collaboration with iwi artists with respect to the cultural significance of the location.

A landmark 210m long the composite steel girder ladder deck structure spans 73.5m over a central navigation channel. The main girders are the largest of this type fabricated in New Zealand. The haunched profile, varying in depth from 3.8m over river piers to 2.3m at midspan, was optimised to minimise weight, and also provides a striking architectural feature of the bridge. The curved soffit presented challenges to the contractor whose preferred erection method was to launch the girders from the east bank. An innovative articulated roller system enabled a gradual launch while accommodating the profile and angle of the twin girders and allowed all the steelwork to be rigged safely over land.

The outcome is an elegant piece of structural engineering carrying multiple transport modes and critical utilities serving communities as feature of the river environment, all constructed while maintaining access on a key commuter route.