https://www.youtube.com/watch?v=quR9AWeasNk&feature=youtu.be
Waka Kotahi NZ Transport Agency says the design and fabrication of the permanent strut for the Auckland Harbour Bridge is now well underway but still weeks away before it’s installed.
The grade 350 L15 steel for the strut has been sourced and manufactured by NZ Steel and delivered to fabricators at Culham Engineering in Whangarei. It will then be transported to Auckland by truck.
A date for the installation is still not known but Waka Kotahi says putting the new strut in will require closure of the southbound lanes of the bridge and will take longer than the temporary fix.
The temporary repair has not restored the strut’s load-bearing function, but when the new strut is installed it will return the bridge to its full load capacity. Two of the bridge’s eight lanes will remain closed until it’s installed.
“Teams are working at pace to design and peer review the replacement part for the permanent solution and to manufacture and plan for installing it,” Waka Kotahi transport services general manager Brett Gliddon says.
“Fabricating the 22.7 metre strut and getting it into position is the quicker part of the process. It will take several weeks before it is tensioned up as a load-bearing part of the bridge superstructure.
“The bulk of this time is in the design, calculation and external peer review of the new strut in relation to how it will impact on the performance of the whole bridge. This includes careful calculations on how to re-balance its load-bearing function.
“On Tuesday night the team only had to remove the damaged part of the strut, install the temporary section and bolt it to the bridge deck. This time, they’ll have to remove the temporary section and the old section connected to the top of the bridge and then install the new permanent strut. That will take much longer.”
As well as the safety and performance of the strut, Waka Kotahi is also paying careful attention to how the new piece will look on the bridge, which is an iconic piece of Auckland’s infrastructure.
The materials of the new strut will not exactly match those that were installed 61 years ago. For example, it will have welds where the old strut had rivets.
Waka Kotahi is working with a consultant conservation architect to ensure the new strut fits appropriately with the landmark status and heritage values of the bridge.
“The aim is that once it’s installed and had a coat of paint, it will blend in with the rest of the bridge superstructure and the subtle differences will go unnoticed,” Gliddon says.
