Harbour bridge closure: Work on temporary fix to reopen lanes to start on Tuesday
Monday, 21 September 2020
Work on a temporary fix that could reopen some lanes on the damaged Auckland Harbour Bridge will begin on Tuesday, the New Zealand Transport Agency says.
It comes as Auckland commuters face extensive delays after a freak accident on Friday saw half of the lanes on the bridge shut down.
Brett Gliddon, NZTA’s general manager transport services, said the repair work meant southbound clip-on lanes would be closed overnight from Tuesday for about two nights, with a detour via the Western Ring Route in place.
The overnight closures, from 9pm until 5am, would allow the NZTA space to bring steel in and ensure the health and safety of workers on the bridge.
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**
Gliddon revealed steel for the temporary fix was being fabricated in Auckland after coming up from Taranaki overnight.
Once installed, there would be “real-life tests” with heavy trucks going over the bridge to test if it performed to design specifications and requirements.
“Only then will a final decision be made about whether the temporary fix is suitable to allow the re-opening of additional lanes,” he said.
“Once that decision has been made it is expected that two extra lanes on the centre-span of the bridge (one northbound and one southbound) could be open up to traffic later this week.”
On Monday morning’s traffic, Gliddon said he was pleased to say there was “good” feed away from the bridge.
Gliddon said 11,500 vehicles crossed the bridge northbound – 30 per cent fewer than the same time last week.
He added 11,000 vehicles from the North Shore crossed the Auckland Harbour Bridge between 6am and 10am – 16,000 fewer than at the same time last week.
Meanwhile, Upper Harbour Hwy (SH18) saw 11,600 vehicles travel southbound, 4000 more along the route than the previous week.
Just over 11,000 vehicles travelled north on Upper Harbour Dr, 14 per cent more than last week.
“We still had quite severe congestion,” he acknowledged. Gliddon himself took a bus.
Prime Minister Jacinda Ardern earlier said there were teams working on both the temporary and permanent solutions to repair the bridge.
She said it was important to remember this was a “one in 50 year event”.
The effects of the closure rippled out across Auckland's already congested motorways and continues to cause long delays and gridlock.
At midday on Monday, NZTA said it was focused on doing “everything possible” to reopen the centre lanes of the bridge as quickly as possible.
“A temporary fix to reopen some lanes may be possible in a few days but a permanent repair is weeks away,” it said.
The permanent fix requires a beam to be designed and manufactured from scratch.
NZTA is asking people on the North Shore to work from home if possible, or to use the Western Ring Route or buses if not.
NZTA senior journey manager Neil Walker said Monday morning’s congestion had been as expected and showed the importance of people changing their usual travel patterns.
A priority bus lane is being implemented before evening peak traffic on State Highway 1 northbound to the bridge.
“The priority lane is to reduce congestion for buses to the North Shore and provide more reliable journeys for customers.
“This bus priority system will allow buses to access the SH1 northbound on-ramp at Fanshawe Street via a new priority lane, allowing buses to bypass the queueing traffic.”
The priority lane onto the motorway will then merge with regular traffic.
To create this lane, NZTA said the Curran Street northbound on-ramp onto the bridge is closed to all traffic.
“Motorists who would usually use the Curran Street on-ramp are advised to follow the sign-posted detour route to the Fanshawe Street northbound on-ramp.”
The priority lane will be in place until the bridge is fully operational again, which could be a number of weeks.
Auckland Transport is urging people to use public transport if needing to travel.
Spokesman Mark Hannan said the agency is “confident” in its available passenger capacity.
Heading into the city in the morning, Hannan said the Northern Busway has an excess of 7000 seats with the current service – based on empty seat numbers from last week.
The Onewa Rd service has an extra 2500 seats.
Heading back to the shore in the afternoon and evening, the Northern Busway has an extra 6500 seats and the Onewa Rd service has an extra 3000.
“Note the above figures are for seats only, and about 10 per cent more could be added with standing room.
“We are also planning to increase frequency outside of peak hours so that more customers can take advantage of our 30 per cent off-peak fare discount. Ferries are operating as usual and have spare seating capacity.”
Hannan said people are asked to travel off-peak if possible and allow extra time for their journey as there might be delays from joining the queues to cross the bridge.
Brett Gliddon, NZTA transport services general manager, said a team of about nine structural engineers were working on a fix.
How exactly did this happen?
About 11am on Friday, strong and sudden gusts toppled two trucks as they crossed the bridge, Gliddon said.
One was at the peak of the bridge when it was knocked over by a gust and slammed into a steel beam, twisting the metal and shearing it clean off where it connected to the bridge below the road surface.
Gliddon said the wind was 60kmh before it shot up to a gust of 127kmh before dying down again.
“We were hit by an absolute freak gust of wind which caught a truck as it was right on the top of the bridge.
“That's really hard to design for.”
The beam did what it was supposed to, shearing off at the bolts rather than pulling on and damaging other support member, with its load transferred to other supports on the steel truss.
The bridge continues to be able to support itself, but engineers are unwilling to allow traffic over the original inner lanes, which opened in 1959.
The outer two lanes on each side, clipped on 10 years after it opened, have their own support structure and do not rely on the damaged truss.