A 500-tonne bridge, which is also one of Christchurch's busiest, will be lifted several times over the next few months as engineers carry out earthquake repairs.
After months of preparation, 28 jacks are set for some serious heavy lifting along Durham St.
The worn-out old bridge carries 11,000 cars every day. It looks like it came through the earthquakes almost unscathed. It's still perfectly safe but there's internal damage, and that means jacking the bridge up to replace the damaged concrete.
"It's perfectly safe still," says Paul Thornton of Fulton Hogan. "There are no problems with it, it's just durability."
It's a difficult job, and crews will be working at night to reduce road delays.
With all the jacking and steel work, they'll the lift the bridge by just 10mm, replace a rubber bearing and then put it right back down.
But before they lower it, crews will water blast away and replace the damaged concrete where the crossbeams meet the uprights.
"The only delay will be overnight for those jacking operations, and I think there's 15 or 18 of those spread over the next 10 months, but they'll happen at night, between the hours of 8pm and 5am," says Ian Campbell of Stronger Christchurch Infrastructure Rebuild Team.
The first lift is tomorrow night, but all going well, motorists will never know the difference.