Sydney Harbour Bridge could close for new maintenance system

It is Sydney's biggest single piece of infrastructure, and her importance in linking the city's two halves bordering Port Jackson is such, means that the Harbour Bridge gets a lot of love and care to maintain her looks and strength.

But like an itch on your back that you can't reach, there are some spots on the bridge that have always been difficult to access.

Even before the two spans were joined in the middle, four small grey huts, the coat hanger's maintenance units, were positioned so they could regularly crawl across the shoulders of the bridge to maintain her healthy grey glow with regular layers of paint once construction was complete.

And despite the until-recently dangerous, yet casual panache of workers, who would swing from the units' baskets or clamber freehand through the girded veins of the spanning arch to give her attention, not every cranny could be reached for its lick of coat.

As regular teams of bridge climbers climbed her span to imbibe one of the best views of Sydney, the maintenance director for Transport NSW, David Fishburn, and I travel across a gantry high above the road deck to the western side of the bridge, to view what is now the old technology that cared for her.

"When the bridge was first started in 1930, the original arch maintenance units were put in place; since that time, they've been replaced once, so the ones that you're looking at, were actually replaced in 1997," says David.

They received a 10 year refurbishment in 2007, but their equipment now needs to be retired.

But now a new maintenance system is proposed to care for the bridge, the first change to her look since De Groot slashed the opening ribbon in 1932.

The new system will see one unit on each of the bridge's arches, joined by a span that will carry her crew, lowering them by crane through the superstructure.

"The idea is that we'll have full access, from arch to arch, and down the sides into the future", says David.

"We'll have full access through a safe, reliable, efficient process, ensuring the bridge, the iconic nature of the bridge, and the heritage of the bridge, is protected going forward."

The project is now undergoing community consultation, with 12 to 18 months anticipated before any movement on the ground, in clearing sites alongside before the work begins.

It will also mean the bridge may need to take some time out from her regular duties.

"We will need to close the bridge," says David.

"In fact, we may have to close the whole bridge, maintaining one lane for emergency access."

And while this new work is some time away from commencing, the profile of one of Sydney's most famous faces, will soon have a small but significant change to her silhouette.