A bridge linking Montreal to its nearby islands is being repaired – but unlike other bridge work, this time, the span is actually remaining open as it happens.

Completed in 1965, the 700-metre-long Concorde Bridge over the St. Lawrence River is old and rusted.

It needs repairs, but it’s also an important span: Every summer, thousands of visitors depend on the steel structure as they flock to Île Sainte-Hélène and Île Notre-Dame for major events, including the Grand Prix, Heavy MTL, Osheaga and Île Sonique, or even just to escape the city.

Work needs to be done, said City of Montreal spokesperson Philippe Sabourin.

“We’re (removing) the rust with sandblasting, and we’re adding a new treatment – an anti-corrosion treatment - on the bridge,” he said.

Montrealers are no strangers to bridge work, but what makes this job different is how the work is being carried out.

Engineers built a temporary platform underneath the bridge so workers can get to work without disrupting drivers, cyclists and pedestrians up above.

“It's important to keep the mobility here even if we have a construction site. Everything is done in order to maintain the mobility in the area, in order to keep people going to Parc Jean-Drapeau,” said Sabourin.

Repairs began in March and will last two years at a $20-million cost.

“We still have a bike path. We have also two lines into the direction of Parc Jean-Drapeau and one line for Montreal,” said Sabourin.

Water, gas and electricity will still run through the bridge, ensuring the islands get the utilities they need to serve the 25,000 people who visit the island every weekend in the summer.