Crowds gather as Ridout Street bridge arches get lifted into place in London, Ont.

Under a blue sky on this bright Tuesday, one of North America's largest cranes hoisted a 130-tonne steel arch spanning 90 metres across the Thames River in London, Ont., as a crowd of dozens of onlookers marvelled at the massive operation of machines and men with ropes who guided the arch into place. 

The Victoria Bridge, which has carried people in and out of the downtown area over the river on Ridout Street, south of Horton, for almost a century is being replaced with a wider span and arches 10 metres above the road surface. 

Crane crews are busying hoisting the steel arches into place, an operation you can watch live by clicking on the YouTube embed in this story. 

The two-day operation continues Thursday.

WATCH | Here's how the project is going to work

2 years ago

Duration 1:32

Construction and infrastructure services director for the City of London Jennie Dann explains how crews plan to hoist two massive arches into place over a period of three days.

Each arch is approximately 90 metres in length and weighs more than 130 tonnes.  A large 650-tonne crawler crane has been secured for the operation, marking one of the largest lifts in the province this year.

To keep everyone safe while the lift is underway, there will be periodic closures of the temporary active transportation bridge, and limited access to the project area. Access to Thames Park will be maintained at the Wortley Street entrance.

On Tuesday, dozens of onlookers could be seen on both banks of the Thames, many of them taking pictures or holding young children who took the day off from work and school to see the massive steel arches suspended in mid-air. 

Among those in the crowds was Liam Williamson, who, at age 3½ brought his own safety vest and hard hat and enjoyed the show perched on his dad's shoulders.

Matt Williamson described his son as a "huge fan" of construction. 

Throughout the day, more people stopped to look and point at the cranes, soaring high above the treetops of the forest city and the massive piece of steel dangling from their cables. 

"It was incredible," said Norma Boyle, who watched the arch hoisted on Tuesday from home with her husband, Christopher. The couple saw the operation on Tuesday unfold on YouTube, through a webcam placed by the city on the nearby London Hydro building. 

"It would have to be very exact," said Christopher Boyle. "Amazing.

"I don't know how they did the old one," she said, referring to the nearly century-old structure. "Let's hope it's going to be another one that lasts a hundred years."