Mega Builders

S04:E03 - Floating Bridge

Engineers had no choice. They had to build a "floating bridge" in Kelowna, British Columbia. Lake Okanagan was too deep and too muddy to sink columns to support a standard bridge. So the engineers designed a bridge of nine pontoons, each as long as a football field. Then they decided to make the floating pontoons out of concrete! But, with only a dozen or so floating bridges around the world, no one has any experience building a floating bridge. Engineers and work crews must learn from scratch how to build the 6000 tonne pontoons. Then marine crews must tow the concrete behemoths across the lake, and line up each pontoon to the next to tolerances of millimetres. It's a tense day when the pontoon that marine project manager Kevin Giberson and his second in command Kevin Hamakawa are towing is pushed dangerously close to submerged cables by trick lake currents. But after two and a half years of hard work through blistering Canadian summers and frigid winters, Kelowna and the world gets a new floating bridge.