NIAGARA FALLS, ONT.—The world’s biggest tunnel boring machine completed its 10.2-km long dig in southwestern Ontario this week.
Better known as Big Becky, the 4,000-tonne machine been blasting through rock about 90 to 140 metres underground since 2006.
The new tunnel is more than twice the size of the Chunnel that runs from underwater from England to France.
It will be used to redirect water from the Niagara River to generating stations in a hydroelectric project that’s expected to power 160,000 homes.
The $1.6-billion project is expected to be completed by 2013 and provide hydro power for at least 100 years.
Currently, Niagara River water is channeled to stations using the existing Sir Adam Beck power canal and diversion tunnels.
But the amount of water available for power generation exceeds the tunnels’ capacity about two-thirds of the time. The new tunnel will reduce that to about 15 per cent of the time, according to the Ontario Power Generation.
Ontario’s Energy Minister Brad Duguid called Big Becky’s breakthrough an “incredible engineering feat.”
“It’s a tunnel that’s four storeys in diameter and may well be the largest tunnel ever dug to this point, anywhere in the world,” Duguid said.
Critics have complained the project is four years late and half a billion dollars over budget.
Duguid said construction crews hit harder-than-expected rock early in the project and had to redesign the tunnel to make it safer for workers, slowing things down and adding to cost overruns.
Frank Caroli, one of the project workers, says it was rough go at times. Shifts inside the tunnel lasted as long as 11 hours, for 11 consecutive days.
“You really didn’t know how much you miss the sun until you don’t have it anymore,” Caroli said.
“It’s a great feeling to hear the machine from this side and watch it come through.”