Boring beneath Bytown

[guest]

Boring machines? Not for Ottawa’s light-rail project. We’re talking, to be clear, about tunnel boring machines, aka TBMs or “moles.” TBMs are giant cylinders with spinning-disc faces that rip through substrate like monstrous meat slicers; one of the world’s largest, the 4,000-tonne “Big Becky,” just finished chewing out a 10-kilometre tunnel beneath Niagara Falls to supply more water to the Sir Adam Beck Generating Station.

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