Demolition of world's second-tallest chimney continues in Ontario

Demolition crews are quickly chipping away at what was, until just a few months ago, the world's second-tallest chimney in Northern Ontario.

The gargantuan Vale (formerly Inco) Superstack towered over Sudbury, Ont., for over a half-century, and ranked as both Ontario's and Canada's second-tallest structure behind the CN Tower prior to the start of demolition.

Work to demolish the enormous chimney kicked off back on June 1, with Vale Base Metals, which owns the decommissioned structure within its broader Copper Cliff processing facility, sharing updates on its gradual disassembly along the way.

Constructed between 1970 and 1972, the 381-metre-tall smokestack held the title of the world's tallest power plant from 1971 to 1987, when it was overtaken by Kazakhstan's Ekibastuz GRES-2 Power Station. It was also briefly the tallest structure in Canada from its completion until the opening of the CN Tower in 1976. 

Vale announced in 2018 that the chimney would be decommissioned and dismantled, with the structure taken out of service by July 2020 following the installation of two smaller stacks at the Coffer Cliff facility.

It remained the second-tallest chimney in the world, and the tallest in the Western Hemisphere until a few months after demolition finally began last spring.

The meticulous disassembly of the Superstack has been ongoing for five months now, and has stripped it of its place in the record books along the way. The structure lost its status as Canada's second-tallest back in July, and has dropped out of its second-place ranking for the world's tallest chimneys.

By mid-August, the chimney had lost 100 metres in height, and has continued to get shorter in the months since. Vale shared its latest update on the demolition work in late October, revealing just how much the Superstack's profile has changed in recent months.

The Superstack's title of Canada's second-tallest structure now belongs to the 352-metre-tall Pinnacle SkyTower, with the 309-metre One Bloor West bumped up to Canada's third-tallest structure, and the 298-metre First Canadian Place falling to fourth place. These rankings will continue to change as the Superstack loses further height in the months to come.