Toppled Halifax crane sparks new focus on safety


Originally Published by The Chronicle Herald
Author: Brett Bundale

Atlantic provinces monitoring fallout from Dorian damage to Halifax tower crane

It’s a deserted stretch of prime real estate, a once-bustling block of downtown Halifax now eerily still.

Inside the cordoned off area, the ravages of a long-departed storm are visible in mangled trees, broken glass and a contorted yellow crane draped on a battered, concrete structure.

The collapsed tower crane continues to draw onlookers, weeks after powerful winds and torrential rains swept the region.

Its dramatic crash into a building under construction was captured on video, turning the twisted and leaning metal into a minor social media sensation.

But the city’s notorious new tourist attraction has also attracted the attention of crane regulators across the region.

With Atlantic Canada expected to become increasingly vulnerable to severe storms due to climate change, governments are casting a sober second look at cranes and the rules that regulate them.

Officials in Newfoundland and Labrador, New Brunswick and P.E.I. have told SaltWire they are closely following the situation on the ground in Halifax.

“It is estimated that approximately 15 tower cranes are in operation at any one time in Newfoundland and Labrador,” Krista Dalton, a spokeswoman for Service NL, said in an email.

She added that the department’s Occupational Health and Safety division is monitoring the situation in Halifax, echoing comments from officials in other provinces.

A spokeswoman for New Brunswick’s Labour Department said the province “is aware of the situation and paying close attention,” while a spokeswoman for P.E.I.’s Department of Economic Development said the government is “monitoring developments” in Halifax.

Cranes in the sky, cranes on the ground

It’s not the first time a crane has come crashing down in the region.

A crane tipped onto its side at the Muskrat Falls hydroelectric megaproject in Labrador last year.

And in 2010, a 200-tonne industrial crane fell in Saint John, smashing into a fence, damaging cars and sending the operator to hospital.

Still, falling cranes is a relatively rare occurrence, given the number in operation in Atlantic Canada.

New Brunswick is estimated to currently have about five tower cranes, Newfoundland has about 15 while the machines are a rarity in Prince Edward Island.

Nova Scotia’s capital, meanwhile, has roughly two-dozen cranes dotting the city’s skyline, outnumbering the other three Atlantic provinces combined.

Yet neighbouring provinces share similar weather conditions and, given predictions of more frequent storms and potentially powerful winds, they’re watching the fallout from the collapsed crane in Halifax closely.

In the wake of the accident, several businesses have been shuttered and scores of residents have been evacuated from the South Park Street area.

The Nova Scotia government stepped in last week to declare a localized state of emergency, a move that allows provincial officials to oversee the crane’s removal.

But it could also leave the public on the hook for the cost of removing the crane, adding financial uncertainty to the situation.

Meanwhile, despite efforts to quickly develop a plan to address the precarious crane leaning on a half-finished building, the site itself remains at an apparent standstill.

But Marla MacInnis, a spokeswoman for the Department of Transportation and Infrastructure Renewal, said officials are working both on and off site to design a plan for the complex and unpredictable situation.

“The crane collapsed onto a building under construction adding to the complexity of the crane’s removal,” she said, noting that there is a significant amount of debris, scaffolding and wiring in the area.

MacInnis said engineers are planning for the potential that moving one part of the crane could result in the unpredictable movement of debris or other material in another area of the site.

She said 3D scanning of the building structure will begin on Thursday, which will help engineers finalize their approach.

Cause Unclear

Although the focus is on removing the crane, questions remain about how it could have toppled over in the first place – only narrowly missing residential buildings.

Dalhousie University engineering professor Fadi Oudah said there are three possible factors that may have contributed to the collapse of the crane.

The first involves the crane’s design, and whether it was properly built to withstand the wind loads outlined in national regulations.

The second is related to the crane’s operation, and if it was set up to freely rotate on its vertical axes like a weather vane in the wind.

But the third possibility relates to the actual codes and standards governing cranes themselves – and could carry the greatest implications in a region set to receive more frequent and powerful storms.

The regulations – known as the Canadian Standard of Tower Cranes, or CSA Z248 – may not adequately account for the “extreme loading” experienced during Dorian, Oudah said.

“This is a very interesting possibility,” Oudah, a structural engineer specializing in structural assessment and remediation, said in an email.

“Hurricanes are associated with high wind speed and complex air dynamics,” Oudah said, noting that the wind pressure increases by a factor of four as the wind speed doubles.

Moreover, he said the collapsed crane was roughly positioned on a corner between two high-rise buildings.

“The aerodynamics near building corners is complex and may not be suitably accounted in design standards,” Oudah said.

For now, however, it remains unclear what caused the crane to collapse and any actions that might be required.

“Once our inspection concludes, we will be able to determine next steps,” Labour Department spokeswoman Shannon Kerr said in an email.

“It is too early in our inspection to determine what action may be taken as a result of this incident.”

She added that details related to any previous inspection of the crane could not be released.

Yet a construction industry expert said a review of the province’s Technical Safety Act and the Crane Operators Regulations – regardless of the outcome – would ensure the rules and training are up to date.

“Like any legislation, it should be reviewed and renewed, and looked at periodically to make sure it reflects the current environment,” said Duncan Williams, president and CEO of the Construction Association of Nova Scotia.

He took umbrage at the portrayal of the construction industry is the “wild west” of safety, noting that crane operators are highly trained, heavily regulated and committed to safety.

Yet as the evacuation of the residents and businesses in the area turns from days to weeks, questions about who will pick up the tab for the costs related to the collapsed crane remain.

MacInnis said it’s too soon to put a dollar figure on the work.

“This is a complex project, so we do not yet have a cost estimate.”

Read original article at thechronicleherald.ca