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What investigators will be looking for on Kelowna crane collapse

July 28, 2021 - 7:00 AM

Determining what led up to the tragic event of July 12 in Kelowna is no simple matter.

That’s the day a tower crane attached to the Brooklyn condo tower crashed, killing five.

“Each crane accident is dangerous,” Yannick Morin, a professional engineer and president of Montreal-based Kraning Inc., told iNFOnews.ca. “None of them is similar. Each accident is very different.”

READ MORE: Five men dead in Kelowna crane collapse

There are all kinds of factors to consider, such as whether the manufacturer’s instructions were followed, when the crane was built, whether it had “mismatched” components, whether safety inspections were followed and other factors.

The problem for Morin and the few others in Canada who are qualified to do this work, in commenting on the Kelowna collapse, is that there is virtually no information available publicly.

For example, many tower cranes in Canada were built in the 1970s and 1980s with little technology in their operating cabins.

Over the years they may be modified with “mismatched” tower components. Those are considered perfectly legal if designed by a professional engineer and built to those standards.

A newer generation of cranes with better technology started being built in the 2000s.

There is no information available to Morin on the age of the tower crane used in Kelowna.

Because of that lack of information, Morin could not comment on the possible cause of the Kelowna collapse.

Davis MacGillivray, a vice-president with Skycrane in Niagara-on-the-Lake, was willing to be a bit more blunt.

“Tower cranes are in use across the country,” MacGillivray said. “They are a safe and efficient way to participate in highrise construction. The machines are working every day making thousands of lifts in almost every city.”

When they do collapse, there tends to be a common cause, MacGillivray said.

“These incidents are rare and almost always related to human error when it comes to putting them up and taking them down.”

READ MORE: Kelowna tower crane collapse one of the deadliest in recent memory

But, it can be too simplistic to say simple human error, Morin said.

As a professional engineer, he investigated a tower crane collapse in Montreal in 2018. The disassembly was being done on a Sunday so, fortunately, no one was killed.

“While waiting for the mobile crane to attach the slings, two riggers removed two safety pins,” Morin said. “That was the human factor. But, it’s more than human error. It could have been a lack of supervision. It might be a lack of following the instructions of the manufacturer. There’s many, many questions that the investigating team need to find the answers to in order to find out what were the root causes of that accident.”

That’s the job of the RCMP, WorkSafeBC and others in dealing with the Kelowna collapse.

“The first thing WorkSafeBC will do is to check out if the crew respected the instructions of the manufacturer,” Morin said.

There’s also a possibility of some structural failing since these cranes can be in place for months or years. But there’s a human factor there as well.

Each morning, when crane operators climb their towers, they need to do visual inspections of the structures, Morin said. That means log books have to be checked out by investigators.

Less frequent inspections of the outside surfaces of the tower have to be made with cameras and other technology to check things like the welds and for cracks. Those inspections will also have to be reviewed.

Assembly and disassembly is generally done by specialized companies. It’s not known whether that was the case in Kelowna.

No companies in B.C. contacted by iNFOnews.ca would comment on any aspects of the accident. They either refused to talk or didn’t return calls.

No one would even talk in general terms about how the remaining tower structure was determined to be safe enough to remove the body of Brad Zawislak who was crushed in the neighbouring office where he worked.

Such work requires a professional engineer and a team of support workers, Morin said. There are few such qualified people that he knows of in Eastern Canada and he's not familiar with the situation in Western Canada.

“First of all, you go into the building and you look for the brace of the tower crane,” Morin said. “If you see there are cracks in the concrete or it is stretched, you have the idea that you don’t go there. If you feel it’s safe to start dismantling the tower crane, then you go to the mobile cranes.”

In the Kelowna case, two mobile cranes were initially used. One secured the top of the damaged tower crane while another held a platform for two workers to unbolt that section. Later a third mobile crane was added.

At times, it was likely necessary to cut the steel beams where they had bent, preventing the bolts from being removed.

The Kelowna crane was brought down safely within a week of the initial collapse.

That’s not always the case.

“In some cases, (the safest process) can literally be to evacuate the area and cut it out from under or attach a rope and drag it to the ground so all that kinetic energy stored up when we lifted those pieces up into the air can be released safely while there is no human beings in the area,” MacGillivray said. “That would be the worst-case scenario – to evacuate the area, drag the thing to the ground and clean up the mess afterwards.”

Morin noted that tower cranes are not built to “go to the moon.” They are mostly an immobile steel structure with a crane swinging at the top.

Mobile cranes, he said, are more like spaceships with much more technology involved. They are much more dangerous since they’re not anchored to anything and operators improvise more.

There is no word on how long it will take the investigations into the Kelowna tragedy to be completed.

MacGillivray estimated it will take a year to get a coroner’s report on the incident.

To contact a reporter for this story, email Rob Munro or call 250-808-0143 or email the editor. You can also submit photos, videos or news tips to the newsroom and be entered to win a monthly prize draw.

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