Trapped Toronto boring machine finally freed after 19 months, millions of dollars
Lucas Powers | CBC News | Posted: October 11, 2023 5:23 PM | Last Updated: October 11, 2023
Tunnel boring machine had been stuck 18 metres underground since spring 2022
On Wednesday, a crew removed the last section of a boring machine trapped 18 metres beneath a west Toronto neighbourhood since spring 2022, finally ending a saga that will likely cost taxpayers tens of millions of dollars.
"I am happy to see it is out of the ground," said Mika Raisanen, director of design and construction at the city. Raisanen was on scene to speak to media after the work was completed.
"I understand it has gone on way too long. Longer than we expected," he said. "I do feel for the community and I do thank them for their patience and understanding."
The rear part of the 1.5-metre wide, five-metre long micro-tunneling machine was the only piece still underground after the head was freed and removed several weeks ago.
The machine was being used to dig a new storm sewer under Old Mill Drive as part of a larger project to limit chronic basement flooding in the area. That work began in March 2022, with the remote-controlled borer meant to carve a 282 metre-long sewer path to a pre-built exit shaft on Bloor Street West. It had to be placed so deep underground to avoid the Bloor-Danforth subway line.
WATCH | Trapped boring machine finally rescued:
But with just seven metres left to go on its route, the machine hit 14 underground steel tiebacks, which had been part of the construction of two nearby condo buildings. It became ensnared in them and then got twisted and turned off course.
The effort to rescue the machine "became very complex," Raisanen said. "We had to do ground stabilization work while looking at the safety of the workers and the community and all the infrastructure that is here."
The struggle to remove the tunnel borer has repeatedly pushed back the completion date of the bigger project, which was initially expected to cost about $9 million. In September, the city estimated it would actually cost at least $25 million. But Raisanen said the final bill is still being tallied.
"The cost is still under review. We're at the stage where the tunneling machine has been removed and we are able to start putting numbers together and take a look at what the cost will be," he said.
Raisanen explained the city considered the possibility of simply leaving the $3-million machine in the ground. But that would have required a complete redesign of the project, and given the number of utilities and other infrastructure in the area, it would have cost even more than the rescue.
He says there will be an investigation into how the mistake happened, who is responsible and what can be done to avoid situations like this in the future. He hopes the remainder of the project will be finished by year's end, with some restoration work in early 2024.
Speaking to reporters before a council meeting, Toronto Mayor Olivia Chow said the city will publish a full report outlining the investigation's results. Chow said she couldn't comment on the final cost, only saying "it is millions of dollars.
"It came up for discussion while we were talking about budgeting. I can assure when I was asking our city manager about the capital operating budget that machine was stuck in my mind," she said.
Greg Tershakowec has a dental practice in the area. He said the year and a half of work to remove the tunnel borer has been stressful and completion was long overdue.
"Noisy, dirty, always something going wrong. It had an impact on my practice in terms of access ... Eventually it came to a point where there was destruction to my building because of an obstruction in the sanitation pipe," he told CBC Toronto.
"Everybody is frustrated because we never got a good timeline from the city itself. It was always very vague and never turned out the way they claimed it would happen," he said.
Tershakowec says he wants to see accountability for the error.
"It's outrageous," he said. "Who made the decision to go ahead with the boring machine without considering the tiebacks?"
Paul Doyle, lives in the area, said it was a relief to see the machine finally removed.
"It was about time, but I understand it was a very complicated thing," he said. "It took a long time and an extraordinarily large sum of money."
Asked how he felt about taxpayers footing the bill for the costly error, Doyle paused, and then sighed.