September 7, 2012

Hydro One ready to bore on $115-million Toronto electrical project

GREG MECKBACH

digital media editor

Hydro One is about to begin the tunneling phase of a $114.85-million transmission cable project in Toronto. Energy Minister Chris Bentley was recently on hand with officials to unveil the tunnel boring machine.

“This project is intended to maintain reliability in Toronto, replace aging electrical equipment and increase capacity for Toronto,” said Peter Gregg, executive vice-president of operations of Hydro One, during a news conference at the tunnel launch site on Mount Pleasant Road, about three kilometres northeast of Queen’s Park.

The Midtown Electricity Infrastructure Renewal Project is intended to refurbish an existing 115-Kilovolt transmission infrastructure between the Leaside Transformer Station at Millwood Road and Laird Drive, and the Bridgman transformer about half a kilometer east of the George Brown College Casa Loma campus.

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The project includes the replacement of an underground cable and the addition of a second cable, from the Bayview Junction, south of Bayview and Moore Avenues, to the Birch Junction, near Yonge Street at the Canadian Pacific Railway tracks about 1.5 kilometres north of Bloor Street.

The 2.4-kilometre tunnel itself will roughly follow the route of the CPR track, under the wealthy neighbourhood of Rosedale.

GREG MECKBACH

Anthony Haines, president and CEO of Toronto Hydro Electric System, speaks with Peter Gregg, executive vice-president operations of Hydro One, before a news conference in Toronto. In the background is a tunnel boring machine made by Technicore Underground Corp., which is about to be lowered 60 metres into a launch shaft to build a 2.4-kilometre tunnel for electrical cables, part of the Midtown Electricity Infrastructure Renewal Project.

The corridor “was originally built way back in the 1920s with the first underground cable in the 1950s,” Gregg said during the news conference. “The area has experienced steady load growth as a result of land use intensification and redevelopment.”

Bentley agreed.

“Toronto is growing,” he said. “We see on the waterfront, the condominiums – growing. The demands that those buildings entail in terms of energy is growing, so you have to plan not just for today and tomorrow, but to three, five, 10, 20 years down the road.”

Gregg said the underground cable is approaching its end of life. The renewal project includes the tunnel 60 metres below the ground, which is intended to have room for six high-voltage cables capable of delivering an additional 100 Megawatts of electricity to the served area. Above-ground work on the portion east from the Bayview Junction to the Leaside Transformer station is already complete, according to the Toronto Hydro website.

“The construction work that was required is at the stage where we’re now going to start digging a tunnel,” Gregg said, in front of a tunnel boring machine at the launch site, at a water pumping station on the west side of Mount Pleasant Road north of the CPR tracks, between the Rosedale and Moore Park neighbourhoods.

The 120-tonne TBM was manufactured by Technicore Underground Corp., based about 50 kilometres north of Toronto in Newmarket. The firm’s president, Tony DiMillo, said in an interview that the machine was built specifically for the Midtown project, with dual articulation to negotiate tight curves.

“The Birch Avenue turn is really really tight,” he said referring to the west end of the tunnel. The TBM will be disassembled and reassembled once it’s lowered into the launch shaft.

DiMillo said Technicore will first bore east from Mount Pleasant Road to the Bayview Junction. Then the TBM will be removed and brought back to the launch site and the rest of the tunnel will be bored west to the Birch junction, which is just west of the Summerhill subway station and the former CPR passenger station that has been converted to a liquor store.

DiMillo said he hopes the TBM could be used for other projects in the Toronto area.

Gregg said 60 per cent of the cost will be borne by Hydro One, a crown corporation which was part of Ontario Hydro before the province unbundled the transmission and generation sides of the business. The other 40 per cent paid by Toronto Hydro. During an interview with DCN, Gregg said there was some delay in the launch because crews encountered more water than they expected.

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