Saturday, June 18, 2011

Summer in the City: Monster boring machines: New northern extension of subway launched




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Toronto Star (June16,2k11)
This momentous subway moment has been in the making for about 20 years.

The TTC is about to launch the first of four giant tunnel-boring machines that will dig the route for tracks and trains on the Spadina subway extension to York Region.

“It’s really exciting. After 25 years we’re finally building the subway line. It’s going to connect York to rapid transit, it’s going to open up an entire new area of the city. It’s going to link us to our regional neighbours,” TTC chair Karen Stintz said Thursday.

Stintz will join Mayor Rob Ford and federal, provincial and regional politicians on Friday to announce the launch at the site of the future Sheppard West subway station.

“What I’d like to do is just keep the borers, so when we finish on Spadina-York we just keep on going. It’s a long time in coming, it’s so needed,” said Stintz, citing the 2,000 buses a day that serve York University and the city’s planned development of Downsview Park, which will also feed the subway.

The $2.4 billion extension, which will extend 6.7 kilometres from Downsview station to the Vaughan Metropolitan Centre Vaughn [Municipality], is scheduled to open by 2015. So far, construction is on time and on budget, she said.

The first of the machines has already been lowered into the ground at Sheppard West to begin the dig by the end of the month.

There are three shafts along the six-stop route into which the machines will be lowered and extracted at various phases.

The first machine will dig northwest, parallel to Keele St. to just south of Finch Ave. About a month later, its twin will begin boring a parallel tunnel. The time gap is necessary to let the ground settle.
Once they reach Finch, the machines will be pulled out through an extraction shaft and returned to Sheppard, where they will begin boring south to Downsview station.

That completes their task.

The second set of tunneling machines will be launched in fall atnSteeles West Station, from which they will travel south to Finch West. There they will be extracted and taken up to Highway 407 to dig southward to Steeles West. Finally, those machines will be used to tunnel north to Vaughan.
Custom-built by Lovat in Toronto, the machines are assembled at the subway site.

The Spadina tunnel will be 5.4 metres in diameter, compared with 5.2 metres on the Sheppard line, because of different curves on Spadina and to accommodate new fire rules requiring wider walkways.

The tunnels won’t be as wide, however, as the underground Eglinton light rail, which requires a 6.5-metre diameter to accommodate the overhead catenary.

As well as boring tunnels, the machines are equipped with arms that will be used to lift and install the segmented tunnel liners.

The stations will cost $100 million to $200 million each, including tail track at the north end, where trains will be stored.
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-- Star / Kalinowski materials posted here by Owlb

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