Paula Wallis, TunnelTalk

Four Lovat EPBMs are on order for Toronto's new Spadina metro extension in preparation for an early 2010 call for tenders on the CAN$300 million tunnelling contracts.

Spadina extension alignment

"The Toronto Transit Commission (TTC) purchased the TBMs to get the exact diameter of the machines and other requirements," said Andy Bertolo, Project Manager for the TTC." "Procuring a new TBM takes more than 12 months and the TTC wanted to purchase them early to minimize the impact to the construction schedule."

The TTC signed the CAN$58 million contract with LOVAT on August 7, 2009. Along with the four TBMs, the contract includes trailing gear, segment cars and supply of mixed ground cutterheads with face isolation doors. Two of the TBMs have a planned delivery date of December 2010 with the remaining two to arrive in January 2011.

The Spadina Subway Extension will run 8.6km (5.4mile) from Downsview Station northwest through York University, within the City of Toronto and north to the Vaughan Corporate Centre in the Regional Municipality of York.

The CAN$2.8 billion design-bid-build project is to be delivered in six major construction contracts, including two tunnelling contacts of approximately equal length. One of the contracts could include construction of one of the six stations, which are all planned as cut-and-cover construction operations.

"The two tunnelling contracts have an approximate value of CAN$300M million, excluding TBMs and the tunnel liners which are also being pre-purchased and issued to the tunnelling contract." said Bertolo. "The tunnelling contracts also include some cut and cover work."

The four TBMs will excavate 6.7km of twin tunnels in reasonable tunnelling conditions said Bertolo. "The geology along the alignment is mostly consolidated till, sand deposit and clay. We will be below the water table for almost all of the drive and we expect to encounter some boulders."

Hatch Mott MacDonald was awarded the twin tunnel design contract, with a value of up to $12 million, in November 2008. HMM/Del/MMM Group JV is responsible for managing delivery of the design and construction of the project, and is also performing the preliminary design of track and signals, traction power supply, communications and SCADA. Tunnel design moved past the 30% milestone last month.

The $2.8 billion extension is funded jointly by the Government of Canada, which has committed $697 million, the Province of Ontario that has provided $870 million, and the Cities of Toronto and York Region have pledged $526 million $352 million respectivaly.

The TTC plans to advertise invitations to tender the tunnelling contracts in March or April of 2010 and the six-station, 8.6km (5.4m) Spadina Line is scheduled for completion in later 2015.

References

Toronto Transit Commission