Ontario Power Generation reports the in-service date of a new power tunnel for the 2,000-MW Sir Adam Beck hydroelectric complex at Niagara Falls will be extended.
The tunnel hadd been scheduled for completion by 2009 (HNN 8/29/07), then in 2010. However, Strabag AG of Austria, the contractor digging the 10.4-kilometer tunnel, advised the in-service date of the tunnel must be reset, and is investigating alternatives, including rerouting a portion of the tunnel.
Ontario Power Generation and Strabag are using recommendations from a dispute review board as a basis for negotiating revisions to the contract. Negotiations could be completed by April, OPG said in a financial report.
The province initially said it would invest C$985 million (US$804 million) in the tunnel. However, revisions could significantly affect cost and schedule, the utility said.
A 2,000-ton tunnel-boring machine, dubbed �Big Becky,� advanced 3,124 meters by the end of the third quarter of 2008, roughly one-third of the length needed. As originally proposed, the machine is expected to chew up 1.6 million cubic meters of rock and dirt. The machine makes a hole 14.4 meters in diameter and has been called the largest hard rock tunnel-boring machine in the world.
Once completed, the new tunnel beneath the city of Niagara Falls is to supply additional water from the Niagara River above Niagara Falls to the Beck complex, boosting annual generation of existing turbines by 1.6 terawatt-hours.