Megastructures - Niagara Tunnel Project

The Niagara Tunnel Project is the most recent in a series of additions to the Sir Adam Beck hydroelectric generation complex in Niagara Falls, Ontario, Canada.

First constructed in 1922, the initial Sir Adam Beck power generating station, now abbreviated as SAB 1, derived its water supply from a canal connected to the Welland River. However, due to increased power demand in later years, a second generating station, known as SAB 2, was constructed in 1954. It in turn derives its water supply from two diversion tunnels, each about 9 kilometers in length. In 1958, a reservoir and the SAB Pump were constructed in order to make better use of available water by storing it during periods of low demand and using it in periods of greater demand in order to maximize the efficiency of the stations in regards to electricity supply and demand.

Between 1996 and 2005, Ontario Power Generation, which owns and operates the SAB complex, completed a series of major upgrades at the SAB 2 plant, increasing its potential generating capacity by 194 megawatts. Water delivered by the new Niagara Tunnel will complement this SAB 2 upgrade, and overall will increase the efficient use of the power of the Niagara River.

The Niagara Tunnel is being dug using a Tunnel Boring Machine, or TBM affectionately named "Big Becky" in honor of Sir Adam Beck. The machine will bore a hole about 10.4 kilometers long and about 14.4 meters in diameter under the City of Niagara falls from the Niagara River to the SAB complex. This massive undertaking will create about 1.6 million cubic meters of rock and debris, which is enough to fill Toronto's Rogers Centre baseball stadium to the top. The TBM operates about 140 meters below the ground, and as a result, the vibrations from the machine will not be felt on the surface. The design-build contractor for the project is Strabag AG, a large construction group with extensive experience in large tunnel construction. The tunnel is to be completed in 2010.

• The tunnel creates enough clean renewable electricity to power a city twice the size of Niagara Falls. The generation capacity of SAB 2 will be increased by about 1.6 billion kilowatt hours per year. This is enough to power over 160,000 homes.
• The tunnel is wider than 6 tractor-trailers side by side, and longer than 100 football fields.
• The machine used in the construction of the Niagara Tunnel can bore through over 15 meters of solid rock per day.
• Over 500 cubic meters of water will enter the Tunnel per second.
• 400,000 cubic meters of concrete are used to line the inside of the Tunnel.
• It will take about 3 years to construct the Niagara Tunnel.
• The tunnel is 14.4 meters in diameter — 65 percent wider than the Channel Tunnel, which is 8.6 meters in diameter, and 2.5 times wider than the subway tunnels in Toronto, Canada which is 5.7 meters in diameter.
• Once completed, the Niagara Tunnel will be the largest hard rock tunnel in the world.
• The machine requires 7 megawatts of electricity — enough to power the United Nations Building in New York City.
• The machine uses 85 watermelon-sized cutting teeth on the face and each tooth weighs as much as a male gorilla.

credited to niagarafrontier.com