On August 17, 2009 a massive hydroelectric dam on the Yenisei River, near Sayanogorsk in Khakassia, Russia experienced a catastrophic failure in the turbine room, which destroyed the turbine and engine room and flooded the structure. Six days later, when the structure had been pumped out, 76 people were known dead.
The Sayano-Shushenskaya dam is one of the largest hydroelectric dams in the world, the sixth largest in terms of output, and supplies 70% of the power used by United Company RUSAL, the largest aluminum producer in the world. The dam also produces 10% of the power used in Siberia, but it’s the loss of the smelters that is the main economic loss (500,000 tons of aluminum) not counting the estimated $300m required to rebuild the dam’s turbine room.
What is truly awesome about this accident is that the cause is presumed to water pressure surge in one of the turbines, also known as water hammer (this is the same thing that happens at home sometimes when you turn off a faucet and there is an audible bang in the pipes, that’s water hammer). In this case the water hammer was supersized and the force was strong enough to lift a 900 ton turbine off it’s base and destroy and entire concrete and steel turbine room structure.