Wednesday, June 07, 2006

THREE GORGES DAM - Demolished!

The BBC has news, and a video report, of the destruction of the "cofferdam" which has been holding back the Yangtze while the controversial Three Gorges Dam has been constructed.
Chinese engineers have demolished the temporary barrier behind the Three Gorges dam, in a spectacular explosion.

The barrier, called a cofferdam, was used to hold back the waters of the Yangtze River while the permanent structure of the dam was built.

Enough explosives to topple 400 10-storey buildings were used in the blast, China's Xinhua news agency said.
According to the Shanghai Daily, special electrical pulses were used to drive fish away from the cofferdam, prior to the massive explosion.
Professor Tan Xichang from the Water Biological Engineering Institute under the Chinese Academy of Sciences took charge of a fish dispelling operation three hours before the demolition that occurred at 4pm.

He said the two dispelling vessels succeeded in driving 90 percent of fish within 600 meters of the cofferdam an hour before the explosion of the protective dam, according to ultrasonic monitoring in the reservoir.

Tan said that based on fish behavior study, the startled fish will take up to three hours to recover from the explosive force.