The demolition of the last cofferdam protecting central China's the Three Gorges dam, the world's largest such construction, moved a step closer on Sunday when the installation of a network of electronic triggers for explosives was completed.

"About 192 tons of dynamite was positioned between May 27 and June 2 and all the preparations are ready," said Song Ling, general manager of Chongqing Gezhouba Yipuli Chemical Co., who are responsible for the blasting.

The electronic triggers will control 2,540 detonators which in turn will set off 971 consecutive explosions around the cofferdam. Experts are positioning sandbags and installing a steel cage around the top of the cofferdam to catch any flying rubble.

The area behind the cofferdam has been filled with water since Saturday and the level is expected to reach 139 meters when the demolition goes ahead on June 6.

A temporary structure erected for the construction of the Three Gorges Dam the cofferdam went into operation in 2003. It generated power for construction crews in the early stages of work on the dam's right bank.

It's 580 meters long, 140 meters high and eight meters wide at the top.

Its removal means the Three Gorges Dam will formally begin its role in flood control two years ahead of schedule.

(Xinhua News Agency June 5, 2006)