A major technical advance in hydroelectric dam safety was achieved this March as Alstom’s Chinese arm, the Tianjin Alstom Hydro Co. (TAH), delivered what it called “the world’s first self-closing electronic ring gate control system” to the Ahai hydropower project in China.

5. A giant safety valve. A self-closing electronic ring gate control system—which developer Alstom says is the first in the world—works to choke off the flow of water to a hydroelectric turbine in an emergency. The device—roughly 10 meters in diameter, 2.6 meters high, and 110 metric tons—was delivered to the Ahai dam in China this March. Courtesy: Alstom

The hydraulically synchronized system cuts off the flow of water to the turbine in an emergency. Alstom says that from start to finish—model design to testing—development took less than nine months (Figure 5). The device will be installed at the Yunnan Jinsha River Hydropower Co.’s dam under construction on the Jinsha River in northwest Yunnan Province. That project, whose first unit will be commissioned in spring 2012, comprises five 400-MW Francis hydro turbine generators.

—Sonal Patel is POWER’s senior writer.