Head Gate Refurbishment, Smith Mountain Hydroelectric Plant
American Electric Power
Sandy Level, VA
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Smith Mountain Project is a two-reservoir hydroelectric generation project operated by Appalachian Power. Smith Mountain Dam houses five hydroelectric generators with a combined capacity of more than 605 megawatts. The five generating units are at depths ranging from 70 feet to 200 feet deep for Unit 5. Marine Solutions was contracted to perform an underwater inspection and high-pressure cleaning, removal, and replacement of steel guides at Generating Unit 5 intake structure to support installation and sealing of stop logs so that it could be dewatered. Marine Solutions mobilized a 60-foot by 80-foot barge and 40-ton rough terrain (RT) crane, along with two decompression chambers, a diving bell, and 150 high-pressure bottles of diver breathing mixed gas comprised of helium and oxygen. A variety of hydraulic and air tools were used with underwater welding and cutting gear, and an underwater remotely operated vehicle (ROV) for inspection purposes. It was Marine Solutions deepest dive to date, and the first mixed-gas diving operation.