In the past, inspecting hydoelectic dams was a difficult and expensive operation.  Water flow at the dam had to be shut down or slowed significantly to allow access by divers.  The diver was often working in a dark overhead environment and had to contend with piles of debris around the dam structure, making it a particularly hazardous job.  Today more and more companies are using ROVs to perform these inspections.  Having an ROV allows them to perform an inspection whenever they want. If a problem arises the camera can immediately be launched. For many companies JW Fishers ROVs have become a popular choice for these inspections.

Ontario Power in Toronto is one of the companies that routinely inspect their dams and adjacent structures using an ROV.  They used Fishers SeaLion ROV for inspection operations at several of their hydro plants.  Spokesman Mike Ostroski says, “In our Smokey Falls plant in northern Ontario the SeaLion inspected tailrace concrete piers, went up the draft tube to the underside of the runners, inspected the headworks concrete, and checked for erosion under the sluiceway aprons.  At our Sir Adam Beck plant we inspected the headworks concrete piers, the headgate, and it’s gains on one of the units.  We’ve found the ROV to be an effective tool for this work and it has quickly paid for itself.  One advantage of the ROV is that we don’t have to shut down the units on either side of the one being inspected, letting us maintain a higher operating capacity.  Also, we can put it in on the downstream side of the trash racks and it’s perfectly safe.” 

Another Canadian dam inspected with an ROV is the Centrale Shipshaw Dam in northern Quebec.  Fishers SeaOtter ROV performed an inspection of the intake chambers and trash rakes.  The ROV was deployed from a small boat at the dam face and submerged to 290 feet.  The ROV was able to operate around the dangerous currents near the intakes and successfully perform an the inspection of all chambers.  The majority of the chambers were found to free of debris, however, several were clogged with logs, drums, and other materials.  Video tapes of the inspection along with a written report were submitted to the unit’s managers. 

 In Caracas, Venezuela marine services company Trime C.A. used a SeaLion to find a leak in the face of a dam.  The ROV surveyed the 305 meter long face to a depth of 50 meters.  According to company spokesman Betram Bruhl, the SeaLion successfully located the leak which minimized the amount of time divers had to spend in the water, reducing the overall cost of the job.  And at the Ice Harbor Dam in Pasco, Washington a group connected with the US Army Corps of Engineers are using a SeaLion ROV for a variety of inspection projects and to monitor fish populations affected by the structure. 

For more information on Fishers SeaOtter and SeaLion ROVs, or a brochure on their complete line of underwater camera systems, call (800) 822-4744, e-mail jwfishers@aol.com, or visit the website www.jwfishers.com.