The United States Bureau of Reclamation's Underwater Investigations Dive Team (an agency of the US Department of the Interior) is responsible for all underwater investigation for the Bureau's hydro-electric dams. Under pressure to work faster, safer, and more efficiently, they investigated the latest observation class or "micro" ROV (remotely operated vehicle) technology to use when human diving was not necessary. ROVs can work in hazardous areas without requiring the dam to stop and tag out intakes, and are not subject to diving limits of depth or duration. After investigating available units, a VideoRay Pro 4 ROV Configuration was selected and purchased from VideoRay LLC in Phoenixville, Pennsylvania. VideoRay has Pro 4 ROV systems specifically designed for hydro-electric dam inspection.
Training was included with the procurement – a critical aspect to successfully deploying this advanced technology. VideoRay contracted with Craig Thorngren of Submerged Recovery and Inspection Services, an expert in micro ROVs. Craig's expertise in VideoRay usage goes back to the first VideoRays in the United States Coast guard fleet in 2002, and he has pioneered several techniques for inspecting difficult to access areas, and retrieving heavy articles in difficult conditions with VideoRays.
US Bureau of Reclamation Team with their new VideoRay Pro 4 ROVs – Back Row L-R: Russel Chatterton, Jesse Chan, Ryan Hedrick. Front Row L-R: Dennis Hawkins, Bill Parks . Image: Craig Thorngren
The training started out in a local pool, where the Bureau of Reclamation employees learned the basics of maneuvering, tether handling and how to get the ROV free from entanglements. The last day of training involved inspecting the trash racks at a Dam from a vessel – without securing the intakes. The training allowed the team learn what their ROV system was capable of doing, and gave them the confidence to push it to accomplish more than they thought possible when the system was acquired.
Less than a month after the training the first serious mission came up. There was a difficult problem in a stop log gate at a depth of 175 feet. ROV Pilot Ryan Hedrick, a Hydrologist and Dive Team member, flew the VideoRay down to the through the 2 foot by 8 foot stop log slot and attached a tag line to the pressurizing valve lever arm at 175 feet. The existing 1/8 inch wire rope attached to the lever had rusted or broken off. This operation was critical in pressurizing the stop log chamber in order to remove the stop log. Maintenance crews were able to open the valve, thus removing the ten foot square stop log. Without VideoRay technology, the solution would require days and dangerous deep diving by humans. However, was able to quickly open that valve with his VideoRay. Dive Team Supervisor Dennis Hawkins commented that Ryan's actions with the VideoRay had probably saved the Bureau of Reclamation more than the entire cost of the ROV system.