Glenn Underwater Services, Inc. (GUS) was contracted to perform an underwater inspection and make repairs on the malfunctioning roller train at a hydroelectric facility in North Carolina. The outage for the facility head gate and roller train inspection and repair began with the divers arriving onsite to setup the dive station and conduct a site safety meeting. After completion of the lock and tag out of all units, head gates and partial spillway gates, the GUS dive crew began the inspection and repairs which were finalized within 48 hours. Before beginning repairs, Glenn Underwater Services, Inc. (GUS) deployed a Remotely Operated Vehicle (ROV) to inspect the intake gates at the facility to determine if any differential pressures (DP) or other dive hazards were present. Water visibility at the time of the inspection was poor at approximately four (4) to six (6) inches. Unusually large amounts of rain and runoff during the winter months muddied the water.

Glenn Underwater Services, Inc. (GUS) designed an underwater remote cleaning and restoration system as well as provided diving support services to repair the erosion of the downstream column at a bridge in South America. The bridge is located downstream of the powerhouse and is a part of the overall hydroelectric plant. During the underwater dam and bridge inspection conducted by Glenn Underwater Services, Inc., it was discovered that the erosion area at the base of the bridge column had increased in size and the concrete had become weaker.

By thoroughly removing contaminates and loose material in the surface of the concrete, there is an increase in the surface area of the substrate which in turn increases adhesion and extends the life cycle of the repair material. A clean water supply was provided to prevent the possible introduction of contaminates into the system. Contaminates under high pressure can be impregnated into the pores of the concrete substrate, thus impeding and weakening the bond. In addition, the clean water also prevented blockage within the high pressure pumps.