Mesa was contracted by a large Southeastern power utility to act as Responsible Engineer for a phase reversal switch replacement project at a 1,616 MW pumped storage plant. The project consisted of engineering and design support for the replacement of the existing phase reversal switches, drive mechanisms, controls and interlocks, structural modifications, addition of new grounding switches, as well as, interfacing the new equipment to existing plant systems. Additionally, a design for new switch platforms was developed to provide a safe means to conduct maintenance and inspection activities. A very aggressive procurement and design schedule were kept in order to install and commission the switches during the scheduled outage. The new switches allow the turbine/generators to effectively work either in pumping or generating mode, while at the same time, enhancing personnel safety.