Start time: 2015 Completion time: 2019 Client: Georgian-Co-Investment Fund Peri has completed the excavation of the longest and widest Double Shield TBM ever bored using a Double Shield TBM in Georgia under the Mtkvari HPP project. The tunnel is 9.6 km in length and 6 m in diameter. The boring of the tunnel by Peri was one of the most challenging and prolonged phases of the project. Now, as the phase is over, the construction has moved on to the final phase. The diversion tunnel of the Mtkvari HPP will divert water from the the Mtkvari HPP headworks to the powerhouse where electricity is generated by means of turbines. The machine acquired to bore the Mtkvari HPP tunnel is a Double Shield TBM designed for solid rocks. The technology allowed the use of only one machine to bore the tunnel according to advanced methods and current trends. The method that has been widely practiced in the last 25 years to bore tunnels through solid rocks is safe, fast and cost efficient. The Mtkvari HPP has a total installed capacity of 53 mw and the annual energy generation of 251.5 mln kwh that accounts for 1.9% of Georgia’s total energy generation for 2019. The tunnel boring operations were performed using a TBM made by Herrenknecht AG, a German company.