Second Herrenknecht launched at Veligonda projectThe 7.96 m-diameter hard rock double shield Herrenknecht TBM launched at Dornala last year on an 18.5 km water tunnel drive has been joined by a similar 9.2 m-diameter machine launched early last month running parallel at a separation of 60 m. Both tunnels are being lined with honeycomb precast concrete segments produced at a Herrenknecht plant at site. The tunnels, located beneath the Nagarjunasagar tiger reserve, will draw irrigation water from Srisailam dam to Veligonda reservoir in the Prakasam district of Andhra Pradesh.For full background and history of this project, visit tunnelbuilder archive in/42. 34/09.