The TBM will travel 1.484km through the adit to reach the underground assembly chamber, where the remaining components will be assembled. The Lesotho Highlands Development Authority (LHDA) says the stepping-in process is expected to be completed by the end of November.
Once at the chamber, the TBM will be reoriented to commence boring the 38km transfer tunnel towards Katse where it will meet its twin, Khoiti ea Ngoaha Kholo, midway through the tunnel.
To date, the major components assembled include the cutterhead, main drive, segment erector, and the bridge that will connect the back-up units – bringing the machine’s current length to approximately 43m. LHDA says the TBM will be 305m long when fully assembled.
The Lesotho Highlands Water Project Phase II comprises construction of the Polihali Dam and reservoir, water transfer tunnel and associated structures. The dam will create a 5,053ha reservoir on the Senqu and Khubelu rivers at full supply level and add 2.325 million m3 in storage capacity to the Lesotho Highlands Water Project.
