By rosebell
On November 1, the Lesotho Highlands Water Project TBM commenced its reverse entry into the access adit.
With the aim of reaching the underground assembly chamber, where the remaining components are due to be assembled, the TBM will travel 1.484km through the adit and the scheduled date by Lesotho Highlands Development Authority (LHDA) for that stepping-in process to be completed is the end of November.
In order to starting excavation of the 38km transfer tunnel towards Katse where it is going to meet its twin, Khoiti ea Ngoaha Kholo, midway through the tunnel, the TBM will be reoriented after arriving at the chamber.
Increasing the machine’s current length to almost 43m,and the bridge that will link the back-up units, the major components assembled include the cutterhead, main drive and segment erector until now. LHDA says the TBM will be 305m long when fully assembled.
While construction of the Polihali Dam and reservoir, water transfer tunnel as well as associated structures are the contents of the Lesotho Highlands Water Project Phase II, the dam is slated to 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.
