In a hydrostatic head to head construction race against India to claim the water potential of the River Neelum, Pakistan will now use TBMs instead of drill and blast to complete the majority of the remaining 55km of tunnel – two years ahead of schedule – on the Neelum-Jhelum Hydroelectric Project in Azad Jammu and Kashmir, official sources have said.
“It is vital for Pakistan to complete the 969MW Neelum-Jhelum Hydroelectric Project before India completes a similar project on the same river, so that Pakistan can claim its right to water use,” sources in Pakistan’s Water and Power Development Authority said.
India is currently building the 348MW Kishanganga Hydroelectric Project on the same river, and its completion before the Neelum-Jhelum project would give India the right to use the water for electricity generation. But WAPDA officials have said that the hydroelectric potential of their Neelum Jhelum Hydro Project would be dramatically reduced by the Kishanganaga project.
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Project completion for the Neelum-Jhelum Hydroelectric Project was originally planned for 2016 but the TBM use could see completion in 2014.
TBMs have not just been chosen to speed up delivery of this period. Sources say, successful TBM implementation on this project will pave the way for using the method on upcoming hydropower projects, including the 1100MW Kohala and 7100MW Bunji hydropower projects.
Allegedly, TBM acquisition is in its final stage after a technical delegation led by WAPDA Member (Water) Syed Raghib Abbas Shah, visited manufacturing facilities and projects in Germany and Switzerland.
On commissioning, NJHEP will generate 5.15bn units of electricity per year, while financial returns from the US$2.6bn project have been estimated at US$600M per annum.
Very long TBM tunnels may not be faster, in the end, than two-faces D+B, because there is a steady decline in m/hr as weeks are succeeded by months and then by years of construction. This is despite improved PR and AR during the 'learning curve' period. Choosing a TBM because the tunnel is very long is a way to increase risk of needing drill-and-blast from the other end to complete 'on time'. However with two TBM, the race might be won!