National Thermal Power Corporation (NTPC) has signed a MoU with the government of Uttaranchal for the initial survey and investigation for the 3 x 120 MW Tapovan Vishnugad hydro scheme on river Dhauliganga. It is a tributary to river Alakananda which itself is a tributary to river Ganga. A 11,646 m-long headrace tunnel will be built, standard horse shoe-shaped cross section with 4.8 m diameter. The project area is located in the central Himalayan crystalline group of rocks. The rock comprises metamorphic rocks, mostly granetiferous augen gneiss, schist, quartzites with intermittent bands of schist and basic rocks. It is expected the headrace tunnel will mainly encounter this type of rocks. Presence of hot water springs of nearly 80-100°C in nearby areas and in the drilling activities along the Main Central Thrust (MCT) areas. Not much exploration drilling is possible along the tunnel alignment which will be covered with a 1 to 1.5 km overburden. The horizontal cover is also very thick. The tunnel alignment is covered with snow and thick forest areas of rugged topography. The zone may not be suitable for geophysical exploration due to the difficult topographic condition. Vertical drilling may result unnecessary, long and difficult. The planned method of construction is drill/blast with rockbolts, shotcrete, wiremesh and steel arches (I and H sections) as support. Final concrete lining. Date to invite tenders not decided yet. Detailed survey and investigation started as of 1st January, 2003. Estimated cost Rs5.55 billion (value 1992) to be revaluated 9.5% approximately per year. Self financing by NTPC for survey and investigation. More from debadatta_ray@yahoo.com and abirkar@rediffmail.com 02/03.Invitation for bids, deadline 17th June, 2005 for construction of a headrace tunnel for the 4 x 150 MW Loharinag Pala hydroelectric power project on the river Bhagirathi in Uttarkashi district, State of Uttaranchal. The scope of work includes construction of an approx. 13 km-long, 6 m-finished diameter modified horseshoe-shaped, concrete lined headrace tunnel, including three intermediate 6 m-diameter D-shaped adits. Contact National Thermal Power Corporation, Sr. Manager (CS-Hydro), Sixth Floor, Engineering Office Complex, Plot A-8A, Sector-24, Noida 201301, Uttar Pradesh, India. Tel. +91 1202596669 or 1202596620, fax +91 1202410215 or 1202410011. Visit www.ntpctender.com/nit/listJobs.asp?nitId=2098 17/05.The National Thermal Power Corporation (NTPC) has awarded a Rs3.18 billion headrace tunnel contract for the Loharinag Pala hydroelectric power project to Patel Engineering. The 600 MW Loharinag Pala project is a run-of-river scheme situated on the river Bhagirathi in the Uttarkashi district of Uttaranchal. Patel Engineering's contract involves construction of a 6 m-diameter 13 km-long horseshoe shaped concrete lined headrace tunnel on the right bank of the Bhagirathi. The tunnel will be executed through three access adits using the drill-and-blast method. The Loharinag Pala project is expected to be completed in 38 months. Visit www.patelengineering.com 35/06.Larsen & Toubro, in joint venture with Alpine Mayreder, has bagged an order valued at Rs4.56 billion from NTPC for the execution of 4 x 130 MW Tapovan Vishnugad hydropower project in Uttaranchal. The package includes construction of a concrete lined headrace tunnel of approx. 11.3 km and 5.6 m finished diameter, using partly a TBM, and partly a roadheader and drilling and blasting. The project is located in district Chamoli on the Dhauliganga river, a major tributary of Alaknanda. Visit www.lntecc.com and www.alpine.at 50/06.Invitation for prequalification, deadline 28th June, 2007 for EPC turnkey package for construction of the 444 MW Vishnugad-Pipalkoti hydro electric project. Civil works include a 65 m-high gravity concrete dam; a 10 m-diameter diversion and spill tunnel; a 12 m-diameter spill tunnel, intake structures followed by three desilting chambers, each 350 m long, 16 m wide and 20.6 m high; a 13.4 km-long 8.8 m-diameter horseshoe-shaped headrace tunnel; a 130 m-high, 22 m-diameter surge shaft; a 351 m-long, 5.2 m-diameter pressure shaft; an underground power house for four 111 MW generating units; an underground transformer cavern to accommodate 13 transformers and switchgear; a 120 m-long x 27 m-high underground downstream surge tank; a 3.07 km-long, 8.8 m-diameter horseshoe-shaped tailrace tunnel; a cofferdam, etc. The invitation for prequalification is also for hydro-mechanical works, electro-mechanical works and assistance in the successful operation of the plant for six months. Contact Tehri Hydro Development Corporation, Executive Director, Ganga Bhawan, Bypass Road, Pragatipuram, Rishikesh-249 201 Uttarakhand. Tel. +91 1352430721, fax +91 1352438379, e-mail bansallk_2004@yahoo.com.sg. Visit http://thdc.nic.in 16/07.National Thermal Power Corp (NTPC) has awarded Patel Engineering the construction contract for key civil works on the 520 MW Tapovan Vishnugad hydropower project. The value of the contract is INR4.3 billion, and the contract period is 48 months. The scope of the work includes construction of the surge shaft, pressure shaft, penstock, tailrace tunnel, switchyards and the power house. The plant will house four 130 MW units. The headrace tunnel was awarded last year to Larsen & Toubro and Alpine Mayreder. Click in/35. Visit www.patelengineering.com 52/07-01/08.Invitation for prequalification, deadline 26th February, 2008 for engineering, procurement and construction (EPC) package for civil works and hydromechanical equipment works for the Vishnugad Pipalkoti hydroelectric project. Civil works include a 65 m-high gravity concrete dam; a 10 m-diameter diversion and spill tunnel; a 12 m-diameter spill tunnel; an intake structure followed by three desilting chambers (each 350 m long x 16 m wide x 20.6 m high); a 13.4 km-long x 8.8 m-diameter horse shoe-shaped headrace tunnel; a 130 m-high x 22 m-diameter surge shaft; a 351 m-long x 5.2 m-diameter pressure shaft; an underground power house for four vertical Francis turbine generating each 111 MW; an underground transformer cavern; a 120 m-long x 12 m-wide x 27 m-high underground surge tank; a 3.07 km-long x 8.8 m-diameter horse shoe-shaped tailrace tunnel, a cofferdam, etc. This is a re-bid. Contact Tehri Hydro Development Corporation, Ganga Bhawan, Bypass Road, Pragatipuram, Rishikesh 249201, Uttarakhand. Tel. +91 1352430721, fax +91 1352438379, e-mail thdccontract_vphep@yahoo.co.in or visit http://thdc.gov.in/English/Scripts/tender_link_link.aspx?vid=281 03/08.
Award of contract by THDC India Ltd, value EUR288 million, to Hindustan Construction Company with Alsthom for construction of 1,000 MW Tehri pumped storage project in Uttarakhand. The plant comprises headrace tunnel, surge shaft, penstocks, underground powerhouse, busbar galley and cavern, and tailrace. Four reversible 250 MW pump turbine units will be installed. Project completion in 54 months. More from www.thdc.gov.in. Full project history at tunnelbuilder archive in/35. 26/11.