Engineering marvels at Teesta-III; Teesta Urja in full swing

·         South African giant Shaft Sinkers achieves wonders

GANGTOK: In an engineering marvel at ongoing Teesta-III hydro electric project, Shaft Sinking method has been deployed to save as much as 15 months in the Project schedule.

The technique is being executed by Shaft Sinkers of South Africa and this is their first such assignment in India.

Official sources say the results are “very much encouraging”. Shaft Sinking method was adopted when all other traditional methods are found either unsuitable or unfeasible.

This method usually applied in Mines. With Teesta-III Shaft Sinkers diversified into hydro-electric schemes.

Teesta Urja is environmental friendly and has got the most dependable hydrology as the major project component is underground, having minimum impact on environment.

On winning the Sikkim contract, Shaft Sinkers MD, Rob Schroder said the challenges involved in this project were immense: “For one, the road is a single narrow track in the Himalayas and it will take more than 14 hours to move equipment 15 kilometres to the site and the laydown area is extremely narrow. It is similar to the conditions we worked in previously at a job in Laos.

Shaft Sinkers has been sinking shafts through every type of rock strata for more than 47 years and has achieved worldwide acclaim helping cement South Africa’s reputation as one of the world’s most advanced countries in shaft sinking and mining technology.Projects include not only vertical shaft sinking but also a variety of excavations for underground winders, pump chambers, rock silos, loading stations, settlers and dams. The company is also involved in hydro-electric schemes, road and railway tunnels and other major civil engineering projects.

Shaft Sinkers has been active internationally in Lesotho, Zambia, the DRC, Namibia, Tanzania, Botswana, Ghana, Sierra Leone, Mali, Zimbabwe Swaziland, Israel, Ireland, England, France, Switzerland, Laos, Indonesia, Tasmania, Chile, Argentina, and Brazil.

Teesta Urja set to bring relief to Sikkim

GANGTOK: Men and machines are racing against time to complete the work on the Teesta – Stage III Hydro Electric Project which is expected to mitigate the ongoing power crisis in the tiny Himalayan State.

Sikkim which is endowed with vast hydro power potential and Teesta is the main river stream in Sikkim. The potential of Teesta River is being harnessed through a cascade of six Hydro projects.

The 1200 MW Teesta-III is part of this cascade development – the highest capacity power project in Sikkim. 

The Teesta Project was conceived as part of cascade development of river Teesta by CWC in the year 1974. An SPV called “Teesta Urja Limited” was formed in April 2005 and Implementation agreement signed with the Sikkim Government in July 2005.

The project received all statuary clearances in Record time.  The construction is being executed under EPC by a consortium led by M/s Navayuga Engineering Company Ltd.

As much as 99.2% of Tunneling Works completed (around 34.4 Km out of total 34.6 Km). The Excavation of 13.824 Km of Head Race Tunnel was also completed. 

Power produced to be transmitted till Kishenganj through 400 KV DC line to be constructed by Teesta valley Power Transmission , a JV between Teesta Urja Ltd

and Power grid Corporation of India Limited (PGCIL). PGCIL is to wheel the power to the beneficiary states in the northern region beyond Kishenganj.

The positive news about the progress of Teesta-III comes as a big relief to the people of Sikkim who are bracing themselves to pay higher tariff.

Power Secretary AK Giri had said that the state currently is procuring electricity from NTPC and thermal power is subject to vagaries of coal supply and prices. As such the price per unit Rs 3 will be applicable from this month itself, Mr Giri said.

Latest updates of Teesta-III

• The Project is conferred with Mega Project Status by the Ministry of Power, Government of India on 2nd June 2010.
• River Diversion achieved on 15th January 2010.
• Around 99.4% of cumulative tunneling completed in the project.
• 71% of the Rock filling completed in Concrete Face Fill Dam (CFRD).
• Cut off Wall Excavation works commenced in Dam Site.
• HRT Excavation achieved on June 4, 2011. Till date 5856 m of overt lining completed.
• Surge Shaft - Break Through achieved between the pilot hole and sinking face on July 8, 2011.
• Vertical Pressure Shaft 1 (645 m): Excavation completed.
• Vertical Pressure Shaft 2 (645 m): Break Through achieved between the pilot hole and sinking face on July 30, 2011.
• Electro-Mechanical works commenced in all six units.
• Steel liners erection commenced in Pressure Shaft.