Spanish construction company NECSO has completed a 7.5km long tunnel, which forms part of the Ralco hydroelectric project, in Chile. The project, with a budget of US$90M, commenced in April 2000. Completion of the 9.2m wide tunnel marks the end of the first phase of the overall scheme.
The first phase scope of the Ralco scheme includes the intake works, a subsurface 110m deep surge shaft and all of the maintenance projects for the interior roads in the dam zone, as well as the 7.5km tunnel. Driven at 9.2m, the tunnel will have a finished internal diameter of 9m.
The second stage of the contract will involve the construction of a powerhouse cavern, an evacuation system to return waters to the Biobio River, roads and access tunnels to the works, and a cable gallery to take the generated energy to the transmission system.
With completion of the first phase, NECSO considers it has consolidated its position as one of the main players in the Chilean construction industry, where it has built up a wide portfolio over the last 10 years.
The client, Endesa, plans to use the scheme to harness the hydroelectric resources of the high basin of the Biobio River to generate 570MW of power. It will contribute 3,380GW to the country’s Interconnected Central System. This equates to 9% of the Chilean system’s electricity requirements.
The project is located approximately 105km southeast of la Ciudad de Los Angeles, an area considered as ‘an outstanding natural resource’, and has created in the region of 700 jobs.
Endesa Chile, Endesa’s generation subsidiary in Latin America, has invested US$540M in the construction of the scheme and started loading Ralco’s dam in mid-April. It is anticipated that the plant will be launched in the second half of this year.
