With the construction of the voussoir factory that will cover the tunnels between the stations, work has work begun on Line 7 of the Santiago Metro in city of Santiago, the capital of Chile. Chile President Mr Sebastián Piñera said “As Chileans we are going to invest more than USD 2.5 billion in this line, which is going to generate 22 thousand new jobs. It is a gigantic effort.”The line will have an extension of about 26 kilometers with 19 stations, reducing travel times between Renca and Vitacura by 50%. With its layout, Line 7 will join the communes of Renca, Cerro Navia, Quinta Normal, Santiago, Providencia, Las Condes and Vitacura . With this, the communes of Renca, Cerro Navia and Vitacura will be incorporated for the first time into the Metro network with stations in their territories. Each voussoir measures 4.4 meters long, 1.7 meters wide and 32 centimeters thick, with an approximate weight of 2.5 tons. The voussoirs, prefabricated concrete linings that form a ring, will ensure the support of the conduit while the TBM Tunnel Boring Machine advances in the underground construction. This method, which is being applied for the first time in Metro, will be used in the construction of the tunnel in Renca, Cerro Navia and part of Quinta Normal. The tunnel boring machine installs seven voussoirs for a ring of 11 meters in diameter. 15 meters of tunnel will be advanced per day and there will be 26 thousand voussoirs for Section 1, he detailed.