BRAZIL: Work is now underway in Rio de Janeiro to assemble a 2 000 tonne Herrenknecht tunnel boring machine that is to be used in the construction of metro Line 4 from Ipanema to Barra da Tijuca.

At 120 m long and with a diameter of 11⋅5 m, the TBM is the largest ever deployed in Latin America, according to the Rio de Janeiro state government, as well as the biggest ever used on a metro construction project in Brazil.

Tunnelling is expected to start in October from a launch cavern adjacent to General Osório station in Ipanema, from where the TBM will proceed towards Gávea at an expected rate of between 15 m and 18 m a day. This is ‘four times faster than the methods previously used in Rio de Janeiro’, according to the state government.